diff --git a/libcxx/.clang-format b/libcxx/.clang-format
--- a/libcxx/.clang-format
+++ b/libcxx/.clang-format
@@ -12,9 +12,9 @@
 AllowShortLambdasOnASingleLine: All
 AttributeMacros: ['_LIBCPP_HIDE_FROM_ABI',
                   '_LIBCPP_CONSTEXPR',
-                  '_LIBCPP_CONSTEXPR_AFTER_CXX11',
-                  '_LIBCPP_CONSTEXPR_AFTER_CXX14',
-                  '_LIBCPP_CONSTEXPR_AFTER_CXX17',
+                  '_LIBCPP_CONSTEXPR_CXX14',
+                  '_LIBCPP_CONSTEXPR_CXX17',
+                  '_LIBCPP_CONSTEXPR_CXX20',
                   '_LIBCPP_CONSTEXPR_AFTER_CXX20',
                   '_LIBCPP_ALIGNOF',
                   '_ALIGNAS_TYPE',
diff --git a/libcxx/include/__algorithm/adjacent_find.h b/libcxx/include/__algorithm/adjacent_find.h
--- a/libcxx/include/__algorithm/adjacent_find.h
+++ b/libcxx/include/__algorithm/adjacent_find.h
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Iter, class _Sent, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _Iter
+_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _Iter
 __adjacent_find(_Iter __first, _Sent __last, _BinaryPredicate&& __pred) {
   if (__first == __last)
     return __first;
@@ -37,13 +37,13 @@
 }
 
 template <class _ForwardIterator, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred) {
   return std::__adjacent_find(std::move(__first), std::move(__last), __pred);
 }
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 adjacent_find(_ForwardIterator __first, _ForwardIterator __last) {
   typedef typename iterator_traits<_ForwardIterator>::value_type __v;
   return std::adjacent_find(std::move(__first), std::move(__last), __equal_to<__v>());
diff --git a/libcxx/include/__algorithm/all_of.h b/libcxx/include/__algorithm/all_of.h
--- a/libcxx/include/__algorithm/all_of.h
+++ b/libcxx/include/__algorithm/all_of.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 bool
 all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
   for (; __first != __last; ++__first)
     if (!__pred(*__first))
diff --git a/libcxx/include/__algorithm/any_of.h b/libcxx/include/__algorithm/any_of.h
--- a/libcxx/include/__algorithm/any_of.h
+++ b/libcxx/include/__algorithm/any_of.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 bool
 any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
   for (; __first != __last; ++__first)
     if (__pred(*__first))
diff --git a/libcxx/include/__algorithm/binary_search.h b/libcxx/include/__algorithm/binary_search.h
--- a/libcxx/include/__algorithm/binary_search.h
+++ b/libcxx/include/__algorithm/binary_search.h
@@ -23,7 +23,7 @@
 
 template <class _ForwardIterator, class _Tp, class _Compare>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp)
 {
@@ -34,7 +34,7 @@
 
 template <class _ForwardIterator, class _Tp>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
 {
diff --git a/libcxx/include/__algorithm/comp.h b/libcxx/include/__algorithm/comp.h
--- a/libcxx/include/__algorithm/comp.h
+++ b/libcxx/include/__algorithm/comp.h
@@ -23,67 +23,67 @@
 template <class _T1, class _T2 = _T1>
 struct __equal_to
 {
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T2& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T1& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T2& __y) const {return __x == __y;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 bool operator()(const _T1& __x, const _T2& __y) const {return __x == __y;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 bool operator()(const _T2& __x, const _T1& __y) const {return __x == __y;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 bool operator()(const _T2& __x, const _T2& __y) const {return __x == __y;}
 };
 
 template <class _T1>
 struct __equal_to<_T1, _T1>
 {
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
 };
 
 template <class _T1>
 struct __equal_to<const _T1, _T1>
 {
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
 };
 
 template <class _T1>
 struct __equal_to<_T1, const _T1>
 {
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
 };
 
 template <class _T1, class _T2 = _T1>
 struct __less
 {
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _T1& __x, const _T2& __y) const {return __x < __y;}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _T2& __x, const _T1& __y) const {return __x < __y;}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _T2& __x, const _T2& __y) const {return __x < __y;}
 };
 
 template <class _T1>
 struct __less<_T1, _T1>
 {
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
 };
 
 template <class _T1>
 struct __less<const _T1, _T1>
 {
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
 };
 
 template <class _T1>
 struct __less<_T1, const _T1>
 {
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
 };
 
diff --git a/libcxx/include/__algorithm/comp_ref_type.h b/libcxx/include/__algorithm/comp_ref_type.h
--- a/libcxx/include/__algorithm/comp_ref_type.h
+++ b/libcxx/include/__algorithm/comp_ref_type.h
@@ -23,11 +23,11 @@
 struct __debug_less
 {
     _Compare &__comp_;
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     __debug_less(_Compare& __c) : __comp_(__c) {}
 
     template <class _Tp, class _Up>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _Tp& __x,  const _Up& __y)
     {
         bool __r = __comp_(__x, __y);
@@ -37,7 +37,7 @@
     }
 
     template <class _Tp, class _Up>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     bool operator()(_Tp& __x,  _Up& __y)
     {
         bool __r = __comp_(__x, __y);
@@ -47,7 +47,7 @@
     }
 
     template <class _LHS, class _RHS>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     inline _LIBCPP_INLINE_VISIBILITY
     decltype((void)declval<_Compare&>()(
         declval<_LHS &>(), declval<_RHS &>()))
@@ -59,7 +59,7 @@
     }
 
     template <class _LHS, class _RHS>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     inline _LIBCPP_INLINE_VISIBILITY
     void __do_compare_assert(long, _LHS &, _RHS &) {}
 };
diff --git a/libcxx/include/__algorithm/copy.h b/libcxx/include/__algorithm/copy.h
--- a/libcxx/include/__algorithm/copy.h
+++ b/libcxx/include/__algorithm/copy.h
@@ -28,7 +28,7 @@
 // copy
 
 template <class _InIter, class _Sent, class _OutIter>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_InIter, _OutIter> __copy_impl(_InIter __first, _Sent __last, _OutIter __result) {
   while (__first != __last) {
     *__result = *__first;
@@ -42,7 +42,7 @@
           class _OutValueT,
           class = __enable_if_t<is_same<typename remove_const<_InValueT>::type, _OutValueT>::value
                              && is_trivially_copy_assignable<_OutValueT>::value> >
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_InValueT*, _OutValueT*> __copy_impl(_InValueT* __first, _InValueT* __last, _OutValueT* __result) {
   if (__libcpp_is_constant_evaluated()
 // TODO: Remove this once GCC supports __builtin_memmove during constant evaluation
@@ -64,7 +64,7 @@
                       && is_trivially_copy_assignable<__iter_value_type<_OutIter> >::value
                       && __is_reverse_iterator<_InIter>::value
                       && __is_reverse_iterator<_OutIter>::value, int> = 0>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_InIter, _OutIter>
 __copy_impl(_InIter __first, _InIter __last, _OutIter __result) {
   auto __first_base = std::__unwrap_iter(__first.base());
@@ -79,7 +79,7 @@
           __enable_if_t<!(is_copy_constructible<_InIter>::value
                        && is_copy_constructible<_Sent>::value
                        && is_copy_constructible<_OutIter>::value), int> = 0 >
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_InIter, _OutIter> __copy(_InIter __first, _Sent __last, _OutIter __result) {
   return std::__copy_impl(std::move(__first), std::move(__last), std::move(__result));
 }
@@ -88,7 +88,7 @@
           __enable_if_t<is_copy_constructible<_InIter>::value
                      && is_copy_constructible<_Sent>::value
                      && is_copy_constructible<_OutIter>::value, int> = 0>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_InIter, _OutIter> __copy(_InIter __first, _Sent __last, _OutIter __result) {
   auto __range = std::__unwrap_range(__first, __last);
   auto __ret   = std::__copy_impl(std::move(__range.first), std::move(__range.second), std::__unwrap_iter(__result));
@@ -97,7 +97,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
   return std::__copy(__first, __last, __result).second;
diff --git a/libcxx/include/__algorithm/copy_backward.h b/libcxx/include/__algorithm/copy_backward.h
--- a/libcxx/include/__algorithm/copy_backward.h
+++ b/libcxx/include/__algorithm/copy_backward.h
@@ -30,7 +30,7 @@
 
 template <class _AlgPolicy, class _InputIterator, class _OutputIterator,
           __enable_if_t<is_same<_AlgPolicy, _ClassicAlgPolicy>::value, int> = 0>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 pair<_InputIterator, _OutputIterator>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 pair<_InputIterator, _OutputIterator>
 __copy_backward(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
   auto __ret = std::__copy(
       __unconstrained_reverse_iterator<_InputIterator>(__last),
@@ -51,7 +51,7 @@
 #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 template <class _BidirectionalIterator1, class _BidirectionalIterator2>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator2
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _BidirectionalIterator2
 copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last, _BidirectionalIterator2 __result) {
   return std::__copy_backward<_ClassicAlgPolicy>(__first, __last, __result).second;
 }
diff --git a/libcxx/include/__algorithm/copy_if.h b/libcxx/include/__algorithm/copy_if.h
--- a/libcxx/include/__algorithm/copy_if.h
+++ b/libcxx/include/__algorithm/copy_if.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template<class _InputIterator, class _OutputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 copy_if(_InputIterator __first, _InputIterator __last,
         _OutputIterator __result, _Predicate __pred)
diff --git a/libcxx/include/__algorithm/copy_n.h b/libcxx/include/__algorithm/copy_n.h
--- a/libcxx/include/__algorithm/copy_n.h
+++ b/libcxx/include/__algorithm/copy_n.h
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template<class _InputIterator, class _Size, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 typename enable_if
 <
     __is_cpp17_input_iterator<_InputIterator>::value &&
@@ -47,7 +47,7 @@
 }
 
 template<class _InputIterator, class _Size, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 typename enable_if
 <
     __is_cpp17_random_access_iterator<_InputIterator>::value,
diff --git a/libcxx/include/__algorithm/count.h b/libcxx/include/__algorithm/count.h
--- a/libcxx/include/__algorithm/count.h
+++ b/libcxx/include/__algorithm/count.h
@@ -20,7 +20,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     typename iterator_traits<_InputIterator>::difference_type
     count(_InputIterator __first, _InputIterator __last, const _Tp& __value) {
   typename iterator_traits<_InputIterator>::difference_type __r(0);
diff --git a/libcxx/include/__algorithm/count_if.h b/libcxx/include/__algorithm/count_if.h
--- a/libcxx/include/__algorithm/count_if.h
+++ b/libcxx/include/__algorithm/count_if.h
@@ -20,7 +20,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     typename iterator_traits<_InputIterator>::difference_type
     count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
   typename iterator_traits<_InputIterator>::difference_type __r(0);
diff --git a/libcxx/include/__algorithm/equal.h b/libcxx/include/__algorithm/equal.h
--- a/libcxx/include/__algorithm/equal.h
+++ b/libcxx/include/__algorithm/equal.h
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 bool
 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
   for (; __first1 != __last1; ++__first1, (void)++__first2)
     if (!__pred(*__first1, *__first2))
@@ -31,7 +31,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 bool
 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
   typedef typename iterator_traits<_InputIterator1>::value_type __v1;
   typedef typename iterator_traits<_InputIterator2>::value_type __v2;
@@ -40,7 +40,7 @@
 
 #if _LIBCPP_STD_VER > 11
 template <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 bool
 __equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
         _BinaryPredicate __pred, input_iterator_tag, input_iterator_tag) {
   for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void)++__first2)
@@ -50,7 +50,7 @@
 }
 
 template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 bool
 __equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1, _RandomAccessIterator2 __first2,
         _RandomAccessIterator2 __last2, _BinaryPredicate __pred, random_access_iterator_tag,
         random_access_iterator_tag) {
@@ -61,7 +61,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 bool
 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
       _BinaryPredicate __pred) {
   return _VSTD::__equal<_BinaryPredicate&>(
@@ -70,7 +70,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 bool
 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
   typedef typename iterator_traits<_InputIterator1>::value_type __v1;
   typedef typename iterator_traits<_InputIterator2>::value_type __v2;
diff --git a/libcxx/include/__algorithm/equal_range.h b/libcxx/include/__algorithm/equal_range.h
--- a/libcxx/include/__algorithm/equal_range.h
+++ b/libcxx/include/__algorithm/equal_range.h
@@ -34,7 +34,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Compare, class _Iter, class _Sent, class _Tp, class _Proj>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_Iter, _Iter>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 pair<_Iter, _Iter>
 __equal_range(_Iter __first, _Sent __last, const _Tp& __value, _Compare&& __comp, _Proj&& __proj) {
   auto __len  = _IterOps<_AlgPolicy>::distance(__first, __last);
   _Iter __end = _IterOps<_AlgPolicy>::next(__first, __last);
@@ -58,7 +58,7 @@
 }
 
 template <class _ForwardIterator, class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_ForwardIterator, _ForwardIterator>
+_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 pair<_ForwardIterator, _ForwardIterator>
 equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp) {
   static_assert(__is_callable<_Compare, decltype(*__first), const _Tp&>::value,
                 "The comparator has to be callable");
@@ -70,7 +70,7 @@
 }
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_ForwardIterator, _ForwardIterator>
+_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 pair<_ForwardIterator, _ForwardIterator>
 equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
   return std::equal_range(
       std::move(__first),
diff --git a/libcxx/include/__algorithm/fill.h b/libcxx/include/__algorithm/fill.h
--- a/libcxx/include/__algorithm/fill.h
+++ b/libcxx/include/__algorithm/fill.h
@@ -23,7 +23,7 @@
 // fill isn't specialized for std::memset, because the compiler already optimizes the loop to a call to std::memset.
 
 template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 __fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, forward_iterator_tag)
 {
@@ -32,7 +32,7 @@
 }
 
 template <class _RandomAccessIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 __fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value, random_access_iterator_tag)
 {
@@ -40,7 +40,7 @@
 }
 
 template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
 {
diff --git a/libcxx/include/__algorithm/fill_n.h b/libcxx/include/__algorithm/fill_n.h
--- a/libcxx/include/__algorithm/fill_n.h
+++ b/libcxx/include/__algorithm/fill_n.h
@@ -22,7 +22,7 @@
 // fill_n isn't specialized for std::memset, because the compiler already optimizes the loop to a call to std::memset.
 
 template <class _OutputIterator, class _Size, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 __fill_n(_OutputIterator __first, _Size __n, const _Tp& __value)
 {
@@ -32,7 +32,7 @@
 }
 
 template <class _OutputIterator, class _Size, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 fill_n(_OutputIterator __first, _Size __n, const _Tp& __value)
 {
diff --git a/libcxx/include/__algorithm/find.h b/libcxx/include/__algorithm/find.h
--- a/libcxx/include/__algorithm/find.h
+++ b/libcxx/include/__algorithm/find.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _InputIterator
 find(_InputIterator __first, _InputIterator __last, const _Tp& __value) {
   for (; __first != __last; ++__first)
     if (*__first == __value)
diff --git a/libcxx/include/__algorithm/find_end.h b/libcxx/include/__algorithm/find_end.h
--- a/libcxx/include/__algorithm/find_end.h
+++ b/libcxx/include/__algorithm/find_end.h
@@ -37,7 +37,7 @@
     class _Pred,
     class _Proj1,
     class _Proj2>
-_LIBCPP_HIDE_FROM_ABI inline _LIBCPP_CONSTEXPR_AFTER_CXX11 pair<_Iter1, _Iter1> __find_end_impl(
+_LIBCPP_HIDE_FROM_ABI inline _LIBCPP_CONSTEXPR_CXX14 pair<_Iter1, _Iter1> __find_end_impl(
     _Iter1 __first1,
     _Sent1 __last1,
     _Iter2 __first2,
@@ -91,7 +91,7 @@
     class _Sent2,
     class _Proj1,
     class _Proj2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _Iter1 __find_end(
+_LIBCPP_CONSTEXPR_CXX20 _Iter1 __find_end(
     _Iter1 __first1,
     _Sent1 __sent1,
     _Iter2 __first2,
@@ -144,7 +144,7 @@
     class _Sent2,
     class _Proj1,
     class _Proj2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _Iter1 __find_end(
+_LIBCPP_CONSTEXPR_CXX14 _Iter1 __find_end(
     _Iter1 __first1,
     _Sent1 __sent1,
     _Iter2 __first2,
@@ -189,7 +189,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 _ForwardIterator1 __find_end_classic(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
                                      _ForwardIterator2 __first2, _ForwardIterator2 __last2,
                                      _BinaryPredicate& __pred) {
@@ -208,7 +208,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator1 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
                            _ForwardIterator2 __first2, _ForwardIterator2 __last2,
                            _BinaryPredicate __pred) {
@@ -216,7 +216,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator1 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
                            _ForwardIterator2 __first2, _ForwardIterator2 __last2) {
   using __v1 = typename iterator_traits<_ForwardIterator1>::value_type;
diff --git a/libcxx/include/__algorithm/find_first_of.h b/libcxx/include/__algorithm/find_first_of.h
--- a/libcxx/include/__algorithm/find_first_of.h
+++ b/libcxx/include/__algorithm/find_first_of.h
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator1 __find_first_of_ce(_ForwardIterator1 __first1,
+_LIBCPP_CONSTEXPR_CXX14 _ForwardIterator1 __find_first_of_ce(_ForwardIterator1 __first1,
                                                                    _ForwardIterator1 __last1,
                                                                    _ForwardIterator2 __first2,
                                                                    _ForwardIterator2 __last2,
@@ -34,14 +34,14 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator1
 find_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
               _ForwardIterator2 __last2, _BinaryPredicate __pred) {
   return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __pred);
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1 find_first_of(
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator1 find_first_of(
     _ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2) {
   typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
   typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
diff --git a/libcxx/include/__algorithm/find_if.h b/libcxx/include/__algorithm/find_if.h
--- a/libcxx/include/__algorithm/find_if.h
+++ b/libcxx/include/__algorithm/find_if.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _InputIterator
 find_if(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
   for (; __first != __last; ++__first)
     if (__pred(*__first))
diff --git a/libcxx/include/__algorithm/find_if_not.h b/libcxx/include/__algorithm/find_if_not.h
--- a/libcxx/include/__algorithm/find_if_not.h
+++ b/libcxx/include/__algorithm/find_if_not.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _InputIterator
 find_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
   for (; __first != __last; ++__first)
     if (!__pred(*__first))
diff --git a/libcxx/include/__algorithm/for_each.h b/libcxx/include/__algorithm/for_each.h
--- a/libcxx/include/__algorithm/for_each.h
+++ b/libcxx/include/__algorithm/for_each.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Function>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _Function for_each(_InputIterator __first,
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _Function for_each(_InputIterator __first,
                                                                                   _InputIterator __last,
                                                                                   _Function __f) {
   for (; __first != __last; ++__first)
diff --git a/libcxx/include/__algorithm/for_each_n.h b/libcxx/include/__algorithm/for_each_n.h
--- a/libcxx/include/__algorithm/for_each_n.h
+++ b/libcxx/include/__algorithm/for_each_n.h
@@ -22,7 +22,7 @@
 #if _LIBCPP_STD_VER > 14
 
 template <class _InputIterator, class _Size, class _Function>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator for_each_n(_InputIterator __first,
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _InputIterator for_each_n(_InputIterator __first,
                                                                                          _Size __orig_n,
                                                                                          _Function __f) {
   typedef decltype(_VSTD::__convert_to_integral(__orig_n)) _IntegralSize;
diff --git a/libcxx/include/__algorithm/generate.h b/libcxx/include/__algorithm/generate.h
--- a/libcxx/include/__algorithm/generate.h
+++ b/libcxx/include/__algorithm/generate.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Generator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 generate(_ForwardIterator __first, _ForwardIterator __last, _Generator __gen)
 {
diff --git a/libcxx/include/__algorithm/generate_n.h b/libcxx/include/__algorithm/generate_n.h
--- a/libcxx/include/__algorithm/generate_n.h
+++ b/libcxx/include/__algorithm/generate_n.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _OutputIterator, class _Size, class _Generator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 generate_n(_OutputIterator __first, _Size __orig_n, _Generator __gen)
 {
diff --git a/libcxx/include/__algorithm/includes.h b/libcxx/include/__algorithm/includes.h
--- a/libcxx/include/__algorithm/includes.h
+++ b/libcxx/include/__algorithm/includes.h
@@ -25,7 +25,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Comp, class _Proj1, class _Proj2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 __includes(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2,
            _Comp&& __comp, _Proj1&& __proj1, _Proj2&& __proj2) {
   for (; __first2 != __last2; ++__first1) {
@@ -39,7 +39,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _Compare>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool includes(
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool includes(
     _InputIterator1 __first1,
     _InputIterator1 __last1,
     _InputIterator2 __first2,
@@ -55,7 +55,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
   return std::includes(
       std::move(__first1),
diff --git a/libcxx/include/__algorithm/is_heap.h b/libcxx/include/__algorithm/is_heap.h
--- a/libcxx/include/__algorithm/is_heap.h
+++ b/libcxx/include/__algorithm/is_heap.h
@@ -23,7 +23,7 @@
 
 template <class _RandomAccessIterator, class _Compare>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
 {
@@ -33,7 +33,7 @@
 
 template<class _RandomAccessIterator>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
 {
diff --git a/libcxx/include/__algorithm/is_heap_until.h b/libcxx/include/__algorithm/is_heap_until.h
--- a/libcxx/include/__algorithm/is_heap_until.h
+++ b/libcxx/include/__algorithm/is_heap_until.h
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Compare, class _RandomAccessIterator>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _RandomAccessIterator
 __is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare&& __comp)
 {
     typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
@@ -48,7 +48,7 @@
 }
 
 template <class _RandomAccessIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _RandomAccessIterator
 is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
 {
     typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
@@ -56,7 +56,7 @@
 }
 
 template<class _RandomAccessIterator>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _RandomAccessIterator
 is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last)
 {
     return _VSTD::__is_heap_until(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
diff --git a/libcxx/include/__algorithm/is_partitioned.h b/libcxx/include/__algorithm/is_partitioned.h
--- a/libcxx/include/__algorithm/is_partitioned.h
+++ b/libcxx/include/__algorithm/is_partitioned.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_CXX20 bool
 is_partitioned(_InputIterator __first, _InputIterator __last, _Predicate __pred)
 {
     for (; __first != __last; ++__first)
diff --git a/libcxx/include/__algorithm/is_permutation.h b/libcxx/include/__algorithm/is_permutation.h
--- a/libcxx/include/__algorithm/is_permutation.h
+++ b/libcxx/include/__algorithm/is_permutation.h
@@ -55,7 +55,7 @@
 template <class _AlgPolicy,
           class _Iter1, class _Sent1, class _Iter2, class _Sent2,
           class _Proj1, class _Proj2, class _Pred>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 __is_permutation_impl(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2,
                       _Pred&& __pred, _Proj1&& __proj1, _Proj2&& __proj2) {
   using _D1 = __iter_diff_t<_Iter1>;
@@ -94,7 +94,7 @@
 
 // 2+1 iterators, predicate. Not used by range algorithms.
 template <class _AlgPolicy, class _ForwardIterator1, class _Sentinel1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 __is_permutation(_ForwardIterator1 __first1, _Sentinel1 __last1, _ForwardIterator2 __first2,
                  _BinaryPredicate&& __pred) {
   // Shorten sequences as much as possible by lopping of any equal prefix.
@@ -122,7 +122,7 @@
 template <class _AlgPolicy,
           class _Iter1, class _Sent1, class _Iter2, class _Sent2,
           class _Proj1, class _Proj2, class _Pred>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 __is_permutation(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2,
                  _Pred&& __pred, _Proj1&& __proj1, _Proj2&& __proj2,
                  /*_ConstTimeDistance=*/false_type) {
@@ -156,7 +156,7 @@
 template <class _AlgPolicy,
           class _Iter1, class _Sent1, class _Iter2, class _Sent2,
           class _Proj1, class _Proj2, class _Pred>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 __is_permutation(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2,
                  _Pred&& __pred, _Proj1&& __proj1, _Proj2&& __proj2,
                  /*_ConstTimeDistance=*/true_type) {
@@ -172,7 +172,7 @@
 template <class _AlgPolicy,
           class _Iter1, class _Sent1, class _Iter2, class _Sent2,
           class _Proj1, class _Proj2, class _Pred>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 __is_permutation(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2,
                  _Pred&& __pred, _Proj1&& __proj1, _Proj2&& __proj2) {
   return std::__is_permutation<_AlgPolicy>(
@@ -185,7 +185,7 @@
 
 // 2+1 iterators, predicate
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
                _BinaryPredicate __pred) {
   static_assert(__is_callable<_BinaryPredicate, decltype(*__first1), decltype(*__first2)>::value,
@@ -197,7 +197,7 @@
 
 // 2+1 iterators
 template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2) {
   using __v1 = __iter_value_type<_ForwardIterator1>;
   using __v2 = __iter_value_type<_ForwardIterator2>;
@@ -208,7 +208,7 @@
 
 // 2+2 iterators
 template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
                _ForwardIterator2 __last2) {
   using __v1 = __iter_value_type<_ForwardIterator1>;
@@ -221,7 +221,7 @@
 
 // 2+2 iterators, predicate
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool
 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
                _ForwardIterator2 __last2, _BinaryPredicate __pred) {
   static_assert(__is_callable<_BinaryPredicate, decltype(*__first1), decltype(*__first2)>::value,
diff --git a/libcxx/include/__algorithm/is_sorted.h b/libcxx/include/__algorithm/is_sorted.h
--- a/libcxx/include/__algorithm/is_sorted.h
+++ b/libcxx/include/__algorithm/is_sorted.h
@@ -23,7 +23,7 @@
 
 template <class _ForwardIterator, class _Compare>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 is_sorted(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
 {
@@ -33,7 +33,7 @@
 
 template<class _ForwardIterator>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 is_sorted(_ForwardIterator __first, _ForwardIterator __last)
 {
diff --git a/libcxx/include/__algorithm/is_sorted_until.h b/libcxx/include/__algorithm/is_sorted_until.h
--- a/libcxx/include/__algorithm/is_sorted_until.h
+++ b/libcxx/include/__algorithm/is_sorted_until.h
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Compare, class _ForwardIterator>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 __is_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
 {
     if (__first != __last)
@@ -38,7 +38,7 @@
 }
 
 template <class _ForwardIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 is_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
 {
     typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
@@ -46,7 +46,7 @@
 }
 
 template<class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 is_sorted_until(_ForwardIterator __first, _ForwardIterator __last)
 {
     return _VSTD::is_sorted_until(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
diff --git a/libcxx/include/__algorithm/iter_swap.h b/libcxx/include/__algorithm/iter_swap.h
--- a/libcxx/include/__algorithm/iter_swap.h
+++ b/libcxx/include/__algorithm/iter_swap.h
@@ -20,7 +20,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 void iter_swap(_ForwardIterator1 __a,
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 void iter_swap(_ForwardIterator1 __a,
                                                                               _ForwardIterator2 __b)
     //                                  _NOEXCEPT_(_NOEXCEPT_(swap(*__a, *__b)))
     _NOEXCEPT_(_NOEXCEPT_(swap(*declval<_ForwardIterator1>(), *declval<_ForwardIterator2>()))) {
diff --git a/libcxx/include/__algorithm/iterator_operations.h b/libcxx/include/__algorithm/iterator_operations.h
--- a/libcxx/include/__algorithm/iterator_operations.h
+++ b/libcxx/include/__algorithm/iterator_operations.h
@@ -76,14 +76,14 @@
 
   // advance
   template <class _Iter, class _Distance>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
   static void advance(_Iter& __iter, _Distance __count) {
     std::advance(__iter, __count);
   }
 
   // distance
   template <class _Iter>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
   static typename iterator_traits<_Iter>::difference_type distance(_Iter __first, _Iter __last) {
     return std::distance(__first, __last);
   }
@@ -95,7 +95,7 @@
   using __move_t = decltype(std::move(*std::declval<_Iter&>()));
 
   template <class _Iter>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
   static void __validate_iter_reference() {
     static_assert(is_same<__deref_t<_Iter>, typename iterator_traits<__uncvref_t<_Iter> >::reference>::value,
         "It looks like your iterator's `iterator_traits<It>::reference` does not match the return type of "
@@ -105,7 +105,7 @@
 
   // iter_move
   template <class _Iter>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 static
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 static
   // If the result of dereferencing `_Iter` is a reference type, deduce the result of calling `std::move` on it. Note
   // that the C++03 mode doesn't support `decltype(auto)` as the return type.
   __enable_if_t<
@@ -118,7 +118,7 @@
   }
 
   template <class _Iter>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 static
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 static
   // If the result of dereferencing `_Iter` is a value type, deduce the return value of this function to also be a
   // value -- otherwise, after `operator*` returns a temporary, this function would return a dangling reference to that
   // temporary. Note that the C++03 mode doesn't support `auto` as the return type.
@@ -133,20 +133,20 @@
 
   // iter_swap
   template <class _Iter1, class _Iter2>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
   static void iter_swap(_Iter1&& __a, _Iter2&& __b) {
     std::iter_swap(std::forward<_Iter1>(__a), std::forward<_Iter2>(__b));
   }
 
   // next
   template <class _Iterator>
-  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_CXX14
   _Iterator next(_Iterator, _Iterator __last) {
     return __last;
   }
 
   template <class _Iter>
-  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_CXX14
   __uncvref_t<_Iter> next(_Iter&& __it,
                           typename iterator_traits<__uncvref_t<_Iter> >::difference_type __n = 1) {
     return std::next(std::forward<_Iter>(__it), __n);
@@ -154,14 +154,14 @@
 
   // prev
   template <class _Iter>
-  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_CXX14
   __uncvref_t<_Iter> prev(_Iter&& __iter,
                  typename iterator_traits<__uncvref_t<_Iter> >::difference_type __n = 1) {
     return std::prev(std::forward<_Iter>(__iter), __n);
   }
 
   template <class _Iter>
-  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_CXX14
   void __advance_to(_Iter& __first, _Iter __last) {
     __first = __last;
   }
diff --git a/libcxx/include/__algorithm/lexicographical_compare.h b/libcxx/include/__algorithm/lexicographical_compare.h
--- a/libcxx/include/__algorithm/lexicographical_compare.h
+++ b/libcxx/include/__algorithm/lexicographical_compare.h
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Compare, class _InputIterator1, class _InputIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_CONSTEXPR_CXX20 bool
 __lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
                           _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
 {
@@ -37,7 +37,7 @@
 
 template <class _InputIterator1, class _InputIterator2, class _Compare>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
                         _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
@@ -48,7 +48,7 @@
 
 template <class _InputIterator1, class _InputIterator2>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
                         _InputIterator2 __first2, _InputIterator2 __last2)
diff --git a/libcxx/include/__algorithm/lower_bound.h b/libcxx/include/__algorithm/lower_bound.h
--- a/libcxx/include/__algorithm/lower_bound.h
+++ b/libcxx/include/__algorithm/lower_bound.h
@@ -29,7 +29,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Iter, class _Sent, class _Type, class _Proj, class _Comp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _Iter __lower_bound_impl(_Iter __first, _Sent __last, const _Type& __value, _Comp& __comp, _Proj& __proj) {
   auto __len = _IterOps<_AlgPolicy>::distance(__first, __last);
 
@@ -48,7 +48,7 @@
 }
 
 template <class _ForwardIterator, class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp) {
   static_assert(__is_callable<_Compare, decltype(*__first), const _Tp&>::value,
                 "The comparator has to be callable");
@@ -57,7 +57,7 @@
 }
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
   return std::lower_bound(__first, __last, __value,
                           __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
diff --git a/libcxx/include/__algorithm/make_heap.h b/libcxx/include/__algorithm/make_heap.h
--- a/libcxx/include/__algorithm/make_heap.h
+++ b/libcxx/include/__algorithm/make_heap.h
@@ -24,7 +24,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 void __make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare&& __comp) {
   using _CompRef = typename __comp_ref_type<_Compare>::type;
   _CompRef __comp_ref = __comp;
@@ -40,13 +40,13 @@
 }
 
 template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
   std::__make_heap<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __comp);
 }
 
 template <class _RandomAccessIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) {
   std::make_heap(std::move(__first), std::move(__last),
       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
diff --git a/libcxx/include/__algorithm/max.h b/libcxx/include/__algorithm/max.h
--- a/libcxx/include/__algorithm/max.h
+++ b/libcxx/include/__algorithm/max.h
@@ -26,7 +26,7 @@
 
 template <class _Tp, class _Compare>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const _Tp&
 max(const _Tp& __a, const _Tp& __b, _Compare __comp)
 {
@@ -35,7 +35,7 @@
 
 template <class _Tp>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const _Tp&
 max(const _Tp& __a, const _Tp& __b)
 {
@@ -46,7 +46,7 @@
 
 template<class _Tp, class _Compare>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp
 max(initializer_list<_Tp> __t, _Compare __comp)
 {
@@ -56,7 +56,7 @@
 
 template<class _Tp>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp
 max(initializer_list<_Tp> __t)
 {
diff --git a/libcxx/include/__algorithm/max_element.h b/libcxx/include/__algorithm/max_element.h
--- a/libcxx/include/__algorithm/max_element.h
+++ b/libcxx/include/__algorithm/max_element.h
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Compare, class _ForwardIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 _ForwardIterator
 __max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
 {
     static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -37,7 +37,7 @@
 }
 
 template <class _ForwardIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 _ForwardIterator
 max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
 {
     typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
@@ -46,7 +46,7 @@
 
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 _ForwardIterator
 max_element(_ForwardIterator __first, _ForwardIterator __last)
 {
     return _VSTD::max_element(__first, __last,
diff --git a/libcxx/include/__algorithm/merge.h b/libcxx/include/__algorithm/merge.h
--- a/libcxx/include/__algorithm/merge.h
+++ b/libcxx/include/__algorithm/merge.h
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 __merge(_InputIterator1 __first1, _InputIterator1 __last1,
         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
@@ -46,7 +46,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 merge(_InputIterator1 __first1, _InputIterator1 __last1,
       _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
@@ -56,7 +56,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 merge(_InputIterator1 __first1, _InputIterator1 __last1,
       _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
diff --git a/libcxx/include/__algorithm/min.h b/libcxx/include/__algorithm/min.h
--- a/libcxx/include/__algorithm/min.h
+++ b/libcxx/include/__algorithm/min.h
@@ -26,7 +26,7 @@
 
 template <class _Tp, class _Compare>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const _Tp&
 min(const _Tp& __a, const _Tp& __b, _Compare __comp)
 {
@@ -35,7 +35,7 @@
 
 template <class _Tp>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const _Tp&
 min(const _Tp& __a, const _Tp& __b)
 {
@@ -46,7 +46,7 @@
 
 template<class _Tp, class _Compare>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp
 min(initializer_list<_Tp> __t, _Compare __comp)
 {
@@ -56,7 +56,7 @@
 
 template<class _Tp>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp
 min(initializer_list<_Tp> __t)
 {
diff --git a/libcxx/include/__algorithm/min_element.h b/libcxx/include/__algorithm/min_element.h
--- a/libcxx/include/__algorithm/min_element.h
+++ b/libcxx/include/__algorithm/min_element.h
@@ -25,7 +25,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Comp, class _Iter, class _Sent, class _Proj>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 _Iter __min_element(_Iter __first, _Sent __last, _Comp __comp, _Proj& __proj) {
   if (__first == __last)
     return __first;
@@ -39,14 +39,14 @@
 }
 
 template <class _Comp, class _Iter, class _Sent>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 _Iter __min_element(_Iter __first, _Sent __last, _Comp __comp) {
   auto __proj = __identity();
   return std::__min_element<_Comp>(std::move(__first), std::move(__last), __comp, __proj);
 }
 
 template <class _ForwardIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 _ForwardIterator
 min_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
 {
   static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -59,7 +59,7 @@
 }
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 _ForwardIterator
 min_element(_ForwardIterator __first, _ForwardIterator __last)
 {
     return _VSTD::min_element(__first, __last,
diff --git a/libcxx/include/__algorithm/minmax.h b/libcxx/include/__algorithm/minmax.h
--- a/libcxx/include/__algorithm/minmax.h
+++ b/libcxx/include/__algorithm/minmax.h
@@ -25,7 +25,7 @@
 
 template<class _Tp, class _Compare>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 pair<const _Tp&, const _Tp&>
 minmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
 {
@@ -35,7 +35,7 @@
 
 template<class _Tp>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 pair<const _Tp&, const _Tp&>
 minmax(const _Tp& __a, const _Tp& __b)
 {
@@ -45,7 +45,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template<class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_Tp, _Tp> minmax(initializer_list<_Tp> __t, _Compare __comp) {
     static_assert(__is_callable<_Compare, _Tp, _Tp>::value, "The comparator has to be callable");
     __identity __proj;
@@ -55,7 +55,7 @@
 
 template<class _Tp>
 _LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 pair<_Tp, _Tp>
 minmax(initializer_list<_Tp> __t)
 {
diff --git a/libcxx/include/__algorithm/minmax_element.h b/libcxx/include/__algorithm/minmax_element.h
--- a/libcxx/include/__algorithm/minmax_element.h
+++ b/libcxx/include/__algorithm/minmax_element.h
@@ -32,14 +32,14 @@
   _MinmaxElementLessFunc(_Comp& __comp, _Proj& __proj) : __comp_(__comp), __proj_(__proj) {}
 
   template <class _Iter>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
   bool operator()(_Iter& __it1, _Iter& __it2) {
     return std::__invoke(__comp_, std::__invoke(__proj_, *__it1), std::__invoke(__proj_, *__it2));
   }
 };
 
 template <class _Iter, class _Sent, class _Proj, class _Comp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_Iter, _Iter> __minmax_element_impl(_Iter __first, _Sent __last, _Comp& __comp, _Proj& __proj) {
   auto __less = _MinmaxElementLessFunc<_Comp, _Proj>(__comp, __proj);
 
@@ -79,7 +79,7 @@
 }
 
 template <class _ForwardIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_CXX14
 pair<_ForwardIterator, _ForwardIterator>
 minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) {
   static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -91,7 +91,7 @@
 }
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_ForwardIterator, _ForwardIterator> minmax_element(_ForwardIterator __first, _ForwardIterator __last) {
     return std::minmax_element(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
 }
diff --git a/libcxx/include/__algorithm/mismatch.h b/libcxx/include/__algorithm/mismatch.h
--- a/libcxx/include/__algorithm/mismatch.h
+++ b/libcxx/include/__algorithm/mismatch.h
@@ -23,7 +23,7 @@
 
 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
+    _LIBCPP_CONSTEXPR_CXX20 pair<_InputIterator1, _InputIterator2>
     mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
   for (; __first1 != __last1; ++__first1, (void)++__first2)
     if (!__pred(*__first1, *__first2))
@@ -33,7 +33,7 @@
 
 template <class _InputIterator1, class _InputIterator2>
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
+    _LIBCPP_CONSTEXPR_CXX20 pair<_InputIterator1, _InputIterator2>
     mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
   typedef typename iterator_traits<_InputIterator1>::value_type __v1;
   typedef typename iterator_traits<_InputIterator2>::value_type __v2;
@@ -43,7 +43,7 @@
 #if _LIBCPP_STD_VER > 11
 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
+    _LIBCPP_CONSTEXPR_CXX20 pair<_InputIterator1, _InputIterator2>
     mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
              _BinaryPredicate __pred) {
   for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void)++__first2)
@@ -54,7 +54,7 @@
 
 template <class _InputIterator1, class _InputIterator2>
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
+    _LIBCPP_CONSTEXPR_CXX20 pair<_InputIterator1, _InputIterator2>
     mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
   typedef typename iterator_traits<_InputIterator1>::value_type __v1;
   typedef typename iterator_traits<_InputIterator2>::value_type __v2;
diff --git a/libcxx/include/__algorithm/move.h b/libcxx/include/__algorithm/move.h
--- a/libcxx/include/__algorithm/move.h
+++ b/libcxx/include/__algorithm/move.h
@@ -28,7 +28,7 @@
 // move
 
 template <class _AlgPolicy, class _InIter, class _Sent, class _OutIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 pair<_InIter, _OutIter> __move_impl(_InIter __first, _Sent __last, _OutIter __result) {
   while (__first != __last) {
     *__result = _IterOps<_AlgPolicy>::__iter_move(__first);
@@ -43,7 +43,7 @@
           class _OutType,
           class = __enable_if_t<is_same<typename remove_const<_InType>::type, _OutType>::value
                              && is_trivially_move_assignable<_OutType>::value> >
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_InType*, _OutType*> __move_impl(_InType* __first, _InType* __last, _OutType* __result) {
   if (__libcpp_is_constant_evaluated()
 // TODO: Remove this once GCC supports __builtin_memmove during constant evaluation
@@ -75,7 +75,7 @@
                      && __is_cpp17_contiguous_iterator<_InIter>::value
                      && __is_cpp17_contiguous_iterator<_OutIter>::value
                      && is_trivially_move_assignable<__iter_value_type<_OutIter> >::value, int> = 0>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 pair<reverse_iterator<_InIter>, reverse_iterator<_OutIter> >
 __move_impl(reverse_iterator<_InIter> __first,
             reverse_iterator<_InIter> __last,
@@ -89,7 +89,7 @@
 }
 
 template <class _AlgPolicy, class _InIter, class _Sent, class _OutIter>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 __enable_if_t<is_copy_constructible<_InIter>::value
            && is_copy_constructible<_Sent>::value
            && is_copy_constructible<_OutIter>::value, pair<_InIter, _OutIter> >
@@ -100,7 +100,7 @@
 }
 
 template <class _AlgPolicy, class _InIter, class _Sent, class _OutIter>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 __enable_if_t<!is_copy_constructible<_InIter>::value
            || !is_copy_constructible<_Sent>::value
            || !is_copy_constructible<_OutIter>::value, pair<_InIter, _OutIter> >
@@ -109,7 +109,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator move(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
   return std::__move<_ClassicAlgPolicy>(__first, __last, __result).second;
 }
diff --git a/libcxx/include/__algorithm/move_backward.h b/libcxx/include/__algorithm/move_backward.h
--- a/libcxx/include/__algorithm/move_backward.h
+++ b/libcxx/include/__algorithm/move_backward.h
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 _OutputIterator
 __move_backward_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
 {
@@ -33,7 +33,7 @@
 }
 
 template <class _AlgPolicy, class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 _OutputIterator
 __move_backward_impl(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
 {
@@ -41,7 +41,7 @@
 }
 
 template <class _AlgPolicy, class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 typename enable_if
 <
     is_same<typename remove_const<_Tp>::type, _Up>::value &&
@@ -60,7 +60,7 @@
 }
 
 template <class _AlgPolicy, class _BidirectionalIterator1, class _BidirectionalIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _BidirectionalIterator2
 __move_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
                 _BidirectionalIterator2 __result)
@@ -76,7 +76,7 @@
 }
 
 template <class _BidirectionalIterator1, class _BidirectionalIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _BidirectionalIterator2
 move_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
               _BidirectionalIterator2 __result)
diff --git a/libcxx/include/__algorithm/next_permutation.h b/libcxx/include/__algorithm/next_permutation.h
--- a/libcxx/include/__algorithm/next_permutation.h
+++ b/libcxx/include/__algorithm/next_permutation.h
@@ -25,7 +25,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Compare, class _BidirectionalIterator, class _Sentinel>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 pair<_BidirectionalIterator, bool>
 __next_permutation(_BidirectionalIterator __first, _Sentinel __last, _Compare&& __comp)
 {
@@ -57,7 +57,7 @@
 }
 
 template <class _BidirectionalIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
 {
@@ -67,7 +67,7 @@
 }
 
 template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
 {
diff --git a/libcxx/include/__algorithm/none_of.h b/libcxx/include/__algorithm/none_of.h
--- a/libcxx/include/__algorithm/none_of.h
+++ b/libcxx/include/__algorithm/none_of.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 bool
 none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
   for (; __first != __last; ++__first)
     if (__pred(*__first))
diff --git a/libcxx/include/__algorithm/nth_element.h b/libcxx/include/__algorithm/nth_element.h
--- a/libcxx/include/__algorithm/nth_element.h
+++ b/libcxx/include/__algorithm/nth_element.h
@@ -26,7 +26,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template<class _Compare, class _RandomAccessIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 bool
+_LIBCPP_CONSTEXPR_CXX14 bool
 __nth_element_find_guard(_RandomAccessIterator& __i, _RandomAccessIterator& __j,
                          _RandomAccessIterator __m, _Compare __comp)
 {
@@ -42,7 +42,7 @@
 }
 
 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 void
+_LIBCPP_CONSTEXPR_CXX14 void
 __nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
 {
     using _Ops = _IterOps<_AlgPolicy>;
@@ -223,7 +223,7 @@
 }
 
 template <class _AlgPolicy, class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void __nth_element_impl(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last,
                         _Compare& __comp) {
   if (__nth == __last)
@@ -241,14 +241,14 @@
 }
 
 template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last,
                  _Compare __comp) {
   std::__nth_element_impl<_ClassicAlgPolicy>(std::move(__first), std::move(__nth), std::move(__last), __comp);
 }
 
 template <class _RandomAccessIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last) {
   std::nth_element(std::move(__first), std::move(__nth), std::move(__last), __less<typename
       iterator_traits<_RandomAccessIterator>::value_type>());
diff --git a/libcxx/include/__algorithm/partial_sort.h b/libcxx/include/__algorithm/partial_sort.h
--- a/libcxx/include/__algorithm/partial_sort.h
+++ b/libcxx/include/__algorithm/partial_sort.h
@@ -29,7 +29,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator, class _Sentinel>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 _RandomAccessIterator __partial_sort_impl(
     _RandomAccessIterator __first, _RandomAccessIterator __middle, _Sentinel __last, _Compare&& __comp) {
   if (__first == __middle) {
@@ -55,7 +55,7 @@
 }
 
 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator, class _Sentinel>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 _RandomAccessIterator __partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _Sentinel __last,
                                      _Compare& __comp) {
   if (__first == __middle)
@@ -72,7 +72,7 @@
 }
 
 template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
              _Compare __comp)
@@ -84,7 +84,7 @@
 }
 
 template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
 {
diff --git a/libcxx/include/__algorithm/partial_sort_copy.h b/libcxx/include/__algorithm/partial_sort_copy.h
--- a/libcxx/include/__algorithm/partial_sort_copy.h
+++ b/libcxx/include/__algorithm/partial_sort_copy.h
@@ -33,7 +33,7 @@
 template <class _AlgPolicy, class _Compare,
           class _InputIterator, class _Sentinel1, class _RandomAccessIterator, class _Sentinel2,
           class _Proj1, class _Proj2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator, _RandomAccessIterator>
+_LIBCPP_CONSTEXPR_CXX20 pair<_InputIterator, _RandomAccessIterator>
 __partial_sort_copy(_InputIterator __first, _Sentinel1 __last,
                     _RandomAccessIterator __result_first, _Sentinel2 __result_last,
                     _Compare&& __comp, _Proj1&& __proj1, _Proj2&& __proj2)
@@ -60,7 +60,7 @@
 }
 
 template <class _InputIterator, class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _RandomAccessIterator
 partial_sort_copy(_InputIterator __first, _InputIterator __last,
                   _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
@@ -75,7 +75,7 @@
 }
 
 template <class _InputIterator, class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _RandomAccessIterator
 partial_sort_copy(_InputIterator __first, _InputIterator __last,
                   _RandomAccessIterator __result_first, _RandomAccessIterator __result_last)
diff --git a/libcxx/include/__algorithm/partition.h b/libcxx/include/__algorithm/partition.h
--- a/libcxx/include/__algorithm/partition.h
+++ b/libcxx/include/__algorithm/partition.h
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Predicate, class _AlgPolicy, class _ForwardIterator, class _Sentinel>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_ForwardIterator, _ForwardIterator>
+_LIBCPP_CONSTEXPR_CXX20 pair<_ForwardIterator, _ForwardIterator>
 __partition_impl(_ForwardIterator __first, _Sentinel __last, _Predicate __pred, forward_iterator_tag)
 {
     while (true)
@@ -48,7 +48,7 @@
 }
 
 template <class _Predicate, class _AlgPolicy, class _BidirectionalIterator, class _Sentinel>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_BidirectionalIterator, _BidirectionalIterator>
+_LIBCPP_CONSTEXPR_CXX20 pair<_BidirectionalIterator, _BidirectionalIterator>
 __partition_impl(_BidirectionalIterator __first, _Sentinel __sentinel, _Predicate __pred,
             bidirectional_iterator_tag)
 {
@@ -76,7 +76,7 @@
 }
 
 template <class _AlgPolicy, class _ForwardIterator, class _Sentinel, class _Predicate, class _IterCategory>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 pair<_ForwardIterator, _ForwardIterator> __partition(
     _ForwardIterator __first, _Sentinel __last, _Predicate&& __pred, _IterCategory __iter_category) {
   return std::__partition_impl<__uncvref_t<_Predicate>&, _AlgPolicy>(
@@ -84,7 +84,7 @@
 }
 
 template <class _ForwardIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator
 partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
 {
diff --git a/libcxx/include/__algorithm/partition_copy.h b/libcxx/include/__algorithm/partition_copy.h
--- a/libcxx/include/__algorithm/partition_copy.h
+++ b/libcxx/include/__algorithm/partition_copy.h
@@ -21,7 +21,7 @@
 
 template <class _InputIterator, class _OutputIterator1,
           class _OutputIterator2, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_OutputIterator1, _OutputIterator2>
+_LIBCPP_CONSTEXPR_CXX20 pair<_OutputIterator1, _OutputIterator2>
 partition_copy(_InputIterator __first, _InputIterator __last,
                _OutputIterator1 __out_true, _OutputIterator2 __out_false,
                _Predicate __pred)
diff --git a/libcxx/include/__algorithm/partition_point.h b/libcxx/include/__algorithm/partition_point.h
--- a/libcxx/include/__algorithm/partition_point.h
+++ b/libcxx/include/__algorithm/partition_point.h
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template<class _ForwardIterator, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 partition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
 {
     typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
diff --git a/libcxx/include/__algorithm/pop_heap.h b/libcxx/include/__algorithm/pop_heap.h
--- a/libcxx/include/__algorithm/pop_heap.h
+++ b/libcxx/include/__algorithm/pop_heap.h
@@ -27,7 +27,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 void __pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare& __comp,
     typename iterator_traits<_RandomAccessIterator>::difference_type __len) {
   _LIBCPP_ASSERT(__len > 0, "The heap given to pop_heap must be non-empty");
@@ -53,7 +53,7 @@
 }
 
 template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
   static_assert(std::is_copy_constructible<_RandomAccessIterator>::value, "Iterators must be copy constructible.");
   static_assert(std::is_copy_assignable<_RandomAccessIterator>::value, "Iterators must be copy assignable.");
@@ -63,7 +63,7 @@
 }
 
 template <class _RandomAccessIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) {
   std::pop_heap(std::move(__first), std::move(__last),
       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
diff --git a/libcxx/include/__algorithm/prev_permutation.h b/libcxx/include/__algorithm/prev_permutation.h
--- a/libcxx/include/__algorithm/prev_permutation.h
+++ b/libcxx/include/__algorithm/prev_permutation.h
@@ -25,7 +25,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Compare, class _BidirectionalIterator, class _Sentinel>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 pair<_BidirectionalIterator, bool>
 __prev_permutation(_BidirectionalIterator __first, _Sentinel __last, _Compare&& __comp)
 {
@@ -57,7 +57,7 @@
 }
 
 template <class _BidirectionalIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
 {
@@ -67,7 +67,7 @@
 }
 
 template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
 {
diff --git a/libcxx/include/__algorithm/push_heap.h b/libcxx/include/__algorithm/push_heap.h
--- a/libcxx/include/__algorithm/push_heap.h
+++ b/libcxx/include/__algorithm/push_heap.h
@@ -24,7 +24,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 void __sift_up(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare&& __comp,
         typename iterator_traits<_RandomAccessIterator>::difference_type __len) {
   using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
@@ -50,7 +50,7 @@
 }
 
 template <class _AlgPolicy, class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 void __push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare& __comp) {
   using _CompRef = typename __comp_ref_type<_Compare>::type;
   typename iterator_traits<_RandomAccessIterator>::difference_type __len = __last - __first;
@@ -58,7 +58,7 @@
 }
 
 template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
   static_assert(std::is_copy_constructible<_RandomAccessIterator>::value, "Iterators must be copy constructible.");
   static_assert(std::is_copy_assignable<_RandomAccessIterator>::value, "Iterators must be copy assignable.");
@@ -67,7 +67,7 @@
 }
 
 template <class _RandomAccessIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) {
   std::push_heap(std::move(__first), std::move(__last),
       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
diff --git a/libcxx/include/__algorithm/remove.h b/libcxx/include/__algorithm/remove.h
--- a/libcxx/include/__algorithm/remove.h
+++ b/libcxx/include/__algorithm/remove.h
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 remove(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
 {
     __first = _VSTD::find(__first, __last, __value);
diff --git a/libcxx/include/__algorithm/remove_copy.h b/libcxx/include/__algorithm/remove_copy.h
--- a/libcxx/include/__algorithm/remove_copy.h
+++ b/libcxx/include/__algorithm/remove_copy.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _OutputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 remove_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, const _Tp& __value)
 {
diff --git a/libcxx/include/__algorithm/remove_copy_if.h b/libcxx/include/__algorithm/remove_copy_if.h
--- a/libcxx/include/__algorithm/remove_copy_if.h
+++ b/libcxx/include/__algorithm/remove_copy_if.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _OutputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 remove_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred)
 {
diff --git a/libcxx/include/__algorithm/remove_if.h b/libcxx/include/__algorithm/remove_if.h
--- a/libcxx/include/__algorithm/remove_if.h
+++ b/libcxx/include/__algorithm/remove_if.h
@@ -20,7 +20,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 remove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
 {
     __first = _VSTD::find_if<_ForwardIterator, _Predicate&>(__first, __last, __pred);
diff --git a/libcxx/include/__algorithm/replace.h b/libcxx/include/__algorithm/replace.h
--- a/libcxx/include/__algorithm/replace.h
+++ b/libcxx/include/__algorithm/replace.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 replace(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __old_value, const _Tp& __new_value)
 {
diff --git a/libcxx/include/__algorithm/replace_copy.h b/libcxx/include/__algorithm/replace_copy.h
--- a/libcxx/include/__algorithm/replace_copy.h
+++ b/libcxx/include/__algorithm/replace_copy.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _OutputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 replace_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
              const _Tp& __old_value, const _Tp& __new_value)
diff --git a/libcxx/include/__algorithm/replace_copy_if.h b/libcxx/include/__algorithm/replace_copy_if.h
--- a/libcxx/include/__algorithm/replace_copy_if.h
+++ b/libcxx/include/__algorithm/replace_copy_if.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _OutputIterator, class _Predicate, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 replace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
                 _Predicate __pred, const _Tp& __new_value)
diff --git a/libcxx/include/__algorithm/replace_if.h b/libcxx/include/__algorithm/replace_if.h
--- a/libcxx/include/__algorithm/replace_if.h
+++ b/libcxx/include/__algorithm/replace_if.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Predicate, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 replace_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, const _Tp& __new_value)
 {
diff --git a/libcxx/include/__algorithm/reverse.h b/libcxx/include/__algorithm/reverse.h
--- a/libcxx/include/__algorithm/reverse.h
+++ b/libcxx/include/__algorithm/reverse.h
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 __reverse_impl(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag)
 {
@@ -36,7 +36,7 @@
 }
 
 template <class _AlgPolicy, class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 __reverse_impl(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag)
 {
@@ -46,14 +46,14 @@
 }
 
 template <class _AlgPolicy, class _BidirectionalIterator, class _Sentinel>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void __reverse(_BidirectionalIterator __first, _Sentinel __last) {
   using _IterCategory = typename _IterOps<_AlgPolicy>::template __iterator_category<_BidirectionalIterator>;
   std::__reverse_impl<_AlgPolicy>(std::move(__first), std::move(__last), _IterCategory());
 }
 
 template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
 {
diff --git a/libcxx/include/__algorithm/reverse_copy.h b/libcxx/include/__algorithm/reverse_copy.h
--- a/libcxx/include/__algorithm/reverse_copy.h
+++ b/libcxx/include/__algorithm/reverse_copy.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _BidirectionalIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 reverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
 {
diff --git a/libcxx/include/__algorithm/rotate.h b/libcxx/include/__algorithm/rotate.h
--- a/libcxx/include/__algorithm/rotate.h
+++ b/libcxx/include/__algorithm/rotate.h
@@ -26,7 +26,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
+_LIBCPP_CONSTEXPR_CXX14 _ForwardIterator
 __rotate_left(_ForwardIterator __first, _ForwardIterator __last)
 {
     typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
@@ -40,7 +40,7 @@
 }
 
 template <class _AlgPolicy, class _BidirectionalIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _BidirectionalIterator
+_LIBCPP_CONSTEXPR_CXX14 _BidirectionalIterator
 __rotate_right(_BidirectionalIterator __first, _BidirectionalIterator __last)
 {
     typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
@@ -54,7 +54,7 @@
 }
 
 template <class _AlgPolicy, class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX14 _ForwardIterator
+_LIBCPP_CONSTEXPR_CXX17 _ForwardIterator
 __rotate_forward(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
 {
     _ForwardIterator __i = __middle;
@@ -90,7 +90,7 @@
 
 template<typename _Integral>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX14 _Integral
+_LIBCPP_CONSTEXPR_CXX17 _Integral
 __algo_gcd(_Integral __x, _Integral __y)
 {
     do
@@ -103,7 +103,7 @@
 }
 
 template <class _AlgPolicy, typename _RandomAccessIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX14 _RandomAccessIterator
+_LIBCPP_CONSTEXPR_CXX17 _RandomAccessIterator
 __rotate_gcd(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
 {
     typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
@@ -140,7 +140,7 @@
 
 template <class _AlgPolicy, class _ForwardIterator>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator
+_LIBCPP_CONSTEXPR_CXX14 _ForwardIterator
 __rotate_impl(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last,
          _VSTD::forward_iterator_tag)
 {
@@ -155,7 +155,7 @@
 
 template <class _AlgPolicy, class _BidirectionalIterator>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _BidirectionalIterator
+_LIBCPP_CONSTEXPR_CXX14 _BidirectionalIterator
 __rotate_impl(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
          bidirectional_iterator_tag)
 {
@@ -172,7 +172,7 @@
 
 template <class _AlgPolicy, class _RandomAccessIterator>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator
+_LIBCPP_CONSTEXPR_CXX14 _RandomAccessIterator
 __rotate_impl(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
          random_access_iterator_tag)
 {
@@ -189,7 +189,7 @@
 }
 
 template <class _AlgPolicy, class _Iterator, class _Sentinel>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_Iterator, _Iterator>
 __rotate(_Iterator __first, _Iterator __middle, _Sentinel __last) {
   using _Ret = pair<_Iterator, _Iterator>;
@@ -209,7 +209,7 @@
 
 template <class _ForwardIterator>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
 {
   return std::__rotate<_ClassicAlgPolicy>(
diff --git a/libcxx/include/__algorithm/rotate_copy.h b/libcxx/include/__algorithm/rotate_copy.h
--- a/libcxx/include/__algorithm/rotate_copy.h
+++ b/libcxx/include/__algorithm/rotate_copy.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 rotate_copy(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last, _OutputIterator __result)
 {
diff --git a/libcxx/include/__algorithm/search.h b/libcxx/include/__algorithm/search.h
--- a/libcxx/include/__algorithm/search.h
+++ b/libcxx/include/__algorithm/search.h
@@ -33,7 +33,7 @@
           class _Pred,
           class _Proj1,
           class _Proj2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_Iter1, _Iter1> __search_forward_impl(_Iter1 __first1, _Sent1 __last1,
                                            _Iter2 __first2, _Sent2 __last2,
                                            _Pred& __pred,
@@ -80,7 +80,7 @@
           class _Proj2,
           class _DiffT1,
           class _DiffT2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_Iter1, _Iter1> __search_random_access_impl(_Iter1 __first1, _Sent1 __last1,
                                                  _Iter2 __first2, _Sent2 __last2,
                                                  _Pred& __pred,
@@ -120,7 +120,7 @@
           class _Pred,
           class _Proj1,
           class _Proj2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_Iter1, _Iter1> __search_impl(_Iter1 __first1, _Sent1 __last1,
                                    _Iter2 __first2, _Sent2 __last2,
                                    _Pred& __pred,
@@ -152,7 +152,7 @@
           class _Pred,
           class _Proj1,
           class _Proj2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_Iter1, _Iter1> __search_impl(_Iter1 __first1, _Sent1 __last1,
                                    _Iter2 __first2, _Sent2 __last2,
                                    _Pred& __pred,
@@ -170,7 +170,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator1 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
                          _ForwardIterator2 __first2, _ForwardIterator2 __last2,
                          _BinaryPredicate __pred) {
@@ -181,7 +181,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator1 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
                          _ForwardIterator2 __first2, _ForwardIterator2 __last2) {
   using __v1 = typename iterator_traits<_ForwardIterator1>::value_type;
@@ -191,7 +191,7 @@
 
 #if _LIBCPP_STD_VER > 14
 template <class _ForwardIterator, class _Searcher>
-_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher& __s) {
   return __s(__f, __l).first;
 }
diff --git a/libcxx/include/__algorithm/search_n.h b/libcxx/include/__algorithm/search_n.h
--- a/libcxx/include/__algorithm/search_n.h
+++ b/libcxx/include/__algorithm/search_n.h
@@ -29,7 +29,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Pred, class _Iter, class _Sent, class _SizeT, class _Type, class _Proj>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_Iter, _Iter> __search_n_forward_impl(_Iter __first, _Sent __last,
                                            _SizeT __count,
                                            const _Type& __value,
@@ -71,7 +71,7 @@
 }
 
 template <class _AlgPolicy, class _Pred, class _Iter, class _Sent, class _SizeT, class _Type, class _Proj, class _DiffT>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 std::pair<_Iter, _Iter> __search_n_random_access_impl(_Iter __first, _Sent __last,
                                                       _SizeT __count,
                                                       const _Type& __value,
@@ -122,7 +122,7 @@
           class _Type,
           class _Pred,
           class _Proj>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_Iter, _Iter> __search_n_impl(_Iter __first, _Sent __last,
                                    _DiffT __count,
                                    const _Type& __value,
@@ -142,7 +142,7 @@
           class _Type,
           class _Pred,
           class _Proj>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 pair<_Iter1, _Iter1> __search_n_impl(_Iter1 __first, _Sent1 __last,
                                      _DiffT __count,
                                      const _Type& __value,
@@ -158,7 +158,7 @@
 }
 
 template <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator search_n(_ForwardIterator __first, _ForwardIterator __last,
                           _Size __count,
                           const _Tp& __value,
@@ -170,7 +170,7 @@
 }
 
 template <class _ForwardIterator, class _Size, class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator search_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value) {
   typedef typename iterator_traits<_ForwardIterator>::value_type __v;
   return std::search_n(__first, __last, std::__convert_to_integral(__count), __value, __equal_to<__v, _Tp>());
diff --git a/libcxx/include/__algorithm/set_difference.h b/libcxx/include/__algorithm/set_difference.h
--- a/libcxx/include/__algorithm/set_difference.h
+++ b/libcxx/include/__algorithm/set_difference.h
@@ -27,7 +27,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template < class _Comp, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<__uncvref_t<_InIter1>, __uncvref_t<_OutIter> >
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 pair<__uncvref_t<_InIter1>, __uncvref_t<_OutIter> >
 __set_difference(
     _InIter1&& __first1, _Sent1&& __last1, _InIter2&& __first2, _Sent2&& __last2, _OutIter&& __result, _Comp&& __comp) {
   while (__first1 != __last1 && __first2 != __last2) {
@@ -46,7 +46,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator set_difference(
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _OutputIterator set_difference(
     _InputIterator1 __first1,
     _InputIterator1 __last1,
     _InputIterator2 __first2,
@@ -58,7 +58,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator set_difference(
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _OutputIterator set_difference(
     _InputIterator1 __first1,
     _InputIterator1 __last1,
     _InputIterator2 __first2,
diff --git a/libcxx/include/__algorithm/set_intersection.h b/libcxx/include/__algorithm/set_intersection.h
--- a/libcxx/include/__algorithm/set_intersection.h
+++ b/libcxx/include/__algorithm/set_intersection.h
@@ -30,13 +30,13 @@
   _OutIter __out_;
 
   // need a constructor as C++03 aggregate init is hard
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
   __set_intersection_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
       : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
 };
 
 template <class _AlgPolicy, class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 __set_intersection_result<_InIter1, _InIter2, _OutIter>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 __set_intersection_result<_InIter1, _InIter2, _OutIter>
 __set_intersection(
     _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
   while (__first1 != __last1 && __first2 != __last2) {
@@ -59,7 +59,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator set_intersection(
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _OutputIterator set_intersection(
     _InputIterator1 __first1,
     _InputIterator1 __last1,
     _InputIterator2 __first2,
@@ -78,7 +78,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator set_intersection(
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _OutputIterator set_intersection(
     _InputIterator1 __first1,
     _InputIterator1 __last1,
     _InputIterator2 __first2,
diff --git a/libcxx/include/__algorithm/set_symmetric_difference.h b/libcxx/include/__algorithm/set_symmetric_difference.h
--- a/libcxx/include/__algorithm/set_symmetric_difference.h
+++ b/libcxx/include/__algorithm/set_symmetric_difference.h
@@ -29,13 +29,13 @@
   _OutIter __out_;
 
   // need a constructor as C++03 aggregate init is hard
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
   __set_symmetric_difference_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
       : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
 };
 
 template <class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>
 __set_symmetric_difference(
     _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
   while (__first1 != __last1) {
@@ -64,7 +64,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator set_symmetric_difference(
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _OutputIterator set_symmetric_difference(
     _InputIterator1 __first1,
     _InputIterator1 __last1,
     _InputIterator2 __first2,
@@ -83,7 +83,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator set_symmetric_difference(
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _OutputIterator set_symmetric_difference(
     _InputIterator1 __first1,
     _InputIterator1 __last1,
     _InputIterator2 __first2,
diff --git a/libcxx/include/__algorithm/set_union.h b/libcxx/include/__algorithm/set_union.h
--- a/libcxx/include/__algorithm/set_union.h
+++ b/libcxx/include/__algorithm/set_union.h
@@ -29,13 +29,13 @@
   _OutIter __out_;
 
   // need a constructor as C++03 aggregate init is hard
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
   __set_union_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
       : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
 };
 
 template <class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 __set_union_result<_InIter1, _InIter2, _OutIter> __set_union(
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 __set_union_result<_InIter1, _InIter2, _OutIter> __set_union(
     _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
   for (; __first1 != __last1; ++__result) {
     if (__first2 == __last2) {
@@ -60,7 +60,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator set_union(
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _OutputIterator set_union(
     _InputIterator1 __first1,
     _InputIterator1 __last1,
     _InputIterator2 __first2,
@@ -79,7 +79,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator set_union(
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _OutputIterator set_union(
     _InputIterator1 __first1,
     _InputIterator1 __last1,
     _InputIterator2 __first2,
diff --git a/libcxx/include/__algorithm/sift_down.h b/libcxx/include/__algorithm/sift_down.h
--- a/libcxx/include/__algorithm/sift_down.h
+++ b/libcxx/include/__algorithm/sift_down.h
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 void
+_LIBCPP_CONSTEXPR_CXX14 void
 __sift_down(_RandomAccessIterator __first, _Compare&& __comp,
             typename iterator_traits<_RandomAccessIterator>::difference_type __len,
             _RandomAccessIterator __start)
@@ -78,7 +78,7 @@
 }
 
 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator
+_LIBCPP_CONSTEXPR_CXX14 _RandomAccessIterator
 __floyd_sift_down(_RandomAccessIterator __first, _Compare&& __comp,
                   typename iterator_traits<_RandomAccessIterator>::difference_type __len)
 {
diff --git a/libcxx/include/__algorithm/sort.h b/libcxx/include/__algorithm/sort.h
--- a/libcxx/include/__algorithm/sort.h
+++ b/libcxx/include/__algorithm/sort.h
@@ -43,7 +43,7 @@
   using _Comp = _CompT;
   _Comp& __comp;
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
   _WrapAlgPolicy(_Comp& __c) : __comp(__c) {}
 };
 
@@ -62,7 +62,7 @@
   using _AlgPolicy = _ClassicAlgPolicy;
   using _Comp = _CompT;
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 static
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 static
   _Comp __get_comp(_Comp __comp) { return __comp; }
 };
 
@@ -73,14 +73,14 @@
   using _AlgPolicy = typename _Wrapped::_AlgPolicy;
   using _Comp = typename _Wrapped::_Comp;
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 static
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 static
   _Comp __get_comp(_Wrapped& __w) { return __w.__comp; }
 };
 
 // stable, 2-3 compares, 0-2 swaps
 
 template <class _AlgPolicy, class _Compare, class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 unsigned __sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z,
+_LIBCPP_CONSTEXPR_CXX14 unsigned __sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z,
                                                _Compare __c) {
   using _Ops = _IterOps<_AlgPolicy>;
 
@@ -281,7 +281,7 @@
 
 // Assumes size > 0
 template <class _AlgPolicy, class _Compare, class _BidirectionalIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 void __selection_sort(_BidirectionalIterator __first, _BidirectionalIterator __last,
+_LIBCPP_CONSTEXPR_CXX14 void __selection_sort(_BidirectionalIterator __first, _BidirectionalIterator __last,
                                                     _Compare __comp) {
   _BidirectionalIterator __lm1 = __last;
   for (--__lm1; __first != __lm1; ++__first) {
@@ -672,7 +672,7 @@
 extern template _LIBCPP_FUNC_VIS unsigned __sort5<__less<long double>&, long double*>(long double*, long double*, long double*, long double*, long double*, __less<long double>&);
 
 template <class _AlgPolicy, class _RandomAccessIterator, class _Comp>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void __sort_impl(_RandomAccessIterator __first, _RandomAccessIterator __last, _Comp& __comp) {
   std::__debug_randomize_range<_AlgPolicy>(__first, __last);
 
@@ -689,13 +689,13 @@
 }
 
 template <class _RandomAccessIterator, class _Comp>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Comp __comp) {
   std::__sort_impl<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __comp);
 }
 
 template <class _RandomAccessIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void sort(_RandomAccessIterator __first, _RandomAccessIterator __last) {
   std::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
 }
diff --git a/libcxx/include/__algorithm/sort_heap.h b/libcxx/include/__algorithm/sort_heap.h
--- a/libcxx/include/__algorithm/sort_heap.h
+++ b/libcxx/include/__algorithm/sort_heap.h
@@ -25,7 +25,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Compare, class _RandomAccessIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 void __sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare&& __comp) {
   using _CompRef = typename __comp_ref_type<_Compare>::type;
   _CompRef __comp_ref = __comp;
@@ -36,7 +36,7 @@
 }
 
 template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
   static_assert(std::is_copy_constructible<_RandomAccessIterator>::value, "Iterators must be copy constructible.");
   static_assert(std::is_copy_assignable<_RandomAccessIterator>::value, "Iterators must be copy assignable.");
@@ -45,7 +45,7 @@
 }
 
 template <class _RandomAccessIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) {
   std::sort_heap(std::move(__first), std::move(__last),
       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
diff --git a/libcxx/include/__algorithm/swap_ranges.h b/libcxx/include/__algorithm/swap_ranges.h
--- a/libcxx/include/__algorithm/swap_ranges.h
+++ b/libcxx/include/__algorithm/swap_ranges.h
@@ -22,7 +22,7 @@
 
 // 2+2 iterators: the shorter size will be used.
 template <class _AlgPolicy, class _ForwardIterator1, class _Sentinel1, class _ForwardIterator2, class _Sentinel2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 pair<_ForwardIterator1, _ForwardIterator2>
 __swap_ranges(_ForwardIterator1 __first1, _Sentinel1 __last1, _ForwardIterator2 __first2, _Sentinel2 __last2) {
   while (__first1 != __last1 && __first2 != __last2) {
@@ -36,7 +36,7 @@
 
 // 2+1 iterators: size2 >= size1.
 template <class _AlgPolicy, class _ForwardIterator1, class _Sentinel1, class _ForwardIterator2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 pair<_ForwardIterator1, _ForwardIterator2>
 __swap_ranges(_ForwardIterator1 __first1, _Sentinel1 __last1, _ForwardIterator2 __first2) {
   while (__first1 != __last1) {
@@ -49,7 +49,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator2
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator2
 swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2) {
   return std::__swap_ranges<_ClassicAlgPolicy>(
       std::move(__first1), std::move(__last1), std::move(__first2)).second;
diff --git a/libcxx/include/__algorithm/transform.h b/libcxx/include/__algorithm/transform.h
--- a/libcxx/include/__algorithm/transform.h
+++ b/libcxx/include/__algorithm/transform.h
@@ -18,7 +18,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _OutputIterator, class _UnaryOperation>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 transform(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _UnaryOperation __op)
 {
@@ -28,7 +28,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _BinaryOperation>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 transform(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
           _OutputIterator __result, _BinaryOperation __binary_op)
diff --git a/libcxx/include/__algorithm/unique.h b/libcxx/include/__algorithm/unique.h
--- a/libcxx/include/__algorithm/unique.h
+++ b/libcxx/include/__algorithm/unique.h
@@ -26,7 +26,7 @@
 // unique
 
 template <class _AlgPolicy, class _Iter, class _Sent, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 std::pair<_Iter, _Iter>
+_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 std::pair<_Iter, _Iter>
 __unique(_Iter __first, _Sent __last, _BinaryPredicate&& __pred) {
   __first = std::__adjacent_find(__first, __last, __pred);
   if (__first != __last) {
@@ -43,13 +43,13 @@
 }
 
 template <class _ForwardIterator, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 unique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred) {
   return std::__unique<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __pred).first;
 }
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 unique(_ForwardIterator __first, _ForwardIterator __last) {
   typedef typename iterator_traits<_ForwardIterator>::value_type __v;
   return std::unique(__first, __last, __equal_to<__v>());
diff --git a/libcxx/include/__algorithm/unique_copy.h b/libcxx/include/__algorithm/unique_copy.h
--- a/libcxx/include/__algorithm/unique_copy.h
+++ b/libcxx/include/__algorithm/unique_copy.h
@@ -34,7 +34,7 @@
 } // namespace __unique_copy_tags
 
 template <class _AlgPolicy, class _BinaryPredicate, class _InputIterator, class _Sent, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _OutputIterator>
+_LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _OutputIterator>
 __unique_copy(_InputIterator __first,
               _Sent __last,
               _OutputIterator __result,
@@ -56,7 +56,7 @@
 }
 
 template <class _AlgPolicy, class _BinaryPredicate, class _ForwardIterator, class _Sent, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI pair<_ForwardIterator, _OutputIterator>
+_LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI pair<_ForwardIterator, _OutputIterator>
 __unique_copy(_ForwardIterator __first,
               _Sent __last,
               _OutputIterator __result,
@@ -78,7 +78,7 @@
 }
 
 template <class _AlgPolicy, class _BinaryPredicate, class _InputIterator, class _Sent, class _InputAndOutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _InputAndOutputIterator>
+_LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _InputAndOutputIterator>
 __unique_copy(_InputIterator __first,
               _Sent __last,
               _InputAndOutputIterator __result,
@@ -95,7 +95,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _OutputIterator
 unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred) {
   using __algo_tag = typename conditional<
       is_base_of<forward_iterator_tag, typename iterator_traits<_InputIterator>::iterator_category>::value,
@@ -112,7 +112,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _OutputIterator
 unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
   typedef typename iterator_traits<_InputIterator>::value_type __v;
   return std::unique_copy(std::move(__first), std::move(__last), std::move(__result), __equal_to<__v>());
diff --git a/libcxx/include/__algorithm/unwrap_iter.h b/libcxx/include/__algorithm/unwrap_iter.h
--- a/libcxx/include/__algorithm/unwrap_iter.h
+++ b/libcxx/include/__algorithm/unwrap_iter.h
@@ -57,7 +57,7 @@
 template<class _Iter,
          class _Impl = __unwrap_iter_impl<_Iter>,
          __enable_if_t<is_copy_constructible<_Iter>::value, int> = 0>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 decltype(_Impl::__unwrap(std::declval<_Iter>())) __unwrap_iter(_Iter __i) _NOEXCEPT {
   return _Impl::__unwrap(__i);
 }
diff --git a/libcxx/include/__algorithm/upper_bound.h b/libcxx/include/__algorithm/upper_bound.h
--- a/libcxx/include/__algorithm/upper_bound.h
+++ b/libcxx/include/__algorithm/upper_bound.h
@@ -28,7 +28,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Compare, class _Iter, class _Sent, class _Tp, class _Proj>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _Iter
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _Iter
 __upper_bound(_Iter __first, _Sent __last, const _Tp& __value, _Compare&& __comp, _Proj&& __proj) {
   auto __len = _IterOps<_AlgPolicy>::distance(__first, __last);
   while (__len != 0) {
@@ -45,7 +45,7 @@
 }
 
 template <class _ForwardIterator, class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp) {
   static_assert(is_copy_constructible<_ForwardIterator>::value,
                 "Iterator has to be copy constructible");
@@ -54,7 +54,7 @@
 }
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _ForwardIterator
 upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
   return std::upper_bound(
       std::move(__first),
diff --git a/libcxx/include/__bit_reference b/libcxx/include/__bit_reference
--- a/libcxx/include/__bit_reference
+++ b/libcxx/include/__bit_reference
@@ -54,15 +54,15 @@
     friend class __bit_const_reference<_Cp>;
     friend class __bit_iterator<_Cp, false>;
 public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     __bit_reference(const __bit_reference&) = default;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 operator bool() const _NOEXCEPT
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 operator bool() const _NOEXCEPT
         {return static_cast<bool>(*__seg_ & __mask_);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool operator ~() const _NOEXCEPT
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 bool operator ~() const _NOEXCEPT
         {return !static_cast<bool>(*this);}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     __bit_reference& operator=(bool __x) _NOEXCEPT
     {
         if (__x)
@@ -82,15 +82,15 @@
     }
 #endif
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     __bit_reference& operator=(const __bit_reference& __x) _NOEXCEPT
         {return operator=(static_cast<bool>(__x));}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 void flip() _NOEXCEPT {*__seg_ ^= __mask_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator<_Cp, false> operator&() const _NOEXCEPT
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 void flip() _NOEXCEPT {*__seg_ ^= __mask_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator<_Cp, false> operator&() const _NOEXCEPT
         {return __bit_iterator<_Cp, false>(__seg_, static_cast<unsigned>(__libcpp_ctz(__mask_)));}
 private:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     explicit __bit_reference(__storage_pointer __s, __storage_type __m) _NOEXCEPT
         : __seg_(__s), __mask_(__m) {}
 };
@@ -101,7 +101,7 @@
 };
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 swap(__bit_reference<_Cp> __x, __bit_reference<_Cp> __y) _NOEXCEPT
 {
@@ -111,7 +111,7 @@
 }
 
 template <class _Cp, class _Dp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 swap(__bit_reference<_Cp> __x, __bit_reference<_Dp> __y) _NOEXCEPT
 {
@@ -121,7 +121,7 @@
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 swap(__bit_reference<_Cp> __x, bool& __y) _NOEXCEPT
 {
@@ -131,7 +131,7 @@
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 swap(bool& __x, __bit_reference<_Cp> __y) _NOEXCEPT
 {
@@ -155,14 +155,14 @@
     _LIBCPP_INLINE_VISIBILITY
     __bit_const_reference(const __bit_const_reference&) = default;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     __bit_const_reference(const __bit_reference<_Cp>& __x) _NOEXCEPT
         : __seg_(__x.__seg_), __mask_(__x.__mask_) {}
 
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR operator bool() const _NOEXCEPT
         {return static_cast<bool>(*__seg_ & __mask_);}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator<_Cp, true> operator&() const _NOEXCEPT
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator<_Cp, true> operator&() const _NOEXCEPT
         {return __bit_iterator<_Cp, true>(__seg_, static_cast<unsigned>(__libcpp_ctz(__mask_)));}
 private:
     _LIBCPP_INLINE_VISIBILITY
@@ -176,7 +176,7 @@
 // find
 
 template <class _Cp, bool _IsConst>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator<_Cp, _IsConst>
+_LIBCPP_CONSTEXPR_CXX20 __bit_iterator<_Cp, _IsConst>
 __find_bool_true(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
 {
     typedef __bit_iterator<_Cp, _IsConst> _It;
@@ -212,7 +212,7 @@
 }
 
 template <class _Cp, bool _IsConst>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator<_Cp, _IsConst>
+_LIBCPP_CONSTEXPR_CXX20 __bit_iterator<_Cp, _IsConst>
 __find_bool_false(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
 {
     typedef __bit_iterator<_Cp, _IsConst> _It;
@@ -251,7 +251,7 @@
 }
 
 template <class _Cp, bool _IsConst, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 __bit_iterator<_Cp, _IsConst>
 find(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, const _Tp& __value)
 {
@@ -337,7 +337,7 @@
 // fill_n
 
 template <class _Cp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 __fill_n_false(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n)
 {
     typedef __bit_iterator<_Cp, false> _It;
@@ -367,7 +367,7 @@
 }
 
 template <class _Cp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 __fill_n_true(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n)
 {
     typedef __bit_iterator<_Cp, false> _It;
@@ -398,7 +398,7 @@
 }
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 fill_n(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n, bool __value)
 {
@@ -414,7 +414,7 @@
 // fill
 
 template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 fill(__bit_iterator<_Cp, false> __first, __bit_iterator<_Cp, false> __last, bool __value)
 {
@@ -424,7 +424,7 @@
 // copy
 
 template <class _Cp, bool _IsConst>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __bit_iterator<_Cp, false>
 __copy_aligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
                                                      __bit_iterator<_Cp, false> __result)
@@ -472,7 +472,7 @@
 }
 
 template <class _Cp, bool _IsConst>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __bit_iterator<_Cp, false>
 __copy_unaligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
                                                        __bit_iterator<_Cp, false> __result)
@@ -551,7 +551,7 @@
 }
 
 template <class _Cp, bool _IsConst>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 __bit_iterator<_Cp, false>
 copy(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, __bit_iterator<_Cp, false> __result)
 {
@@ -563,7 +563,7 @@
 // copy_backward
 
 template <class _Cp, bool _IsConst>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator<_Cp, false>
+_LIBCPP_CONSTEXPR_CXX20 __bit_iterator<_Cp, false>
 __copy_backward_aligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
                                                      __bit_iterator<_Cp, false> __result)
 {
@@ -610,7 +610,7 @@
 }
 
 template <class _Cp, bool _IsConst>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator<_Cp, false>
+_LIBCPP_CONSTEXPR_CXX20 __bit_iterator<_Cp, false>
 __copy_backward_unaligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
                                                        __bit_iterator<_Cp, false> __result)
 {
@@ -696,7 +696,7 @@
 }
 
 template <class _Cp, bool _IsConst>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 __bit_iterator<_Cp, false>
 copy_backward(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, __bit_iterator<_Cp, false> __result)
 {
@@ -903,19 +903,19 @@
     difference_type __size_;
     __storage_type __word_[_Np];
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 static difference_type capacity()
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 static difference_type capacity()
         {return static_cast<difference_type>(_Np * __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit __bit_array(difference_type __s) : __size_(__s) {
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 explicit __bit_array(difference_type __s) : __size_(__s) {
         if (__libcpp_is_constant_evaluated()) {
             for (size_t __i = 0; __i != __bit_array<_Cp>::_Np; ++__i)
                 std::__construct_at(__word_ + __i, 0);
         }
     }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator begin()
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 iterator begin()
     {
         return iterator(pointer_traits<__storage_pointer>::pointer_to(__word_[0]), 0);
     }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator end()
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 iterator end()
     {
         return iterator(pointer_traits<__storage_pointer>::pointer_to(__word_[0]) + __size_ / __bits_per_word,
                                                   static_cast<unsigned>(__size_ % __bits_per_word));
@@ -923,7 +923,7 @@
 };
 
 template <class _Cp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator<_Cp, false>
+_LIBCPP_CONSTEXPR_CXX20 __bit_iterator<_Cp, false>
 rotate(__bit_iterator<_Cp, false> __first, __bit_iterator<_Cp, false> __middle, __bit_iterator<_Cp, false> __last)
 {
     typedef __bit_iterator<_Cp, false> _I1;
@@ -974,7 +974,7 @@
 // equal
 
 template <class _Cp, bool _IC1, bool _IC2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_CONSTEXPR_CXX20 bool
 __equal_unaligned(__bit_iterator<_Cp, _IC1> __first1, __bit_iterator<_Cp, _IC1> __last1,
                   __bit_iterator<_Cp, _IC2> __first2)
 {
@@ -1056,7 +1056,7 @@
 }
 
 template <class _Cp, bool _IC1, bool _IC2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_CONSTEXPR_CXX20 bool
 __equal_aligned(__bit_iterator<_Cp, _IC1> __first1, __bit_iterator<_Cp, _IC1> __last1,
                 __bit_iterator<_Cp, _IC2> __first2)
 {
@@ -1099,7 +1099,7 @@
 }
 
 template <class _Cp, bool _IC1, bool _IC2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool
 equal(__bit_iterator<_Cp, _IC1> __first1, __bit_iterator<_Cp, _IC1> __last1, __bit_iterator<_Cp, _IC2> __first2)
 {
@@ -1133,7 +1133,7 @@
     unsigned          __ctz_;
 
 public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator() _NOEXCEPT
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator() _NOEXCEPT
 #if _LIBCPP_STD_VER > 11
     : __seg_(nullptr), __ctz_(0)
 #endif
@@ -1144,7 +1144,7 @@
     // When _IsConst=true, this is a converting constructor;
     // the copy and move constructors are implicitly generated
     // and trivial.
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     __bit_iterator(const __bit_iterator<_Cp, false>& __it) _NOEXCEPT
         : __seg_(__it.__seg_), __ctz_(__it.__ctz_) {}
 
@@ -1153,19 +1153,19 @@
     // the implicit generation of a defaulted one is deprecated.
     // When _IsConst=true, the assignment operators are
     // implicitly generated and trivial.
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     __bit_iterator& operator=(const _If<_IsConst, struct __private_nat, __bit_iterator>& __it) {
         __seg_ = __it.__seg_;
         __ctz_ = __it.__ctz_;
         return *this;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 reference operator*() const _NOEXCEPT {
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 reference operator*() const _NOEXCEPT {
         return typename conditional<_IsConst, __bit_const_reference<_Cp>, __bit_reference<_Cp> >
                 ::type(__seg_, __storage_type(1) << __ctz_);
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator& operator++()
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator& operator++()
     {
         if (__ctz_ != __bits_per_word-1)
             ++__ctz_;
@@ -1177,14 +1177,14 @@
         return *this;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator operator++(int)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator operator++(int)
     {
         __bit_iterator __tmp = *this;
         ++(*this);
         return __tmp;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator& operator--()
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator& operator--()
     {
         if (__ctz_ != 0)
             --__ctz_;
@@ -1196,14 +1196,14 @@
         return *this;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator operator--(int)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator operator--(int)
     {
         __bit_iterator __tmp = *this;
         --(*this);
         return __tmp;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator& operator+=(difference_type __n)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator& operator+=(difference_type __n)
     {
         if (__n >= 0)
             __seg_ += (__n + __ctz_) / __bits_per_word;
@@ -1215,54 +1215,54 @@
         return *this;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator& operator-=(difference_type __n)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator& operator-=(difference_type __n)
     {
         return *this += -__n;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator operator+(difference_type __n) const
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator operator+(difference_type __n) const
     {
         __bit_iterator __t(*this);
         __t += __n;
         return __t;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 __bit_iterator operator-(difference_type __n) const
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 __bit_iterator operator-(difference_type __n) const
     {
         __bit_iterator __t(*this);
         __t -= __n;
         return __t;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     friend __bit_iterator operator+(difference_type __n, const __bit_iterator& __it) {return __it + __n;}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     friend difference_type operator-(const __bit_iterator& __x, const __bit_iterator& __y)
         {return (__x.__seg_ - __y.__seg_) * __bits_per_word + __x.__ctz_ - __y.__ctz_;}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 reference operator[](difference_type __n) const {return *(*this + __n);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 reference operator[](difference_type __n) const {return *(*this + __n);}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 friend bool operator==(const __bit_iterator& __x, const __bit_iterator& __y)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 friend bool operator==(const __bit_iterator& __x, const __bit_iterator& __y)
         {return __x.__seg_ == __y.__seg_ && __x.__ctz_ == __y.__ctz_;}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 friend bool operator!=(const __bit_iterator& __x, const __bit_iterator& __y)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 friend bool operator!=(const __bit_iterator& __x, const __bit_iterator& __y)
         {return !(__x == __y);}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 friend bool operator<(const __bit_iterator& __x, const __bit_iterator& __y)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 friend bool operator<(const __bit_iterator& __x, const __bit_iterator& __y)
         {return __x.__seg_ < __y.__seg_ || (__x.__seg_ == __y.__seg_ && __x.__ctz_ < __y.__ctz_);}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 friend bool operator>(const __bit_iterator& __x, const __bit_iterator& __y)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 friend bool operator>(const __bit_iterator& __x, const __bit_iterator& __y)
         {return __y < __x;}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 friend bool operator<=(const __bit_iterator& __x, const __bit_iterator& __y)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 friend bool operator<=(const __bit_iterator& __x, const __bit_iterator& __y)
         {return !(__y < __x);}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 friend bool operator>=(const __bit_iterator& __x, const __bit_iterator& __y)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 friend bool operator>=(const __bit_iterator& __x, const __bit_iterator& __y)
         {return !(__x < __y);}
 
 private:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     explicit __bit_iterator(__storage_pointer __s, unsigned __ctz) _NOEXCEPT
         : __seg_(__s), __ctz_(__ctz) {}
 
@@ -1273,40 +1273,40 @@
     friend class __bit_iterator<_Cp, true>;
     template <class _Dp> friend struct __bit_array;
     template <class _Dp>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend void __fill_n_false(__bit_iterator<_Dp, false> __first, typename _Dp::size_type __n);
 
     template <class _Dp>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend void __fill_n_true(__bit_iterator<_Dp, false> __first, typename _Dp::size_type __n);
 
     template <class _Dp, bool _IC>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend __bit_iterator<_Dp, false> __copy_aligned(__bit_iterator<_Dp, _IC> __first,
                                                      __bit_iterator<_Dp, _IC> __last,
                                                      __bit_iterator<_Dp, false> __result);
     template <class _Dp, bool _IC>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend __bit_iterator<_Dp, false> __copy_unaligned(__bit_iterator<_Dp, _IC> __first,
                                                        __bit_iterator<_Dp, _IC> __last,
                                                        __bit_iterator<_Dp, false> __result);
     template <class _Dp, bool _IC>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend __bit_iterator<_Dp, false> copy(__bit_iterator<_Dp, _IC> __first,
                                            __bit_iterator<_Dp, _IC> __last,
                                            __bit_iterator<_Dp, false> __result);
     template <class _Dp, bool _IC>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend __bit_iterator<_Dp, false> __copy_backward_aligned(__bit_iterator<_Dp, _IC> __first,
                                                               __bit_iterator<_Dp, _IC> __last,
                                                               __bit_iterator<_Dp, false> __result);
     template <class _Dp, bool _IC>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend __bit_iterator<_Dp, false> __copy_backward_unaligned(__bit_iterator<_Dp, _IC> __first,
                                                                 __bit_iterator<_Dp, _IC> __last,
                                                                 __bit_iterator<_Dp, false> __result);
     template <class _Dp, bool _IC>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend __bit_iterator<_Dp, false> copy_backward(__bit_iterator<_Dp, _IC> __first,
                                                     __bit_iterator<_Dp, _IC> __last,
                                                     __bit_iterator<_Dp, false> __result);
@@ -1320,30 +1320,30 @@
                                                                                  __bit_iterator<__C1, false>,
                                                                                  __bit_iterator<__C2, false>);
     template <class _Dp>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend __bit_iterator<_Dp, false> rotate(__bit_iterator<_Dp, false>,
                                              __bit_iterator<_Dp, false>,
                                              __bit_iterator<_Dp, false>);
     template <class _Dp, bool _IC1, bool _IC2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend bool __equal_aligned(__bit_iterator<_Dp, _IC1>,
                                 __bit_iterator<_Dp, _IC1>,
                                 __bit_iterator<_Dp, _IC2>);
     template <class _Dp, bool _IC1, bool _IC2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend bool __equal_unaligned(__bit_iterator<_Dp, _IC1>,
                                   __bit_iterator<_Dp, _IC1>,
                                   __bit_iterator<_Dp, _IC2>);
     template <class _Dp, bool _IC1, bool _IC2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend bool equal(__bit_iterator<_Dp, _IC1>,
                       __bit_iterator<_Dp, _IC1>,
                       __bit_iterator<_Dp, _IC2>);
     template <class _Dp, bool _IC>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend __bit_iterator<_Dp, _IC> __find_bool_true(__bit_iterator<_Dp, _IC>, typename _Dp::size_type);
     template <class _Dp, bool _IC>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     friend __bit_iterator<_Dp, _IC> __find_bool_false(__bit_iterator<_Dp, _IC>, typename _Dp::size_type);
     template <class _Dp, bool _IC> friend typename __bit_iterator<_Dp, _IC>::difference_type
                    __count_bool_true(__bit_iterator<_Dp, _IC>, typename _Dp::size_type);
diff --git a/libcxx/include/__charconv/chars_format.h b/libcxx/include/__charconv/chars_format.h
--- a/libcxx/include/__charconv/chars_format.h
+++ b/libcxx/include/__charconv/chars_format.h
@@ -52,19 +52,19 @@
                       _VSTD::__to_underlying(__y));
 }
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 chars_format&
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 chars_format&
 operator&=(chars_format& __x, chars_format __y) {
   __x = __x & __y;
   return __x;
 }
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 chars_format&
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 chars_format&
 operator|=(chars_format& __x, chars_format __y) {
   __x = __x | __y;
   return __x;
 }
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 chars_format&
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 chars_format&
 operator^=(chars_format& __x, chars_format __y) {
   __x = __x ^ __y;
   return __x;
diff --git a/libcxx/include/__chrono/duration.h b/libcxx/include/__chrono/duration.h
--- a/libcxx/include/__chrono/duration.h
+++ b/libcxx/include/__chrono/duration.h
@@ -278,18 +278,18 @@
 
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator-() const {return typename common_type<duration>::type(-__rep_);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator++()      {++__rep_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration  operator++(int)   {return duration(__rep_++);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator--()      {--__rep_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration  operator--(int)   {return duration(__rep_--);}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator+=(const duration& __d) {__rep_ += __d.count(); return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator-=(const duration& __d) {__rep_ -= __d.count(); return *this;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator*=(const rep& __rhs) {__rep_ *= __rhs; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator/=(const rep& __rhs) {__rep_ /= __rhs; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator%=(const rep& __rhs) {__rep_ %= __rhs; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator%=(const duration& __rhs) {__rep_ %= __rhs.count(); return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 duration& operator++()      {++__rep_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 duration  operator++(int)   {return duration(__rep_++);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 duration& operator--()      {--__rep_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 duration  operator--(int)   {return duration(__rep_--);}
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 duration& operator+=(const duration& __d) {__rep_ += __d.count(); return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 duration& operator-=(const duration& __d) {__rep_ -= __d.count(); return *this;}
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 duration& operator*=(const rep& __rhs) {__rep_ *= __rhs; return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 duration& operator/=(const rep& __rhs) {__rep_ /= __rhs; return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 duration& operator%=(const rep& __rhs) {__rep_ %= __rhs; return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 duration& operator%=(const duration& __rhs) {__rep_ %= __rhs.count(); return *this;}
 
     // special values
 
diff --git a/libcxx/include/__chrono/file_clock.h b/libcxx/include/__chrono/file_clock.h
--- a/libcxx/include/__chrono/file_clock.h
+++ b/libcxx/include/__chrono/file_clock.h
@@ -61,7 +61,7 @@
   typedef chrono::time_point<_FilesystemClock> time_point;
 
   _LIBCPP_EXPORTED_FROM_ABI
-  static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
+  static _LIBCPP_CONSTEXPR_CXX14 const bool is_steady = false;
 
   _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_FUNC_VIS static time_point now() noexcept;
 
diff --git a/libcxx/include/__chrono/steady_clock.h b/libcxx/include/__chrono/steady_clock.h
--- a/libcxx/include/__chrono/steady_clock.h
+++ b/libcxx/include/__chrono/steady_clock.h
@@ -31,7 +31,7 @@
     typedef duration::rep                                 rep;
     typedef duration::period                              period;
     typedef chrono::time_point<steady_clock, duration>    time_point;
-    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = true;
+    static _LIBCPP_CONSTEXPR_CXX14 const bool is_steady = true;
 
     static time_point now() _NOEXCEPT;
 };
diff --git a/libcxx/include/__chrono/system_clock.h b/libcxx/include/__chrono/system_clock.h
--- a/libcxx/include/__chrono/system_clock.h
+++ b/libcxx/include/__chrono/system_clock.h
@@ -31,7 +31,7 @@
     typedef duration::rep                    rep;
     typedef duration::period                 period;
     typedef chrono::time_point<system_clock> time_point;
-    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
+    static _LIBCPP_CONSTEXPR_CXX14 const bool is_steady = false;
 
     static time_point now() _NOEXCEPT;
     static time_t     to_time_t  (const time_point& __t) _NOEXCEPT;
diff --git a/libcxx/include/__chrono/time_point.h b/libcxx/include/__chrono/time_point.h
--- a/libcxx/include/__chrono/time_point.h
+++ b/libcxx/include/__chrono/time_point.h
@@ -41,12 +41,12 @@
     duration __d_;
 
 public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 time_point() : __d_(duration::zero()) {}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 explicit time_point(const duration& __d) : __d_(__d) {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 time_point() : __d_(duration::zero()) {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 explicit time_point(const duration& __d) : __d_(__d) {}
 
     // conversions
     template <class _Duration2>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     time_point(const time_point<clock, _Duration2>& __t,
         typename enable_if
         <
@@ -56,12 +56,12 @@
 
     // observer
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 duration time_since_epoch() const {return __d_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 duration time_since_epoch() const {return __d_;}
 
     // arithmetic
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 time_point& operator+=(const duration& __d) {__d_ += __d; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 time_point& operator-=(const duration& __d) {__d_ -= __d; return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 time_point& operator+=(const duration& __d) {__d_ += __d; return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 time_point& operator-=(const duration& __d) {__d_ -= __d; return *this;}
 
     // special values
 
@@ -81,7 +81,7 @@
 namespace chrono {
 
 template <class _ToDuration, class _Clock, class _Duration>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 time_point<_Clock, _ToDuration>
 time_point_cast(const time_point<_Clock, _Duration>& __t)
 {
@@ -141,7 +141,7 @@
 // time_point ==
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator==(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -151,7 +151,7 @@
 // time_point !=
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator!=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -161,7 +161,7 @@
 // time_point <
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator<(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -171,7 +171,7 @@
 // time_point >
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator>(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -181,7 +181,7 @@
 // time_point <=
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator<=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -191,7 +191,7 @@
 // time_point >=
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator>=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -201,7 +201,7 @@
 // time_point operator+(time_point x, duration y);
 
 template <class _Clock, class _Duration1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
 operator+(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
 {
@@ -212,7 +212,7 @@
 // time_point operator+(duration x, time_point y);
 
 template <class _Rep1, class _Period1, class _Clock, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 time_point<_Clock, typename common_type<duration<_Rep1, _Period1>, _Duration2>::type>
 operator+(const duration<_Rep1, _Period1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -222,7 +222,7 @@
 // time_point operator-(time_point x, duration y);
 
 template <class _Clock, class _Duration1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
 operator-(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
 {
@@ -233,7 +233,7 @@
 // duration operator-(time_point x, time_point y);
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename common_type<_Duration1, _Duration2>::type
 operator-(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -832,21 +832,21 @@
 #  endif
 
 #  if _LIBCPP_STD_VER > 11
-#    define _LIBCPP_CONSTEXPR_AFTER_CXX11 constexpr
+#    define _LIBCPP_CONSTEXPR_CXX14 constexpr
 #  else
-#    define _LIBCPP_CONSTEXPR_AFTER_CXX11
+#    define _LIBCPP_CONSTEXPR_CXX14
 #  endif
 
 #  if _LIBCPP_STD_VER > 14
-#    define _LIBCPP_CONSTEXPR_AFTER_CXX14 constexpr
+#    define _LIBCPP_CONSTEXPR_CXX17 constexpr
 #  else
-#    define _LIBCPP_CONSTEXPR_AFTER_CXX14
+#    define _LIBCPP_CONSTEXPR_CXX17
 #  endif
 
 #  if _LIBCPP_STD_VER > 17
-#    define _LIBCPP_CONSTEXPR_AFTER_CXX17 constexpr
+#    define _LIBCPP_CONSTEXPR_CXX20 constexpr
 #  else
-#    define _LIBCPP_CONSTEXPR_AFTER_CXX17
+#    define _LIBCPP_CONSTEXPR_CXX20
 #  endif
 
 #  if __has_cpp_attribute(nodiscard) || defined(_LIBCPP_COMPILER_MSVC)
diff --git a/libcxx/include/__debug b/libcxx/include/__debug
--- a/libcxx/include/__debug
+++ b/libcxx/include/__debug
@@ -212,7 +212,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 inline void __debug_db_insert_c(_Tp* __c) {
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 inline void __debug_db_insert_c(_Tp* __c) {
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
     if (!__libcpp_is_constant_evaluated())
         __get_db()->__insert_c(__c);
@@ -222,7 +222,7 @@
 }
 
 template <class _Tp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 inline void __debug_db_insert_i(_Tp* __i) {
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 inline void __debug_db_insert_i(_Tp* __i) {
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
     if (!__libcpp_is_constant_evaluated())
         __get_db()->__insert_i(__i);
@@ -232,7 +232,7 @@
 }
 
 template <class _Tp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 inline void __debug_db_erase_c(_Tp* __c) {
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 inline void __debug_db_erase_c(_Tp* __c) {
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
     if (!__libcpp_is_constant_evaluated())
         __get_db()->__erase_c(__c);
@@ -242,7 +242,7 @@
 }
 
 template <class _Tp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 inline void __debug_db_swap(_Tp* __lhs, _Tp* __rhs) {
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 inline void __debug_db_swap(_Tp* __lhs, _Tp* __rhs) {
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
     if (!__libcpp_is_constant_evaluated())
         __get_db()->swap(__lhs, __rhs);
@@ -253,7 +253,7 @@
 }
 
 template <class _Tp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 inline void __debug_db_invalidate_all(_Tp* __c) {
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 inline void __debug_db_invalidate_all(_Tp* __c) {
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
     if (!__libcpp_is_constant_evaluated())
         __get_db()->__invalidate_all(__c);
diff --git a/libcxx/include/__debug_utils/randomize_range.h b/libcxx/include/__debug_utils/randomize_range.h
--- a/libcxx/include/__debug_utils/randomize_range.h
+++ b/libcxx/include/__debug_utils/randomize_range.h
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _AlgPolicy, class _Iterator, class _Sentinel>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 void __debug_randomize_range(_Iterator __first, _Sentinel __last) {
 #ifdef _LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY
 #  ifdef _LIBCPP_CXX03_LANG
diff --git a/libcxx/include/__functional/binary_negate.h b/libcxx/include/__functional/binary_negate.h
--- a/libcxx/include/__functional/binary_negate.h
+++ b/libcxx/include/__functional/binary_negate.h
@@ -29,17 +29,17 @@
 {
     _Predicate __pred_;
 public:
-    _LIBCPP_INLINE_VISIBILITY explicit _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY explicit _LIBCPP_CONSTEXPR_CXX14
     binary_negate(const _Predicate& __pred) : __pred_(__pred) {}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const typename _Predicate::first_argument_type& __x,
                     const typename _Predicate::second_argument_type& __y) const
         {return !__pred_(__x, __y);}
 };
 
 template <class _Predicate>
-_LIBCPP_DEPRECATED_IN_CXX17 inline _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_DEPRECATED_IN_CXX17 inline _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 binary_negate<_Predicate>
 not2(const _Predicate& __pred) {return binary_negate<_Predicate>(__pred);}
 
diff --git a/libcxx/include/__functional/bind.h b/libcxx/include/__functional/bind.h
--- a/libcxx/include/__functional/bind.h
+++ b/libcxx/include/__functional/bind.h
@@ -282,13 +282,13 @@
                                   !is_same<typename remove_reference<_Gp>::type,
                                            __bind>::value
                                >::type>
-      _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+      _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
       explicit __bind(_Gp&& __f, _BA&& ...__bound_args)
         : __f_(_VSTD::forward<_Gp>(__f)),
           __bound_args_(_VSTD::forward<_BA>(__bound_args)...) {}
 
     template <class ..._Args>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
         typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type
         operator()(_Args&& ...__args)
         {
@@ -297,7 +297,7 @@
         }
 
     template <class ..._Args>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
         typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type
         operator()(_Args&& ...__args) const
         {
@@ -327,13 +327,13 @@
                                   !is_same<typename remove_reference<_Gp>::type,
                                            __bind_r>::value
                                >::type>
-      _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+      _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
       explicit __bind_r(_Gp&& __f, _BA&& ...__bound_args)
         : base(_VSTD::forward<_Gp>(__f),
                _VSTD::forward<_BA>(__bound_args)...) {}
 
     template <class ..._Args>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
         typename enable_if
         <
             is_convertible<typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type,
@@ -347,7 +347,7 @@
         }
 
     template <class ..._Args>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
         typename enable_if
         <
             is_convertible<typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type,
@@ -365,7 +365,7 @@
 struct is_bind_expression<__bind_r<_Rp, _Fp, _BoundArgs...> > : public true_type {};
 
 template<class _Fp, class ..._BoundArgs>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 __bind<_Fp, _BoundArgs...>
 bind(_Fp&& __f, _BoundArgs&&... __bound_args)
 {
@@ -374,7 +374,7 @@
 }
 
 template<class _Rp, class _Fp, class ..._BoundArgs>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 __bind_r<_Rp, _Fp, _BoundArgs...>
 bind(_Fp&& __f, _BoundArgs&&... __bound_args)
 {
diff --git a/libcxx/include/__functional/default_searcher.h b/libcxx/include/__functional/default_searcher.h
--- a/libcxx/include/__functional/default_searcher.h
+++ b/libcxx/include/__functional/default_searcher.h
@@ -29,13 +29,13 @@
 template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
 class _LIBCPP_TEMPLATE_VIS default_searcher {
 public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     default_searcher(_ForwardIterator __f, _ForwardIterator __l,
                        _BinaryPredicate __p = _BinaryPredicate())
         : __first_(__f), __last_(__l), __pred_(__p) {}
 
     template <typename _ForwardIterator2>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     pair<_ForwardIterator2, _ForwardIterator2>
     operator () (_ForwardIterator2 __f, _ForwardIterator2 __l) const
     {
diff --git a/libcxx/include/__functional/invoke.h b/libcxx/include/__functional/invoke.h
--- a/libcxx/include/__functional/invoke.h
+++ b/libcxx/include/__functional/invoke.h
@@ -524,7 +524,7 @@
 using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
 
 template <class _Fn, class ..._Args>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 invoke_result_t<_Fn, _Args...>
+_LIBCPP_CONSTEXPR_CXX20 invoke_result_t<_Fn, _Args...>
 invoke(_Fn&& __f, _Args&&... __args)
     noexcept(is_nothrow_invocable_v<_Fn, _Args...>)
 {
diff --git a/libcxx/include/__functional/mem_fn.h b/libcxx/include/__functional/mem_fn.h
--- a/libcxx/include/__functional/mem_fn.h
+++ b/libcxx/include/__functional/mem_fn.h
@@ -33,12 +33,12 @@
     type __f_;
 
 public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     __mem_fn(type __f) _NOEXCEPT : __f_(__f) {}
 
     // invoke
     template <class... _ArgTypes>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 
     typename __invoke_return<type, _ArgTypes...>::type
     operator() (_ArgTypes&&... __args) const {
@@ -47,7 +47,7 @@
 };
 
 template<class _Rp, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 __mem_fn<_Rp _Tp::*>
 mem_fn(_Rp _Tp::* __pm) _NOEXCEPT
 {
diff --git a/libcxx/include/__functional/not_fn.h b/libcxx/include/__functional/not_fn.h
--- a/libcxx/include/__functional/not_fn.h
+++ b/libcxx/include/__functional/not_fn.h
@@ -27,7 +27,7 @@
 struct __not_fn_op {
     template <class... _Args>
     _LIBCPP_HIDE_FROM_ABI
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 auto operator()(_Args&&... __args) const
+    _LIBCPP_CONSTEXPR_CXX20 auto operator()(_Args&&... __args) const
         noexcept(noexcept(!_VSTD::invoke(_VSTD::forward<_Args>(__args)...)))
         -> decltype(      !_VSTD::invoke(_VSTD::forward<_Args>(__args)...))
         { return          !_VSTD::invoke(_VSTD::forward<_Args>(__args)...); }
@@ -43,7 +43,7 @@
     is_move_constructible_v<decay_t<_Fn>>
 >>
 _LIBCPP_HIDE_FROM_ABI
-_LIBCPP_CONSTEXPR_AFTER_CXX17 auto not_fn(_Fn&& __f) {
+_LIBCPP_CONSTEXPR_CXX20 auto not_fn(_Fn&& __f) {
     return __not_fn_t<decay_t<_Fn>>(_VSTD::forward<_Fn>(__f));
 }
 
diff --git a/libcxx/include/__functional/operations.h b/libcxx/include/__functional/operations.h
--- a/libcxx/include/__functional/operations.h
+++ b/libcxx/include/__functional/operations.h
@@ -32,7 +32,7 @@
     : __binary_function<_Tp, _Tp, _Tp>
 {
     typedef _Tp __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x, const _Tp& __y) const
         {return __x + __y;}
 };
@@ -42,7 +42,7 @@
 struct _LIBCPP_TEMPLATE_VIS plus<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
@@ -60,7 +60,7 @@
     : __binary_function<_Tp, _Tp, _Tp>
 {
     typedef _Tp __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x, const _Tp& __y) const
         {return __x - __y;}
 };
@@ -70,7 +70,7 @@
 struct _LIBCPP_TEMPLATE_VIS minus<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u))
@@ -88,7 +88,7 @@
     : __binary_function<_Tp, _Tp, _Tp>
 {
     typedef _Tp __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x, const _Tp& __y) const
         {return __x * __y;}
 };
@@ -98,7 +98,7 @@
 struct _LIBCPP_TEMPLATE_VIS multiplies<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u))
@@ -116,7 +116,7 @@
     : __binary_function<_Tp, _Tp, _Tp>
 {
     typedef _Tp __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x, const _Tp& __y) const
         {return __x / __y;}
 };
@@ -126,7 +126,7 @@
 struct _LIBCPP_TEMPLATE_VIS divides<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u))
@@ -144,7 +144,7 @@
     : __binary_function<_Tp, _Tp, _Tp>
 {
     typedef _Tp __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x, const _Tp& __y) const
         {return __x % __y;}
 };
@@ -154,7 +154,7 @@
 struct _LIBCPP_TEMPLATE_VIS modulus<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u))
@@ -172,7 +172,7 @@
     : __unary_function<_Tp, _Tp>
 {
     typedef _Tp __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
         {return -__x;}
 };
@@ -182,7 +182,7 @@
 struct _LIBCPP_TEMPLATE_VIS negate<void>
 {
     template <class _Tp>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_Tp&& __x) const
         noexcept(noexcept(- _VSTD::forward<_Tp>(__x)))
         -> decltype(      - _VSTD::forward<_Tp>(__x))
@@ -202,7 +202,7 @@
     : __binary_function<_Tp, _Tp, _Tp>
 {
     typedef _Tp __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x, const _Tp& __y) const
         {return __x & __y;}
 };
@@ -212,7 +212,7 @@
 struct _LIBCPP_TEMPLATE_VIS bit_and<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u))
@@ -226,7 +226,7 @@
 struct _LIBCPP_TEMPLATE_VIS bit_not
     : __unary_function<_Tp, _Tp>
 {
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x) const
         {return ~__x;}
 };
@@ -235,7 +235,7 @@
 struct _LIBCPP_TEMPLATE_VIS bit_not<void>
 {
     template <class _Tp>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_Tp&& __x) const
         noexcept(noexcept(~_VSTD::forward<_Tp>(__x)))
         -> decltype(      ~_VSTD::forward<_Tp>(__x))
@@ -253,7 +253,7 @@
     : __binary_function<_Tp, _Tp, _Tp>
 {
     typedef _Tp __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x, const _Tp& __y) const
         {return __x | __y;}
 };
@@ -263,7 +263,7 @@
 struct _LIBCPP_TEMPLATE_VIS bit_or<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u))
@@ -281,7 +281,7 @@
     : __binary_function<_Tp, _Tp, _Tp>
 {
     typedef _Tp __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     _Tp operator()(const _Tp& __x, const _Tp& __y) const
         {return __x ^ __y;}
 };
@@ -291,7 +291,7 @@
 struct _LIBCPP_TEMPLATE_VIS bit_xor<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u))
@@ -311,7 +311,7 @@
     : __binary_function<_Tp, _Tp, bool>
 {
     typedef bool __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _Tp& __x, const _Tp& __y) const
         {return __x == __y;}
 };
@@ -321,7 +321,7 @@
 struct _LIBCPP_TEMPLATE_VIS equal_to<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u))
@@ -339,7 +339,7 @@
     : __binary_function<_Tp, _Tp, bool>
 {
     typedef bool __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _Tp& __x, const _Tp& __y) const
         {return __x != __y;}
 };
@@ -349,7 +349,7 @@
 struct _LIBCPP_TEMPLATE_VIS not_equal_to<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u))
@@ -367,7 +367,7 @@
     : __binary_function<_Tp, _Tp, bool>
 {
     typedef bool __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _Tp& __x, const _Tp& __y) const
         {return __x < __y;}
 };
@@ -377,7 +377,7 @@
 struct _LIBCPP_TEMPLATE_VIS less<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u))
@@ -395,7 +395,7 @@
     : __binary_function<_Tp, _Tp, bool>
 {
     typedef bool __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _Tp& __x, const _Tp& __y) const
         {return __x <= __y;}
 };
@@ -405,7 +405,7 @@
 struct _LIBCPP_TEMPLATE_VIS less_equal<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u))
@@ -423,7 +423,7 @@
     : __binary_function<_Tp, _Tp, bool>
 {
     typedef bool __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _Tp& __x, const _Tp& __y) const
         {return __x >= __y;}
 };
@@ -433,7 +433,7 @@
 struct _LIBCPP_TEMPLATE_VIS greater_equal<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u))
@@ -451,7 +451,7 @@
     : __binary_function<_Tp, _Tp, bool>
 {
     typedef bool __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _Tp& __x, const _Tp& __y) const
         {return __x > __y;}
 };
@@ -461,7 +461,7 @@
 struct _LIBCPP_TEMPLATE_VIS greater<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u))
@@ -481,7 +481,7 @@
     : __binary_function<_Tp, _Tp, bool>
 {
     typedef bool __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _Tp& __x, const _Tp& __y) const
         {return __x && __y;}
 };
@@ -491,7 +491,7 @@
 struct _LIBCPP_TEMPLATE_VIS logical_and<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u))
@@ -509,7 +509,7 @@
     : __unary_function<_Tp, bool>
 {
     typedef bool __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _Tp& __x) const
         {return !__x;}
 };
@@ -519,7 +519,7 @@
 struct _LIBCPP_TEMPLATE_VIS logical_not<void>
 {
     template <class _Tp>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_Tp&& __x) const
         noexcept(noexcept(!_VSTD::forward<_Tp>(__x)))
         -> decltype(      !_VSTD::forward<_Tp>(__x))
@@ -537,7 +537,7 @@
     : __binary_function<_Tp, _Tp, bool>
 {
     typedef bool __result_type;  // used by valarray
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _Tp& __x, const _Tp& __y) const
         {return __x || __y;}
 };
@@ -547,7 +547,7 @@
 struct _LIBCPP_TEMPLATE_VIS logical_or<void>
 {
     template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
         noexcept(noexcept(_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u)))
         -> decltype(      _VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u))
diff --git a/libcxx/include/__functional/reference_wrapper.h b/libcxx/include/__functional/reference_wrapper.h
--- a/libcxx/include/__functional/reference_wrapper.h
+++ b/libcxx/include/__functional/reference_wrapper.h
@@ -36,21 +36,21 @@
 
 public:
     template <class _Up, class = __enable_if_t<!__is_same_uncvref<_Up, reference_wrapper>::value, decltype(__fun(declval<_Up>())) > >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     reference_wrapper(_Up&& __u) _NOEXCEPT_(noexcept(__fun(declval<_Up>()))) {
         type& __f = static_cast<_Up&&>(__u);
         __f_ = _VSTD::addressof(__f);
     }
 
     // access
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     operator type&() const _NOEXCEPT {return *__f_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     type& get() const _NOEXCEPT {return *__f_;}
 
     // invoke
     template <class... _ArgTypes>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     typename __invoke_of<type&, _ArgTypes...>::type
     operator() (_ArgTypes&&... __args) const {
         return std::__invoke(get(), std::forward<_ArgTypes>(__args)...);
@@ -63,7 +63,7 @@
 #endif
 
 template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 reference_wrapper<_Tp>
 ref(_Tp& __t) _NOEXCEPT
 {
@@ -71,7 +71,7 @@
 }
 
 template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 reference_wrapper<_Tp>
 ref(reference_wrapper<_Tp> __t) _NOEXCEPT
 {
@@ -79,7 +79,7 @@
 }
 
 template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 reference_wrapper<const _Tp>
 cref(const _Tp& __t) _NOEXCEPT
 {
@@ -87,7 +87,7 @@
 }
 
 template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 reference_wrapper<const _Tp>
 cref(reference_wrapper<_Tp> __t) _NOEXCEPT
 {
diff --git a/libcxx/include/__functional/unary_negate.h b/libcxx/include/__functional/unary_negate.h
--- a/libcxx/include/__functional/unary_negate.h
+++ b/libcxx/include/__functional/unary_negate.h
@@ -27,16 +27,16 @@
 {
     _Predicate __pred_;
 public:
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     explicit unary_negate(const _Predicate& __pred)
         : __pred_(__pred) {}
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     bool operator()(const typename _Predicate::argument_type& __x) const
         {return !__pred_(__x);}
 };
 
 template <class _Predicate>
-_LIBCPP_DEPRECATED_IN_CXX17 inline _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_DEPRECATED_IN_CXX17 inline _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 unary_negate<_Predicate>
 not1(const _Predicate& __pred) {return unary_negate<_Predicate>(__pred);}
 
diff --git a/libcxx/include/__hash_table b/libcxx/include/__hash_table
--- a/libcxx/include/__hash_table
+++ b/libcxx/include/__hash_table
@@ -2279,7 +2279,7 @@
                     else
                     {
                         __next_pointer __np = __cp;
-                        if _LIBCPP_CONSTEXPR_AFTER_CXX14 (!_UniqueKeys)
+                        if _LIBCPP_CONSTEXPR_CXX17 (!_UniqueKeys)
                         {
                             for (; __np->__next_ != nullptr &&
                                    key_eq()(__cp->__upcast()->__value_,
diff --git a/libcxx/include/__iterator/access.h b/libcxx/include/__iterator/access.h
--- a/libcxx/include/__iterator/access.h
+++ b/libcxx/include/__iterator/access.h
@@ -20,7 +20,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp, size_t _Np>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp*
 begin(_Tp (&__array)[_Np])
 {
@@ -28,7 +28,7 @@
 }
 
 template <class _Tp, size_t _Np>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp*
 end(_Tp (&__array)[_Np])
 {
@@ -38,7 +38,7 @@
 #if !defined(_LIBCPP_CXX03_LANG)
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto
 begin(_Cp& __c) -> decltype(__c.begin())
 {
@@ -46,7 +46,7 @@
 }
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto
 begin(const _Cp& __c) -> decltype(__c.begin())
 {
@@ -54,7 +54,7 @@
 }
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto
 end(_Cp& __c) -> decltype(__c.end())
 {
@@ -62,7 +62,7 @@
 }
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto
 end(const _Cp& __c) -> decltype(__c.end())
 {
@@ -72,14 +72,14 @@
 #if _LIBCPP_STD_VER > 11
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 auto cbegin(const _Cp& __c) -> decltype(_VSTD::begin(__c))
 {
     return _VSTD::begin(__c);
 }
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 auto cend(const _Cp& __c) -> decltype(_VSTD::end(__c))
 {
     return _VSTD::end(__c);
diff --git a/libcxx/include/__iterator/advance.h b/libcxx/include/__iterator/advance.h
--- a/libcxx/include/__iterator/advance.h
+++ b/libcxx/include/__iterator/advance.h
@@ -29,14 +29,14 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIter>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 void __advance(_InputIter& __i, typename iterator_traits<_InputIter>::difference_type __n, input_iterator_tag) {
   for (; __n > 0; --__n)
     ++__i;
 }
 
 template <class _BiDirIter>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 void __advance(_BiDirIter& __i, typename iterator_traits<_BiDirIter>::difference_type __n, bidirectional_iterator_tag) {
   if (__n >= 0)
     for (; __n > 0; --__n)
@@ -47,7 +47,7 @@
 }
 
 template <class _RandIter>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 void __advance(_RandIter& __i, typename iterator_traits<_RandIter>::difference_type __n, random_access_iterator_tag) {
   __i += __n;
 }
@@ -56,7 +56,7 @@
     class _InputIter, class _Distance,
     class _IntegralDistance = decltype(_VSTD::__convert_to_integral(declval<_Distance>())),
     class = __enable_if_t<is_integral<_IntegralDistance>::value> >
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 void advance(_InputIter& __i, _Distance __orig_n) {
   typedef typename iterator_traits<_InputIter>::difference_type _Difference;
   _Difference __n = static_cast<_Difference>(_VSTD::__convert_to_integral(__orig_n));
diff --git a/libcxx/include/__iterator/back_insert_iterator.h b/libcxx/include/__iterator/back_insert_iterator.h
--- a/libcxx/include/__iterator/back_insert_iterator.h
+++ b/libcxx/include/__iterator/back_insert_iterator.h
@@ -45,22 +45,22 @@
     typedef void reference;
     typedef _Container container_type;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit back_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 back_insert_iterator& operator=(const typename _Container::value_type& __value)
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 explicit back_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 back_insert_iterator& operator=(const typename _Container::value_type& __value)
         {container->push_back(__value); return *this;}
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 back_insert_iterator& operator=(typename _Container::value_type&& __value)
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 back_insert_iterator& operator=(typename _Container::value_type&& __value)
         {container->push_back(_VSTD::move(__value)); return *this;}
 #endif // _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 back_insert_iterator& operator*()     {return *this;}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 back_insert_iterator& operator++()    {return *this;}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 back_insert_iterator  operator++(int) {return *this;}
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 back_insert_iterator& operator*()     {return *this;}
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 back_insert_iterator& operator++()    {return *this;}
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 back_insert_iterator  operator++(int) {return *this;}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _Container* __get_container() const { return container; }
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _Container* __get_container() const { return container; }
 };
 
 template <class _Container>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 back_insert_iterator<_Container>
 back_inserter(_Container& __x)
 {
diff --git a/libcxx/include/__iterator/bounded_iter.h b/libcxx/include/__iterator/bounded_iter.h
--- a/libcxx/include/__iterator/bounded_iter.h
+++ b/libcxx/include/__iterator/bounded_iter.h
@@ -73,7 +73,7 @@
   //
   // Since it is non-standard for iterators to have this constructor, __bounded_iter must
   // be created via `std::__make_bounded_iter`.
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 explicit __bounded_iter(
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 explicit __bounded_iter(
       _Iterator __current, _Iterator __begin, _Iterator __end)
       : __current_(__current), __begin_(__begin), __end_(__end) {
     _LIBCPP_ASSERT(__begin <= __end, "__bounded_iter(current, begin, end): [begin, end) is not a valid range");
@@ -86,19 +86,19 @@
   // Dereference and indexing operations.
   //
   // These operations check that the iterator is dereferenceable, that is within [begin, end).
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 reference operator*() const _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 reference operator*() const _NOEXCEPT {
     _LIBCPP_ASSERT(
         __in_bounds(__current_), "__bounded_iter::operator*: Attempt to dereference an out-of-range iterator");
     return *__current_;
   }
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 pointer operator->() const _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 pointer operator->() const _NOEXCEPT {
     _LIBCPP_ASSERT(
         __in_bounds(__current_), "__bounded_iter::operator->: Attempt to dereference an out-of-range iterator");
     return std::__to_address(__current_);
   }
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 reference operator[](difference_type __n) const _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 reference operator[](difference_type __n) const _NOEXCEPT {
     _LIBCPP_ASSERT(
         __in_bounds(__current_ + __n), "__bounded_iter::operator[]: Attempt to index an iterator out-of-range");
     return __current_[__n];
@@ -108,54 +108,54 @@
   //
   // These operations do not check that the resulting iterator is within the bounds, since that
   // would make it impossible to create a past-the-end iterator.
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __bounded_iter& operator++() _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __bounded_iter& operator++() _NOEXCEPT {
     ++__current_;
     return *this;
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __bounded_iter operator++(int) _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __bounded_iter operator++(int) _NOEXCEPT {
     __bounded_iter __tmp(*this);
     ++*this;
     return __tmp;
   }
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __bounded_iter& operator--() _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __bounded_iter& operator--() _NOEXCEPT {
     --__current_;
     return *this;
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __bounded_iter operator--(int) _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __bounded_iter operator--(int) _NOEXCEPT {
     __bounded_iter __tmp(*this);
     --*this;
     return __tmp;
   }
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __bounded_iter& operator+=(difference_type __n) _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __bounded_iter& operator+=(difference_type __n) _NOEXCEPT {
     __current_ += __n;
     return *this;
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 friend __bounded_iter
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 friend __bounded_iter
   operator+(__bounded_iter const& __self, difference_type __n) _NOEXCEPT {
     __bounded_iter __tmp(__self);
     __tmp += __n;
     return __tmp;
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 friend __bounded_iter
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 friend __bounded_iter
   operator+(difference_type __n, __bounded_iter const& __self) _NOEXCEPT {
     __bounded_iter __tmp(__self);
     __tmp += __n;
     return __tmp;
   }
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __bounded_iter& operator-=(difference_type __n) _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __bounded_iter& operator-=(difference_type __n) _NOEXCEPT {
     __current_ -= __n;
     return *this;
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 friend __bounded_iter
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 friend __bounded_iter
   operator-(__bounded_iter const& __self, difference_type __n) _NOEXCEPT {
     __bounded_iter __tmp(__self);
     __tmp -= __n;
     return __tmp;
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 friend difference_type
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 friend difference_type
   operator-(__bounded_iter const& __x, __bounded_iter const& __y) _NOEXCEPT {
     return __x.__current_ - __y.__current_;
   }
diff --git a/libcxx/include/__iterator/distance.h b/libcxx/include/__iterator/distance.h
--- a/libcxx/include/__iterator/distance.h
+++ b/libcxx/include/__iterator/distance.h
@@ -26,7 +26,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 typename iterator_traits<_InputIter>::difference_type
 __distance(_InputIter __first, _InputIter __last, input_iterator_tag)
 {
@@ -37,7 +37,7 @@
 }
 
 template <class _RandIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 typename iterator_traits<_RandIter>::difference_type
 __distance(_RandIter __first, _RandIter __last, random_access_iterator_tag)
 {
@@ -45,7 +45,7 @@
 }
 
 template <class _InputIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 typename iterator_traits<_InputIter>::difference_type
 distance(_InputIter __first, _InputIter __last)
 {
diff --git a/libcxx/include/__iterator/front_insert_iterator.h b/libcxx/include/__iterator/front_insert_iterator.h
--- a/libcxx/include/__iterator/front_insert_iterator.h
+++ b/libcxx/include/__iterator/front_insert_iterator.h
@@ -45,20 +45,20 @@
     typedef void reference;
     typedef _Container container_type;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit front_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator=(const typename _Container::value_type& __value)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 explicit front_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 front_insert_iterator& operator=(const typename _Container::value_type& __value)
         {container->push_front(__value); return *this;}
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator=(typename _Container::value_type&& __value)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 front_insert_iterator& operator=(typename _Container::value_type&& __value)
         {container->push_front(_VSTD::move(__value)); return *this;}
 #endif // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator*()     {return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator++()    {return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator  operator++(int) {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 front_insert_iterator& operator*()     {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 front_insert_iterator& operator++()    {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 front_insert_iterator  operator++(int) {return *this;}
 };
 
 template <class _Container>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 front_insert_iterator<_Container>
 front_inserter(_Container& __x)
 {
diff --git a/libcxx/include/__iterator/insert_iterator.h b/libcxx/include/__iterator/insert_iterator.h
--- a/libcxx/include/__iterator/insert_iterator.h
+++ b/libcxx/include/__iterator/insert_iterator.h
@@ -55,21 +55,21 @@
     typedef void reference;
     typedef _Container container_type;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator(_Container& __x, __insert_iterator_iter_t<_Container> __i)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 insert_iterator(_Container& __x, __insert_iterator_iter_t<_Container> __i)
         : container(_VSTD::addressof(__x)), iter(__i) {}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator=(const typename _Container::value_type& __value)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 insert_iterator& operator=(const typename _Container::value_type& __value)
         {iter = container->insert(iter, __value); ++iter; return *this;}
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator=(typename _Container::value_type&& __value)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 insert_iterator& operator=(typename _Container::value_type&& __value)
         {iter = container->insert(iter, _VSTD::move(__value)); ++iter; return *this;}
 #endif // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator*()        {return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator++()       {return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator++(int)    {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 insert_iterator& operator*()        {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 insert_iterator& operator++()       {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 insert_iterator& operator++(int)    {return *this;}
 };
 
 template <class _Container>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 insert_iterator<_Container>
 inserter(_Container& __x, __insert_iterator_iter_t<_Container> __i)
 {
diff --git a/libcxx/include/__iterator/move_iterator.h b/libcxx/include/__iterator/move_iterator.h
--- a/libcxx/include/__iterator/move_iterator.h
+++ b/libcxx/include/__iterator/move_iterator.h
@@ -87,13 +87,13 @@
         >::type reference;
 #endif // _LIBCPP_STD_VER > 17
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     explicit move_iterator(_Iter __i) : __current_(std::move(__i)) {}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator& operator++() { ++__current_; return *this; }
 
-    _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     pointer operator->() const { return __current_; }
 
 #if _LIBCPP_STD_VER > 17
@@ -133,13 +133,13 @@
     _LIBCPP_HIDE_FROM_ABI constexpr
     void operator++(int) { ++__current_; }
 #else
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator() : __current_() {}
 
     template <class _Up, class = __enable_if_t<
         !is_same<_Up, _Iter>::value && is_convertible<const _Up&, _Iter>::value
     > >
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator(const move_iterator<_Up>& __u) : __current_(__u.base()) {}
 
     template <class _Up, class = __enable_if_t<
@@ -147,35 +147,35 @@
         is_convertible<const _Up&, _Iter>::value &&
         is_assignable<_Iter&, const _Up&>::value
     > >
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator& operator=(const move_iterator<_Up>& __u) {
         __current_ = __u.base();
         return *this;
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     _Iter base() const { return __current_; }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     reference operator*() const { return static_cast<reference>(*__current_); }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     reference operator[](difference_type __n) const { return static_cast<reference>(__current_[__n]); }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator operator++(int) { move_iterator __tmp(*this); ++__current_; return __tmp; }
 #endif // _LIBCPP_STD_VER > 17
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator& operator--() { --__current_; return *this; }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator operator--(int) { move_iterator __tmp(*this); --__current_; return __tmp; }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator operator+(difference_type __n) const { return move_iterator(__current_ + __n); }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator& operator+=(difference_type __n) { __current_ += __n; return *this; }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator operator-(difference_type __n) const { return move_iterator(__current_ - __n); }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
     move_iterator& operator-=(difference_type __n) { __current_ -= __n; return *this; }
 
 #if _LIBCPP_STD_VER > 17
@@ -224,7 +224,7 @@
 };
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 bool operator==(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
 {
     return __x.base() == __y.base();
@@ -232,7 +232,7 @@
 
 #if _LIBCPP_STD_VER <= 17
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 bool operator!=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
 {
     return __x.base() != __y.base();
@@ -240,28 +240,28 @@
 #endif // _LIBCPP_STD_VER <= 17
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 bool operator<(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
 {
     return __x.base() < __y.base();
 }
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 bool operator>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
 {
     return __x.base() > __y.base();
 }
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 bool operator<=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
 {
     return __x.base() <= __y.base();
 }
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 bool operator>=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
 {
     return __x.base() >= __y.base();
@@ -279,7 +279,7 @@
 
 #ifndef _LIBCPP_CXX03_LANG
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 auto operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
     -> decltype(__x.base() - __y.base())
 {
@@ -305,7 +305,7 @@
 }
 #else
 template <class _Iter>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 move_iterator<_Iter>
 operator+(typename move_iterator<_Iter>::difference_type __n, const move_iterator<_Iter>& __x)
 {
@@ -314,7 +314,7 @@
 #endif // _LIBCPP_STD_VER > 17
 
 template <class _Iter>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
 move_iterator<_Iter>
 make_move_iterator(_Iter __i)
 {
diff --git a/libcxx/include/__iterator/next.h b/libcxx/include/__iterator/next.h
--- a/libcxx/include/__iterator/next.h
+++ b/libcxx/include/__iterator/next.h
@@ -25,7 +25,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     typename enable_if<__is_cpp17_input_iterator<_InputIter>::value, _InputIter>::type
     next(_InputIter __x, typename iterator_traits<_InputIter>::difference_type __n = 1) {
   _LIBCPP_ASSERT(__n >= 0 || __is_cpp17_bidirectional_iterator<_InputIter>::value,
diff --git a/libcxx/include/__iterator/prev.h b/libcxx/include/__iterator/prev.h
--- a/libcxx/include/__iterator/prev.h
+++ b/libcxx/include/__iterator/prev.h
@@ -25,7 +25,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     typename enable_if<__is_cpp17_input_iterator<_InputIter>::value, _InputIter>::type
     prev(_InputIter __x, typename iterator_traits<_InputIter>::difference_type __n = 1) {
   _LIBCPP_ASSERT(__n <= 0 || __is_cpp17_bidirectional_iterator<_InputIter>::value,
diff --git a/libcxx/include/__iterator/reverse_access.h b/libcxx/include/__iterator/reverse_access.h
--- a/libcxx/include/__iterator/reverse_access.h
+++ b/libcxx/include/__iterator/reverse_access.h
@@ -24,70 +24,70 @@
 #if _LIBCPP_STD_VER > 11
 
 template <class _Tp, size_t _Np>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 reverse_iterator<_Tp*> rbegin(_Tp (&__array)[_Np])
 {
     return reverse_iterator<_Tp*>(__array + _Np);
 }
 
 template <class _Tp, size_t _Np>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 reverse_iterator<_Tp*> rend(_Tp (&__array)[_Np])
 {
     return reverse_iterator<_Tp*>(__array);
 }
 
 template <class _Ep>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 reverse_iterator<const _Ep*> rbegin(initializer_list<_Ep> __il)
 {
     return reverse_iterator<const _Ep*>(__il.end());
 }
 
 template <class _Ep>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 reverse_iterator<const _Ep*> rend(initializer_list<_Ep> __il)
 {
     return reverse_iterator<const _Ep*>(__il.begin());
 }
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto rbegin(_Cp& __c) -> decltype(__c.rbegin())
 {
     return __c.rbegin();
 }
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto rbegin(const _Cp& __c) -> decltype(__c.rbegin())
 {
     return __c.rbegin();
 }
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto rend(_Cp& __c) -> decltype(__c.rend())
 {
     return __c.rend();
 }
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto rend(const _Cp& __c) -> decltype(__c.rend())
 {
     return __c.rend();
 }
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto crbegin(const _Cp& __c) -> decltype(_VSTD::rbegin(__c))
 {
     return _VSTD::rbegin(__c);
 }
 
 template <class _Cp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto crend(const _Cp& __c) -> decltype(_VSTD::rend(__c))
 {
     return _VSTD::rend(__c);
diff --git a/libcxx/include/__iterator/reverse_iterator.h b/libcxx/include/__iterator/reverse_iterator.h
--- a/libcxx/include/__iterator/reverse_iterator.h
+++ b/libcxx/include/__iterator/reverse_iterator.h
@@ -81,16 +81,16 @@
 #endif
 
 #ifndef _LIBCPP_ABI_NO_ITERATOR_BASES
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator() : __t(), current() {}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}
 
     template <class _Up, class = __enable_if_t<
         !is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value
     > >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator(const reverse_iterator<_Up>& __u)
         : __t(__u.base()), current(__u.base())
     { }
@@ -100,22 +100,22 @@
         is_convertible<_Up const&, _Iter>::value &&
         is_assignable<_Iter&, _Up const&>::value
     > >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator& operator=(const reverse_iterator<_Up>& __u) {
         __t = current = __u.base();
         return *this;
     }
 #else
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator() : current() {}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     explicit reverse_iterator(_Iter __x) : current(__x) {}
 
     template <class _Up, class = __enable_if_t<
         !is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value
     > >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator(const reverse_iterator<_Up>& __u)
         : current(__u.base())
     { }
@@ -125,15 +125,15 @@
         is_convertible<_Up const&, _Iter>::value &&
         is_assignable<_Iter&, _Up const&>::value
     > >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator& operator=(const reverse_iterator<_Up>& __u) {
         current = __u.base();
         return *this;
     }
 #endif
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     _Iter base() const {return current;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reference operator*() const {_Iter __tmp = current; return *--__tmp;}
 
 #if _LIBCPP_STD_VER > 17
@@ -148,29 +148,29 @@
       }
     }
 #else
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     pointer operator->() const {
       return std::addressof(operator*());
     }
 #endif // _LIBCPP_STD_VER > 17
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator& operator++() {--current; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator operator++(int) {reverse_iterator __tmp(*this); --current; return __tmp;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator& operator--() {++current; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator operator--(int) {reverse_iterator __tmp(*this); ++current; return __tmp;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator operator+(difference_type __n) const {return reverse_iterator(current - __n);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator& operator+=(difference_type __n) {current -= __n; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator operator-(difference_type __n) const {return reverse_iterator(current + __n);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator& operator-=(difference_type __n) {current += __n; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reference operator[](difference_type __n) const {return *(*this + __n);}
 
 #if _LIBCPP_STD_VER > 17
@@ -202,7 +202,7 @@
 struct __is_reverse_iterator<reverse_iterator<_Iter> > : true_type {};
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 bool
 operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
@@ -215,7 +215,7 @@
 }
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 bool
 operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
@@ -228,7 +228,7 @@
 }
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 bool
 operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
@@ -241,7 +241,7 @@
 }
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 bool
 operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
@@ -254,7 +254,7 @@
 }
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 bool
 operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
@@ -267,7 +267,7 @@
 }
 
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 bool
 operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
@@ -291,7 +291,7 @@
 
 #ifndef _LIBCPP_CXX03_LANG
 template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 auto
 operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 -> decltype(__y.base() - __x.base())
@@ -309,7 +309,7 @@
 #endif
 
 template <class _Iter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 reverse_iterator<_Iter>
 operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x)
 {
@@ -324,7 +324,7 @@
 
 #if _LIBCPP_STD_VER > 11
 template <class _Iter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
 reverse_iterator<_Iter> make_reverse_iterator(_Iter __i)
 {
     return reverse_iterator<_Iter>(__i);
diff --git a/libcxx/include/__iterator/wrap_iter.h b/libcxx/include/__iterator/wrap_iter.h
--- a/libcxx/include/__iterator/wrap_iter.h
+++ b/libcxx/include/__iterator/wrap_iter.h
@@ -40,12 +40,12 @@
 private:
     iterator_type __i;
 public:
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter() _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __wrap_iter() _NOEXCEPT
                 : __i()
     {
         _VSTD::__debug_db_insert_i(this);
     }
-    template <class _Up> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+    template <class _Up> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
         __wrap_iter(const __wrap_iter<_Up>& __u,
             typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = nullptr) _NOEXCEPT
             : __i(__u.base())
@@ -56,14 +56,14 @@
 #endif
     }
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
     __wrap_iter(const __wrap_iter& __x)
         : __i(__x.base())
     {
       if (!__libcpp_is_constant_evaluated())
         __get_db()->__iterator_copy(this, _VSTD::addressof(__x));
     }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
     __wrap_iter& operator=(const __wrap_iter& __x)
     {
         if (this != _VSTD::addressof(__x))
@@ -74,68 +74,68 @@
         }
         return *this;
     }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     ~__wrap_iter()
     {
       if (!__libcpp_is_constant_evaluated())
         __get_db()->__erase_i(this);
     }
 #endif
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 reference operator*() const _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 reference operator*() const _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                              "Attempted to dereference a non-dereferenceable iterator");
         return *__i;
     }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 pointer operator->() const _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 pointer operator->() const _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                              "Attempted to dereference a non-dereferenceable iterator");
         return _VSTD::__to_address(__i);
     }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator++() _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __wrap_iter& operator++() _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                              "Attempted to increment a non-incrementable iterator");
         ++__i;
         return *this;
     }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator++(int) _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __wrap_iter  operator++(int) _NOEXCEPT
         {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator--() _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __wrap_iter& operator--() _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__decrementable(this),
                              "Attempted to decrement a non-decrementable iterator");
         --__i;
         return *this;
     }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator--(int) _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __wrap_iter  operator--(int) _NOEXCEPT
         {__wrap_iter __tmp(*this); --(*this); return __tmp;}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT
         {__wrap_iter __w(*this); __w += __n; return __w;}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator+=(difference_type __n) _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __wrap_iter& operator+=(difference_type __n) _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__addable(this, __n),
                              "Attempted to add/subtract an iterator outside its valid range");
         __i += __n;
         return *this;
     }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator- (difference_type __n) const _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __wrap_iter  operator- (difference_type __n) const _NOEXCEPT
         {return *this + (-__n);}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator-=(difference_type __n) _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 __wrap_iter& operator-=(difference_type __n) _NOEXCEPT
         {*this += -__n; return *this;}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 reference    operator[](difference_type __n) const _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 reference    operator[](difference_type __n) const _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__subscriptable(this, __n),
                              "Attempted to subscript an iterator outside its valid range");
         return __i[__n];
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 iterator_type base() const _NOEXCEPT {return __i;}
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 iterator_type base() const _NOEXCEPT {return __i;}
 
 private:
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
     explicit __wrap_iter(const void* __p, iterator_type __x) _NOEXCEPT : __i(__x)
     {
         (void)__p;
@@ -166,7 +166,7 @@
 }
 
 template <class _Iter1>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 bool operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
 {
     _LIBCPP_DEBUG_ASSERT(__get_const_db()->__less_than_comparable(_VSTD::addressof(__x), _VSTD::addressof(__y)),
@@ -175,7 +175,7 @@
 }
 
 template <class _Iter1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 bool operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
 {
     _LIBCPP_DEBUG_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
@@ -240,7 +240,7 @@
 }
 
 template <class _Iter1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 #ifndef _LIBCPP_CXX03_LANG
 auto operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
     -> decltype(__x.base() - __y.base())
@@ -255,7 +255,7 @@
 }
 
 template <class _Iter1>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 __wrap_iter<_Iter1> operator+(typename __wrap_iter<_Iter1>::difference_type __n, __wrap_iter<_Iter1> __x) _NOEXCEPT
 {
     __x += __n;
diff --git a/libcxx/include/__memory/addressof.h b/libcxx/include/__memory/addressof.h
--- a/libcxx/include/__memory/addressof.h
+++ b/libcxx/include/__memory/addressof.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 _LIBCPP_NO_CFI _LIBCPP_INLINE_VISIBILITY
 _Tp*
 addressof(_Tp& __x) _NOEXCEPT
diff --git a/libcxx/include/__memory/allocator.h b/libcxx/include/__memory/allocator.h
--- a/libcxx/include/__memory/allocator.h
+++ b/libcxx/include/__memory/allocator.h
@@ -95,14 +95,14 @@
     typedef true_type   propagate_on_container_move_assignment;
     typedef true_type   is_always_equal;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     allocator() _NOEXCEPT = default;
 
     template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     allocator(const allocator<_Up>&) _NOEXCEPT { }
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     _Tp* allocate(size_t __n) {
         if (__n > allocator_traits<allocator>::max_size(*this))
             __throw_bad_array_new_length();
@@ -120,7 +120,7 @@
     }
 #endif
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void deallocate(_Tp* __p, size_t __n) _NOEXCEPT {
         if (__libcpp_is_constant_evaluated()) {
             ::operator delete(__p);
@@ -184,14 +184,14 @@
     typedef true_type   propagate_on_container_move_assignment;
     typedef true_type   is_always_equal;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     allocator() _NOEXCEPT = default;
 
     template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     allocator(const allocator<_Up>&) _NOEXCEPT { }
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const _Tp* allocate(size_t __n) {
         if (__n > allocator_traits<allocator>::max_size(*this))
             __throw_bad_array_new_length();
@@ -209,7 +209,7 @@
     }
 #endif
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void deallocate(const _Tp* __p, size_t __n) {
         if (__libcpp_is_constant_evaluated()) {
             ::operator delete(const_cast<_Tp*>(__p));
@@ -258,11 +258,11 @@
 };
 
 template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
 
 template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__memory/allocator_traits.h b/libcxx/include/__memory/allocator_traits.h
--- a/libcxx/include/__memory/allocator_traits.h
+++ b/libcxx/include/__memory/allocator_traits.h
@@ -257,14 +257,14 @@
     };
 #endif // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static pointer allocate(allocator_type& __a, size_type __n) {
         return __a.allocate(__n);
     }
 
     template <class _Ap = _Alloc, class =
         __enable_if_t<__has_allocate_hint<_Ap, size_type, const_void_pointer>::value> >
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint) {
         _LIBCPP_SUPPRESS_DEPRECATED_PUSH
         return __a.allocate(__n, __hint);
@@ -272,19 +272,19 @@
     }
     template <class _Ap = _Alloc, class = void, class =
         __enable_if_t<!__has_allocate_hint<_Ap, size_type, const_void_pointer>::value> >
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer) {
         return __a.allocate(__n);
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT {
         __a.deallocate(__p, __n);
     }
 
     template <class _Tp, class... _Args, class =
         __enable_if_t<__has_construct<allocator_type, _Tp*, _Args...>::value> >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args) {
         _LIBCPP_SUPPRESS_DEPRECATED_PUSH
         __a.construct(__p, _VSTD::forward<_Args>(__args)...);
@@ -292,7 +292,7 @@
     }
     template <class _Tp, class... _Args, class = void, class =
         __enable_if_t<!__has_construct<allocator_type, _Tp*, _Args...>::value> >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static void construct(allocator_type&, _Tp* __p, _Args&&... __args) {
 #if _LIBCPP_STD_VER > 17
         _VSTD::construct_at(__p, _VSTD::forward<_Args>(__args)...);
@@ -303,7 +303,7 @@
 
     template <class _Tp, class =
         __enable_if_t<__has_destroy<allocator_type, _Tp*>::value> >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static void destroy(allocator_type& __a, _Tp* __p) {
         _LIBCPP_SUPPRESS_DEPRECATED_PUSH
         __a.destroy(__p);
@@ -311,7 +311,7 @@
     }
     template <class _Tp, class = void, class =
         __enable_if_t<!__has_destroy<allocator_type, _Tp*>::value> >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static void destroy(allocator_type&, _Tp* __p) {
 #if _LIBCPP_STD_VER > 17
         _VSTD::destroy_at(__p);
@@ -322,7 +322,7 @@
 
     template <class _Ap = _Alloc, class =
         __enable_if_t<__has_max_size<const _Ap>::value> >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static size_type max_size(const allocator_type& __a) _NOEXCEPT {
         _LIBCPP_SUPPRESS_DEPRECATED_PUSH
         return __a.max_size();
@@ -330,20 +330,20 @@
     }
     template <class _Ap = _Alloc, class = void, class =
         __enable_if_t<!__has_max_size<const _Ap>::value> >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static size_type max_size(const allocator_type&) _NOEXCEPT {
         return numeric_limits<size_type>::max() / sizeof(value_type);
     }
 
     template <class _Ap = _Alloc, class =
         __enable_if_t<__has_select_on_container_copy_construction<const _Ap>::value> >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static allocator_type select_on_container_copy_construction(const allocator_type& __a) {
         return __a.select_on_container_copy_construction();
     }
     template <class _Ap = _Alloc, class = void, class =
         __enable_if_t<!__has_select_on_container_copy_construction<const _Ap>::value> >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static allocator_type select_on_container_copy_construction(const allocator_type& __a) {
         return __a;
     }
diff --git a/libcxx/include/__memory/compressed_pair.h b/libcxx/include/__memory/compressed_pair.h
--- a/libcxx/include/__memory/compressed_pair.h
+++ b/libcxx/include/__memory/compressed_pair.h
@@ -41,12 +41,12 @@
 
 #ifndef _LIBCPP_CXX03_LANG
   template <class... _Args, size_t... _Indices>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
   explicit __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args, __tuple_indices<_Indices...>)
       : __value_(std::forward<_Args>(std::get<_Indices>(__args))...) {}
 #endif
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 reference __get() _NOEXCEPT { return __value_; }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 reference __get() _NOEXCEPT { return __value_; }
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR const_reference __get() const _NOEXCEPT { return __value_; }
 
 private:
@@ -70,12 +70,12 @@
 
 #ifndef _LIBCPP_CXX03_LANG
   template <class... _Args, size_t... _Indices>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
   __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args, __tuple_indices<_Indices...>)
       : __value_type(std::forward<_Args>(std::get<_Indices>(__args))...) {}
 #endif
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 reference __get() _NOEXCEPT { return *this; }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 reference __get() _NOEXCEPT { return *this; }
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR const_reference __get() const _NOEXCEPT { return *this; }
 };
 
@@ -109,14 +109,14 @@
 
 #ifndef _LIBCPP_CXX03_LANG
   template <class... _Args1, class... _Args2>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX17
   explicit __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
                              tuple<_Args2...> __second_args)
       : _Base1(__pc, std::move(__first_args), typename __make_tuple_indices<sizeof...(_Args1)>::type()),
         _Base2(__pc, std::move(__second_args), typename __make_tuple_indices<sizeof...(_Args2)>::type()) {}
 #endif
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
   typename _Base1::reference first() _NOEXCEPT {
     return static_cast<_Base1&>(*this).__get();
   }
@@ -126,7 +126,7 @@
     return static_cast<_Base1 const&>(*this).__get();
   }
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
   typename _Base2::reference second() _NOEXCEPT {
     return static_cast<_Base2&>(*this).__get();
   }
@@ -145,7 +145,7 @@
     return static_cast<_Base2*>(__pair);
   }
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
   void swap(__compressed_pair& __x)
       _NOEXCEPT_(__is_nothrow_swappable<_T1>::value && __is_nothrow_swappable<_T2>::value) {
     using std::swap;
@@ -155,7 +155,7 @@
 };
 
 template <class _T1, class _T2>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
     _NOEXCEPT_(__is_nothrow_swappable<_T1>::value && __is_nothrow_swappable<_T2>::value) {
   __x.swap(__y);
diff --git a/libcxx/include/__memory/construct_at.h b/libcxx/include/__memory/construct_at.h
--- a/libcxx/include/__memory/construct_at.h
+++ b/libcxx/include/__memory/construct_at.h
@@ -53,11 +53,11 @@
 // taking an array).
 
 template <class _ForwardIterator>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator __destroy(_ForwardIterator, _ForwardIterator);
 
 template <class _Tp, typename enable_if<!is_array<_Tp>::value, int>::type = 0>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void __destroy_at(_Tp* __loc) {
     _LIBCPP_ASSERT(__loc != nullptr, "null pointer given to destroy_at");
     __loc->~_Tp();
@@ -65,7 +65,7 @@
 
 #if _LIBCPP_STD_VER > 17
 template <class _Tp, typename enable_if<is_array<_Tp>::value, int>::type = 0>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void __destroy_at(_Tp* __loc) {
     _LIBCPP_ASSERT(__loc != nullptr, "null pointer given to destroy_at");
     _VSTD::__destroy(_VSTD::begin(*__loc), _VSTD::end(*__loc));
@@ -73,7 +73,7 @@
 #endif
 
 template <class _ForwardIterator>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator __destroy(_ForwardIterator __first, _ForwardIterator __last) {
     for (; __first != __last; ++__first)
         _VSTD::__destroy_at(_VSTD::addressof(*__first));
@@ -83,27 +83,27 @@
 #if _LIBCPP_STD_VER > 14
 
 template <class _Tp, enable_if_t<!is_array_v<_Tp>, int> = 0>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void destroy_at(_Tp* __loc) {
     _VSTD::__destroy_at(__loc);
 }
 
 #if _LIBCPP_STD_VER > 17
 template <class _Tp, enable_if_t<is_array_v<_Tp>, int> = 0>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void destroy_at(_Tp* __loc) {
   _VSTD::__destroy_at(__loc);
 }
 #endif
 
 template <class _ForwardIterator>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void destroy(_ForwardIterator __first, _ForwardIterator __last) {
   (void)_VSTD::__destroy(_VSTD::move(__first), _VSTD::move(__last));
 }
 
 template <class _ForwardIterator, class _Size>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 _ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) {
     for (; __n > 0; (void)++__first, --__n)
         _VSTD::__destroy_at(_VSTD::addressof(*__first));
diff --git a/libcxx/include/__memory/pointer_traits.h b/libcxx/include/__memory/pointer_traits.h
--- a/libcxx/include/__memory/pointer_traits.h
+++ b/libcxx/include/__memory/pointer_traits.h
@@ -122,7 +122,7 @@
 private:
     struct __nat {};
 public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static pointer pointer_to(typename conditional<is_void<element_type>::value,
                                            __nat, element_type>::type& __r)
         {return pointer::pointer_to(__r);}
@@ -144,7 +144,7 @@
 private:
     struct __nat {};
 public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static pointer pointer_to(typename conditional<is_void<element_type>::value,
                                       __nat, element_type>::type& __r) _NOEXCEPT
         {return _VSTD::addressof(__r);}
diff --git a/libcxx/include/__memory/swap_allocator.h b/libcxx/include/__memory/swap_allocator.h
--- a/libcxx/include/__memory/swap_allocator.h
+++ b/libcxx/include/__memory/swap_allocator.h
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <typename _Alloc>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 void __swap_allocator(_Alloc& __a1, _Alloc& __a2, true_type)
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 void __swap_allocator(_Alloc& __a1, _Alloc& __a2, true_type)
 #if _LIBCPP_STD_VER > 11
     _NOEXCEPT
 #else
@@ -33,11 +33,11 @@
 }
 
 template <typename _Alloc>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 void
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 void
 __swap_allocator(_Alloc&, _Alloc&, false_type) _NOEXCEPT {}
 
 template <typename _Alloc>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 void __swap_allocator(_Alloc& __a1, _Alloc& __a2)
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 void __swap_allocator(_Alloc& __a1, _Alloc& __a2)
 #if _LIBCPP_STD_VER > 11
     _NOEXCEPT
 #else
diff --git a/libcxx/include/__memory/uninitialized_algorithms.h b/libcxx/include/__memory/uninitialized_algorithms.h
--- a/libcxx/include/__memory/uninitialized_algorithms.h
+++ b/libcxx/include/__memory/uninitialized_algorithms.h
@@ -500,7 +500,7 @@
 
 // Destroy all elements in [__first, __last) from left to right using allocator destruction.
 template <class _Alloc, class _Iter, class _Sent>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void
 __allocator_destroy(_Alloc& __alloc, _Iter __first, _Sent __last) {
   for (; __first != __last; ++__first)
      allocator_traits<_Alloc>::destroy(__alloc, std::__to_address(__first));
@@ -509,11 +509,11 @@
 template <class _Alloc, class _Iter>
 class _AllocatorDestroyRangeReverse {
 public:
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
   _AllocatorDestroyRangeReverse(_Alloc& __alloc, _Iter& __first, _Iter& __last)
       : __alloc_(__alloc), __first_(__first), __last_(__last) {}
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 void operator()() const {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 void operator()() const {
     std::__allocator_destroy(__alloc_, std::reverse_iterator<_Iter>(__last_), std::reverse_iterator<_Iter>(__first_));
   }
 
@@ -528,7 +528,7 @@
 // The caller has to ensure that __first2 can hold at least N uninitialized elements. If an exception is thrown the
 // already copied elements are destroyed in reverse order of their construction.
 template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _Iter2
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _Iter2
 __uninitialized_allocator_copy(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
 #ifndef _LIBCPP_NO_EXCEPTIONS
   auto __destruct_first = __first2;
@@ -561,7 +561,7 @@
               // using _RawType because of the allocator<T const> extension
               is_trivially_copy_constructible<_RawType>::value && is_trivially_copy_assignable<_RawType>::value &&
               __allocator_has_trivial_copy_construct<_Alloc, _RawType>::value>* = nullptr>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _Type*
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _Type*
 __uninitialized_allocator_copy(_Alloc&, const _Type* __first1, const _Type* __last1, _Type* __first2) {
   // TODO: Remove the const_cast once we drop support for std::allocator<T const>
   if (__libcpp_is_constant_evaluated()) {
@@ -582,7 +582,7 @@
 // Otherwise try to copy all elements. If an exception is thrown the already copied
 // elements are destroyed in reverse order of their construction.
 template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _Iter2 __uninitialized_allocator_move_if_noexcept(
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _Iter2 __uninitialized_allocator_move_if_noexcept(
     _Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
   static_assert(__is_cpp17_move_insertable<_Alloc>::value,
                 "The specified type does not meet the requirements of Cpp17MoveInsertable");
@@ -622,7 +622,7 @@
     class _Type = typename iterator_traits<_Iter1>::value_type,
     class = __enable_if_t<is_trivially_move_constructible<_Type>::value && is_trivially_move_assignable<_Type>::value &&
                           __allocator_has_trivial_move_construct<_Alloc, _Type>::value> >
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _Iter2
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 _Iter2
 __uninitialized_allocator_move_if_noexcept(_Alloc&, _Iter1 __first1, _Iter1 __last1, _Iter2 __first2) {
   if (__libcpp_is_constant_evaluated()) {
     while (__first1 != __last1) {
diff --git a/libcxx/include/__memory/voidify.h b/libcxx/include/__memory/voidify.h
--- a/libcxx/include/__memory/voidify.h
+++ b/libcxx/include/__memory/voidify.h
@@ -20,7 +20,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <typename _Tp>
-_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void* __voidify(_Tp& __from) {
+_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void* __voidify(_Tp& __from) {
   // Cast away cv-qualifiers to allow modifying elements of a range through const iterators.
   return const_cast<void*>(static_cast<const volatile void*>(_VSTD::addressof(__from)));
 }
diff --git a/libcxx/include/__numeric/accumulate.h b/libcxx/include/__numeric/accumulate.h
--- a/libcxx/include/__numeric/accumulate.h
+++ b/libcxx/include/__numeric/accumulate.h
@@ -20,7 +20,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _Tp
 accumulate(_InputIterator __first, _InputIterator __last, _Tp __init)
 {
@@ -34,7 +34,7 @@
 }
 
 template <class _InputIterator, class _Tp, class _BinaryOperation>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _Tp
 accumulate(_InputIterator __first, _InputIterator __last, _Tp __init, _BinaryOperation __binary_op)
 {
diff --git a/libcxx/include/__numeric/adjacent_difference.h b/libcxx/include/__numeric/adjacent_difference.h
--- a/libcxx/include/__numeric/adjacent_difference.h
+++ b/libcxx/include/__numeric/adjacent_difference.h
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _OutputIterator>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
 {
@@ -44,7 +44,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
                       _BinaryOperation __binary_op)
diff --git a/libcxx/include/__numeric/exclusive_scan.h b/libcxx/include/__numeric/exclusive_scan.h
--- a/libcxx/include/__numeric/exclusive_scan.h
+++ b/libcxx/include/__numeric/exclusive_scan.h
@@ -23,7 +23,7 @@
 #if _LIBCPP_STD_VER > 14
 
 template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _OutputIterator
 exclusive_scan(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Tp __init, _BinaryOp __b) {
   if (__first != __last) {
     _Tp __tmp(__b(__init, *__first));
@@ -41,7 +41,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator, class _Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _OutputIterator
 exclusive_scan(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Tp __init) {
   return _VSTD::exclusive_scan(__first, __last, __result, __init, _VSTD::plus<>());
 }
diff --git a/libcxx/include/__numeric/inclusive_scan.h b/libcxx/include/__numeric/inclusive_scan.h
--- a/libcxx/include/__numeric/inclusive_scan.h
+++ b/libcxx/include/__numeric/inclusive_scan.h
@@ -24,7 +24,7 @@
 #if _LIBCPP_STD_VER > 14
 
 template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _OutputIterator
 inclusive_scan(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryOp __b, _Tp __init) {
   for (; __first != __last; ++__first, (void)++__result) {
     __init = __b(__init, *__first);
@@ -34,7 +34,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator, class _BinaryOp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _OutputIterator
 inclusive_scan(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryOp __b) {
   if (__first != __last) {
     typename iterator_traits<_InputIterator>::value_type __init = *__first;
@@ -47,7 +47,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator inclusive_scan(_InputIterator __first,
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _OutputIterator inclusive_scan(_InputIterator __first,
                                                                                        _InputIterator __last,
                                                                                        _OutputIterator __result) {
   return _VSTD::inclusive_scan(__first, __last, __result, _VSTD::plus<>());
diff --git a/libcxx/include/__numeric/inner_product.h b/libcxx/include/__numeric/inner_product.h
--- a/libcxx/include/__numeric/inner_product.h
+++ b/libcxx/include/__numeric/inner_product.h
@@ -20,7 +20,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator1, class _InputIterator2, class _Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _Tp
 inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _Tp __init)
 {
@@ -34,7 +34,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _Tp, class _BinaryOperation1, class _BinaryOperation2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _Tp
 inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
               _Tp __init, _BinaryOperation1 __binary_op1, _BinaryOperation2 __binary_op2)
diff --git a/libcxx/include/__numeric/iota.h b/libcxx/include/__numeric/iota.h
--- a/libcxx/include/__numeric/iota.h
+++ b/libcxx/include/__numeric/iota.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value)
 {
diff --git a/libcxx/include/__numeric/partial_sum.h b/libcxx/include/__numeric/partial_sum.h
--- a/libcxx/include/__numeric/partial_sum.h
+++ b/libcxx/include/__numeric/partial_sum.h
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _OutputIterator>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
 {
@@ -43,7 +43,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
               _BinaryOperation __binary_op)
diff --git a/libcxx/include/__numeric/reduce.h b/libcxx/include/__numeric/reduce.h
--- a/libcxx/include/__numeric/reduce.h
+++ b/libcxx/include/__numeric/reduce.h
@@ -22,7 +22,7 @@
 
 #if _LIBCPP_STD_VER > 14
 template <class _InputIterator, class _Tp, class _BinaryOp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp reduce(_InputIterator __first, _InputIterator __last,
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _Tp reduce(_InputIterator __first, _InputIterator __last,
                                                                    _Tp __init, _BinaryOp __b) {
   for (; __first != __last; ++__first)
     __init = __b(__init, *__first);
@@ -30,13 +30,13 @@
 }
 
 template <class _InputIterator, class _Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp reduce(_InputIterator __first, _InputIterator __last,
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _Tp reduce(_InputIterator __first, _InputIterator __last,
                                                                    _Tp __init) {
   return _VSTD::reduce(__first, __last, __init, _VSTD::plus<>());
 }
 
 template <class _InputIterator>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 typename iterator_traits<_InputIterator>::value_type
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 typename iterator_traits<_InputIterator>::value_type
 reduce(_InputIterator __first, _InputIterator __last) {
   return _VSTD::reduce(__first, __last, typename iterator_traits<_InputIterator>::value_type{});
 }
diff --git a/libcxx/include/__numeric/transform_exclusive_scan.h b/libcxx/include/__numeric/transform_exclusive_scan.h
--- a/libcxx/include/__numeric/transform_exclusive_scan.h
+++ b/libcxx/include/__numeric/transform_exclusive_scan.h
@@ -22,7 +22,7 @@
 
 template <class _InputIterator, class _OutputIterator, class _Tp,
           class _BinaryOp, class _UnaryOp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 transform_exclusive_scan(_InputIterator __first, _InputIterator __last,
                            _OutputIterator __result, _Tp __init,
diff --git a/libcxx/include/__numeric/transform_inclusive_scan.h b/libcxx/include/__numeric/transform_inclusive_scan.h
--- a/libcxx/include/__numeric/transform_inclusive_scan.h
+++ b/libcxx/include/__numeric/transform_inclusive_scan.h
@@ -22,7 +22,7 @@
 #if _LIBCPP_STD_VER > 14
 
 template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp, class _UnaryOp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 transform_inclusive_scan(_InputIterator __first, _InputIterator __last,
                            _OutputIterator __result, _BinaryOp __b, _UnaryOp __u, _Tp __init)
@@ -36,7 +36,7 @@
 }
 
 template <class _InputIterator, class _OutputIterator, class _BinaryOp, class _UnaryOp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _OutputIterator
 transform_inclusive_scan(_InputIterator __first, _InputIterator __last,
                                _OutputIterator __result, _BinaryOp __b, _UnaryOp __u)
diff --git a/libcxx/include/__numeric/transform_reduce.h b/libcxx/include/__numeric/transform_reduce.h
--- a/libcxx/include/__numeric/transform_reduce.h
+++ b/libcxx/include/__numeric/transform_reduce.h
@@ -22,7 +22,7 @@
 
 #if _LIBCPP_STD_VER > 14
 template <class _InputIterator, class _Tp, class _BinaryOp, class _UnaryOp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp transform_reduce(_InputIterator __first,
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _Tp transform_reduce(_InputIterator __first,
                                                                              _InputIterator __last, _Tp __init,
                                                                              _BinaryOp __b, _UnaryOp __u) {
   for (; __first != __last; ++__first)
@@ -31,7 +31,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _Tp, class _BinaryOp1, class _BinaryOp2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp transform_reduce(_InputIterator1 __first1,
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _Tp transform_reduce(_InputIterator1 __first1,
                                                                              _InputIterator1 __last1,
                                                                              _InputIterator2 __first2, _Tp __init,
                                                                              _BinaryOp1 __b1, _BinaryOp2 __b2) {
@@ -41,7 +41,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp transform_reduce(_InputIterator1 __first1,
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 _Tp transform_reduce(_InputIterator1 __first1,
                                                                              _InputIterator1 __last1,
                                                                              _InputIterator2 __first2, _Tp __init) {
   return _VSTD::transform_reduce(__first1, __last1, __first2, _VSTD::move(__init), _VSTD::plus<>(),
diff --git a/libcxx/include/__split_buffer b/libcxx/include/__split_buffer
--- a/libcxx/include/__split_buffer
+++ b/libcxx/include/__split_buffer
@@ -62,107 +62,107 @@
     typedef typename add_lvalue_reference<allocator_type>::type __alloc_ref;
     typedef typename add_lvalue_reference<allocator_type>::type __alloc_const_ref;
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY __alloc_rr&           __alloc() _NOEXCEPT         {return __end_cap_.second();}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const __alloc_rr&     __alloc() const _NOEXCEPT   {return __end_cap_.second();}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY pointer&              __end_cap() _NOEXCEPT       {return __end_cap_.first();}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const pointer&        __end_cap() const _NOEXCEPT {return __end_cap_.first();}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY __alloc_rr&           __alloc() _NOEXCEPT         {return __end_cap_.second();}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const __alloc_rr&     __alloc() const _NOEXCEPT   {return __end_cap_.second();}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY pointer&              __end_cap() _NOEXCEPT       {return __end_cap_.first();}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const pointer&        __end_cap() const _NOEXCEPT {return __end_cap_.first();}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     __split_buffer()
         _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     explicit __split_buffer(__alloc_rr& __a);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     explicit __split_buffer(const __alloc_rr& __a);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 ~__split_buffer();
+    _LIBCPP_CONSTEXPR_CXX20 __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a);
+    _LIBCPP_CONSTEXPR_CXX20 ~__split_buffer();
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __split_buffer(__split_buffer&& __c)
+    _LIBCPP_CONSTEXPR_CXX20 __split_buffer(__split_buffer&& __c)
         _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __split_buffer(__split_buffer&& __c, const __alloc_rr& __a);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __split_buffer& operator=(__split_buffer&& __c)
+    _LIBCPP_CONSTEXPR_CXX20 __split_buffer(__split_buffer&& __c, const __alloc_rr& __a);
+    _LIBCPP_CONSTEXPR_CXX20 __split_buffer& operator=(__split_buffer&& __c)
         _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
                 is_nothrow_move_assignable<allocator_type>::value) ||
                !__alloc_traits::propagate_on_container_move_assignment::value);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY       iterator begin() _NOEXCEPT       {return __begin_;}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const_iterator begin() const _NOEXCEPT {return __begin_;}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY       iterator end() _NOEXCEPT         {return __end_;}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const_iterator end() const _NOEXCEPT   {return __end_;}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY       iterator begin() _NOEXCEPT       {return __begin_;}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const_iterator begin() const _NOEXCEPT {return __begin_;}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY       iterator end() _NOEXCEPT         {return __end_;}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const_iterator end() const _NOEXCEPT   {return __end_;}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void clear() _NOEXCEPT
         {__destruct_at_end(__begin_);}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY size_type size() const {return static_cast<size_type>(__end_ - __begin_);}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY bool empty()     const {return __end_ == __begin_;}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY size_type capacity() const {return static_cast<size_type>(__end_cap() - __first_);}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY size_type __front_spare() const {return static_cast<size_type>(__begin_ - __first_);}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY size_type __back_spare() const {return static_cast<size_type>(__end_cap() - __end_);}
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY       reference front()       {return *__begin_;}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const_reference front() const {return *__begin_;}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY       reference back()        {return *(__end_ - 1);}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const_reference back() const  {return *(__end_ - 1);}
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void reserve(size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void shrink_to_fit() _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void push_front(const_reference __x);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void push_front(value_type&& __x);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void push_back(value_type&& __x);
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY size_type size() const {return static_cast<size_type>(__end_ - __begin_);}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY bool empty()     const {return __end_ == __begin_;}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY size_type capacity() const {return static_cast<size_type>(__end_cap() - __first_);}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY size_type __front_spare() const {return static_cast<size_type>(__begin_ - __first_);}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY size_type __back_spare() const {return static_cast<size_type>(__end_cap() - __end_);}
+
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY       reference front()       {return *__begin_;}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const_reference front() const {return *__begin_;}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY       reference back()        {return *(__end_ - 1);}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const_reference back() const  {return *(__end_ - 1);}
+
+    _LIBCPP_CONSTEXPR_CXX20 void reserve(size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 void shrink_to_fit() _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 void push_front(const_reference __x);
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
+    _LIBCPP_CONSTEXPR_CXX20 void push_front(value_type&& __x);
+    _LIBCPP_CONSTEXPR_CXX20 void push_back(value_type&& __x);
     template <class... _Args>
-        _LIBCPP_CONSTEXPR_AFTER_CXX17 void emplace_back(_Args&&... __args);
+        _LIBCPP_CONSTEXPR_CXX20 void emplace_back(_Args&&... __args);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY void pop_front() {__destruct_at_begin(__begin_+1);}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY void pop_back() {__destruct_at_end(__end_-1);}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY void pop_front() {__destruct_at_begin(__begin_+1);}
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY void pop_back() {__destruct_at_end(__end_-1);}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct_at_end(size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct_at_end(size_type __n, const_reference __x);
+    _LIBCPP_CONSTEXPR_CXX20 void __construct_at_end(size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 void __construct_at_end(size_type __n, const_reference __x);
     template <class _InputIter>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __enable_if_t<__is_exactly_cpp17_input_iterator<_InputIter>::value>
+    _LIBCPP_CONSTEXPR_CXX20 __enable_if_t<__is_exactly_cpp17_input_iterator<_InputIter>::value>
         __construct_at_end(_InputIter __first, _InputIter __last);
     template <class _ForwardIterator>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __enable_if_t<__is_cpp17_forward_iterator<_ForwardIterator>::value>
+    _LIBCPP_CONSTEXPR_CXX20 __enable_if_t<__is_cpp17_forward_iterator<_ForwardIterator>::value>
         __construct_at_end(_ForwardIterator __first, _ForwardIterator __last);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY void __destruct_at_begin(pointer __new_begin)
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY void __destruct_at_begin(pointer __new_begin)
         {__destruct_at_begin(__new_begin, is_trivially_destructible<value_type>());}
-        _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
         void __destruct_at_begin(pointer __new_begin, false_type);
-        _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
         void __destruct_at_begin(pointer __new_begin, true_type);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void __destruct_at_end(pointer __new_last) _NOEXCEPT
         {__destruct_at_end(__new_last, false_type());}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
         void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
         void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT;
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void swap(__split_buffer& __x)
+    _LIBCPP_CONSTEXPR_CXX20 void swap(__split_buffer& __x)
         _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value||
                    __is_nothrow_swappable<__alloc_rr>::value);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 bool __invariants() const;
+    _LIBCPP_CONSTEXPR_CXX20 bool __invariants() const;
 
 private:
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void __move_assign_alloc(__split_buffer& __c, true_type)
         _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
         {
             __alloc() = _VSTD::move(__c.__alloc());
         }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT
         {}
 
     struct _ConstructTransaction {
-      _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit _ConstructTransaction(pointer* __p, size_type __n) _NOEXCEPT
+      _LIBCPP_CONSTEXPR_CXX20 explicit _ConstructTransaction(pointer* __p, size_type __n) _NOEXCEPT
       : __pos_(*__p), __end_(*__p + __n), __dest_(__p) {
       }
-      _LIBCPP_CONSTEXPR_AFTER_CXX17 ~_ConstructTransaction() {
+      _LIBCPP_CONSTEXPR_CXX20 ~_ConstructTransaction() {
         *__dest_ = __pos_;
       }
       pointer __pos_;
@@ -173,7 +173,7 @@
 };
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 bool
 __split_buffer<_Tp, _Allocator>::__invariants() const
 {
@@ -204,7 +204,7 @@
 //  Precondition:  size() + __n <= capacity()
 //  Postcondition:  size() == size() + __n
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 __split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n)
 {
@@ -221,7 +221,7 @@
 //  Postcondition:  size() == old size() + __n
 //  Postcondition:  [i] == __x for all i in [size() - __n, __n)
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 __split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x)
 {
@@ -234,7 +234,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _InputIter>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 __enable_if_t<__is_exactly_cpp17_input_iterator<_InputIter>::value>
+_LIBCPP_CONSTEXPR_CXX20 __enable_if_t<__is_exactly_cpp17_input_iterator<_InputIter>::value>
 __split_buffer<_Tp, _Allocator>::__construct_at_end(_InputIter __first, _InputIter __last)
 {
     __alloc_rr& __a = this->__alloc();
@@ -257,7 +257,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 __enable_if_t<__is_cpp17_forward_iterator<_ForwardIterator>::value>
+_LIBCPP_CONSTEXPR_CXX20 __enable_if_t<__is_cpp17_forward_iterator<_ForwardIterator>::value>
 __split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last)
 {
     _ConstructTransaction __tx(&this->__end_, _VSTD::distance(__first, __last));
@@ -268,7 +268,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline
 void
 __split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type)
@@ -278,7 +278,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline
 void
 __split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type)
@@ -287,7 +287,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 void
 __split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT
@@ -297,7 +297,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 void
 __split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT
@@ -306,7 +306,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a)
     : __end_cap_(nullptr, __a)
 {
@@ -322,7 +322,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline
 __split_buffer<_Tp, _Allocator>::__split_buffer()
     _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
@@ -331,7 +331,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline
 __split_buffer<_Tp, _Allocator>::__split_buffer(__alloc_rr& __a)
     : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a)
@@ -339,7 +339,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline
 __split_buffer<_Tp, _Allocator>::__split_buffer(const __alloc_rr& __a)
     : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a)
@@ -347,7 +347,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __split_buffer<_Tp, _Allocator>::~__split_buffer()
 {
     clear();
@@ -356,7 +356,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c)
     _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
     : __first_(_VSTD::move(__c.__first_)),
@@ -371,7 +371,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a)
     : __end_cap_(nullptr, __a)
 {
@@ -398,7 +398,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __split_buffer<_Tp, _Allocator>&
 __split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c)
     _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
@@ -419,7 +419,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 __split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x)
         _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value||
@@ -433,7 +433,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 __split_buffer<_Tp, _Allocator>::reserve(size_type __n)
 {
@@ -450,7 +450,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 __split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
 {
@@ -478,7 +478,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 __split_buffer<_Tp, _Allocator>::push_front(const_reference __x)
 {
@@ -508,7 +508,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 __split_buffer<_Tp, _Allocator>::push_front(value_type&& __x)
 {
@@ -539,7 +539,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 void
 __split_buffer<_Tp, _Allocator>::push_back(const_reference __x)
@@ -570,7 +570,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 __split_buffer<_Tp, _Allocator>::push_back(value_type&& __x)
 {
@@ -602,7 +602,7 @@
 
 template <class _Tp, class _Allocator>
 template <class... _Args>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 __split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args)
 {
@@ -633,7 +633,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 void
 swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y)
diff --git a/libcxx/include/__string/char_traits.h b/libcxx/include/__string/char_traits.h
--- a/libcxx/include/__string/char_traits.h
+++ b/libcxx/include/__string/char_traits.h
@@ -46,26 +46,26 @@
     typedef streampos pos_type;
     typedef mbstate_t state_type;
 
-    static inline void _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static inline void _LIBCPP_CONSTEXPR_CXX17
         assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
     static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
         {return __c1 == __c2;}
     static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
         {return __c1 < __c2;}
 
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static _LIBCPP_CONSTEXPR_CXX17
     int compare(const char_type* __s1, const char_type* __s2, size_t __n);
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_CXX17
     size_t length(const char_type* __s);
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_CXX17
     const char_type* find(const char_type* __s, size_t __n, const char_type& __a);
-    static _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static _LIBCPP_CONSTEXPR_CXX20
     char_type*       move(char_type* __s1, const char_type* __s2, size_t __n);
     _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static _LIBCPP_CONSTEXPR_CXX20
     char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n);
     _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static _LIBCPP_CONSTEXPR_CXX20
     char_type*       assign(char_type* __s, size_t __n, char_type __a);
 
     static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
@@ -81,7 +81,7 @@
 };
 
 template <class _CharT>
-_LIBCPP_CONSTEXPR_AFTER_CXX14 int
+_LIBCPP_CONSTEXPR_CXX17 int
 char_traits<_CharT>::compare(const char_type* __s1, const char_type* __s2, size_t __n)
 {
     for (; __n; --__n, ++__s1, ++__s2)
@@ -96,7 +96,7 @@
 
 template <class _CharT>
 inline
-_LIBCPP_CONSTEXPR_AFTER_CXX14 size_t
+_LIBCPP_CONSTEXPR_CXX17 size_t
 char_traits<_CharT>::length(const char_type* __s)
 {
     size_t __len = 0;
@@ -107,7 +107,7 @@
 
 template <class _CharT>
 inline
-_LIBCPP_CONSTEXPR_AFTER_CXX14 const _CharT*
+_LIBCPP_CONSTEXPR_CXX17 const _CharT*
 char_traits<_CharT>::find(const char_type* __s, size_t __n, const char_type& __a)
 {
     for (; __n; --__n)
@@ -120,7 +120,7 @@
 }
 
 template <class _CharT>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _CharT*
+_LIBCPP_CONSTEXPR_CXX20 _CharT*
 char_traits<_CharT>::move(char_type* __s1, const char_type* __s2, size_t __n)
 {
     if (__n == 0) return __s1;
@@ -141,7 +141,7 @@
 }
 
 template <class _CharT>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 _CharT*
 char_traits<_CharT>::copy(char_type* __s1, const char_type* __s2, size_t __n)
 {
@@ -155,7 +155,7 @@
 }
 
 template <class _CharT>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 _CharT*
 char_traits<_CharT>::assign(char_type* __s, size_t __n, char_type __a)
 {
@@ -166,7 +166,7 @@
 }
 
 template <class _CharT>
-static inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+static inline _LIBCPP_CONSTEXPR_CXX20
 _CharT* __char_traits_move(_CharT* __dest, const _CharT* __source, size_t __n) _NOEXCEPT
 {
 #ifdef _LIBCPP_COMPILER_GCC
@@ -198,17 +198,17 @@
     using comparison_category = strong_ordering;
 #endif
 
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static inline _LIBCPP_CONSTEXPR_CXX17
     void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
     static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
             {return __c1 == __c2;}
     static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
         {return (unsigned char)__c1 < (unsigned char)__c2;}
 
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static _LIBCPP_CONSTEXPR_CXX17
     int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
 
-    static inline size_t _LIBCPP_CONSTEXPR_AFTER_CXX14 length(const char_type* __s)  _NOEXCEPT {
+    static inline size_t _LIBCPP_CONSTEXPR_CXX17 length(const char_type* __s)  _NOEXCEPT {
       // GCC currently does not support __builtin_strlen during constant evaluation.
       // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70816
 #ifdef _LIBCPP_COMPILER_GCC
@@ -222,15 +222,15 @@
       return __builtin_strlen(__s);
     }
 
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static _LIBCPP_CONSTEXPR_CXX17
     const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
 
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static inline _LIBCPP_CONSTEXPR_CXX20
     char_type* move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT {
         return std::__char_traits_move(__s1, __s2, __n);
     }
 
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static inline _LIBCPP_CONSTEXPR_CXX20
     char_type* copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT {
         if (!__libcpp_is_constant_evaluated())
             _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
@@ -238,7 +238,7 @@
         return __s1;
     }
 
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static inline _LIBCPP_CONSTEXPR_CXX20
     char_type* assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT {
         std::fill_n(__s, __n, __a);
         return __s;
@@ -256,7 +256,7 @@
         {return int_type(EOF);}
 };
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 int
 char_traits<char>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
 {
@@ -278,7 +278,7 @@
 #endif
 }
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 const char*
 char_traits<char>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
 {
@@ -315,26 +315,26 @@
     using comparison_category = strong_ordering;
 #  endif
 
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static inline _LIBCPP_CONSTEXPR_CXX17
     void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
     static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
         {return __c1 == __c2;}
     static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
         {return __c1 < __c2;}
 
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static _LIBCPP_CONSTEXPR_CXX17
     int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static _LIBCPP_CONSTEXPR_CXX17
     size_t length(const char_type* __s) _NOEXCEPT;
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static _LIBCPP_CONSTEXPR_CXX17
     const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
 
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static inline _LIBCPP_CONSTEXPR_CXX20
     char_type* move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT {
         return std::__char_traits_move(__s1, __s2, __n);
     }
 
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static inline _LIBCPP_CONSTEXPR_CXX20
     char_type* copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT {
         if (!__libcpp_is_constant_evaluated())
             _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
@@ -342,7 +342,7 @@
         return __s1;
     }
 
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static inline _LIBCPP_CONSTEXPR_CXX20
     char_type* assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT {
         std::fill_n(__s, __n, __a);
         return __s;
@@ -360,7 +360,7 @@
         {return int_type(WEOF);}
 };
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 int
 char_traits<wchar_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
 {
@@ -382,7 +382,7 @@
 #endif
 }
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 size_t
 char_traits<wchar_t>::length(const char_type* __s) _NOEXCEPT
 {
@@ -398,7 +398,7 @@
 #endif
 }
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 const wchar_t*
 char_traits<wchar_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
 {
@@ -450,12 +450,12 @@
     _LIBCPP_INLINE_VISIBILITY static constexpr
     const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
 
-    static _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static _LIBCPP_CONSTEXPR_CXX20
     char_type*       move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT {
         return std::__char_traits_move(__s1, __s2, __n);
     }
 
-    static _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static _LIBCPP_CONSTEXPR_CXX20
     char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT {
         if (!__libcpp_is_constant_evaluated())
             _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
@@ -463,7 +463,7 @@
         return __s1;
     }
 
-    static _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static _LIBCPP_CONSTEXPR_CXX20
     char_type*       assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT {
         std::fill_n(__s, __n, __a);
         return __s;
@@ -538,26 +538,26 @@
     using comparison_category = strong_ordering;
 #endif
 
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static inline _LIBCPP_CONSTEXPR_CXX17
     void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
     static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
         {return __c1 == __c2;}
     static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
         {return __c1 < __c2;}
 
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_CXX17
     int              compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_CXX17
     size_t           length(const char_type* __s) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_CXX17
     const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT {
         return std::__char_traits_move(__s1, __s2, __n);
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT {
         if (!__libcpp_is_constant_evaluated())
             _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
@@ -565,7 +565,7 @@
         return __s1;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static char_type*       assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT {
         std::fill_n(__s, __n, __a);
         return __s;
@@ -583,7 +583,7 @@
         {return int_type(0xFFFF);}
 };
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 int
 char_traits<char16_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
 {
@@ -597,7 +597,7 @@
     return 0;
 }
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 size_t
 char_traits<char16_t>::length(const char_type* __s) _NOEXCEPT
 {
@@ -607,7 +607,7 @@
     return __len;
 }
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 const char16_t*
 char_traits<char16_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
 {
@@ -632,32 +632,32 @@
     using comparison_category = strong_ordering;
 #endif
 
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+    static inline _LIBCPP_CONSTEXPR_CXX17
     void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
     static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
         {return __c1 == __c2;}
     static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
         {return __c1 < __c2;}
 
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_CXX17
     int              compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_CXX17
     size_t           length(const char_type* __s) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_CXX17
     const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT {
         return std::__char_traits_move(__s1, __s2, __n);
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT {
         std::copy_n(__s2, __n, __s1);
         return __s1;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static char_type*       assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT {
         std::fill_n(__s, __n, __a);
         return __s;
@@ -675,7 +675,7 @@
         {return int_type(0xFFFFFFFF);}
 };
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 int
 char_traits<char32_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
 {
@@ -689,7 +689,7 @@
     return 0;
 }
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 size_t
 char_traits<char32_t>::length(const char_type* __s) _NOEXCEPT
 {
@@ -699,7 +699,7 @@
     return __len;
 }
 
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+inline _LIBCPP_CONSTEXPR_CXX17
 const char32_t*
 char_traits<char32_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
 {
@@ -716,7 +716,7 @@
 
 // __str_find
 template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+inline _SizeT _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 __str_find(const _CharT *__p, _SizeT __sz,
              _CharT __c, _SizeT __pos) _NOEXCEPT
 {
@@ -729,7 +729,7 @@
 }
 
 template <class _CharT, class _Traits>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX11 const _CharT *
+inline _LIBCPP_CONSTEXPR_CXX14 const _CharT *
 __search_substring(const _CharT *__first1, const _CharT *__last1,
                    const _CharT *__first2, const _CharT *__last2) _NOEXCEPT {
   // Take advantage of knowing source and pattern lengths.
@@ -768,7 +768,7 @@
 }
 
 template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+inline _SizeT _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 __str_find(const _CharT *__p, _SizeT __sz,
        const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
 {
@@ -790,7 +790,7 @@
 // __str_rfind
 
 template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+inline _SizeT _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 __str_rfind(const _CharT *__p, _SizeT __sz,
               _CharT __c, _SizeT __pos) _NOEXCEPT
 {
@@ -809,7 +809,7 @@
 }
 
 template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+inline _SizeT _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 __str_rfind(const _CharT *__p, _SizeT __sz,
         const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
 {
@@ -826,7 +826,7 @@
 
 // __str_find_first_of
 template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+inline _SizeT _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 __str_find_first_of(const _CharT *__p, _SizeT __sz,
                 const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
 {
@@ -842,7 +842,7 @@
 
 // __str_find_last_of
 template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+inline _SizeT _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 __str_find_last_of(const _CharT *__p, _SizeT __sz,
                const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
     {
@@ -865,7 +865,7 @@
 
 // __str_find_first_not_of
 template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+inline _SizeT _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 __str_find_first_not_of(const _CharT *__p, _SizeT __sz,
                     const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
 {
@@ -881,7 +881,7 @@
 
 
 template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+inline _SizeT _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 __str_find_first_not_of(const _CharT *__p, _SizeT __sz,
                           _CharT __c, _SizeT __pos) _NOEXCEPT
 {
@@ -898,7 +898,7 @@
 
 // __str_find_last_not_of
 template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+inline _SizeT _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 __str_find_last_not_of(const _CharT *__p, _SizeT __sz,
                    const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
 {
@@ -914,7 +914,7 @@
 
 
 template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+inline _SizeT _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 __str_find_last_not_of(const _CharT *__p, _SizeT __sz,
                          _CharT __c, _SizeT __pos) _NOEXCEPT
 {
diff --git a/libcxx/include/__tuple b/libcxx/include/__tuple
--- a/libcxx/include/__tuple
+++ b/libcxx/include/__tuple
@@ -167,22 +167,22 @@
 };
 
 template <size_t _Ip, class ..._Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename tuple_element<_Ip, tuple<_Tp...> >::type&
 get(tuple<_Tp...>&) _NOEXCEPT;
 
 template <size_t _Ip, class ..._Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const typename tuple_element<_Ip, tuple<_Tp...> >::type&
 get(const tuple<_Tp...>&) _NOEXCEPT;
 
 template <size_t _Ip, class ..._Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename tuple_element<_Ip, tuple<_Tp...> >::type&&
 get(tuple<_Tp...>&&) _NOEXCEPT;
 
 template <size_t _Ip, class ..._Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const typename tuple_element<_Ip, tuple<_Tp...> >::type&&
 get(const tuple<_Tp...>&&) _NOEXCEPT;
 
@@ -193,23 +193,23 @@
 template <class _T1, class _T2> struct __tuple_like<pair<_T1, _T2> > : true_type {};
 
 template <size_t _Ip, class _T1, class _T2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename tuple_element<_Ip, pair<_T1, _T2> >::type&
 get(pair<_T1, _T2>&) _NOEXCEPT;
 
 template <size_t _Ip, class _T1, class _T2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
 get(const pair<_T1, _T2>&) _NOEXCEPT;
 
 #ifndef _LIBCPP_CXX03_LANG
 template <size_t _Ip, class _T1, class _T2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
 get(pair<_T1, _T2>&&) _NOEXCEPT;
 
 template <size_t _Ip, class _T1, class _T2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
 get(const pair<_T1, _T2>&&) _NOEXCEPT;
 #endif
@@ -221,23 +221,23 @@
 template <class _Tp, size_t _Size> struct __tuple_like<array<_Tp, _Size> > : true_type {};
 
 template <size_t _Ip, class _Tp, size_t _Size>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp&
 get(array<_Tp, _Size>&) _NOEXCEPT;
 
 template <size_t _Ip, class _Tp, size_t _Size>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const _Tp&
 get(const array<_Tp, _Size>&) _NOEXCEPT;
 
 #ifndef _LIBCPP_CXX03_LANG
 template <size_t _Ip, class _Tp, size_t _Size>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp&&
 get(array<_Tp, _Size>&&) _NOEXCEPT;
 
 template <size_t _Ip, class _Tp, size_t _Size>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const _Tp&&
 get(const array<_Tp, _Size>&&) _NOEXCEPT;
 #endif
diff --git a/libcxx/include/__utility/exchange.h b/libcxx/include/__utility/exchange.h
--- a/libcxx/include/__utility/exchange.h
+++ b/libcxx/include/__utility/exchange.h
@@ -22,7 +22,7 @@
 
 #if _LIBCPP_STD_VER > 11
 template<class _T1, class _T2 = _T1>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 _T1 exchange(_T1& __obj, _T2&& __new_value)
     noexcept(is_nothrow_move_constructible<_T1>::value && is_nothrow_assignable<_T1&, _T2>::value)
 {
diff --git a/libcxx/include/__utility/move.h b/libcxx/include/__utility/move.h
--- a/libcxx/include/__utility/move.h
+++ b/libcxx/include/__utility/move.h
@@ -32,7 +32,7 @@
                          _Tp&&>::type;
 
 template <class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 __move_if_noexcept_result_t<_Tp>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 __move_if_noexcept_result_t<_Tp>
 move_if_noexcept(_Tp& __x) _NOEXCEPT {
   return _VSTD::move(__x);
 }
diff --git a/libcxx/include/__utility/pair.h b/libcxx/include/__utility/pair.h
--- a/libcxx/include/__utility/pair.h
+++ b/libcxx/include/__utility/pair.h
@@ -31,7 +31,7 @@
 struct __non_trivially_copyable_base {
   _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
   __non_trivially_copyable_base() _NOEXCEPT {}
-  _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
   __non_trivially_copyable_base(__non_trivially_copyable_base const&) _NOEXCEPT {}
 };
 #endif
@@ -153,7 +153,7 @@
     template <bool _Dummy = true, typename enable_if<
              _CheckArgsDep<_Dummy>::template __enable_explicit<_T1 const&, _T2 const&>()
     >::type* = nullptr>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit pair(_T1 const& __t1, _T2 const& __t2)
         _NOEXCEPT_(is_nothrow_copy_constructible<first_type>::value &&
                    is_nothrow_copy_constructible<second_type>::value)
@@ -162,7 +162,7 @@
     template<bool _Dummy = true, typename enable_if<
             _CheckArgsDep<_Dummy>::template __enable_implicit<_T1 const&, _T2 const&>()
     >::type* = nullptr>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     pair(_T1 const& __t1, _T2 const& __t2)
         _NOEXCEPT_(is_nothrow_copy_constructible<first_type>::value &&
                    is_nothrow_copy_constructible<second_type>::value)
@@ -176,7 +176,7 @@
 #endif
         typename enable_if<_CheckArgs::template __enable_explicit<_U1, _U2>()>::type* = nullptr
     >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit pair(_U1&& __u1, _U2&& __u2)
         _NOEXCEPT_((is_nothrow_constructible<first_type, _U1>::value &&
                     is_nothrow_constructible<second_type, _U2>::value))
@@ -190,7 +190,7 @@
 #endif
         typename enable_if<_CheckArgs::template __enable_implicit<_U1, _U2>()>::type* = nullptr
     >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     pair(_U1&& __u1, _U2&& __u2)
         _NOEXCEPT_((is_nothrow_constructible<first_type, _U1>::value &&
                     is_nothrow_constructible<second_type, _U2>::value))
@@ -199,7 +199,7 @@
     template<class _U1, class _U2, typename enable_if<
             _CheckArgs::template __enable_explicit<_U1 const&, _U2 const&>()
     >::type* = nullptr>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit pair(pair<_U1, _U2> const& __p)
         _NOEXCEPT_((is_nothrow_constructible<first_type, _U1 const&>::value &&
                     is_nothrow_constructible<second_type, _U2 const&>::value))
@@ -208,7 +208,7 @@
     template<class _U1, class _U2, typename enable_if<
             _CheckArgs::template __enable_implicit<_U1 const&, _U2 const&>()
     >::type* = nullptr>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     pair(pair<_U1, _U2> const& __p)
         _NOEXCEPT_((is_nothrow_constructible<first_type, _U1 const&>::value &&
                     is_nothrow_constructible<second_type, _U2 const&>::value))
@@ -217,7 +217,7 @@
     template<class _U1, class _U2, typename enable_if<
             _CheckArgs::template __enable_explicit<_U1, _U2>()
     >::type* = nullptr>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit pair(pair<_U1, _U2>&&__p)
         _NOEXCEPT_((is_nothrow_constructible<first_type, _U1&&>::value &&
                     is_nothrow_constructible<second_type, _U2&&>::value))
@@ -226,7 +226,7 @@
     template<class _U1, class _U2, typename enable_if<
             _CheckArgs::template __enable_implicit<_U1, _U2>()
     >::type* = nullptr>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     pair(pair<_U1, _U2>&& __p)
         _NOEXCEPT_((is_nothrow_constructible<first_type, _U1&&>::value &&
                     is_nothrow_constructible<second_type, _U2&&>::value))
@@ -235,7 +235,7 @@
     template<class _Tuple, typename enable_if<
             _CheckTLC<_Tuple>::template __enable_explicit<_Tuple>()
     >::type* = nullptr>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit pair(_Tuple&& __p)
         : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
           second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
@@ -243,13 +243,13 @@
     template<class _Tuple, typename enable_if<
             _CheckTLC<_Tuple>::template __enable_implicit<_Tuple>()
     >::type* = nullptr>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     pair(_Tuple&& __p)
         : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
           second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
 
     template <class... _Args1, class... _Args2>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     pair(piecewise_construct_t __pc,
          tuple<_Args1...> __first_args, tuple<_Args2...> __second_args)
         _NOEXCEPT_((is_nothrow_constructible<first_type, _Args1...>::value &&
@@ -258,7 +258,7 @@
                 typename __make_tuple_indices<sizeof...(_Args1)>::type(),
                 typename __make_tuple_indices<sizeof...(_Args2) >::type()) {}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     pair& operator=(typename conditional<
                         is_copy_assignable<first_type>::value &&
                         is_copy_assignable<second_type>::value,
@@ -271,7 +271,7 @@
         return *this;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     pair& operator=(typename conditional<
                         is_move_assignable<first_type>::value &&
                         is_move_assignable<second_type>::value,
@@ -287,7 +287,7 @@
     template <class _Tuple, typename enable_if<
             _CheckTLC<_Tuple>::template __enable_assign<_Tuple>()
      >::type* = nullptr>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     pair& operator=(_Tuple&& __p) {
         first = _VSTD::get<0>(_VSTD::forward<_Tuple>(__p));
         second = _VSTD::get<1>(_VSTD::forward<_Tuple>(__p));
@@ -295,7 +295,7 @@
     }
 #endif
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void
     swap(pair& __p) _NOEXCEPT_(__is_nothrow_swappable<first_type>::value &&
                                __is_nothrow_swappable<second_type>::value)
@@ -308,7 +308,7 @@
 
 #ifndef _LIBCPP_CXX03_LANG
     template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     pair(piecewise_construct_t,
          tuple<_Args1...>& __first_args, tuple<_Args2...>& __second_args,
          __tuple_indices<_I1...>, __tuple_indices<_I2...>);
@@ -323,7 +323,7 @@
 // [pairs.spec], specialized algorithms
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator==(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -348,7 +348,7 @@
 #else // _LIBCPP_STD_VER > 17
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator!=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -356,7 +356,7 @@
 }
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator< (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -364,7 +364,7 @@
 }
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator> (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -372,7 +372,7 @@
 }
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator>=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -380,7 +380,7 @@
 }
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator<=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -406,7 +406,7 @@
 #endif // _LIBCPP_STD_VER > 20
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 typename enable_if
 <
     __is_swappable<_T1>::value &&
@@ -423,7 +423,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 pair<typename __unwrap_ref_decay<_T1>::type, typename __unwrap_ref_decay<_T2>::type>
 make_pair(_T1&& __t1, _T2&& __t2)
 {
@@ -472,26 +472,26 @@
 {
     template <class _T1, class _T2>
     static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     _T1&
     get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
 
     template <class _T1, class _T2>
     static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     const _T1&
     get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
 
 #ifndef _LIBCPP_CXX03_LANG
     template <class _T1, class _T2>
     static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     _T1&&
     get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T1>(__p.first);}
 
     template <class _T1, class _T2>
     static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     const _T1&&
     get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T1>(__p.first);}
 #endif // _LIBCPP_CXX03_LANG
@@ -502,33 +502,33 @@
 {
     template <class _T1, class _T2>
     static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     _T2&
     get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
 
     template <class _T1, class _T2>
     static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     const _T2&
     get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
 
 #ifndef _LIBCPP_CXX03_LANG
     template <class _T1, class _T2>
     static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     _T2&&
     get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T2>(__p.second);}
 
     template <class _T1, class _T2>
     static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     const _T2&&
     get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T2>(__p.second);}
 #endif // _LIBCPP_CXX03_LANG
 };
 
 template <size_t _Ip, class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename tuple_element<_Ip, pair<_T1, _T2> >::type&
 get(pair<_T1, _T2>& __p) _NOEXCEPT
 {
@@ -536,7 +536,7 @@
 }
 
 template <size_t _Ip, class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
 get(const pair<_T1, _T2>& __p) _NOEXCEPT
 {
@@ -545,7 +545,7 @@
 
 #ifndef _LIBCPP_CXX03_LANG
 template <size_t _Ip, class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
 get(pair<_T1, _T2>&& __p) _NOEXCEPT
 {
@@ -553,7 +553,7 @@
 }
 
 template <size_t _Ip, class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
 get(const pair<_T1, _T2>&& __p) _NOEXCEPT
 {
diff --git a/libcxx/include/__utility/swap.h b/libcxx/include/__utility/swap.h
--- a/libcxx/include/__utility/swap.h
+++ b/libcxx/include/__utility/swap.h
@@ -30,7 +30,7 @@
 #endif
 
 template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY __swap_result_t<_Tp> _LIBCPP_CONSTEXPR_AFTER_CXX17 swap(_Tp& __x, _Tp& __y)
+inline _LIBCPP_INLINE_VISIBILITY __swap_result_t<_Tp> _LIBCPP_CONSTEXPR_CXX20 swap(_Tp& __x, _Tp& __y)
     _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value&& is_nothrow_move_assignable<_Tp>::value) {
   _Tp __t(_VSTD::move(__x));
   __x = _VSTD::move(__y);
@@ -38,7 +38,7 @@
 }
 
 template <class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 typename enable_if<__is_swappable<_Tp>::value>::type
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 typename enable_if<__is_swappable<_Tp>::value>::type
 swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
   for (size_t __i = 0; __i != _Np; ++__i) {
     swap(__a[__i], __b[__i]);
diff --git a/libcxx/include/__utility/transaction.h b/libcxx/include/__utility/transaction.h
--- a/libcxx/include/__utility/transaction.h
+++ b/libcxx/include/__utility/transaction.h
@@ -52,13 +52,13 @@
     __transaction() = delete;
 
     _LIBCPP_HIDE_FROM_ABI
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit __transaction(_Rollback __rollback)
+    _LIBCPP_CONSTEXPR_CXX20 explicit __transaction(_Rollback __rollback)
         : __rollback_(_VSTD::move(__rollback))
         , __completed_(false)
     { }
 
     _LIBCPP_HIDE_FROM_ABI
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __transaction(__transaction&& __other)
+    _LIBCPP_CONSTEXPR_CXX20 __transaction(__transaction&& __other)
         _NOEXCEPT_(is_nothrow_move_constructible<_Rollback>::value)
         : __rollback_(_VSTD::move(__other.__rollback_))
         , __completed_(__other.__completed_)
@@ -71,12 +71,12 @@
     __transaction& operator=(__transaction&&) = delete;
 
     _LIBCPP_HIDE_FROM_ABI
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __complete() _NOEXCEPT {
+    _LIBCPP_CONSTEXPR_CXX20 void __complete() _NOEXCEPT {
         __completed_ = true;
     }
 
     _LIBCPP_HIDE_FROM_ABI
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 ~__transaction() {
+    _LIBCPP_CONSTEXPR_CXX20 ~__transaction() {
         if (!__completed_)
             __rollback_();
     }
diff --git a/libcxx/include/array b/libcxx/include/array
--- a/libcxx/include/array
+++ b/libcxx/include/array
@@ -168,42 +168,42 @@
     _Tp __elems_[_Size];
 
     // No explicit construct/copy/destroy for aggregate type
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void fill(const value_type& __u) {
         _VSTD::fill_n(data(), _Size, __u);
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void swap(array& __a) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
         _VSTD::swap_ranges(data(), data() + _Size, __a.data());
     }
 
     // iterators:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     iterator begin() _NOEXCEPT {return iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     iterator end() _NOEXCEPT {return iterator(data() + _Size);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_iterator end() const _NOEXCEPT {return const_iterator(data() + _Size);}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_iterator cbegin() const _NOEXCEPT {return begin();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_iterator cend() const _NOEXCEPT {return end();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_reverse_iterator crend() const _NOEXCEPT {return rend();}
 
     // capacity:
@@ -215,39 +215,39 @@
     _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return _Size == 0;}
 
     // element access:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reference operator[](size_type __n) _NOEXCEPT {
         _LIBCPP_ASSERT(__n < _Size, "out-of-bounds access in std::array<T, N>");
         return __elems_[__n];
     }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     const_reference operator[](size_type __n) const _NOEXCEPT {
         _LIBCPP_ASSERT(__n < _Size, "out-of-bounds access in std::array<T, N>");
         return __elems_[__n];
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX14 reference at(size_type __n)
+    _LIBCPP_CONSTEXPR_CXX17 reference at(size_type __n)
     {
         if (__n >= _Size)
             __throw_out_of_range("array::at");
         return __elems_[__n];
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference at(size_type __n) const
+    _LIBCPP_CONSTEXPR_CXX14 const_reference at(size_type __n) const
     {
         if (__n >= _Size)
             __throw_out_of_range("array::at");
         return __elems_[__n];
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference front()             _NOEXCEPT {return (*this)[0];}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const _NOEXCEPT {return (*this)[0];}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference back()              _NOEXCEPT {return (*this)[_Size - 1];}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  _NOEXCEPT {return (*this)[_Size - 1];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 reference front()             _NOEXCEPT {return (*this)[0];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 const_reference front() const _NOEXCEPT {return (*this)[0];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17 reference back()              _NOEXCEPT {return (*this)[_Size - 1];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 const_reference back() const  _NOEXCEPT {return (*this)[_Size - 1];}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     value_type* data() _NOEXCEPT {return __elems_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const value_type* data() const _NOEXCEPT {return __elems_;}
 };
 
@@ -274,50 +274,50 @@
     struct  _ArrayInStructT { _Tp __data_[1]; };
     _ALIGNAS_TYPE(_ArrayInStructT) _CharType __elems_[sizeof(_ArrayInStructT)];
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     value_type* data() _NOEXCEPT {return nullptr;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const value_type* data() const _NOEXCEPT {return nullptr;}
 
     // No explicit construct/copy/destroy for aggregate type
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void fill(const value_type&) {
       static_assert(!is_const<_Tp>::value,
                     "cannot fill zero-sized array of type 'const T'");
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void swap(array&) _NOEXCEPT {
       static_assert(!is_const<_Tp>::value,
                     "cannot swap zero-sized array of type 'const T'");
     }
 
     // iterators:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     iterator begin() _NOEXCEPT {return iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     iterator end() _NOEXCEPT {return iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_iterator end() const _NOEXCEPT {return const_iterator(data());}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_iterator cbegin() const _NOEXCEPT {return begin();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_iterator cend() const _NOEXCEPT {return end();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     const_reverse_iterator crend() const _NOEXCEPT {return rend();}
 
     // capacity:
@@ -329,49 +329,49 @@
     _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
 
     // element access:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reference operator[](size_type) _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
       __libcpp_unreachable();
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     const_reference operator[](size_type) const _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
       __libcpp_unreachable();
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reference at(size_type) {
       __throw_out_of_range("array<T, 0>::at");
       __libcpp_unreachable();
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     const_reference at(size_type) const {
       __throw_out_of_range("array<T, 0>::at");
       __libcpp_unreachable();
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reference front() _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
       __libcpp_unreachable();
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     const_reference front() const _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
       __libcpp_unreachable();
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX17
     reference back() _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
       __libcpp_unreachable();
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     const_reference back() const _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
       __libcpp_unreachable();
@@ -389,7 +389,7 @@
 
 template <class _Tp, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_CONSTEXPR_CXX20 bool
 operator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
 {
     return _VSTD::equal(__x.begin(), __x.end(), __y.begin());
@@ -397,7 +397,7 @@
 
 template <class _Tp, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_CONSTEXPR_CXX20 bool
 operator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
 {
     return !(__x == __y);
@@ -405,7 +405,7 @@
 
 template <class _Tp, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_CONSTEXPR_CXX20 bool
 operator<(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
 {
     return _VSTD::lexicographical_compare(__x.begin(), __x.end(),
@@ -414,7 +414,7 @@
 
 template <class _Tp, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_CONSTEXPR_CXX20 bool
 operator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
 {
     return __y < __x;
@@ -422,7 +422,7 @@
 
 template <class _Tp, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_CONSTEXPR_CXX20 bool
 operator<=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
 {
     return !(__y < __x);
@@ -430,14 +430,14 @@
 
 template <class _Tp, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_CONSTEXPR_CXX20 bool
 operator>=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
 {
     return !(__x < __y);
 }
 
 template <class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 __enable_if_t<_Size == 0 || __is_swappable<_Tp>::value, void>
 swap(array<_Tp, _Size>& __x, array<_Tp, _Size>& __y)
                                   _NOEXCEPT_(noexcept(__x.swap(__y)))
@@ -457,7 +457,7 @@
 };
 
 template <size_t _Ip, class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp&
 get(array<_Tp, _Size>& __a) _NOEXCEPT
 {
@@ -466,7 +466,7 @@
 }
 
 template <size_t _Ip, class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const _Tp&
 get(const array<_Tp, _Size>& __a) _NOEXCEPT
 {
@@ -475,7 +475,7 @@
 }
 
 template <size_t _Ip, class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp&&
 get(array<_Tp, _Size>&& __a) _NOEXCEPT
 {
@@ -484,7 +484,7 @@
 }
 
 template <size_t _Ip, class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const _Tp&&
 get(const array<_Tp, _Size>&& __a) _NOEXCEPT
 {
diff --git a/libcxx/include/atomic b/libcxx/include/atomic
--- a/libcxx/include/atomic
+++ b/libcxx/include/atomic
@@ -1673,7 +1673,7 @@
 {
     typedef __atomic_base<_Tp, false> __base;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     __atomic_base() _NOEXCEPT = default;
 
     _LIBCPP_INLINE_VISIBILITY
diff --git a/libcxx/include/bit b/libcxx/include/bit
--- a/libcxx/include/bit
+++ b/libcxx/include/bit
@@ -89,7 +89,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template<class _Tp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 _Tp __rotr(_Tp __t, unsigned int __cnt) _NOEXCEPT
 {
     static_assert(__libcpp_is_unsigned_integer<_Tp>::value, "__rotr requires an unsigned integer type");
@@ -100,7 +100,7 @@
 }
 
 template<class _Tp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 int __countl_zero(_Tp __t) _NOEXCEPT
 {
     static_assert(__libcpp_is_unsigned_integer<_Tp>::value, "__countl_zero requires an unsigned integer type");
diff --git a/libcxx/include/complex b/libcxx/include/complex
--- a/libcxx/include/complex
+++ b/libcxx/include/complex
@@ -263,15 +263,15 @@
     value_type __re_;
     value_type __im_;
 public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     complex(const value_type& __re = value_type(), const value_type& __im = value_type())
         : __re_(__re), __im_(__im) {}
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     complex(const complex<_Xp>& __c)
         : __re_(__c.real()), __im_(__c.imag()) {}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 value_type real() const {return __re_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 value_type imag() const {return __im_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 value_type real() const {return __re_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 value_type imag() const {return __im_;}
 
     _LIBCPP_INLINE_VISIBILITY void real(value_type __re) {__re_ = __re;}
     _LIBCPP_INLINE_VISIBILITY void imag(value_type __im) {__im_ = __im;}
@@ -740,7 +740,7 @@
 }
 
 template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
 {
@@ -748,7 +748,7 @@
 }
 
 template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator==(const complex<_Tp>& __x, const _Tp& __y)
 {
@@ -756,7 +756,7 @@
 }
 
 template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator==(const _Tp& __x, const complex<_Tp>& __y)
 {
@@ -764,7 +764,7 @@
 }
 
 template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
 {
@@ -772,7 +772,7 @@
 }
 
 template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator!=(const complex<_Tp>& __x, const _Tp& __y)
 {
@@ -780,7 +780,7 @@
 }
 
 template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator!=(const _Tp& __x, const complex<_Tp>& __y)
 {
@@ -813,7 +813,7 @@
 // real
 
 template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp
 real(const complex<_Tp>& __c)
 {
@@ -821,7 +821,7 @@
 }
 
 template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename __libcpp_complex_overload_traits<_Tp>::_ValueType
 real(_Tp __re)
 {
@@ -831,7 +831,7 @@
 // imag
 
 template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 _Tp
 imag(const complex<_Tp>& __c)
 {
@@ -839,7 +839,7 @@
 }
 
 template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename __libcpp_complex_overload_traits<_Tp>::_ValueType
 imag(_Tp)
 {
diff --git a/libcxx/include/experimental/coroutine b/libcxx/include/experimental/coroutine
--- a/libcxx/include/experimental/coroutine
+++ b/libcxx/include/experimental/coroutine
@@ -269,9 +269,9 @@
   _LIBCPP_CONSTEXPR explicit operator bool() const _NOEXCEPT { return true; }
   _LIBCPP_CONSTEXPR bool done() const _NOEXCEPT { return false; }
 
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 void operator()() const _NOEXCEPT {}
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 void resume() const _NOEXCEPT {}
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 void destroy() const _NOEXCEPT {}
+  _LIBCPP_CONSTEXPR_CXX20 void operator()() const _NOEXCEPT {}
+  _LIBCPP_CONSTEXPR_CXX20 void resume() const _NOEXCEPT {}
+  _LIBCPP_CONSTEXPR_CXX20 void destroy() const _NOEXCEPT {}
 
 private:
   _LIBCPP_INLINE_VISIBILITY
diff --git a/libcxx/include/initializer_list b/libcxx/include/initializer_list
--- a/libcxx/include/initializer_list
+++ b/libcxx/include/initializer_list
@@ -62,7 +62,7 @@
     size_t    __size_;
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     initializer_list(const _Ep* __b, size_t __s) _NOEXCEPT
         : __begin_(__b),
           __size_(__s)
@@ -77,25 +77,25 @@
     typedef const _Ep* const_iterator;
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     initializer_list() _NOEXCEPT : __begin_(nullptr), __size_(0) {}
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     size_t    size()  const _NOEXCEPT {return __size_;}
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     const _Ep* begin() const _NOEXCEPT {return __begin_;}
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     const _Ep* end()   const _NOEXCEPT {return __begin_ + __size_;}
 };
 
 template<class _Ep>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_CONSTEXPR_CXX14
 const _Ep*
 begin(initializer_list<_Ep> __il) _NOEXCEPT
 {
@@ -104,7 +104,7 @@
 
 template<class _Ep>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_CONSTEXPR_CXX14
 const _Ep*
 end(initializer_list<_Ep> __il) _NOEXCEPT
 {
diff --git a/libcxx/include/memory b/libcxx/include/memory
--- a/libcxx/include/memory
+++ b/libcxx/include/memory
@@ -964,7 +964,7 @@
 #endif
     _Alloc &__a;
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp *__addr() {
+    _LIBCPP_CONSTEXPR_CXX20 _Tp *__addr() {
 #ifdef _LIBCPP_CXX03_LANG
         return reinterpret_cast<_Tp*>(std::addressof(__v));
 #else
@@ -972,15 +972,15 @@
 #endif
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp &   get() { return *__addr(); }
+    _LIBCPP_CONSTEXPR_CXX20 _Tp &   get() { return *__addr(); }
 
     template<class... _Args>
     _LIBCPP_NO_CFI
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
+    _LIBCPP_CONSTEXPR_CXX20 __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
       _Traits::construct(__a, __addr(), std::forward<_Args>(__args)...);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 ~__temp_value() { _Traits::destroy(__a, __addr()); }
+    _LIBCPP_CONSTEXPR_CXX20 ~__temp_value() { _Traits::destroy(__a, __addr()); }
 };
 
 template<typename _Alloc, typename = void, typename = void>
diff --git a/libcxx/include/optional b/libcxx/include/optional
--- a/libcxx/include/optional
+++ b/libcxx/include/optional
@@ -255,7 +255,7 @@
     bool __engaged_;
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 ~__optional_destruct_base()
+    _LIBCPP_CONSTEXPR_CXX20 ~__optional_destruct_base()
     {
         if (__engaged_)
             __val_.~value_type();
@@ -280,7 +280,7 @@
 #endif
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void reset() noexcept
+    _LIBCPP_CONSTEXPR_CXX20 void reset() noexcept
     {
         if (__engaged_)
         {
@@ -322,7 +322,7 @@
 #endif
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void reset() noexcept
+    _LIBCPP_CONSTEXPR_CXX20 void reset() noexcept
     {
         if (__engaged_)
         {
@@ -367,7 +367,7 @@
 
     template <class... _Args>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct(_Args&&... __args)
+    _LIBCPP_CONSTEXPR_CXX20 void __construct(_Args&&... __args)
     {
         _LIBCPP_ASSERT(!has_value(), "__construct called for engaged __optional_storage");
 #if _LIBCPP_STD_VER > 17
@@ -380,7 +380,7 @@
 
     template <class _That>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct_from(_That&& __opt)
+    _LIBCPP_CONSTEXPR_CXX20 void __construct_from(_That&& __opt)
     {
         if (__opt.has_value())
             __construct(_VSTD::forward<_That>(__opt).__get());
@@ -388,7 +388,7 @@
 
     template <class _That>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __assign_from(_That&& __opt)
+    _LIBCPP_CONSTEXPR_CXX20 void __assign_from(_That&& __opt)
     {
         if (this->__engaged_ == __opt.has_value())
         {
@@ -446,7 +446,7 @@
     }
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void reset() noexcept { __value_ = nullptr; }
+    _LIBCPP_CONSTEXPR_CXX20 void reset() noexcept { __value_ = nullptr; }
 
     _LIBCPP_INLINE_VISIBILITY
     constexpr bool has_value() const noexcept
@@ -462,7 +462,7 @@
 
     template <class _UArg>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct(_UArg&& __val)
+    _LIBCPP_CONSTEXPR_CXX20 void __construct(_UArg&& __val)
     {
         _LIBCPP_ASSERT(!has_value(), "__construct called for engaged __optional_storage");
         static_assert(__can_bind_reference<_UArg>(),
@@ -473,7 +473,7 @@
 
     template <class _That>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct_from(_That&& __opt)
+    _LIBCPP_CONSTEXPR_CXX20 void __construct_from(_That&& __opt)
     {
         if (__opt.has_value())
             __construct(_VSTD::forward<_That>(__opt).__get());
@@ -481,7 +481,7 @@
 
     template <class _That>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __assign_from(_That&& __opt)
+    _LIBCPP_CONSTEXPR_CXX20 void __assign_from(_That&& __opt)
     {
         if (has_value() == __opt.has_value())
         {
@@ -513,7 +513,7 @@
     __optional_copy_base() = default;
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __optional_copy_base(const __optional_copy_base& __opt)
+    _LIBCPP_CONSTEXPR_CXX20 __optional_copy_base(const __optional_copy_base& __opt)
     {
         this->__construct_from(__opt);
     }
@@ -544,7 +544,7 @@
     __optional_move_base(const __optional_move_base&) = default;
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __optional_move_base(__optional_move_base&& __opt)
+    _LIBCPP_CONSTEXPR_CXX20 __optional_move_base(__optional_move_base&& __opt)
         noexcept(is_nothrow_move_constructible_v<value_type>)
     {
         this->__construct_from(_VSTD::move(__opt));
@@ -578,7 +578,7 @@
     __optional_copy_assign_base(__optional_copy_assign_base&&) = default;
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __optional_copy_assign_base& operator=(const __optional_copy_assign_base& __opt)
+    _LIBCPP_CONSTEXPR_CXX20 __optional_copy_assign_base& operator=(const __optional_copy_assign_base& __opt)
     {
         this->__assign_from(__opt);
         return *this;
@@ -613,7 +613,7 @@
     __optional_move_assign_base& operator=(const __optional_move_assign_base&) = default;
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 __optional_move_assign_base& operator=(__optional_move_assign_base&& __opt)
+    _LIBCPP_CONSTEXPR_CXX20 __optional_move_assign_base& operator=(__optional_move_assign_base&& __opt)
         noexcept(is_nothrow_move_assignable_v<value_type> &&
                  is_nothrow_move_constructible_v<value_type>)
     {
@@ -787,7 +787,7 @@
         _CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_implicit<_Up>()
     , int> = 0>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 optional(const optional<_Up>& __v)
+    _LIBCPP_CONSTEXPR_CXX20 optional(const optional<_Up>& __v)
     {
         this->__construct_from(__v);
     }
@@ -795,7 +795,7 @@
         _CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_explicit<_Up>()
     , int> = 0>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit optional(const optional<_Up>& __v)
+    _LIBCPP_CONSTEXPR_CXX20 explicit optional(const optional<_Up>& __v)
     {
         this->__construct_from(__v);
     }
@@ -805,7 +805,7 @@
         _CheckOptionalLikeCtor<_Up, _Up &&>::template __enable_implicit<_Up>()
     , int> = 0>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 optional(optional<_Up>&& __v)
+    _LIBCPP_CONSTEXPR_CXX20 optional(optional<_Up>&& __v)
     {
         this->__construct_from(_VSTD::move(__v));
     }
@@ -813,7 +813,7 @@
         _CheckOptionalLikeCtor<_Up, _Up &&>::template __enable_explicit<_Up>()
     , int> = 0>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit optional(optional<_Up>&& __v)
+    _LIBCPP_CONSTEXPR_CXX20 explicit optional(optional<_Up>&& __v)
     {
         this->__construct_from(_VSTD::move(__v));
     }
@@ -827,7 +827,7 @@
 #endif
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 optional& operator=(nullopt_t) noexcept
+    _LIBCPP_CONSTEXPR_CXX20 optional& operator=(nullopt_t) noexcept
     {
         reset();
         return *this;
@@ -850,7 +850,7 @@
                       >::value>
              >
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 optional&
+    _LIBCPP_CONSTEXPR_CXX20 optional&
     operator=(_Up&& __v)
     {
         if (this->has_value())
@@ -865,7 +865,7 @@
         _CheckOptionalLikeAssign<_Up, _Up const&>::template __enable_assign<_Up>()
     , int> = 0>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 optional&
+    _LIBCPP_CONSTEXPR_CXX20 optional&
     operator=(const optional<_Up>& __v)
     {
         this->__assign_from(__v);
@@ -877,7 +877,7 @@
         _CheckOptionalLikeCtor<_Up, _Up &&>::template __enable_assign<_Up>()
     , int> = 0>
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 optional&
+    _LIBCPP_CONSTEXPR_CXX20 optional&
     operator=(optional<_Up>&& __v)
     {
         this->__assign_from(_VSTD::move(__v));
@@ -891,7 +891,7 @@
                       >
              >
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp &
+    _LIBCPP_CONSTEXPR_CXX20 _Tp &
     emplace(_Args&&... __args)
     {
         reset();
@@ -906,7 +906,7 @@
                       >
              >
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp &
+    _LIBCPP_CONSTEXPR_CXX20 _Tp &
     emplace(initializer_list<_Up> __il, _Args&&... __args)
     {
         reset();
@@ -915,7 +915,7 @@
     }
 
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void swap(optional& __opt)
+    _LIBCPP_CONSTEXPR_CXX20 void swap(optional& __opt)
         noexcept(is_nothrow_move_constructible_v<value_type> &&
                  is_nothrow_swappable_v<value_type>)
     {
@@ -1535,7 +1535,7 @@
 
 
 template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 enable_if_t<
     is_move_constructible_v<_Tp> && is_swappable_v<_Tp>,
     void
diff --git a/libcxx/include/string b/libcxx/include/string
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -593,27 +593,27 @@
 
 template<class _CharT, class _Traits, class _Allocator>
 basic_string<_CharT, _Traits, _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 operator+(const basic_string<_CharT, _Traits, _Allocator>& __x,
           const basic_string<_CharT, _Traits, _Allocator>& __y);
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(const _CharT* __x, const basic_string<_CharT,_Traits,_Allocator>& __y);
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(_CharT __x, const basic_string<_CharT,_Traits,_Allocator>& __y);
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(const basic_string<_CharT, _Traits, _Allocator>& __x, const _CharT* __y);
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(const basic_string<_CharT, _Traits, _Allocator>& __x, _CharT __y);
 
@@ -787,7 +787,7 @@
     // Construct a string with the given allocator and enough storage to hold `__size` characters, but
     // don't initialize the characters. The contents of the string, including the null terminator, must be
     // initialized separately.
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     explicit basic_string(__uninitialized_size_tag, size_type __size, const allocator_type& __a)
             : __r_(__default_init_tag(), __a) {
         if (__size > max_size())
@@ -810,21 +810,21 @@
     _LIBCPP_TEMPLATE_DATA_VIS
     static const size_type npos = -1;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string()
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 basic_string()
         _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit basic_string(const allocator_type& __a)
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 explicit basic_string(const allocator_type& __a)
 #if _LIBCPP_STD_VER <= 14
         _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value);
 #else
         _NOEXCEPT;
 #endif
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string(const basic_string& __str);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string(const basic_string& __str, const allocator_type& __a);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string(const basic_string& __str);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string(const basic_string& __str, const allocator_type& __a);
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string(basic_string&& __str)
 #if _LIBCPP_STD_VER <= 14
         _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
@@ -832,12 +832,12 @@
         _NOEXCEPT;
 #endif
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string(basic_string&& __str, const allocator_type& __a);
 #endif // _LIBCPP_CXX03_LANG
 
     template <class = __enable_if_t<__is_allocator<_Allocator>::value, nullptr_t> >
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string(const _CharT* __s) : __r_(__default_init_tag(), __default_init_tag()) {
       _LIBCPP_ASSERT(__s != nullptr, "basic_string(const char*) detected nullptr");
       __init(__s, traits_type::length(__s));
@@ -845,137 +845,137 @@
     }
 
     template <class = __enable_if_t<__is_allocator<_Allocator>::value, nullptr_t> >
-        _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
         basic_string(const _CharT* __s, const _Allocator& __a);
 
 #if _LIBCPP_STD_VER > 20
     basic_string(nullptr_t) = delete;
 #endif
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string(const _CharT* __s, size_type __n);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string(const _CharT* __s, size_type __n, const _Allocator& __a);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string(size_type __n, _CharT __c);
 
     template <class = __enable_if_t<__is_allocator<_Allocator>::value, nullptr_t> >
-        _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
         basic_string(size_type __n, _CharT __c, const _Allocator& __a);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     basic_string(const basic_string& __str, size_type __pos, size_type __n,
                  const _Allocator& __a = _Allocator());
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string(const basic_string& __str, size_type __pos,
                  const _Allocator& __a = _Allocator());
 
     template<class _Tp, class = __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value && !__is_same_uncvref<_Tp, basic_string>::value> >
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
         basic_string(const _Tp& __t, size_type __pos, size_type __n,
                      const allocator_type& __a = allocator_type());
 
     template<class _Tp, class = __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
                                           !__is_same_uncvref<_Tp, basic_string>::value> >
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
         explicit basic_string(const _Tp& __t);
 
     template<class _Tp, class = __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value && !__is_same_uncvref<_Tp, basic_string>::value> >
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
         explicit basic_string(const _Tp& __t, const allocator_type& __a);
 
     template<class _InputIterator, class = __enable_if_t<__is_cpp17_input_iterator<_InputIterator>::value> >
-        _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
         basic_string(_InputIterator __first, _InputIterator __last);
     template<class _InputIterator, class = __enable_if_t<__is_cpp17_input_iterator<_InputIterator>::value> >
-        _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
         basic_string(_InputIterator __first, _InputIterator __last, const allocator_type& __a);
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string(initializer_list<_CharT> __il);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string(initializer_list<_CharT> __il, const _Allocator& __a);
 #endif // _LIBCPP_CXX03_LANG
 
-    inline _LIBCPP_CONSTEXPR_AFTER_CXX17 ~basic_string();
+    inline _LIBCPP_CONSTEXPR_CXX20 ~basic_string();
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     operator __self_view() const _NOEXCEPT { return __self_view(data(), size()); }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& operator=(const basic_string& __str);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& operator=(const basic_string& __str);
 
     template <class _Tp, class = __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
                                                !__is_same_uncvref<_Tp, basic_string>::value> >
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& operator=(const _Tp& __t) {
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& operator=(const _Tp& __t) {
       __self_view __sv = __t;
       return assign(__sv);
     }
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& operator=(basic_string&& __str)
         _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
-     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& operator=(initializer_list<value_type> __il) {return assign(__il.begin(), __il.size());}
 #endif
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& operator=(const value_type* __s) {return assign(__s);}
 #if _LIBCPP_STD_VER > 20
     basic_string& operator=(nullptr_t) = delete;
 #endif
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& operator=(value_type __c);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& operator=(value_type __c);
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     iterator begin() _NOEXCEPT
         {return iterator(this, __get_pointer());}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_iterator begin() const _NOEXCEPT
         {return const_iterator(this, __get_pointer());}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     iterator end() _NOEXCEPT
         {return iterator(this, __get_pointer() + size());}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_iterator end() const _NOEXCEPT
         {return const_iterator(this, __get_pointer() + size());}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     reverse_iterator rbegin() _NOEXCEPT
         {return reverse_iterator(end());}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_reverse_iterator rbegin() const _NOEXCEPT
         {return const_reverse_iterator(end());}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     reverse_iterator rend() _NOEXCEPT
         {return reverse_iterator(begin());}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_reverse_iterator rend() const _NOEXCEPT
         {return const_reverse_iterator(begin());}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_iterator cbegin() const _NOEXCEPT
         {return begin();}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_iterator cend() const _NOEXCEPT
         {return end();}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_reverse_iterator crbegin() const _NOEXCEPT
         {return rbegin();}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_reverse_iterator crend() const _NOEXCEPT
         {return rend();}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 size_type size() const _NOEXCEPT
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 size_type size() const _NOEXCEPT
         {return __is_long() ? __get_long_size() : __get_short_size();}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 size_type length() const _NOEXCEPT {return size();}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 size_type max_size() const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 size_type capacity() const _NOEXCEPT {
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 size_type length() const _NOEXCEPT {return size();}
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 size_type max_size() const _NOEXCEPT;
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 size_type capacity() const _NOEXCEPT {
         return (__is_long() ? __get_long_cap() : static_cast<size_type>(__min_cap)) - 1;
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void resize(size_type __n, value_type __c);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void resize(size_type __n) { resize(__n, value_type()); }
+    _LIBCPP_CONSTEXPR_CXX20 void resize(size_type __n, value_type __c);
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void resize(size_type __n) { resize(__n, value_type()); }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void reserve(size_type __requested_capacity);
+    _LIBCPP_CONSTEXPR_CXX20 void reserve(size_type __requested_capacity);
 
 #if _LIBCPP_STD_VER > 20
     template <class _Op>
@@ -986,28 +986,28 @@
     }
 #endif
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void __resize_default_init(size_type __n);
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void __resize_default_init(size_type __n);
 
     _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_HIDE_FROM_ABI void reserve() _NOEXCEPT { shrink_to_fit(); }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void shrink_to_fit() _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void clear() _NOEXCEPT;
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void shrink_to_fit() _NOEXCEPT;
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void clear() _NOEXCEPT;
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     bool empty() const _NOEXCEPT {return size() == 0;}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_reference operator[](size_type __pos) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 reference operator[](size_type __pos) _NOEXCEPT;
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 reference operator[](size_type __pos) _NOEXCEPT;
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 const_reference at(size_type __n) const;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 reference       at(size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 const_reference at(size_type __n) const;
+    _LIBCPP_CONSTEXPR_CXX20 reference       at(size_type __n);
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& operator+=(const basic_string& __str) {
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 basic_string& operator+=(const basic_string& __str) {
         return append(__str);
     }
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value
@@ -1018,35 +1018,35 @@
         __self_view __sv = __t; return append(__sv);
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& operator+=(const value_type* __s) {
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 basic_string& operator+=(const value_type* __s) {
         return append(__s);
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& operator+=(value_type __c) {
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 basic_string& operator+=(value_type __c) {
         push_back(__c);
         return *this;
     }
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& operator+=(initializer_list<value_type> __il) { return append(__il); }
 #endif // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& append(const basic_string& __str);
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t<
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value
             && !__is_same_uncvref<_Tp, basic_string>::value,
             basic_string&
         >
                   append(const _Tp& __t) { __self_view __sv = __t; return append(__sv.data(), __sv.size()); }
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& append(const basic_string& __str, size_type __pos, size_type __n=npos);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& append(const basic_string& __str, size_type __pos, size_type __n=npos);
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value
@@ -1054,11 +1054,11 @@
             basic_string&
         >
                   append(const _Tp& __t, size_type __pos, size_type __n=npos);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& append(const value_type* __s, size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& append(const value_type* __s);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& append(size_type __n, value_type __c);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& append(const value_type* __s, size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& append(const value_type* __s);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& append(size_type __n, value_type __c);
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __append_default_init(size_type __n);
 
     template<class _InputIterator>
@@ -1068,7 +1068,7 @@
             __is_exactly_cpp17_input_iterator<_InputIterator>::value,
             basic_string&
         >
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     append(_InputIterator __first, _InputIterator __last) {
       const basic_string __temp(__first, __last, __alloc());
       append(__temp.data(), __temp.size());
@@ -1081,40 +1081,40 @@
             __is_cpp17_forward_iterator<_ForwardIterator>::value,
             basic_string&
         >
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     append(_ForwardIterator __first, _ForwardIterator __last);
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& append(initializer_list<value_type> __il) {return append(__il.begin(), __il.size());}
 #endif // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void push_back(value_type __c);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void pop_back();
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 reference       front() _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 const_reference front() const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 reference       back() _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 const_reference back() const _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 void push_back(value_type __c);
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void pop_back();
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 reference       front() _NOEXCEPT;
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 const_reference front() const _NOEXCEPT;
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 reference       back() _NOEXCEPT;
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 const_reference back() const _NOEXCEPT;
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             basic_string&
         >
                  assign(const _Tp & __t) { __self_view __sv = __t; return assign(__sv.data(), __sv.size()); }
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& assign(const basic_string& __str) { return *this = __str; }
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& assign(basic_string&& __str)
         _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
         {*this = std::move(__str); return *this;}
 #endif
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& assign(const basic_string& __str, size_type __pos, size_type __n=npos);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& assign(const basic_string& __str, size_type __pos, size_type __n=npos);
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value
@@ -1122,11 +1122,11 @@
             basic_string&
         >
                   assign(const _Tp & __t, size_type __pos, size_type __n=npos);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& assign(const value_type* __s, size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& assign(const value_type* __s);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& assign(size_type __n, value_type __c);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& assign(const value_type* __s, size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& assign(const value_type* __s);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& assign(size_type __n, value_type __c);
     template<class _InputIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __is_exactly_cpp17_input_iterator<_InputIterator>::value,
@@ -1134,7 +1134,7 @@
         >
         assign(_InputIterator __first, _InputIterator __last);
     template<class _ForwardIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -1142,15 +1142,15 @@
         >
         assign(_ForwardIterator __first, _ForwardIterator __last);
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& assign(initializer_list<value_type> __il) {return assign(__il.begin(), __il.size());}
 #endif // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& insert(size_type __pos1, const basic_string& __str);
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -1160,23 +1160,23 @@
     { __self_view __sv = __t; return insert(__pos1, __sv.data(), __sv.size()); }
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value && !__is_same_uncvref<_Tp, basic_string>::value,
             basic_string&
         >
                   insert(size_type __pos1, const _Tp& __t, size_type __pos2, size_type __n=npos);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     basic_string& insert(size_type __pos1, const basic_string& __str, size_type __pos2, size_type __n=npos);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& insert(size_type __pos, const value_type* __s, size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& insert(size_type __pos, const value_type* __s);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& insert(size_type __pos, size_type __n, value_type __c);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator      insert(const_iterator __pos, value_type __c);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& insert(size_type __pos, const value_type* __s, size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& insert(size_type __pos, const value_type* __s);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& insert(size_type __pos, size_type __n, value_type __c);
+    _LIBCPP_CONSTEXPR_CXX20 iterator      insert(const_iterator __pos, value_type __c);
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     iterator      insert(const_iterator __pos, size_type __n, value_type __c);
     template<class _InputIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __is_exactly_cpp17_input_iterator<_InputIterator>::value,
@@ -1184,7 +1184,7 @@
         >
         insert(const_iterator __pos, _InputIterator __first, _InputIterator __last);
     template<class _ForwardIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -1192,47 +1192,47 @@
         >
         insert(const_iterator __pos, _ForwardIterator __first, _ForwardIterator __last);
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     iterator insert(const_iterator __pos, initializer_list<value_type> __il)
                     {return insert(__pos, __il.begin(), __il.end());}
 #endif // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& erase(size_type __pos = 0, size_type __n = npos);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& erase(size_type __pos = 0, size_type __n = npos);
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     iterator      erase(const_iterator __pos);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     iterator      erase(const_iterator __first, const_iterator __last);
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& replace(size_type __pos1, size_type __n1, const basic_string& __str);
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             basic_string&
         >
                   replace(size_type __pos1, size_type __n1, const _Tp& __t) { __self_view __sv = __t; return replace(__pos1, __n1, __sv.data(), __sv.size()); }
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     basic_string& replace(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2=npos);
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value  && !__is_same_uncvref<_Tp, basic_string>::value,
             basic_string&
         >
                   replace(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2=npos);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     basic_string& replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& replace(size_type __pos, size_type __n1, const value_type* __s);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& replace(size_type __pos, size_type __n1, size_type __n2, value_type __c);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& replace(size_type __pos, size_type __n1, const value_type* __s);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& replace(size_type __pos, size_type __n1, size_type __n2, value_type __c);
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& replace(const_iterator __i1, const_iterator __i2, const basic_string& __str);
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -1240,14 +1240,14 @@
         >
                   replace(const_iterator __i1, const_iterator __i2, const _Tp& __t) { __self_view __sv = __t; return replace(__i1 - begin(), __i2 - __i1, __sv); }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& replace(const_iterator __i1, const_iterator __i2, const value_type* __s);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c);
     template<class _InputIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __is_cpp17_input_iterator<_InputIterator>::value,
@@ -1255,16 +1255,16 @@
         >
         replace(const_iterator __i1, const_iterator __i2, _InputIterator __j1, _InputIterator __j2);
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& replace(const_iterator __i1, const_iterator __i2, initializer_list<value_type> __il)
         {return replace(__i1, __i2, __il.begin(), __il.end());}
 #endif // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 size_type copy(value_type* __s, size_type __n, size_type __pos = 0) const;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20 size_type copy(value_type* __s, size_type __n, size_type __pos = 0) const;
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string substr(size_type __pos = 0, size_type __n = npos) const;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void swap(basic_string& __str)
 #if _LIBCPP_STD_VER >= 14
         _NOEXCEPT;
@@ -1273,129 +1273,129 @@
                     __is_nothrow_swappable<allocator_type>::value);
 #endif
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const value_type* c_str() const _NOEXCEPT {return data();}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const value_type* data() const _NOEXCEPT  {return std::__to_address(__get_pointer());}
 #if _LIBCPP_STD_VER > 14 || defined(_LIBCPP_BUILDING_LIBRARY)
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     value_type* data()             _NOEXCEPT  {return std::__to_address(__get_pointer());}
 #endif
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     allocator_type get_allocator() const _NOEXCEPT {return __alloc();}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT;
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             size_type
         >
               find(const _Tp& __t, size_type __pos = 0) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     size_type find(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find(const value_type* __s, size_type __pos = 0) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 size_type find(value_type __c, size_type __pos = 0) const _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 size_type find(value_type __c, size_type __pos = 0) const _NOEXCEPT;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type rfind(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT;
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             size_type
         >
               rfind(const _Tp& __t, size_type __pos = npos) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     size_type rfind(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type rfind(const value_type* __s, size_type __pos = npos) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 size_type rfind(value_type __c, size_type __pos = npos) const _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 size_type rfind(value_type __c, size_type __pos = npos) const _NOEXCEPT;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_first_of(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT;
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             size_type
         >
               find_first_of(const _Tp& __t, size_type __pos = 0) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     size_type find_first_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_first_of(const value_type* __s, size_type __pos = 0) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_first_of(value_type __c, size_type __pos = 0) const _NOEXCEPT;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_last_of(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT;
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             size_type
         >
               find_last_of(const _Tp& __t, size_type __pos = npos) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     size_type find_last_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_last_of(const value_type* __s, size_type __pos = npos) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_last_of(value_type __c, size_type __pos = npos) const _NOEXCEPT;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_first_not_of(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT;
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             size_type
         >
               find_first_not_of(const _Tp &__t, size_type __pos = 0) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     size_type find_first_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_first_not_of(const value_type* __s, size_type __pos = 0) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_first_not_of(value_type __c, size_type __pos = 0) const _NOEXCEPT;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_last_not_of(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT;
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             size_type
         >
               find_last_not_of(const _Tp& __t, size_type __pos = npos) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     size_type find_last_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_last_not_of(const value_type* __s, size_type __pos = npos) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type find_last_not_of(value_type __c, size_type __pos = npos) const _NOEXCEPT;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     int compare(const basic_string& __str) const _NOEXCEPT;
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -1404,7 +1404,7 @@
         compare(const _Tp &__t) const _NOEXCEPT;
 
     template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -1412,23 +1412,23 @@
         >
          compare(size_type __pos1, size_type __n1, const _Tp& __t) const;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     int compare(size_type __pos1, size_type __n1, const basic_string& __str) const;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     int compare(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2,
                 size_type __n2 = npos) const;
 
     template <class _Tp>
-    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
         __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value  && !__is_same_uncvref<_Tp, basic_string>::value,
             int
         >
         compare(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2=npos) const;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 int compare(const value_type* __s) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 int compare(size_type __pos1, size_type __n1, const value_type* __s) const;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20 int compare(const value_type* __s) const _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 int compare(size_type __pos1, size_type __n1, const value_type* __s) const;
+    _LIBCPP_CONSTEXPR_CXX20
     int compare(size_type __pos1, size_type __n1, const value_type* __s, size_type __n2) const;
 
 #if _LIBCPP_STD_VER > 17
@@ -1471,9 +1471,9 @@
     { return __self_view(data(), size()).contains(__s); }
 #endif
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 bool __invariants() const;
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 bool __invariants() const;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void __clear_and_shrink() _NOEXCEPT;
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void __clear_and_shrink() _NOEXCEPT;
 
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
 
@@ -1486,20 +1486,20 @@
 
 private:
     template<class _Alloc>
-    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     bool friend operator==(const basic_string<char, char_traits<char>, _Alloc>& __lhs,
                            const basic_string<char, char_traits<char>, _Alloc>& __rhs) _NOEXCEPT;
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void __shrink_or_extend(size_type __target_capacity);
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void __shrink_or_extend(size_type __target_capacity);
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     bool __is_long() const _NOEXCEPT {
         if (__libcpp_is_constant_evaluated())
             return true;
         return __r_.first().__s.__is_long_;
     }
 
-    static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void __begin_lifetime(pointer __begin, size_type __n) {
+    static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void __begin_lifetime(pointer __begin, size_type __n) {
 #if _LIBCPP_STD_VER > 17
         if (__libcpp_is_constant_evaluated()) {
             for (size_type __i = 0; __i != __n; ++__i)
@@ -1511,7 +1511,7 @@
 #endif // _LIBCPP_STD_VER > 17
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void __default_init() {
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void __default_init() {
         __zero();
         if (__libcpp_is_constant_evaluated()) {
             size_type __sz = __recommend(0) + 1;
@@ -1523,7 +1523,7 @@
         }
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void __deallocate_constexpr() {
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void __deallocate_constexpr() {
         if (__libcpp_is_constant_evaluated() && __get_pointer() != nullptr)
             __alloc_traits::deallocate(__alloc(), __get_pointer(), __get_long_cap());
     }
@@ -1534,7 +1534,7 @@
     }
 
     template <class _ForwardIterator>
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
     iterator __insert_from_safe_copy(size_type __n, size_type __ip, _ForwardIterator __first, _ForwardIterator __last) {
         size_type __sz = size();
         size_type __cap = capacity();
@@ -1560,76 +1560,76 @@
         return begin() + __ip;
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 allocator_type& __alloc() _NOEXCEPT { return __r_.second(); }
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14 allocator_type& __alloc() _NOEXCEPT { return __r_.second(); }
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR const allocator_type& __alloc() const _NOEXCEPT { return __r_.second(); }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __set_short_size(size_type __s) _NOEXCEPT {
         _LIBCPP_ASSERT(__s < __min_cap, "__s should never be greater than or equal to the short string capacity");
         __r_.first().__s.__size_ = __s;
         __r_.first().__s.__is_long_ = false;
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type __get_short_size() const _NOEXCEPT {
         _LIBCPP_ASSERT(!__r_.first().__s.__is_long_, "String has to be short when trying to get the short size");
         return __r_.first().__s.__size_;
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __set_long_size(size_type __s) _NOEXCEPT
         {__r_.first().__l.__size_ = __s;}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type __get_long_size() const _NOEXCEPT
         {return __r_.first().__l.__size_;}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __set_size(size_type __s) _NOEXCEPT
         {if (__is_long()) __set_long_size(__s); else __set_short_size(__s);}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __set_long_cap(size_type __s) _NOEXCEPT {
         __r_.first().__l.__cap_ = __s / __endian_factor;
         __r_.first().__l.__is_long_ = true;
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type __get_long_cap() const _NOEXCEPT {
         return __r_.first().__l.__cap_ * __endian_factor;
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __set_long_pointer(pointer __p) _NOEXCEPT
         {__r_.first().__l.__data_ = __p;}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     pointer __get_long_pointer() _NOEXCEPT
         {return __r_.first().__l.__data_;}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_pointer __get_long_pointer() const _NOEXCEPT
         {return __r_.first().__l.__data_;}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     pointer __get_short_pointer() _NOEXCEPT
         {return pointer_traits<pointer>::pointer_to(__r_.first().__s.__data_[0]);}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_pointer __get_short_pointer() const _NOEXCEPT
         {return pointer_traits<const_pointer>::pointer_to(__r_.first().__s.__data_[0]);}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     pointer __get_pointer() _NOEXCEPT
         {return __is_long() ? __get_long_pointer() : __get_short_pointer();}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     const_pointer __get_pointer() const _NOEXCEPT
         {return __is_long() ? __get_long_pointer() : __get_short_pointer();}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __zero() _NOEXCEPT {
         __r_.first() = __rep();
     }
 
     template <size_type __a> static
-        _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
         size_type __align_it(size_type __s) _NOEXCEPT
             {return (__s + (__a-1)) & ~(__a-1);}
     enum {__alignment = 16};
-    static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     size_type __recommend(size_type __s) _NOEXCEPT
     {
         if (__s < __min_cap) {
@@ -1644,11 +1644,11 @@
         return __guess;
     }
 
-    inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_CONSTEXPR_CXX20
     void __init(const value_type* __s, size_type __sz, size_type __reserve);
-    inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_CONSTEXPR_CXX20
     void __init(const value_type* __s, size_type __sz);
-    inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_CONSTEXPR_CXX20
     void __init(size_type __n, value_type __c);
 
     // Slow path for the (inlined) copy constructor for 'long' strings.
@@ -1659,10 +1659,10 @@
     // to call the __init() functions as those are marked as inline which may
     // result in over-aggressive inlining by the compiler, where our aim is
     // to only inline the fast path code directly in the ctor.
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __init_copy_ctor_external(const value_type* __s, size_type __sz);
+    _LIBCPP_CONSTEXPR_CXX20 void __init_copy_ctor_external(const value_type* __s, size_type __sz);
 
     template <class _InputIterator>
-    inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
     <
         __is_exactly_cpp17_input_iterator<_InputIterator>::value
@@ -1670,17 +1670,17 @@
     __init(_InputIterator __first, _InputIterator __last);
 
     template <class _ForwardIterator>
-    inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
     <
         __is_cpp17_forward_iterator<_ForwardIterator>::value
     >
     __init(_ForwardIterator __first, _ForwardIterator __last);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     void __grow_by(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
                    size_type __n_copy,  size_type __n_del,     size_type __n_add = 0);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     void __grow_by_and_replace(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
                                size_type __n_copy,  size_type __n_del,
                                size_type __n_add, const value_type* __p_new_stuff);
@@ -1689,21 +1689,21 @@
     // have proof that the input does not alias the current instance.
     // For example, operator=(basic_string) performs a 'self' check.
     template <bool __is_short>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& __assign_no_alias(const value_type* __s, size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& __assign_no_alias(const value_type* __s, size_type __n);
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __erase_to_end(size_type __pos);
 
     // __erase_external_with_move is invoked for erase() invocations where
     // `n ~= npos`, likely requiring memory moves on the string data.
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __erase_external_with_move(size_type __pos, size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 void __erase_external_with_move(size_type __pos, size_type __n);
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __copy_assign_alloc(const basic_string& __str)
         {__copy_assign_alloc(__str, integral_constant<bool,
                       __alloc_traits::propagate_on_container_copy_assignment::value>());}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __copy_assign_alloc(const basic_string& __str, true_type)
         {
             if (__alloc() == __str.__alloc())
@@ -1729,15 +1729,15 @@
             }
         }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __copy_assign_alloc(const basic_string&, false_type) _NOEXCEPT
         {}
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __move_assign(basic_string& __str, false_type)
         _NOEXCEPT_(__alloc_traits::is_always_equal::value);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __move_assign(basic_string& __str, true_type)
 #if _LIBCPP_STD_VER > 14
         _NOEXCEPT;
@@ -1746,7 +1746,7 @@
 #endif
 #endif
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void
     __move_assign_alloc(basic_string& __str)
         _NOEXCEPT_(
@@ -1755,20 +1755,20 @@
     {__move_assign_alloc(__str, integral_constant<bool,
                       __alloc_traits::propagate_on_container_move_assignment::value>());}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __move_assign_alloc(basic_string& __c, true_type)
         _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
         {
             __alloc() = std::move(__c.__alloc());
         }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     void __move_assign_alloc(basic_string&, false_type)
         _NOEXCEPT
         {}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& __assign_external(const value_type* __s);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string& __assign_external(const value_type* __s, size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& __assign_external(const value_type* __s);
+    _LIBCPP_CONSTEXPR_CXX20 basic_string& __assign_external(const value_type* __s, size_type __n);
 
     // Assigns the value in __s, guaranteed to be __n < __min_cap in length.
     inline basic_string& __assign_short(const value_type* __s, size_type __n) {
@@ -1780,7 +1780,7 @@
       return *this;
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string& __null_terminate_at(value_type* __p, size_type __newsz) {
       __set_size(__newsz);
       __invalidate_iterators_past(__newsz);
@@ -1788,10 +1788,10 @@
       return *this;
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void __invalidate_iterators_past(size_type);
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void __invalidate_iterators_past(size_type);
 
     template<class _Tp>
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     bool __addr_in_range(_Tp&& __t) const {
         // assume that the ranges overlap, because we can't check during constant evaluation
         if (__libcpp_is_constant_evaluated())
@@ -1810,11 +1810,11 @@
         std::__throw_out_of_range("basic_string");
     }
 
-    friend _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string operator+<>(const basic_string&, const basic_string&);
-    friend _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string operator+<>(const value_type*, const basic_string&);
-    friend _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string operator+<>(value_type, const basic_string&);
-    friend _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string operator+<>(const basic_string&, const value_type*);
-    friend _LIBCPP_CONSTEXPR_AFTER_CXX17 basic_string operator+<>(const basic_string&, value_type);
+    friend _LIBCPP_CONSTEXPR_CXX20 basic_string operator+<>(const basic_string&, const basic_string&);
+    friend _LIBCPP_CONSTEXPR_CXX20 basic_string operator+<>(const value_type*, const basic_string&);
+    friend _LIBCPP_CONSTEXPR_CXX20 basic_string operator+<>(value_type, const basic_string&);
+    friend _LIBCPP_CONSTEXPR_CXX20 basic_string operator+<>(const basic_string&, const value_type*);
+    friend _LIBCPP_CONSTEXPR_CXX20 basic_string operator+<>(const basic_string&, value_type);
 };
 
 // These declarations must appear before any functions are implicitly used
@@ -1863,7 +1863,7 @@
 #endif
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__invalidate_iterators_past(size_type __pos)
 {
@@ -1893,7 +1893,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string()
     _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
      : __r_(__default_init_tag(), __default_init_tag())
@@ -1903,7 +1903,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(const allocator_type& __a)
 #if _LIBCPP_STD_VER <= 14
         _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
@@ -1917,7 +1917,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void basic_string<_CharT, _Traits, _Allocator>::__init(const value_type* __s,
                                                        size_type __sz,
                                                        size_type __reserve)
@@ -1946,7 +1946,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__init(const value_type* __s, size_type __sz)
 {
@@ -1975,7 +1975,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(const _CharT* __s, const _Allocator& __a)
     : __r_(__default_init_tag(), __a)
 {
@@ -1985,7 +1985,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(const _CharT* __s, size_type __n)
      : __r_(__default_init_tag(), __default_init_tag())
 {
@@ -1995,7 +1995,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(const _CharT* __s, size_type __n, const _Allocator& __a)
     : __r_(__default_init_tag(), __a)
 {
@@ -2005,7 +2005,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(const basic_string& __str)
     : __r_(__default_init_tag(), __alloc_traits::select_on_container_copy_construction(__str.__alloc()))
 {
@@ -2018,7 +2018,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(
     const basic_string& __str, const allocator_type& __a)
     : __r_(__default_init_tag(), __a)
@@ -2032,7 +2032,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void basic_string<_CharT, _Traits, _Allocator>::__init_copy_ctor_external(
     const value_type* __s, size_type __sz) {
   if (__libcpp_is_constant_evaluated())
@@ -2057,7 +2057,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(basic_string&& __str)
 #if _LIBCPP_STD_VER <= 14
         _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
@@ -2073,7 +2073,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(basic_string&& __str, const allocator_type& __a)
     : __r_(__default_init_tag(), __a)
 {
@@ -2097,7 +2097,7 @@
 #endif // _LIBCPP_CXX03_LANG
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__init(size_type __n, value_type __c)
 {
@@ -2125,7 +2125,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(size_type __n, _CharT __c)
      : __r_(__default_init_tag(), __default_init_tag())
 {
@@ -2135,7 +2135,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(size_type __n, _CharT __c, const _Allocator& __a)
     : __r_(__default_init_tag(), __a)
 {
@@ -2144,7 +2144,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(const basic_string& __str,
                                                         size_type __pos, size_type __n,
                                                         const _Allocator& __a)
@@ -2158,7 +2158,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(const basic_string& __str, size_type __pos,
                                                         const _Allocator& __a)
     : __r_(__default_init_tag(), __a)
@@ -2172,7 +2172,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _Tp, class>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(
              const _Tp& __t, size_type __pos, size_type __n, const allocator_type& __a)
     : __r_(__default_init_tag(), __a)
@@ -2185,7 +2185,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _Tp, class>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(const _Tp & __t)
      : __r_(__default_init_tag(), __default_init_tag())
 {
@@ -2196,7 +2196,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _Tp, class>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(const _Tp & __t, const _Allocator& __a)
     : __r_(__default_init_tag(), __a)
 {
@@ -2207,7 +2207,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __is_exactly_cpp17_input_iterator<_InputIterator>::value
@@ -2234,7 +2234,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value
@@ -2282,7 +2282,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template<class _InputIterator, class>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator __first, _InputIterator __last)
      : __r_(__default_init_tag(), __default_init_tag())
 {
@@ -2292,7 +2292,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template<class _InputIterator, class>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator __first, _InputIterator __last,
                                                         const allocator_type& __a)
     : __r_(__default_init_tag(), __a)
@@ -2304,7 +2304,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(
     initializer_list<_CharT> __il)
      : __r_(__default_init_tag(), __default_init_tag())
@@ -2314,7 +2314,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::basic_string(
     initializer_list<_CharT> __il, const _Allocator& __a)
     : __r_(__default_init_tag(), __a)
@@ -2326,7 +2326,7 @@
 #endif // _LIBCPP_CXX03_LANG
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::~basic_string()
 {
     std::__debug_db_erase_c(this);
@@ -2335,7 +2335,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__grow_by_and_replace
     (size_type __old_cap, size_type __delta_cap, size_type __old_sz,
@@ -2372,7 +2372,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 void
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>::__grow_by(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
                                                      size_type __n_copy,  size_type __n_del,     size_type __n_add)
 {
@@ -2405,7 +2405,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <bool __is_short>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::__assign_no_alias(
     const value_type* __s, size_type __n) {
@@ -2424,7 +2424,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::__assign_external(
     const value_type* __s, size_type __n) {
@@ -2441,7 +2441,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s, size_type __n)
 {
@@ -2452,7 +2452,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::assign(size_type __n, value_type __c)
 {
@@ -2468,7 +2468,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::operator=(value_type __c)
 {
@@ -2490,7 +2490,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::operator=(const basic_string& __str)
 {
@@ -2512,7 +2512,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, false_type)
     _NOEXCEPT_(__alloc_traits::is_always_equal::value)
@@ -2524,7 +2524,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, true_type)
 #if _LIBCPP_STD_VER > 14
@@ -2554,7 +2554,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::operator=(basic_string&& __str)
     _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
@@ -2568,7 +2568,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template<class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
      __is_exactly_cpp17_input_iterator<_InputIterator>::value,
@@ -2583,7 +2583,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template<class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -2619,7 +2619,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::assign(const basic_string& __str, size_type __pos, size_type __n)
 {
@@ -2631,7 +2631,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value
@@ -2649,14 +2649,14 @@
 
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::__assign_external(const value_type* __s) {
   return __assign_external(__s, traits_type::length(__s));
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s)
 {
@@ -2670,7 +2670,7 @@
 // append
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s, size_type __n)
 {
@@ -2694,7 +2694,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::append(size_type __n, value_type __c)
 {
@@ -2714,7 +2714,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 inline void
+_LIBCPP_CONSTEXPR_CXX20 inline void
 basic_string<_CharT, _Traits, _Allocator>::__append_default_init(size_type __n)
 {
     if (__n)
@@ -2731,7 +2731,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::push_back(value_type __c)
 {
@@ -2770,7 +2770,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template<class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -2805,7 +2805,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str)
 {
@@ -2813,7 +2813,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str, size_type __pos, size_type __n)
 {
@@ -2825,7 +2825,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
     __enable_if_t
     <
         __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value  && !__is_same_uncvref<_Tp, basic_string<_CharT, _Traits, _Allocator> >::value,
@@ -2841,7 +2841,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s)
 {
@@ -2852,7 +2852,7 @@
 // insert
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s, size_type __n)
 {
@@ -2892,7 +2892,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, size_type __n, value_type __c)
 {
@@ -2925,7 +2925,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template<class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
    __is_exactly_cpp17_input_iterator<_InputIterator>::value,
@@ -2942,7 +2942,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template<class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -2970,7 +2970,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const basic_string& __str)
 {
@@ -2978,7 +2978,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const basic_string& __str,
                                                   size_type __pos2, size_type __n)
@@ -2991,7 +2991,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value  && !__is_same_uncvref<_Tp, basic_string<_CharT, _Traits, _Allocator> >::value,
@@ -3008,7 +3008,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s)
 {
@@ -3017,7 +3017,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::iterator
 basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, value_type __c)
 {
@@ -3048,7 +3048,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::iterator
 basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, size_type __n, value_type __c)
 {
@@ -3063,7 +3063,7 @@
 // replace
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2)
     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
@@ -3117,7 +3117,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, size_type __n2, value_type __c)
 {
@@ -3148,7 +3148,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template<class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __is_cpp17_input_iterator<_InputIterator>::value,
@@ -3162,7 +3162,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const basic_string& __str)
 {
@@ -3170,7 +3170,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const basic_string& __str,
                                                    size_type __pos2, size_type __n2)
@@ -3183,7 +3183,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value && !__is_same_uncvref<_Tp, basic_string<_CharT, _Traits, _Allocator> >::value,
@@ -3200,7 +3200,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s)
 {
@@ -3209,7 +3209,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const basic_string& __str)
 {
@@ -3218,7 +3218,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n)
 {
@@ -3226,7 +3226,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const value_type* __s)
 {
@@ -3234,7 +3234,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c)
 {
@@ -3246,7 +3246,7 @@
 // 'externally instantiated' erase() implementation, called when __n != npos.
 // Does not check __pos against size()
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__erase_external_with_move(
     size_type __pos, size_type __n)
@@ -3264,7 +3264,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::erase(size_type __pos,
                                                  size_type __n) {
@@ -3279,7 +3279,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::iterator
 basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __pos)
 {
@@ -3295,7 +3295,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::iterator
 basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __first, const_iterator __last)
 {
@@ -3311,7 +3311,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::pop_back()
 {
@@ -3320,7 +3320,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::clear() _NOEXCEPT
 {
@@ -3338,7 +3338,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__erase_to_end(size_type __pos)
 {
@@ -3346,7 +3346,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::resize(size_type __n, value_type __c)
 {
@@ -3358,7 +3358,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 inline void
+_LIBCPP_CONSTEXPR_CXX20 inline void
 basic_string<_CharT, _Traits, _Allocator>::__resize_default_init(size_type __n)
 {
     size_type __sz = size();
@@ -3369,7 +3369,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::max_size() const _NOEXCEPT
 {
@@ -3383,7 +3383,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::reserve(size_type __requested_capacity)
 {
@@ -3404,7 +3404,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::shrink_to_fit() _NOEXCEPT
 {
@@ -3415,7 +3415,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__shrink_or_extend(size_type __target_capacity)
 {
@@ -3479,7 +3479,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::const_reference
 basic_string<_CharT, _Traits, _Allocator>::operator[](size_type __pos) const _NOEXCEPT
 {
@@ -3488,7 +3488,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::reference
 basic_string<_CharT, _Traits, _Allocator>::operator[](size_type __pos) _NOEXCEPT
 {
@@ -3497,7 +3497,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::const_reference
 basic_string<_CharT, _Traits, _Allocator>::at(size_type __n) const
 {
@@ -3507,7 +3507,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::reference
 basic_string<_CharT, _Traits, _Allocator>::at(size_type __n)
 {
@@ -3517,7 +3517,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::reference
 basic_string<_CharT, _Traits, _Allocator>::front() _NOEXCEPT
 {
@@ -3526,7 +3526,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::const_reference
 basic_string<_CharT, _Traits, _Allocator>::front() const _NOEXCEPT
 {
@@ -3535,7 +3535,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::reference
 basic_string<_CharT, _Traits, _Allocator>::back() _NOEXCEPT
 {
@@ -3544,7 +3544,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::const_reference
 basic_string<_CharT, _Traits, _Allocator>::back() const _NOEXCEPT
 {
@@ -3553,7 +3553,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::copy(value_type* __s, size_type __n, size_type __pos) const
 {
@@ -3566,7 +3566,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 basic_string<_CharT, _Traits, _Allocator>::substr(size_type __pos, size_type __n) const
 {
@@ -3574,7 +3574,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::swap(basic_string& __str)
 #if _LIBCPP_STD_VER >= 14
@@ -3610,7 +3610,7 @@
 };
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find(const value_type* __s,
                                                 size_type __pos,
@@ -3622,7 +3622,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find(const basic_string& __str,
                                                 size_type __pos) const _NOEXCEPT
@@ -3633,7 +3633,7 @@
 
 template<class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -3648,7 +3648,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find(const value_type* __s,
                                                 size_type __pos) const _NOEXCEPT
@@ -3659,7 +3659,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find(value_type __c,
                                                 size_type __pos) const _NOEXCEPT
@@ -3671,7 +3671,7 @@
 // rfind
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::rfind(const value_type* __s,
                                                  size_type __pos,
@@ -3683,7 +3683,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::rfind(const basic_string& __str,
                                                  size_type __pos) const _NOEXCEPT
@@ -3694,7 +3694,7 @@
 
 template<class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -3709,7 +3709,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::rfind(const value_type* __s,
                                                  size_type __pos) const _NOEXCEPT
@@ -3720,7 +3720,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::rfind(value_type __c,
                                                  size_type __pos) const _NOEXCEPT
@@ -3732,7 +3732,7 @@
 // find_first_of
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_first_of(const value_type* __s,
                                                          size_type __pos,
@@ -3744,7 +3744,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_first_of(const basic_string& __str,
                                                          size_type __pos) const _NOEXCEPT
@@ -3755,7 +3755,7 @@
 
 template<class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -3770,7 +3770,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_first_of(const value_type* __s,
                                                          size_type __pos) const _NOEXCEPT
@@ -3781,7 +3781,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_first_of(value_type __c,
                                                          size_type __pos) const _NOEXCEPT
@@ -3792,7 +3792,7 @@
 // find_last_of
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_last_of(const value_type* __s,
                                                         size_type __pos,
@@ -3804,7 +3804,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_last_of(const basic_string& __str,
                                                         size_type __pos) const _NOEXCEPT
@@ -3815,7 +3815,7 @@
 
 template<class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -3830,7 +3830,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_last_of(const value_type* __s,
                                                         size_type __pos) const _NOEXCEPT
@@ -3841,7 +3841,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_last_of(value_type __c,
                                                         size_type __pos) const _NOEXCEPT
@@ -3852,7 +3852,7 @@
 // find_first_not_of
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const value_type* __s,
                                                              size_type __pos,
@@ -3864,7 +3864,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const basic_string& __str,
                                                              size_type __pos) const _NOEXCEPT
@@ -3875,7 +3875,7 @@
 
 template<class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -3890,7 +3890,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const value_type* __s,
                                                              size_type __pos) const _NOEXCEPT
@@ -3901,7 +3901,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(value_type __c,
                                                              size_type __pos) const _NOEXCEPT
@@ -3913,7 +3913,7 @@
 // find_last_not_of
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const value_type* __s,
                                                             size_type __pos,
@@ -3925,7 +3925,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const basic_string& __str,
                                                             size_type __pos) const _NOEXCEPT
@@ -3936,7 +3936,7 @@
 
 template<class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -3951,7 +3951,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const value_type* __s,
                                                             size_type __pos) const _NOEXCEPT
@@ -3962,7 +3962,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(value_type __c,
                                                             size_type __pos) const _NOEXCEPT
@@ -3975,7 +3975,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -3998,7 +3998,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 int
 basic_string<_CharT, _Traits, _Allocator>::compare(const basic_string& __str) const _NOEXCEPT
 {
@@ -4006,7 +4006,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 int
 basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
                                                    size_type __n1,
@@ -4031,7 +4031,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
@@ -4046,7 +4046,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 int
 basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
                                                    size_type __n1,
@@ -4057,7 +4057,7 @@
 
 template <class _CharT, class _Traits, class _Allocator>
 template <class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 __enable_if_t
 <
     __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value
@@ -4075,7 +4075,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 int
 basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
                                                    size_type __n1,
@@ -4087,7 +4087,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 int
 basic_string<_CharT, _Traits, _Allocator>::compare(const value_type* __s) const _NOEXCEPT
 {
@@ -4096,7 +4096,7 @@
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 int
 basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
                                                    size_type __n1,
@@ -4109,7 +4109,7 @@
 // __invariants
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 bool
 basic_string<_CharT, _Traits, _Allocator>::__invariants() const
 {
@@ -4127,7 +4127,7 @@
 // __clear_and_shrink
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__clear_and_shrink() _NOEXCEPT
 {
@@ -4144,7 +4144,7 @@
 // operator==
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4156,7 +4156,7 @@
 }
 
 template<class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator==(const basic_string<char, char_traits<char>, _Allocator>& __lhs,
            const basic_string<char, char_traits<char>, _Allocator>& __rhs) _NOEXCEPT
@@ -4175,7 +4175,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator==(const _CharT* __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4188,7 +4188,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator==(const basic_string<_CharT,_Traits,_Allocator>& __lhs,
            const _CharT* __rhs) _NOEXCEPT
@@ -4201,7 +4201,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator!=(const basic_string<_CharT,_Traits,_Allocator>& __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4210,7 +4210,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator!=(const _CharT* __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4219,7 +4219,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator!=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
            const _CharT* __rhs) _NOEXCEPT
@@ -4230,7 +4230,7 @@
 // operator<
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator< (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4239,7 +4239,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator< (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
            const _CharT* __rhs) _NOEXCEPT
@@ -4248,7 +4248,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator< (const _CharT* __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4259,7 +4259,7 @@
 // operator>
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator> (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4268,7 +4268,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator> (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
            const _CharT* __rhs) _NOEXCEPT
@@ -4277,7 +4277,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator> (const _CharT* __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4288,7 +4288,7 @@
 // operator<=
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4297,7 +4297,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
            const _CharT* __rhs) _NOEXCEPT
@@ -4306,7 +4306,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator<=(const _CharT* __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4317,7 +4317,7 @@
 // operator>=
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4326,7 +4326,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
            const _CharT* __rhs) _NOEXCEPT
@@ -4335,7 +4335,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI
+inline _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI
 bool
 operator>=(const _CharT* __lhs,
            const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
@@ -4346,7 +4346,7 @@
 // operator +
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
           const basic_string<_CharT, _Traits, _Allocator>& __rhs)
@@ -4365,7 +4365,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(const _CharT* __lhs , const basic_string<_CharT,_Traits,_Allocator>& __rhs)
 {
@@ -4383,7 +4383,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Allocator>& __rhs)
 {
@@ -4400,7 +4400,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs)
 {
@@ -4418,7 +4418,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, _CharT __rhs)
 {
@@ -4437,7 +4437,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs)
 {
@@ -4445,7 +4445,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs)
 {
@@ -4453,7 +4453,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs)
 {
@@ -4461,7 +4461,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(const _CharT* __lhs , basic_string<_CharT,_Traits,_Allocator>&& __rhs)
 {
@@ -4469,7 +4469,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(_CharT __lhs, basic_string<_CharT,_Traits,_Allocator>&& __rhs)
 {
@@ -4478,7 +4478,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const _CharT* __rhs)
 {
@@ -4486,7 +4486,7 @@
 }
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 basic_string<_CharT, _Traits, _Allocator>
 operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, _CharT __rhs)
 {
@@ -4499,7 +4499,7 @@
 // swap
 
 template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
 void
 swap(basic_string<_CharT, _Traits, _Allocator>& __lhs,
      basic_string<_CharT, _Traits, _Allocator>& __rhs)
@@ -4662,14 +4662,14 @@
 {
   inline namespace string_literals
   {
-    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string<char> operator "" s( const char *__str, size_t __len )
     {
         return basic_string<char> (__str, __len);
     }
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
-    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string<wchar_t> operator "" s( const wchar_t *__str, size_t __len )
     {
         return basic_string<wchar_t> (__str, __len);
@@ -4684,13 +4684,13 @@
     }
 #endif
 
-    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string<char16_t> operator "" s( const char16_t *__str, size_t __len )
     {
         return basic_string<char16_t> (__str, __len);
     }
 
-    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+    inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20
     basic_string<char32_t> operator "" s( const char32_t *__str, size_t __len )
     {
         return basic_string<char32_t> (__str, __len);
diff --git a/libcxx/include/string_view b/libcxx/include/string_view
--- a/libcxx/include/string_view
+++ b/libcxx/include/string_view
@@ -362,16 +362,16 @@
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     const_iterator cend()   const _NOEXCEPT { return __data + __size; }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX17 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX17 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX17 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX17 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
 
     // [string.view.capacity], capacity
@@ -417,7 +417,7 @@
     const_pointer data() const _NOEXCEPT { return __data; }
 
     // [string.view.modifiers], modifiers:
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     void remove_prefix(size_type __n) _NOEXCEPT
     {
         _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
@@ -425,14 +425,14 @@
         __size -= __n;
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     void remove_suffix(size_type __n) _NOEXCEPT
     {
         _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
         __size -= __n;
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     void swap(basic_string_view& __other) _NOEXCEPT
     {
         const value_type *__p = __data;
@@ -444,7 +444,7 @@
         __other.__size = __sz;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
     {
         if (__pos > size())
@@ -462,7 +462,7 @@
             : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT
+    _LIBCPP_CONSTEXPR_CXX14 int compare(basic_string_view __sv) const _NOEXCEPT
     {
         size_type __rlen = _VSTD::min( size(), __sv.size());
         int __retval = _Traits::compare(data(), __sv.data(), __rlen);
@@ -471,39 +471,39 @@
         return __retval;
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
     {
         return substr(__pos1, __n1).compare(__sv);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     int compare(                       size_type __pos1, size_type __n1,
                 basic_string_view __sv, size_type __pos2, size_type __n2) const
     {
         return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     int compare(const _CharT* __s) const _NOEXCEPT
     {
         return compare(basic_string_view(__s));
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
     {
         return substr(__pos1, __n1).compare(basic_string_view(__s));
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
     {
         return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
     }
 
     // find
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
@@ -511,14 +511,14 @@
             (data(), size(), __s.data(), __pos, __s.size());
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
     {
         return __str_find<value_type, size_type, traits_type, npos>
             (data(), size(), __c, __pos);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
@@ -526,7 +526,7 @@
             (data(), size(), __s, __pos, __n);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find(const _CharT* __s, size_type __pos = 0) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr");
@@ -535,7 +535,7 @@
     }
 
     // rfind
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
@@ -543,14 +543,14 @@
             (data(), size(), __s.data(), __pos, __s.size());
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
     {
         return __str_rfind<value_type, size_type, traits_type, npos>
             (data(), size(), __c, __pos);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
@@ -558,7 +558,7 @@
             (data(), size(), __s, __pos, __n);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type rfind(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr");
@@ -567,7 +567,7 @@
     }
 
     // find_first_of
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
@@ -575,11 +575,11 @@
             (data(), size(), __s.data(), __pos, __s.size());
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
     { return find(__c, __pos); }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
@@ -587,7 +587,7 @@
             (data(), size(), __s, __pos, __n);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_first_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr");
@@ -596,7 +596,7 @@
     }
 
     // find_last_of
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
@@ -604,11 +604,11 @@
             (data(), size(), __s.data(), __pos, __s.size());
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
     { return rfind(__c, __pos); }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
@@ -616,7 +616,7 @@
             (data(), size(), __s, __pos, __n);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_last_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr");
@@ -625,7 +625,7 @@
     }
 
     // find_first_not_of
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
@@ -633,14 +633,14 @@
             (data(), size(), __s.data(), __pos, __s.size());
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
     {
         return __str_find_first_not_of<value_type, size_type, traits_type, npos>
             (data(), size(), __c, __pos);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
@@ -648,7 +648,7 @@
             (data(), size(), __s, __pos, __n);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_first_not_of(const _CharT* __s, size_type __pos=0) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
@@ -657,7 +657,7 @@
     }
 
     // find_last_not_of
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_last_not_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): received nullptr");
@@ -665,14 +665,14 @@
             (data(), size(), __s.data(), __pos, __s.size());
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_last_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
     {
         return __str_find_last_not_of<value_type, size_type, traits_type, npos>
             (data(), size(), __c, __pos);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
@@ -680,7 +680,7 @@
             (data(), size(), __s, __pos, __n);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
     size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const _NOEXCEPT
     {
         _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
@@ -757,7 +757,7 @@
 // [string.view.comparison]
 // operator ==
 template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator==(basic_string_view<_CharT, _Traits> __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
@@ -768,7 +768,7 @@
 // The dummy default template parameters are used to work around a MSVC issue with mangling, see VSO-409326 for details.
 // This applies to the other sufficient overloads below for the other comparison operators.
 template<class _CharT, class _Traits, int = 1>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator==(basic_string_view<_CharT, _Traits> __lhs,
                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
 {
@@ -779,7 +779,7 @@
 #if _LIBCPP_STD_VER < 20
 // This overload is automatically generated in C++20.
 template<class _CharT, class _Traits, int = 2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
@@ -824,7 +824,7 @@
 
 // operator !=
 template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     if ( __lhs.size() != __rhs.size())
@@ -833,7 +833,7 @@
 }
 
 template<class _CharT, class _Traits, int = 1>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
 {
@@ -843,7 +843,7 @@
 }
 
 template<class _CharT, class _Traits, int = 2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
@@ -855,14 +855,14 @@
 
 // operator <
 template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) < 0;
 }
 
 template<class _CharT, class _Traits, int = 1>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator<(basic_string_view<_CharT, _Traits> __lhs,
                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
 {
@@ -870,7 +870,7 @@
 }
 
 template<class _CharT, class _Traits, int = 2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
@@ -880,14 +880,14 @@
 
 // operator >
 template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) > 0;
 }
 
 template<class _CharT, class _Traits, int = 1>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator>(basic_string_view<_CharT, _Traits> __lhs,
                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
 {
@@ -895,7 +895,7 @@
 }
 
 template<class _CharT, class _Traits, int = 2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
@@ -905,14 +905,14 @@
 
 // operator <=
 template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) <= 0;
 }
 
 template<class _CharT, class _Traits, int = 1>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
 {
@@ -920,7 +920,7 @@
 }
 
 template<class _CharT, class _Traits, int = 2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
@@ -930,7 +930,7 @@
 
 // operator >=
 template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
     return __lhs.compare(__rhs) >= 0;
@@ -938,7 +938,7 @@
 
 
 template<class _CharT, class _Traits, int = 1>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
                 typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
 {
@@ -946,7 +946,7 @@
 }
 
 template<class _CharT, class _Traits, int = 2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_CXX14 _LIBCPP_INLINE_VISIBILITY
 bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs,
                 basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
 {
diff --git a/libcxx/include/system_error b/libcxx/include/system_error
--- a/libcxx/include/system_error
+++ b/libcxx/include/system_error
@@ -209,7 +209,7 @@
     error_category() noexcept;
 #else
     _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 error_category() _NOEXCEPT = default;
+    _LIBCPP_CONSTEXPR_CXX14 error_category() _NOEXCEPT = default;
 #endif
     error_category(const error_category&) = delete;
     error_category& operator=(const error_category&) = delete;
diff --git a/libcxx/include/tuple b/libcxx/include/tuple
--- a/libcxx/include/tuple
+++ b/libcxx/include/tuple
@@ -247,7 +247,7 @@
 class __tuple_leaf;
 
 template <size_t _Ip, class _Hp, bool _Ep>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 void swap(__tuple_leaf<_Ip, _Hp, _Ep>& __x, __tuple_leaf<_Ip, _Hp, _Ep>& __y)
     _NOEXCEPT_(__is_nothrow_swappable<_Hp>::value)
 {
@@ -255,7 +255,7 @@
 }
 
 template <size_t _Ip, class _Hp, bool _Ep>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX14
 void swap(const __tuple_leaf<_Ip, _Hp, _Ep>& __x, const __tuple_leaf<_Ip, _Hp, _Ep>& __y)
      _NOEXCEPT_(__is_nothrow_swappable<const _Hp>::value) {
   swap(__x.get(), __y.get());
@@ -275,7 +275,7 @@
 #endif
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     __tuple_leaf& operator=(const __tuple_leaf&);
 public:
     _LIBCPP_INLINE_VISIBILITY constexpr __tuple_leaf()
@@ -312,28 +312,28 @@
                     >::value
                 >
             >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
         explicit __tuple_leaf(_Tp&& __t) _NOEXCEPT_((is_nothrow_constructible<_Hp, _Tp>::value))
             : __value_(_VSTD::forward<_Tp>(__t))
         {static_assert(__can_bind_reference<_Tp&&>(),
        "Attempted construction of reference element binds to a temporary whose lifetime has ended");}
 
     template <class _Tp, class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
         explicit __tuple_leaf(integral_constant<int, 0>, const _Alloc&, _Tp&& __t)
             : __value_(_VSTD::forward<_Tp>(__t))
         {static_assert(__can_bind_reference<_Tp&&>(),
        "Attempted construction of reference element binds to a temporary whose lifetime has ended");}
 
     template <class _Tp, class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
         explicit __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a, _Tp&& __t)
             : __value_(allocator_arg_t(), __a, _VSTD::forward<_Tp>(__t))
         {static_assert(!is_reference<_Hp>::value,
             "Attempted to uses-allocator construct a reference element in a tuple");}
 
     template <class _Tp, class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
         explicit __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a, _Tp&& __t)
             : __value_(_VSTD::forward<_Tp>(__t), __a)
         {static_assert(!is_reference<_Hp>::value,
@@ -342,28 +342,28 @@
     __tuple_leaf(const __tuple_leaf& __t) = default;
     __tuple_leaf(__tuple_leaf&& __t) = default;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     int swap(__tuple_leaf& __t) _NOEXCEPT_(__is_nothrow_swappable<__tuple_leaf>::value)
     {
         _VSTD::swap(*this, __t);
         return 0;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     int swap(const __tuple_leaf& __t) const _NOEXCEPT_(__is_nothrow_swappable<const __tuple_leaf>::value) {
         _VSTD::swap(*this, __t);
         return 0;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11       _Hp& get()       _NOEXCEPT {return __value_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const _Hp& get() const _NOEXCEPT {return __value_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14       _Hp& get()       _NOEXCEPT {return __value_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 const _Hp& get() const _NOEXCEPT {return __value_;}
 };
 
 template <size_t _Ip, class _Hp>
 class __tuple_leaf<_Ip, _Hp, true>
     : private _Hp
 {
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_CONSTEXPR_CXX14
     __tuple_leaf& operator=(const __tuple_leaf&);
 public:
     _LIBCPP_INLINE_VISIBILITY constexpr __tuple_leaf()
@@ -391,7 +391,7 @@
                   >::value
                 >
             >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
         explicit __tuple_leaf(_Tp&& __t) _NOEXCEPT_((is_nothrow_constructible<_Hp, _Tp>::value))
             : _Hp(_VSTD::forward<_Tp>(__t)) {}
 
@@ -413,7 +413,7 @@
     __tuple_leaf(__tuple_leaf const &) = default;
     __tuple_leaf(__tuple_leaf &&) = default;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     int
     swap(__tuple_leaf& __t) _NOEXCEPT_(__is_nothrow_swappable<__tuple_leaf>::value)
     {
@@ -421,18 +421,18 @@
         return 0;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     int swap(const __tuple_leaf& __rhs) const _NOEXCEPT_(__is_nothrow_swappable<const __tuple_leaf>::value) {
         _VSTD::swap(*this, __rhs);
         return 0;
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11       _Hp& get()       _NOEXCEPT {return static_cast<_Hp&>(*this);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const _Hp& get() const _NOEXCEPT {return static_cast<const _Hp&>(*this);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14       _Hp& get()       _NOEXCEPT {return static_cast<_Hp&>(*this);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14 const _Hp& get() const _NOEXCEPT {return static_cast<const _Hp&>(*this);}
 };
 
 template <class ..._Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 void __swallow(_Tp&&...) _NOEXCEPT {}
 
 template <class _Tp>
@@ -457,7 +457,7 @@
 
     template <size_t ..._Uf, class ..._Tf,
               size_t ..._Ul, class ..._Tl, class ..._Up>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
         explicit
         __tuple_impl(__tuple_indices<_Uf...>, __tuple_types<_Tf...>,
                      __tuple_indices<_Ul...>, __tuple_types<_Tl...>,
@@ -470,7 +470,7 @@
 
     template <class _Alloc, size_t ..._Uf, class ..._Tf,
               size_t ..._Ul, class ..._Tl, class ..._Up>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
         explicit
         __tuple_impl(allocator_arg_t, const _Alloc& __a,
                      __tuple_indices<_Uf...>, __tuple_types<_Tf...>,
@@ -484,7 +484,7 @@
     template <class _Tuple,
               class = __enable_if_t<__tuple_constructible<_Tuple, tuple<_Tp...> >::value>
              >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
         __tuple_impl(_Tuple&& __t) _NOEXCEPT_((__all<is_nothrow_constructible<_Tp, typename tuple_element<_Indx,
                                        typename __make_tuple_types<_Tuple>::type>::type>::value...>::value))
             : __tuple_leaf<_Indx, _Tp>(_VSTD::forward<typename tuple_element<_Indx,
@@ -494,7 +494,7 @@
     template <class _Alloc, class _Tuple,
               class = __enable_if_t<__tuple_constructible<_Tuple, tuple<_Tp...> >::value>
              >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
         __tuple_impl(allocator_arg_t, const _Alloc& __a, _Tuple&& __t)
             : __tuple_leaf<_Indx, _Tp>(__uses_alloc_ctor<_Tp, _Alloc, typename tuple_element<_Indx,
                                        typename __make_tuple_types<_Tuple>::type>::type>(), __a,
@@ -505,14 +505,14 @@
     __tuple_impl(const __tuple_impl&) = default;
     __tuple_impl(__tuple_impl&&) = default;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     void swap(__tuple_impl& __t)
         _NOEXCEPT_(__all<__is_nothrow_swappable<_Tp>::value...>::value)
     {
         _VSTD::__swallow(__tuple_leaf<_Indx, _Tp>::swap(static_cast<__tuple_leaf<_Indx, _Tp>&>(__t))...);
     }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     void swap(const __tuple_impl& __t) const
         _NOEXCEPT_(__all<__is_nothrow_swappable<const _Tp>::value...>::value)
     {
@@ -521,13 +521,13 @@
 };
 
 template<class _Dest, class _Source, size_t ..._Np>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 void __memberwise_copy_assign(_Dest& __dest, _Source const& __source, __tuple_indices<_Np...>) {
     _VSTD::__swallow(((_VSTD::get<_Np>(__dest) = _VSTD::get<_Np>(__source)), void(), 0)...);
 }
 
 template<class _Dest, class _Source, class ..._Up, size_t ..._Np>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 void __memberwise_forward_assign(_Dest& __dest, _Source&& __source, __tuple_types<_Up...>, __tuple_indices<_Np...>) {
     _VSTD::__swallow(((
         _VSTD::get<_Np>(__dest) = _VSTD::forward<_Up>(_VSTD::get<_Np>(__source))
@@ -541,13 +541,13 @@
 
     _BaseT __base_;
 
-    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
+    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_CXX14
         typename tuple_element<_Jp, tuple<_Up...> >::type& get(tuple<_Up...>&) _NOEXCEPT;
-    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
+    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_CXX14
         const typename tuple_element<_Jp, tuple<_Up...> >::type& get(const tuple<_Up...>&) _NOEXCEPT;
-    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
+    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_CXX14
         typename tuple_element<_Jp, tuple<_Up...> >::type&& get(tuple<_Up...>&&) _NOEXCEPT;
-    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
+    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_CXX14
         const typename tuple_element<_Jp, tuple<_Up...> >::type&& get(const tuple<_Up...>&&) _NOEXCEPT;
 public:
     // [tuple.cnstr]
@@ -580,7 +580,7 @@
             _IsImpDefault<_Tp>... // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple(allocator_arg_t, _Alloc const& __a)
       : __base_(allocator_arg_t(), __a,
                     __tuple_indices<>(), __tuple_types<>(),
@@ -595,7 +595,7 @@
             _Not<_Lazy<_And, _IsImpDefault<_Tp>...> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     explicit tuple(allocator_arg_t, _Alloc const& __a)
       : __base_(allocator_arg_t(), __a,
                     __tuple_indices<>(), __tuple_types<>(),
@@ -610,7 +610,7 @@
             is_convertible<const _Tp&, _Tp>... // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     tuple(const _Tp& ... __t)
         _NOEXCEPT_(_And<is_nothrow_copy_constructible<_Tp>...>::value)
         : __base_(typename __make_tuple_indices<sizeof...(_Tp)>::type(),
@@ -627,7 +627,7 @@
             _Not<_Lazy<_And, is_convertible<const _Tp&, _Tp>...> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit tuple(const _Tp& ... __t)
         _NOEXCEPT_(_And<is_nothrow_copy_constructible<_Tp>...>::value)
         : __base_(typename __make_tuple_indices<sizeof...(_Tp)>::type(),
@@ -644,7 +644,7 @@
             is_convertible<const _Tp&, _Tp>... // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple(allocator_arg_t, const _Alloc& __a, const _Tp& ... __t)
         : __base_(allocator_arg_t(), __a,
                 typename __make_tuple_indices<sizeof...(_Tp)>::type(),
@@ -661,7 +661,7 @@
             _Not<_Lazy<_And, is_convertible<const _Tp&, _Tp>...> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     explicit tuple(allocator_arg_t, const _Alloc& __a, const _Tp& ... __t)
         : __base_(allocator_arg_t(), __a,
                 typename __make_tuple_indices<sizeof...(_Tp)>::type(),
@@ -689,7 +689,7 @@
             is_convertible<_Up, _Tp>... // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     tuple(_Up&&... __u)
         _NOEXCEPT_((_And<is_nothrow_constructible<_Tp, _Up>...>::value))
         : __base_(typename __make_tuple_indices<sizeof...(_Up)>::type(),
@@ -705,7 +705,7 @@
             _Not<_Lazy<_And, is_convertible<_Up, _Tp>...> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit tuple(_Up&&... __u)
         _NOEXCEPT_((_And<is_nothrow_constructible<_Tp, _Up>...>::value))
         : __base_(typename __make_tuple_indices<sizeof...(_Up)>::type(),
@@ -721,7 +721,7 @@
             is_convertible<_Up, _Tp>... // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple(allocator_arg_t, const _Alloc& __a, _Up&&... __u)
         : __base_(allocator_arg_t(), __a,
                     typename __make_tuple_indices<sizeof...(_Up)>::type(),
@@ -737,7 +737,7 @@
             _Not<_Lazy<_And, is_convertible<_Up, _Tp>...> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     explicit tuple(allocator_arg_t, const _Alloc& __a, _Up&&... __u)
         : __base_(allocator_arg_t(), __a,
                     typename __make_tuple_indices<sizeof...(_Up)>::type(),
@@ -753,7 +753,7 @@
     template <class _Alloc, template<class...> class _And = _And, __enable_if_t<
         _And<is_copy_constructible<_Tp>...>::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple(allocator_arg_t, const _Alloc& __alloc, const tuple& __t)
         : __base_(allocator_arg_t(), __alloc, __t)
     { }
@@ -761,7 +761,7 @@
     template <class _Alloc, template<class...> class _And = _And, __enable_if_t<
         _And<is_move_constructible<_Tp>...>::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple(allocator_arg_t, const _Alloc& __alloc, tuple&& __t)
         : __base_(allocator_arg_t(), __alloc, _VSTD::move(__t))
     { }
@@ -797,7 +797,7 @@
             is_convertible<const _Up&, _Tp>... // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     tuple(const tuple<_Up...>& __t)
         _NOEXCEPT_((_And<is_nothrow_constructible<_Tp, const _Up&>...>::value))
         : __base_(__t)
@@ -809,7 +809,7 @@
             _Not<_Lazy<_And, is_convertible<const _Up&, _Tp>...> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit tuple(const tuple<_Up...>& __t)
         _NOEXCEPT_((_And<is_nothrow_constructible<_Tp, const _Up&>...>::value))
         : __base_(__t)
@@ -821,7 +821,7 @@
             is_convertible<const _Up&, _Tp>... // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple(allocator_arg_t, const _Alloc& __a, const tuple<_Up...>& __t)
         : __base_(allocator_arg_t(), __a, __t)
     { }
@@ -832,7 +832,7 @@
             _Not<_Lazy<_And, is_convertible<const _Up&, _Tp>...> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     explicit tuple(allocator_arg_t, const _Alloc& __a, const tuple<_Up...>& __t)
         : __base_(allocator_arg_t(), __a, __t)
     { }
@@ -861,7 +861,7 @@
             is_convertible<_Up, _Tp>... // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     tuple(tuple<_Up...>&& __t)
         _NOEXCEPT_((_And<is_nothrow_constructible<_Tp, _Up>...>::value))
         : __base_(_VSTD::move(__t))
@@ -873,7 +873,7 @@
             _Not<_Lazy<_And, is_convertible<_Up, _Tp>...> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit tuple(tuple<_Up...>&& __t)
         _NOEXCEPT_((_And<is_nothrow_constructible<_Tp, _Up>...>::value))
         : __base_(_VSTD::move(__t))
@@ -885,7 +885,7 @@
             is_convertible<_Up, _Tp>... // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple(allocator_arg_t, const _Alloc& __a, tuple<_Up...>&& __t)
         : __base_(allocator_arg_t(), __a, _VSTD::move(__t))
     { }
@@ -896,7 +896,7 @@
             _Not<_Lazy<_And, is_convertible<_Up, _Tp>...> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     explicit tuple(allocator_arg_t, const _Alloc& __a, tuple<_Up...>&& __t)
         : __base_(allocator_arg_t(), __a, _VSTD::move(__t))
     { }
@@ -950,7 +950,7 @@
             _BothImplicitlyConvertible<const pair<_Up1, _Up2>&> // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     tuple(const pair<_Up1, _Up2>& __p)
         _NOEXCEPT_((_NothrowConstructibleFromPair<const pair<_Up1, _Up2>&>::value))
         : __base_(__p)
@@ -962,7 +962,7 @@
             _Not<_BothImplicitlyConvertible<const pair<_Up1, _Up2>&> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit tuple(const pair<_Up1, _Up2>& __p)
         _NOEXCEPT_((_NothrowConstructibleFromPair<const pair<_Up1, _Up2>&>::value))
         : __base_(__p)
@@ -974,7 +974,7 @@
             _BothImplicitlyConvertible<const pair<_Up1, _Up2>&> // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple(allocator_arg_t, const _Alloc& __a, const pair<_Up1, _Up2>& __p)
         : __base_(allocator_arg_t(), __a, __p)
     { }
@@ -985,7 +985,7 @@
             _Not<_BothImplicitlyConvertible<const pair<_Up1, _Up2>&> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     explicit tuple(allocator_arg_t, const _Alloc& __a, const pair<_Up1, _Up2>& __p)
         : __base_(allocator_arg_t(), __a, __p)
     { }
@@ -1014,7 +1014,7 @@
             _BothImplicitlyConvertible<pair<_Up1, _Up2>&&> // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     tuple(pair<_Up1, _Up2>&& __p)
         _NOEXCEPT_((_NothrowConstructibleFromPair<pair<_Up1, _Up2>&&>::value))
         : __base_(_VSTD::move(__p))
@@ -1026,7 +1026,7 @@
             _Not<_BothImplicitlyConvertible<pair<_Up1, _Up2>&&> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     explicit tuple(pair<_Up1, _Up2>&& __p)
         _NOEXCEPT_((_NothrowConstructibleFromPair<pair<_Up1, _Up2>&&>::value))
         : __base_(_VSTD::move(__p))
@@ -1038,7 +1038,7 @@
             _BothImplicitlyConvertible<pair<_Up1, _Up2>&&> // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple(allocator_arg_t, const _Alloc& __a, pair<_Up1, _Up2>&& __p)
         : __base_(allocator_arg_t(), __a, _VSTD::move(__p))
     { }
@@ -1049,7 +1049,7 @@
             _Not<_BothImplicitlyConvertible<pair<_Up1, _Up2>&&> > // explicit check
         >::value
     , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     explicit tuple(allocator_arg_t, const _Alloc& __a, pair<_Up1, _Up2>&& __p)
         : __base_(allocator_arg_t(), __a, _VSTD::move(__p))
     { }
@@ -1072,7 +1072,7 @@
 #endif // _LIBCPP_STD_VER > 20
 
     // [tuple.assign]
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple& operator=(_If<_And<is_copy_assignable<_Tp>...>::value, tuple, __nat> const& __tuple)
         _NOEXCEPT_((_And<is_nothrow_copy_assignable<_Tp>...>::value))
     {
@@ -1100,7 +1100,7 @@
     }
 #endif // _LIBCPP_STD_VER > 20
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple& operator=(_If<_And<is_move_assignable<_Tp>...>::value, tuple, __nat>&& __tuple)
         _NOEXCEPT_((_And<is_nothrow_move_assignable<_Tp>...>::value))
     {
@@ -1116,7 +1116,7 @@
             is_assignable<_Tp&, _Up const&>...
         >::value
     ,int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple& operator=(tuple<_Up...> const& __tuple)
         _NOEXCEPT_((_And<is_nothrow_assignable<_Tp&, _Up const&>...>::value))
     {
@@ -1131,7 +1131,7 @@
             is_assignable<_Tp&, _Up>...
         >::value
     ,int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple& operator=(tuple<_Up...>&& __tuple)
         _NOEXCEPT_((_And<is_nothrow_assignable<_Tp&, _Up>...>::value))
     {
@@ -1209,7 +1209,7 @@
     template<class _Up1, class _Up2, __enable_if_t<
         _EnableAssignFromPair<false, pair<_Up1, _Up2> const&>::value
     ,int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple& operator=(pair<_Up1, _Up2> const& __pair)
         _NOEXCEPT_((_NothrowAssignFromPair<false, pair<_Up1, _Up2> const&>::value))
     {
@@ -1221,7 +1221,7 @@
     template<class _Up1, class _Up2, __enable_if_t<
         _EnableAssignFromPair<false, pair<_Up1, _Up2>&&>::value
     ,int> = 0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple& operator=(pair<_Up1, _Up2>&& __pair)
         _NOEXCEPT_((_NothrowAssignFromPair<false, pair<_Up1, _Up2>&&>::value))
     {
@@ -1237,7 +1237,7 @@
             is_assignable<_Tp&, _Up const&>...
         >::value
     > >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple& operator=(array<_Up, _Np> const& __array)
         _NOEXCEPT_((_And<is_nothrow_assignable<_Tp&, _Up const&>...>::value))
     {
@@ -1253,7 +1253,7 @@
             is_assignable<_Tp&, _Up>...
         >::value
     > >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     tuple& operator=(array<_Up, _Np>&& __array)
         _NOEXCEPT_((_And<is_nothrow_assignable<_Tp&, _Up>...>::value))
     {
@@ -1264,7 +1264,7 @@
     }
 
     // [tuple.swap]
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void swap(tuple& __t) _NOEXCEPT_(__all<__is_nothrow_swappable<_Tp>::value...>::value)
         {__base_.swap(__t.__base_);}
 
@@ -1283,18 +1283,18 @@
     _LIBCPP_INLINE_VISIBILITY constexpr
         tuple() _NOEXCEPT = default;
     template <class _Alloc>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
         tuple(allocator_arg_t, const _Alloc&) _NOEXCEPT {}
     template <class _Alloc>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
         tuple(allocator_arg_t, const _Alloc&, const tuple&) _NOEXCEPT {}
     template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
         tuple(array<_Up, 0>) _NOEXCEPT {}
     template <class _Alloc, class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
         tuple(allocator_arg_t, const _Alloc&, array<_Up, 0>) _NOEXCEPT {}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void swap(tuple&) _NOEXCEPT {}
 #if _LIBCPP_STD_VER > 20
     _LIBCPP_HIDE_FROM_ABI constexpr void swap(const tuple&) const noexcept {}
@@ -1329,7 +1329,7 @@
 #endif
 
 template <class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 __enable_if_t<__all<__is_swappable<_Tp>::value...>::value, void>
 swap(tuple<_Tp...>& __t, tuple<_Tp...>& __u)
                  _NOEXCEPT_(__all<__is_nothrow_swappable<_Tp>::value...>::value)
@@ -1348,7 +1348,7 @@
 // get
 
 template <size_t _Ip, class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename tuple_element<_Ip, tuple<_Tp...> >::type&
 get(tuple<_Tp...>& __t) _NOEXCEPT
 {
@@ -1357,7 +1357,7 @@
 }
 
 template <size_t _Ip, class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const typename tuple_element<_Ip, tuple<_Tp...> >::type&
 get(const tuple<_Tp...>& __t) _NOEXCEPT
 {
@@ -1366,7 +1366,7 @@
 }
 
 template <size_t _Ip, class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename tuple_element<_Ip, tuple<_Tp...> >::type&&
 get(tuple<_Tp...>&& __t) _NOEXCEPT
 {
@@ -1376,7 +1376,7 @@
 }
 
 template <size_t _Ip, class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 const typename tuple_element<_Ip, tuple<_Tp...> >::type&&
 get(const tuple<_Tp...>&& __t) _NOEXCEPT
 {
@@ -1458,7 +1458,7 @@
 // tie
 
 template <class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 tuple<_Tp&...>
 tie(_Tp&... __t) _NOEXCEPT
 {
@@ -1469,7 +1469,7 @@
 struct __ignore_t
 {
     template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     const __ignore_t& operator=(_Tp&&) const {return *this;}
 };
 
@@ -1478,7 +1478,7 @@
 } // namespace
 
 template <class... _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 tuple<typename __unwrap_ref_decay<_Tp>::type...>
 make_tuple(_Tp&&... __t)
 {
@@ -1486,7 +1486,7 @@
 }
 
 template <class... _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 tuple<_Tp&&...>
 forward_as_tuple(_Tp&&... __t) _NOEXCEPT
 {
@@ -1497,7 +1497,7 @@
 struct __tuple_equal
 {
     template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _Tp& __x, const _Up& __y)
     {
         return __tuple_equal<_Ip - 1>()(__x, __y) && _VSTD::get<_Ip-1>(__x) == _VSTD::get<_Ip-1>(__y);
@@ -1508,7 +1508,7 @@
 struct __tuple_equal<0>
 {
     template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _Tp&, const _Up&)
     {
         return true;
@@ -1516,7 +1516,7 @@
 };
 
 template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator==(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
 {
@@ -1549,7 +1549,7 @@
 #else // _LIBCPP_STD_VER > 17
 
 template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator!=(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
 {
@@ -1560,7 +1560,7 @@
 struct __tuple_less
 {
     template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _Tp& __x, const _Up& __y)
     {
         const size_t __idx = tuple_size<_Tp>::value - _Ip;
@@ -1576,7 +1576,7 @@
 struct __tuple_less<0>
 {
     template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     bool operator()(const _Tp&, const _Up&)
     {
         return false;
@@ -1584,7 +1584,7 @@
 };
 
 template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator<(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
 {
@@ -1593,7 +1593,7 @@
 }
 
 template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator>(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
 {
@@ -1601,7 +1601,7 @@
 }
 
 template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator>=(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
 {
@@ -1609,7 +1609,7 @@
 }
 
 template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 bool
 operator<=(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
 {
@@ -1670,7 +1670,7 @@
     typedef _LIBCPP_NODEBUG tuple<> type;
 };
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 tuple<>
 tuple_cat()
 {
@@ -1717,7 +1717,7 @@
 struct __tuple_cat<tuple<_Types...>, __tuple_indices<_I0...>, __tuple_indices<_J0...> >
 {
     template <class _Tuple0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     typename __tuple_cat_return_ref<tuple<_Types...>&&, _Tuple0&&>::type
     operator()(tuple<_Types...> __t, _Tuple0&& __t0)
     {
@@ -1728,7 +1728,7 @@
     }
 
     template <class _Tuple0, class _Tuple1, class ..._Tuples>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
     typename __tuple_cat_return_ref<tuple<_Types...>&&, _Tuple0&&, _Tuple1&&, _Tuples&&...>::type
     operator()(tuple<_Types...> __t, _Tuple0&& __t0, _Tuple1&& __t1, _Tuples&& ...__tpls)
     {
@@ -1750,7 +1750,7 @@
 };
 
 template <class _Tuple0, class... _Tuples>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX14
 typename __tuple_cat_return<_Tuple0, _Tuples...>::type
 tuple_cat(_Tuple0&& __t0, _Tuples&&... __tpls)
 {
@@ -1767,7 +1767,7 @@
 
 template <class _T1, class _T2>
 template <class... _Args1, class... _Args2, size_t ..._I1, size_t ..._I2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 pair<_T1, _T2>::pair(piecewise_construct_t,
                      tuple<_Args1...>& __first_args, tuple<_Args2...>& __second_args,
                      __tuple_indices<_I1...>, __tuple_indices<_I2...>)
diff --git a/libcxx/include/type_traits b/libcxx/include/type_traits
--- a/libcxx/include/type_traits
+++ b/libcxx/include/type_traits
@@ -604,12 +604,12 @@
 
 template <class _Tp>
 inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 __swap_result_t<_Tp>
+_LIBCPP_CONSTEXPR_CXX20 __swap_result_t<_Tp>
 swap(_Tp& __x, _Tp& __y) _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value &&
                                     is_nothrow_move_assignable<_Tp>::value);
 
 template<class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 typename enable_if<
     __is_swappable<_Tp>::value
 >::type
diff --git a/libcxx/include/vector b/libcxx/include/vector
--- a/libcxx/include/vector
+++ b/libcxx/include/vector
@@ -360,12 +360,12 @@
     static_assert((is_same<typename allocator_type::value_type, value_type>::value),
                   "Allocator::value_type must be same type as value_type");
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     vector() _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
     {
         _VSTD::__debug_db_insert_c(this);
     }
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY explicit vector(const allocator_type& __a)
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY explicit vector(const allocator_type& __a)
 #if _LIBCPP_STD_VER <= 14
         _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
 #else
@@ -375,14 +375,14 @@
     {
         _VSTD::__debug_db_insert_c(this);
     }
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit vector(size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 explicit vector(size_type __n);
 #if _LIBCPP_STD_VER > 11
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit vector(size_type __n, const allocator_type& __a);
+    _LIBCPP_CONSTEXPR_CXX20 explicit vector(size_type __n, const allocator_type& __a);
 #endif
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(size_type __n, const value_type& __x);
+    _LIBCPP_CONSTEXPR_CXX20 vector(size_type __n, const value_type& __x);
 
     template <class = __enable_if_t<__is_allocator<_Allocator>::value> >
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     vector(size_type __n, const value_type& __x, const allocator_type& __a)
         : __end_cap_(nullptr, __a)
     {
@@ -395,7 +395,7 @@
     }
 
     template <class _InputIterator>
-        _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_CONSTEXPR_CXX20
         vector(_InputIterator __first,
                typename enable_if<__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
                                  is_constructible<
@@ -403,14 +403,14 @@
                                     typename iterator_traits<_InputIterator>::reference>::value,
                                  _InputIterator>::type __last);
     template <class _InputIterator>
-        _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_CONSTEXPR_CXX20
         vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a,
                typename enable_if<__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
                                  is_constructible<
                                     value_type,
                                     typename iterator_traits<_InputIterator>::reference>::value>::type* = 0);
     template <class _ForwardIterator>
-        _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_CONSTEXPR_CXX20
         vector(_ForwardIterator __first,
                typename enable_if<__is_cpp17_forward_iterator<_ForwardIterator>::value &&
                                  is_constructible<
@@ -418,14 +418,14 @@
                                     typename iterator_traits<_ForwardIterator>::reference>::value,
                                  _ForwardIterator>::type __last);
     template <class _ForwardIterator>
-        _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_CONSTEXPR_CXX20
         vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a,
                typename enable_if<__is_cpp17_forward_iterator<_ForwardIterator>::value &&
                                  is_constructible<
                                     value_type,
                                     typename iterator_traits<_ForwardIterator>::reference>::value>::type* = 0);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     ~vector()
     {
       __annotate_delete();
@@ -438,24 +438,24 @@
       }
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(const vector& __x);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(const vector& __x, const __type_identity_t<allocator_type>& __a);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 vector(const vector& __x);
+    _LIBCPP_CONSTEXPR_CXX20 vector(const vector& __x, const __type_identity_t<allocator_type>& __a);
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     vector& operator=(const vector& __x);
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     vector(initializer_list<value_type> __il);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     vector(initializer_list<value_type> __il, const allocator_type& __a);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     vector& operator=(initializer_list<value_type> __il)
         {assign(__il.begin(), __il.end()); return *this;}
 #endif // !_LIBCPP_CXX03_LANG
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     vector(vector&& __x)
 #if _LIBCPP_STD_VER > 14
         noexcept;
@@ -463,14 +463,14 @@
         _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
 #endif
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     vector(vector&& __x, const __type_identity_t<allocator_type>& __a);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     vector& operator=(vector&& __x)
         _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
 
     template <class _InputIterator>
-        _LIBCPP_CONSTEXPR_AFTER_CXX17 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
+        _LIBCPP_CONSTEXPR_CXX20 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
             is_constructible<
                  value_type,
                  typename iterator_traits<_InputIterator>::reference>::value,
@@ -478,7 +478,7 @@
         >::type
         assign(_InputIterator __first, _InputIterator __last);
     template <class _ForwardIterator>
-        _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_CONSTEXPR_CXX20
         typename enable_if
         <
             __is_cpp17_forward_iterator<_ForwardIterator>::value &&
@@ -489,120 +489,120 @@
         >::type
         assign(_ForwardIterator __first, _ForwardIterator __last);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void assign(size_type __n, const_reference __u);
+    _LIBCPP_CONSTEXPR_CXX20 void assign(size_type __n, const_reference __u);
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void assign(initializer_list<value_type> __il)
         {assign(__il.begin(), __il.end());}
 #endif
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     allocator_type get_allocator() const _NOEXCEPT
         {return this->__alloc();}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY iterator               begin() _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const_iterator         begin()   const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY iterator               end() _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const_iterator         end()     const _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY iterator               begin() _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const_iterator         begin()   const _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY iterator               end() _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const_iterator         end()     const _NOEXCEPT;
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     reverse_iterator       rbegin() _NOEXCEPT
         {return       reverse_iterator(end());}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator rbegin()  const _NOEXCEPT
         {return const_reverse_iterator(end());}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     reverse_iterator       rend() _NOEXCEPT
         {return       reverse_iterator(begin());}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator rend()    const _NOEXCEPT
         {return const_reverse_iterator(begin());}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     const_iterator         cbegin()  const _NOEXCEPT
         {return begin();}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     const_iterator         cend()    const _NOEXCEPT
         {return end();}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator crbegin() const _NOEXCEPT
         {return rbegin();}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator crend()   const _NOEXCEPT
         {return rend();}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT
         {return static_cast<size_type>(this->__end_ - this->__begin_);}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     size_type capacity() const _NOEXCEPT
         {return static_cast<size_type>(__end_cap() - this->__begin_);}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT
         {return this->__begin_ == this->__end_;}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 size_type max_size() const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void reserve(size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void shrink_to_fit() _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 size_type max_size() const _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 void reserve(size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 void shrink_to_fit() _NOEXCEPT;
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY reference       operator[](size_type __n) _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const_reference operator[](size_type __n) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 reference       at(size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 const_reference at(size_type __n) const;
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY reference       operator[](size_type __n) _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const_reference operator[](size_type __n) const _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 reference       at(size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 const_reference at(size_type __n) const;
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY reference       front() _NOEXCEPT
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY reference       front() _NOEXCEPT
     {
         _LIBCPP_ASSERT(!empty(), "front() called on an empty vector");
         return *this->__begin_;
     }
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const_reference front() const _NOEXCEPT
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const_reference front() const _NOEXCEPT
     {
         _LIBCPP_ASSERT(!empty(), "front() called on an empty vector");
         return *this->__begin_;
     }
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY reference       back() _NOEXCEPT
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY reference       back() _NOEXCEPT
     {
         _LIBCPP_ASSERT(!empty(), "back() called on an empty vector");
         return *(this->__end_ - 1);
     }
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const_reference back()  const _NOEXCEPT
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY const_reference back()  const _NOEXCEPT
     {
         _LIBCPP_ASSERT(!empty(), "back() called on an empty vector");
         return *(this->__end_ - 1);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     value_type*       data() _NOEXCEPT
         {return _VSTD::__to_address(this->__begin_);}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     const value_type* data() const _NOEXCEPT
         {return _VSTD::__to_address(this->__begin_);}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY void push_back(value_type&& __x);
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY void push_back(value_type&& __x);
 
     template <class... _Args>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
 #if _LIBCPP_STD_VER > 14
         reference emplace_back(_Args&&... __args);
 #else
         void      emplace_back(_Args&&... __args);
 #endif
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void pop_back();
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator insert(const_iterator __position, const_reference __x);
+    _LIBCPP_CONSTEXPR_CXX20 iterator insert(const_iterator __position, const_reference __x);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator insert(const_iterator __position, value_type&& __x);
+    _LIBCPP_CONSTEXPR_CXX20 iterator insert(const_iterator __position, value_type&& __x);
     template <class... _Args>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator emplace(const_iterator __position, _Args&&... __args);
+    _LIBCPP_CONSTEXPR_CXX20 iterator emplace(const_iterator __position, _Args&&... __args);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator insert(const_iterator __position, size_type __n, const_reference __x);
+    _LIBCPP_CONSTEXPR_CXX20 iterator insert(const_iterator __position, size_type __n, const_reference __x);
     template <class _InputIterator>
-        _LIBCPP_CONSTEXPR_AFTER_CXX17 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
+        _LIBCPP_CONSTEXPR_CXX20 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
             is_constructible<
                  value_type,
                  typename iterator_traits<_InputIterator>::reference>::value,
@@ -610,7 +610,7 @@
         >::type
         insert(const_iterator __position, _InputIterator __first, _InputIterator __last);
     template <class _ForwardIterator>
-        _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_CONSTEXPR_CXX20
         typename enable_if
         <
             __is_cpp17_forward_iterator<_ForwardIterator>::value &&
@@ -622,15 +622,15 @@
         insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last);
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     iterator insert(const_iterator __position, initializer_list<value_type> __il)
         {return insert(__position, __il.begin(), __il.end());}
 #endif
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY iterator erase(const_iterator __position);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator erase(const_iterator __first, const_iterator __last);
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY iterator erase(const_iterator __position);
+    _LIBCPP_CONSTEXPR_CXX20 iterator erase(const_iterator __first, const_iterator __last);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void clear() _NOEXCEPT
     {
         size_type __old_size = size();
@@ -639,10 +639,10 @@
         std::__debug_db_invalidate_all(this);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void resize(size_type __sz);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void resize(size_type __sz, const_reference __x);
+    _LIBCPP_CONSTEXPR_CXX20 void resize(size_type __sz);
+    _LIBCPP_CONSTEXPR_CXX20 void resize(size_type __sz, const_reference __x);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void swap(vector&)
+    _LIBCPP_CONSTEXPR_CXX20 void swap(vector&)
 #if _LIBCPP_STD_VER >= 14
         _NOEXCEPT;
 #else
@@ -650,7 +650,7 @@
                     __is_nothrow_swappable<allocator_type>::value);
 #endif
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 bool __invariants() const;
+    _LIBCPP_CONSTEXPR_CXX20 bool __invariants() const;
 
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
 
@@ -676,7 +676,7 @@
     //  Precondition:  __n > 0
     //  Postcondition:  capacity() >= __n
     //  Postcondition:  size() == 0
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI void __vallocate(size_type __n) {
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_HIDE_FROM_ABI void __vallocate(size_type __n) {
         if (__n > max_size())
             __throw_length_error();
         auto __allocation = std::__allocate_at_least(__alloc(), __n);
@@ -686,33 +686,33 @@
         __annotate_new(0);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __vdeallocate() _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY size_type __recommend(size_type __new_size) const;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct_at_end(size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 void __vdeallocate() _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY size_type __recommend(size_type __new_size) const;
+    _LIBCPP_CONSTEXPR_CXX20 void __construct_at_end(size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void __construct_at_end(size_type __n, const_reference __x);
     template <class _ForwardIterator>
-        _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_CONSTEXPR_CXX20
         typename enable_if
         <
             __is_cpp17_forward_iterator<_ForwardIterator>::value,
             void
         >::type
         __construct_at_end(_ForwardIterator __first, _ForwardIterator __last, size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __append(size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __append(size_type __n, const_reference __x);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 void __append(size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 void __append(size_type __n, const_reference __x);
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     iterator       __make_iter(pointer __p) _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     const_iterator __make_iter(const_pointer __p) const _NOEXCEPT;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 pointer __swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v, pointer __p);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __move_range(pointer __from_s, pointer __from_e, pointer __to);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __move_assign(vector& __c, true_type)
+    _LIBCPP_CONSTEXPR_CXX20 void __swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v);
+    _LIBCPP_CONSTEXPR_CXX20 pointer __swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v, pointer __p);
+    _LIBCPP_CONSTEXPR_CXX20 void __move_range(pointer __from_s, pointer __from_e, pointer __to);
+    _LIBCPP_CONSTEXPR_CXX20 void __move_assign(vector& __c, true_type)
         _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __move_assign(vector& __c, false_type)
+    _LIBCPP_CONSTEXPR_CXX20 void __move_assign(vector& __c, false_type)
         _NOEXCEPT_(__alloc_traits::is_always_equal::value);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void __destruct_at_end(pointer __new_last) _NOEXCEPT
     {
         if (!__libcpp_is_constant_evaluated())
@@ -723,11 +723,11 @@
     }
 
     template <class _Up>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     inline void __push_back_slow_path(_Up&& __x);
 
     template <class... _Args>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     inline void __emplace_back_slow_path(_Args&&... __args);
 
     // The following functions are no-ops outside of AddressSanitizer mode.
@@ -735,7 +735,7 @@
     // may not meet the AddressSanitizer alignment constraints.
     // See the documentation for __sanitizer_annotate_contiguous_container for more details.
 #ifndef _LIBCPP_HAS_NO_ASAN
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     void __annotate_contiguous_container(const void *__beg, const void *__end,
                                          const void *__old_mid,
                                          const void *__new_mid) const
@@ -745,30 +745,30 @@
         __sanitizer_annotate_contiguous_container(__beg, __end, __old_mid, __new_mid);
     }
 #else
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void __annotate_contiguous_container(const void*, const void*, const void*,
                                          const void*) const _NOEXCEPT {}
 #endif
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void __annotate_new(size_type __current_size) const _NOEXCEPT {
       __annotate_contiguous_container(data(), data() + capacity(),
                                       data() + capacity(), data() + __current_size);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void __annotate_delete() const _NOEXCEPT {
       __annotate_contiguous_container(data(), data() + capacity(),
                                       data() + size(), data() + capacity());
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void __annotate_increase(size_type __n) const _NOEXCEPT
     {
       __annotate_contiguous_container(data(), data() + capacity(),
                                       data() + size(), data() + size() + __n);
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
     void __annotate_shrink(size_type __old_size) const _NOEXCEPT
     {
       __annotate_contiguous_container(data(), data() + capacity(),
@@ -776,14 +776,14 @@
     }
 
   struct _ConstructTransaction {
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20
     explicit _ConstructTransaction(vector &__v, size_type __n)
       : __v_(__v), __pos_(__v.__end_), __new_end_(__v.__end_ + __n) {
 #ifndef _LIBCPP_HAS_NO_ASAN
       __v_.__annotate_increase(__n);
 #endif
     }
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 ~_ConstructTransaction() {
+    _LIBCPP_CONSTEXPR_CXX20 ~_ConstructTransaction() {
       __v_.__end_ = __pos_;
 #ifndef _LIBCPP_HAS_NO_ASAN
       if (__pos_ != __new_end_) {
@@ -802,7 +802,7 @@
   };
 
   template <class ..._Args>
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   void __construct_one_at_end(_Args&& ...__args) {
     _ConstructTransaction __tx(*this, 1);
     __alloc_traits::construct(this->__alloc(), _VSTD::__to_address(__tx.__pos_),
@@ -810,23 +810,23 @@
     ++__tx.__pos_;
   }
 
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   allocator_type& __alloc() _NOEXCEPT
       {return this->__end_cap_.second();}
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   const allocator_type& __alloc() const _NOEXCEPT
       {return this->__end_cap_.second();}
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   pointer& __end_cap() _NOEXCEPT
       {return this->__end_cap_.first();}
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   const pointer& __end_cap() const _NOEXCEPT
       {return this->__end_cap_.first();}
 
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   void __clear() _NOEXCEPT {__base_destruct_at_end(this->__begin_);}
 
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   void __base_destruct_at_end(pointer __new_last) _NOEXCEPT {
     pointer __soon_to_be_end = this->__end_;
     while (__new_last != __soon_to_be_end)
@@ -834,12 +834,12 @@
     this->__end_ = __new_last;
   }
 
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   void __copy_assign_alloc(const vector& __c)
       {__copy_assign_alloc(__c, integral_constant<bool,
                     __alloc_traits::propagate_on_container_copy_assignment::value>());}
 
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   void __move_assign_alloc(vector& __c)
       _NOEXCEPT_(
           !__alloc_traits::propagate_on_container_move_assignment::value ||
@@ -857,7 +857,7 @@
       _VSTD::__throw_out_of_range("vector");
   }
 
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   void __copy_assign_alloc(const vector& __c, true_type)
   {
     if (__alloc() != __c.__alloc())
@@ -869,18 +869,18 @@
     __alloc() = __c.__alloc();
   }
 
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   void __copy_assign_alloc(const vector&, false_type)
   {}
 
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   void __move_assign_alloc(vector& __c, true_type)
       _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
   {
     __alloc() = _VSTD::move(__c.__alloc());
   }
 
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR_CXX20 _LIBCPP_INLINE_VISIBILITY
   void __move_assign_alloc(vector&, false_type)
       _NOEXCEPT
   {}
@@ -905,7 +905,7 @@
 #endif
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v)
 {
@@ -923,7 +923,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<_Tp, _Allocator>::pointer
 vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v, pointer __p)
 {
@@ -944,7 +944,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::__vdeallocate() _NOEXCEPT
 {
@@ -957,7 +957,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<_Tp, _Allocator>::size_type
 vector<_Tp, _Allocator>::max_size() const _NOEXCEPT
 {
@@ -967,7 +967,7 @@
 
 //  Precondition:  __new_size > capacity()
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 typename vector<_Tp, _Allocator>::size_type
 vector<_Tp, _Allocator>::__recommend(size_type __new_size) const
@@ -987,7 +987,7 @@
 //  Precondition:  size() + __n <= capacity()
 //  Postcondition:  size() == size() + __n
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::__construct_at_end(size_type __n)
 {
@@ -1005,7 +1005,7 @@
 //  Postcondition:  size() == old size() + __n
 //  Postcondition:  [i] == __x for all i in [size() - __n, __n)
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline
 void
 vector<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x)
@@ -1019,7 +1019,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename enable_if
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -1036,7 +1036,7 @@
 //  Postcondition:  size() == size() + __n
 //  Exception safety: strong.
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::__append(size_type __n)
 {
@@ -1056,7 +1056,7 @@
 //  Postcondition:  size() == size() + __n
 //  Exception safety: strong.
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::__append(size_type __n, const_reference __x)
 {
@@ -1072,7 +1072,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<_Tp, _Allocator>::vector(size_type __n)
 {
     _VSTD::__debug_db_insert_c(this);
@@ -1085,7 +1085,7 @@
 
 #if _LIBCPP_STD_VER > 11
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<_Tp, _Allocator>::vector(size_type __n, const allocator_type& __a)
     : __end_cap_(nullptr, __a)
 {
@@ -1099,7 +1099,7 @@
 #endif
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<_Tp, _Allocator>::vector(size_type __n, const value_type& __x)
 {
     _VSTD::__debug_db_insert_c(this);
@@ -1112,7 +1112,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<_Tp, _Allocator>::vector(_InputIterator __first,
        typename enable_if<__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
                          is_constructible<
@@ -1127,7 +1127,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<_Tp, _Allocator>::vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a,
        typename enable_if<__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
                          is_constructible<
@@ -1142,7 +1142,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<_Tp, _Allocator>::vector(_ForwardIterator __first,
                                 typename enable_if<__is_cpp17_forward_iterator<_ForwardIterator>::value &&
                                 is_constructible<
@@ -1161,7 +1161,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<_Tp, _Allocator>::vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a,
                                 typename enable_if<__is_cpp17_forward_iterator<_ForwardIterator>::value &&
                                 is_constructible<
@@ -1179,7 +1179,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<_Tp, _Allocator>::vector(const vector& __x)
     : __end_cap_(nullptr, __alloc_traits::select_on_container_copy_construction(__x.__alloc()))
 {
@@ -1193,7 +1193,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<_Tp, _Allocator>::vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
     : __end_cap_(nullptr, __a)
 {
@@ -1207,7 +1207,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 vector<_Tp, _Allocator>::vector(vector&& __x)
 #if _LIBCPP_STD_VER > 14
@@ -1226,7 +1226,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 vector<_Tp, _Allocator>::vector(vector&& __x, const __type_identity_t<allocator_type>& __a)
     : __end_cap_(nullptr, __a)
@@ -1250,7 +1250,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 vector<_Tp, _Allocator>::vector(initializer_list<value_type> __il)
 {
@@ -1263,7 +1263,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 vector<_Tp, _Allocator>::vector(initializer_list<value_type> __il, const allocator_type& __a)
     : __end_cap_(nullptr, __a)
@@ -1279,7 +1279,7 @@
 #endif // _LIBCPP_CXX03_LANG
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 vector<_Tp, _Allocator>&
 vector<_Tp, _Allocator>::operator=(vector&& __x)
@@ -1291,7 +1291,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::__move_assign(vector& __c, false_type)
     _NOEXCEPT_(__alloc_traits::is_always_equal::value)
@@ -1306,7 +1306,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::__move_assign(vector& __c, true_type)
     _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
@@ -1321,7 +1321,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 vector<_Tp, _Allocator>&
 vector<_Tp, _Allocator>::operator=(const vector& __x)
@@ -1336,7 +1336,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
+_LIBCPP_CONSTEXPR_CXX20 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
     is_constructible<
        _Tp,
        typename iterator_traits<_InputIterator>::reference>::value,
@@ -1351,7 +1351,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename enable_if
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value &&
@@ -1389,7 +1389,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::assign(size_type __n, const_reference __u)
 {
@@ -1412,7 +1412,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 typename vector<_Tp, _Allocator>::iterator
 vector<_Tp, _Allocator>::begin() _NOEXCEPT
@@ -1421,7 +1421,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 typename vector<_Tp, _Allocator>::const_iterator
 vector<_Tp, _Allocator>::begin() const _NOEXCEPT
@@ -1430,7 +1430,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 typename vector<_Tp, _Allocator>::iterator
 vector<_Tp, _Allocator>::end() _NOEXCEPT
@@ -1439,7 +1439,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 typename vector<_Tp, _Allocator>::const_iterator
 vector<_Tp, _Allocator>::end() const _NOEXCEPT
@@ -1448,7 +1448,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 typename vector<_Tp, _Allocator>::reference
 vector<_Tp, _Allocator>::operator[](size_type __n) _NOEXCEPT
@@ -1458,7 +1458,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 typename vector<_Tp, _Allocator>::const_reference
 vector<_Tp, _Allocator>::operator[](size_type __n) const _NOEXCEPT
@@ -1468,7 +1468,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<_Tp, _Allocator>::reference
 vector<_Tp, _Allocator>::at(size_type __n)
 {
@@ -1478,7 +1478,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<_Tp, _Allocator>::const_reference
 vector<_Tp, _Allocator>::at(size_type __n) const
 {
@@ -1488,7 +1488,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::reserve(size_type __n)
 {
@@ -1503,7 +1503,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
 {
@@ -1527,7 +1527,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _Up>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::__push_back_slow_path(_Up&& __x)
 {
@@ -1540,7 +1540,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 void
 vector<_Tp, _Allocator>::push_back(const_reference __x)
@@ -1554,7 +1554,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 void
 vector<_Tp, _Allocator>::push_back(value_type&& __x)
@@ -1569,7 +1569,7 @@
 
 template <class _Tp, class _Allocator>
 template <class... _Args>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::__emplace_back_slow_path(_Args&&... __args)
 {
@@ -1583,7 +1583,7 @@
 
 template <class _Tp, class _Allocator>
 template <class... _Args>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline
 #if _LIBCPP_STD_VER > 14
 typename vector<_Tp, _Allocator>::reference
@@ -1604,7 +1604,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline
 void
 vector<_Tp, _Allocator>::pop_back()
@@ -1614,7 +1614,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 typename vector<_Tp, _Allocator>::iterator
 vector<_Tp, _Allocator>::erase(const_iterator __position)
@@ -1633,7 +1633,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<_Tp, _Allocator>::iterator
 vector<_Tp, _Allocator>::erase(const_iterator __first, const_iterator __last)
 {
@@ -1654,7 +1654,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::__move_range(pointer __from_s, pointer __from_e, pointer __to)
 {
@@ -1674,7 +1674,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<_Tp, _Allocator>::iterator
 vector<_Tp, _Allocator>::insert(const_iterator __position, const_reference __x)
 {
@@ -1708,7 +1708,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<_Tp, _Allocator>::iterator
 vector<_Tp, _Allocator>::insert(const_iterator __position, value_type&& __x)
 {
@@ -1739,7 +1739,7 @@
 
 template <class _Tp, class _Allocator>
 template <class... _Args>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<_Tp, _Allocator>::iterator
 vector<_Tp, _Allocator>::emplace(const_iterator __position, _Args&&... __args)
 {
@@ -1770,7 +1770,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<_Tp, _Allocator>::iterator
 vector<_Tp, _Allocator>::insert(const_iterator __position, size_type __n, const_reference __x)
 {
@@ -1812,7 +1812,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
+_LIBCPP_CONSTEXPR_CXX20 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value &&
     is_constructible<
        _Tp,
        typename iterator_traits<_InputIterator>::reference>::value,
@@ -1860,7 +1860,7 @@
 
 template <class _Tp, class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename enable_if
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value &&
@@ -1909,7 +1909,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::resize(size_type __sz)
 {
@@ -1921,7 +1921,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::resize(size_type __sz, const_reference __x)
 {
@@ -1933,7 +1933,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 void
 vector<_Tp, _Allocator>::swap(vector& __x)
 #if _LIBCPP_STD_VER >= 14
@@ -1956,7 +1956,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 bool
 vector<_Tp, _Allocator>::__invariants() const
 {
@@ -2079,81 +2079,81 @@
     typedef __bit_const_reference<vector>            const_reference;
 #endif
 private:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     size_type& __cap() _NOEXCEPT
         {return __cap_alloc_.first();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const size_type& __cap() const _NOEXCEPT
         {return __cap_alloc_.first();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     __storage_allocator& __alloc() _NOEXCEPT
         {return __cap_alloc_.second();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const __storage_allocator& __alloc() const _NOEXCEPT
         {return __cap_alloc_.second();}
 
     static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static size_type __internal_cap_to_external(size_type __n) _NOEXCEPT
         {return __n * __bits_per_word;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static size_type __external_cap_to_internal(size_type __n) _NOEXCEPT
         {return (__n - 1) / __bits_per_word + 1;}
 
 public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     vector() _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit vector(const allocator_type& __a)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 explicit vector(const allocator_type& __a)
 #if _LIBCPP_STD_VER <= 14
         _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value);
 #else
         _NOEXCEPT;
 #endif
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 ~vector();
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit vector(size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 ~vector();
+    _LIBCPP_CONSTEXPR_CXX20 explicit vector(size_type __n);
 #if _LIBCPP_STD_VER > 11
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit vector(size_type __n, const allocator_type& __a);
+    _LIBCPP_CONSTEXPR_CXX20 explicit vector(size_type __n, const allocator_type& __a);
 #endif
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(size_type __n, const value_type& __v);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(size_type __n, const value_type& __v, const allocator_type& __a);
+    _LIBCPP_CONSTEXPR_CXX20 vector(size_type __n, const value_type& __v);
+    _LIBCPP_CONSTEXPR_CXX20 vector(size_type __n, const value_type& __v, const allocator_type& __a);
     template <class _InputIterator>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(_InputIterator __first, _InputIterator __last,
+    _LIBCPP_CONSTEXPR_CXX20 vector(_InputIterator __first, _InputIterator __last,
                typename enable_if<__is_exactly_cpp17_input_iterator<_InputIterator>::value>::type* = 0);
     template <class _InputIterator>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a,
+    _LIBCPP_CONSTEXPR_CXX20 vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a,
                typename enable_if<__is_exactly_cpp17_input_iterator<_InputIterator>::value>::type* = 0);
     template <class _ForwardIterator>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(_ForwardIterator __first, _ForwardIterator __last,
+    _LIBCPP_CONSTEXPR_CXX20 vector(_ForwardIterator __first, _ForwardIterator __last,
                typename enable_if<__is_cpp17_forward_iterator<_ForwardIterator>::value>::type* = 0);
     template <class _ForwardIterator>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a,
+    _LIBCPP_CONSTEXPR_CXX20 vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a,
                typename enable_if<__is_cpp17_forward_iterator<_ForwardIterator>::value>::type* = 0);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(const vector& __v);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(const vector& __v, const allocator_type& __a);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector& operator=(const vector& __v);
+    _LIBCPP_CONSTEXPR_CXX20 vector(const vector& __v);
+    _LIBCPP_CONSTEXPR_CXX20 vector(const vector& __v, const allocator_type& __a);
+    _LIBCPP_CONSTEXPR_CXX20 vector& operator=(const vector& __v);
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(initializer_list<value_type> __il);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(initializer_list<value_type> __il, const allocator_type& __a);
+    _LIBCPP_CONSTEXPR_CXX20 vector(initializer_list<value_type> __il);
+    _LIBCPP_CONSTEXPR_CXX20 vector(initializer_list<value_type> __il, const allocator_type& __a);
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     vector& operator=(initializer_list<value_type> __il)
         {assign(__il.begin(), __il.end()); return *this;}
 
 #endif // !_LIBCPP_CXX03_LANG
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     vector(vector&& __v)
 #if _LIBCPP_STD_VER > 14
         noexcept;
 #else
         _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
 #endif
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 vector(vector&& __v, const __type_identity_t<allocator_type>& __a);
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20 vector(vector&& __v, const __type_identity_t<allocator_type>& __a);
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     vector& operator=(vector&& __v)
         _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
 
@@ -2161,93 +2161,93 @@
         typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value,
            void
         >::type
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 assign(_InputIterator __first, _InputIterator __last);
+    _LIBCPP_CONSTEXPR_CXX20 assign(_InputIterator __first, _InputIterator __last);
     template <class _ForwardIterator>
         typename enable_if
         <
             __is_cpp17_forward_iterator<_ForwardIterator>::value,
            void
         >::type
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 assign(_ForwardIterator __first, _ForwardIterator __last);
+    _LIBCPP_CONSTEXPR_CXX20 assign(_ForwardIterator __first, _ForwardIterator __last);
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void assign(size_type __n, const value_type& __x);
+    _LIBCPP_CONSTEXPR_CXX20 void assign(size_type __n, const value_type& __x);
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void assign(initializer_list<value_type> __il)
         {assign(__il.begin(), __il.end());}
 #endif
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 allocator_type get_allocator() const _NOEXCEPT
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 allocator_type get_allocator() const _NOEXCEPT
         {return allocator_type(this->__alloc());}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 size_type max_size() const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20 size_type max_size() const _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     size_type capacity() const _NOEXCEPT
         {return __internal_cap_to_external(__cap());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     size_type size() const _NOEXCEPT
         {return __size_;}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     bool empty() const _NOEXCEPT
         {return __size_ == 0;}
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void reserve(size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void shrink_to_fit() _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 void reserve(size_type __n);
+    _LIBCPP_CONSTEXPR_CXX20 void shrink_to_fit() _NOEXCEPT;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     iterator begin() _NOEXCEPT
         {return __make_iter(0);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const_iterator begin() const _NOEXCEPT
         {return __make_iter(0);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     iterator end() _NOEXCEPT
         {return __make_iter(__size_);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const_iterator end()   const _NOEXCEPT
         {return __make_iter(__size_);}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     reverse_iterator rbegin() _NOEXCEPT
         {return       reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const_reverse_iterator rbegin() const _NOEXCEPT
         {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     reverse_iterator rend() _NOEXCEPT
         {return       reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const_reverse_iterator rend()   const _NOEXCEPT
         {return const_reverse_iterator(begin());}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const_iterator         cbegin()  const _NOEXCEPT
         {return __make_iter(0);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const_iterator         cend()    const _NOEXCEPT
         {return __make_iter(__size_);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const_reverse_iterator crbegin() const _NOEXCEPT
         {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const_reverse_iterator crend()   const _NOEXCEPT
         {return rend();}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 reference       operator[](size_type __n)       {return __make_ref(__n);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 const_reference operator[](size_type __n) const {return __make_ref(__n);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 reference       operator[](size_type __n)       {return __make_ref(__n);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 const_reference operator[](size_type __n) const {return __make_ref(__n);}
     reference       at(size_type __n);
     const_reference at(size_type __n) const;
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 reference       front()       {return __make_ref(0);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 const_reference front() const {return __make_ref(0);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 reference       back()        {return __make_ref(__size_ - 1);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 const_reference back()  const {return __make_ref(__size_ - 1);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 reference       front()       {return __make_ref(0);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 const_reference front() const {return __make_ref(0);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 reference       back()        {return __make_ref(__size_ - 1);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 const_reference back()  const {return __make_ref(__size_ - 1);}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void push_back(const value_type& __x);
+    _LIBCPP_CONSTEXPR_CXX20 void push_back(const value_type& __x);
 #if _LIBCPP_STD_VER > 11
     template <class... _Args>
 #if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 reference emplace_back(_Args&&... __args)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 reference emplace_back(_Args&&... __args)
 #else
     _LIBCPP_INLINE_VISIBILITY void      emplace_back(_Args&&... __args)
 #endif
@@ -2259,54 +2259,54 @@
     }
 #endif
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 void pop_back() {--__size_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 void pop_back() {--__size_;}
 
 #if _LIBCPP_STD_VER > 11
     template <class... _Args>
-   _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator emplace(const_iterator __position, _Args&&... __args)
+   _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 iterator emplace(const_iterator __position, _Args&&... __args)
         { return insert ( __position, value_type ( _VSTD::forward<_Args>(__args)... )); }
 #endif
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator insert(const_iterator __position, const value_type& __x);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator insert(const_iterator __position, size_type __n, const value_type& __x);
+    _LIBCPP_CONSTEXPR_CXX20 iterator insert(const_iterator __position, const value_type& __x);
+    _LIBCPP_CONSTEXPR_CXX20 iterator insert(const_iterator __position, size_type __n, const value_type& __x);
     template <class _InputIterator>
         typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value,
             iterator
         >::type
-        _LIBCPP_CONSTEXPR_AFTER_CXX17 insert(const_iterator __position, _InputIterator __first, _InputIterator __last);
+        _LIBCPP_CONSTEXPR_CXX20 insert(const_iterator __position, _InputIterator __first, _InputIterator __last);
     template <class _ForwardIterator>
         typename enable_if
         <
             __is_cpp17_forward_iterator<_ForwardIterator>::value,
             iterator
         >::type
-        _LIBCPP_CONSTEXPR_AFTER_CXX17 insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last);
+        _LIBCPP_CONSTEXPR_CXX20 insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last);
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     iterator insert(const_iterator __position, initializer_list<value_type> __il)
         {return insert(__position, __il.begin(), __il.end());}
 #endif
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator erase(const_iterator __position);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 iterator erase(const_iterator __first, const_iterator __last);
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 iterator erase(const_iterator __position);
+    _LIBCPP_CONSTEXPR_CXX20 iterator erase(const_iterator __first, const_iterator __last);
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void clear() _NOEXCEPT {__size_ = 0;}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void swap(vector&)
+    _LIBCPP_CONSTEXPR_CXX20 void swap(vector&)
 #if _LIBCPP_STD_VER >= 14
         _NOEXCEPT;
 #else
         _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
                     __is_nothrow_swappable<allocator_type>::value);
 #endif
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 static void swap(reference __x, reference __y) _NOEXCEPT { _VSTD::swap(__x, __y); }
+    _LIBCPP_CONSTEXPR_CXX20 static void swap(reference __x, reference __y) _NOEXCEPT { _VSTD::swap(__x, __y); }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void resize(size_type __sz, value_type __x = false);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void flip() _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 void resize(size_type __sz, value_type __x = false);
+    _LIBCPP_CONSTEXPR_CXX20 void flip() _NOEXCEPT;
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 bool __invariants() const;
+    _LIBCPP_CONSTEXPR_CXX20 bool __invariants() const;
 
 private:
     _LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI
@@ -2326,7 +2326,7 @@
     //  Precondition:  __n > 0
     //  Postcondition:  capacity() >= __n
     //  Postcondition:  size() == 0
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 void __vallocate(size_type __n) {
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_CXX20 void __vallocate(size_type __n) {
         if (__n > max_size())
             __throw_length_error();
         auto __allocation = std::__allocate_at_least(__alloc(), __external_cap_to_internal(__n));
@@ -2339,43 +2339,43 @@
         }
     }
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __vdeallocate() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_CXX20 void __vdeallocate() _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     static size_type __align_it(size_type __new_size) _NOEXCEPT
         {return (__new_size + (__bits_per_word-1)) & ~((size_type)__bits_per_word-1);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17  size_type __recommend(size_type __new_size) const;
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct_at_end(size_type __n, bool __x);
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20  size_type __recommend(size_type __new_size) const;
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 void __construct_at_end(size_type __n, bool __x);
     template <class _ForwardIterator>
         typename enable_if
         <
             __is_cpp17_forward_iterator<_ForwardIterator>::value,
             void
         >::type
-        _LIBCPP_CONSTEXPR_AFTER_CXX17 __construct_at_end(_ForwardIterator __first, _ForwardIterator __last);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __append(size_type __n, const_reference __x);
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+        _LIBCPP_CONSTEXPR_CXX20 __construct_at_end(_ForwardIterator __first, _ForwardIterator __last);
+    _LIBCPP_CONSTEXPR_CXX20 void __append(size_type __n, const_reference __x);
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     reference __make_ref(size_type __pos) _NOEXCEPT
         {return reference(__begin_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const_reference __make_ref(size_type __pos) const _NOEXCEPT {
         return __bit_const_reference<vector>(__begin_ + __pos / __bits_per_word,
                                              __storage_type(1) << __pos % __bits_per_word);
     }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     iterator __make_iter(size_type __pos) _NOEXCEPT
         {return iterator(__begin_ + __pos / __bits_per_word, static_cast<unsigned>(__pos % __bits_per_word));}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     const_iterator __make_iter(size_type __pos) const _NOEXCEPT
         {return const_iterator(__begin_ + __pos / __bits_per_word, static_cast<unsigned>(__pos % __bits_per_word));}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     iterator __const_iterator_cast(const_iterator __p) _NOEXCEPT
         {return begin() + (__p - cbegin());}
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void __copy_assign_alloc(const vector& __v)
         {__copy_assign_alloc(__v, integral_constant<bool,
                       __storage_traits::propagate_on_container_copy_assignment::value>());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void __copy_assign_alloc(const vector& __c, true_type)
         {
             if (__alloc() != __c.__alloc())
@@ -2383,33 +2383,33 @@
             __alloc() = __c.__alloc();
         }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void __copy_assign_alloc(const vector&, false_type)
         {}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __move_assign(vector& __c, false_type);
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 void __move_assign(vector& __c, true_type)
+    _LIBCPP_CONSTEXPR_CXX20 void __move_assign(vector& __c, false_type);
+    _LIBCPP_CONSTEXPR_CXX20 void __move_assign(vector& __c, true_type)
         _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void __move_assign_alloc(vector& __c)
         _NOEXCEPT_(
             !__storage_traits::propagate_on_container_move_assignment::value ||
             is_nothrow_move_assignable<allocator_type>::value)
         {__move_assign_alloc(__c, integral_constant<bool,
                       __storage_traits::propagate_on_container_move_assignment::value>());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void __move_assign_alloc(vector& __c, true_type)
         _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
         {
             __alloc() = _VSTD::move(__c.__alloc());
         }
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     void __move_assign_alloc(vector&, false_type)
         _NOEXCEPT
         {}
 
-    _LIBCPP_CONSTEXPR_AFTER_CXX17 size_t __hash_code() const _NOEXCEPT;
+    _LIBCPP_CONSTEXPR_CXX20 size_t __hash_code() const _NOEXCEPT;
 
     friend class __bit_reference<vector>;
     friend class __bit_const_reference<vector>;
@@ -2420,7 +2420,7 @@
 };
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 vector<bool, _Allocator>::__vdeallocate() _NOEXCEPT
 {
     if (this->__begin_ != nullptr)
@@ -2433,7 +2433,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<bool, _Allocator>::size_type
 vector<bool, _Allocator>::max_size() const _NOEXCEPT
 {
@@ -2446,7 +2446,7 @@
 
 //  Precondition:  __new_size > capacity()
 template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 typename vector<bool, _Allocator>::size_type
 vector<bool, _Allocator>::__recommend(size_type __new_size) const
 {
@@ -2464,7 +2464,7 @@
 //  Precondition:  size() + __n <= capacity()
 //  Postcondition:  size() == size() + __n
 template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 void
 vector<bool, _Allocator>::__construct_at_end(size_type __n, bool __x)
 {
@@ -2482,7 +2482,7 @@
 
 template <class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename enable_if
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -2503,7 +2503,7 @@
 }
 
 template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector()
     _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
     : __begin_(nullptr),
@@ -2513,7 +2513,7 @@
 }
 
 template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(const allocator_type& __a)
 #if _LIBCPP_STD_VER <= 14
         _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
@@ -2527,7 +2527,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(size_type __n)
     : __begin_(nullptr),
       __size_(0),
@@ -2542,7 +2542,7 @@
 
 #if _LIBCPP_STD_VER > 11
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(size_type __n, const allocator_type& __a)
     : __begin_(nullptr),
       __size_(0),
@@ -2557,7 +2557,7 @@
 #endif
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(size_type __n, const value_type& __x)
     : __begin_(nullptr),
       __size_(0),
@@ -2571,7 +2571,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(size_type __n, const value_type& __x, const allocator_type& __a)
     : __begin_(nullptr),
       __size_(0),
@@ -2586,7 +2586,7 @@
 
 template <class _Allocator>
 template <class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(_InputIterator __first, _InputIterator __last,
        typename enable_if<__is_exactly_cpp17_input_iterator<_InputIterator>::value>::type*)
     : __begin_(nullptr),
@@ -2613,7 +2613,7 @@
 
 template <class _Allocator>
 template <class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a,
        typename enable_if<__is_exactly_cpp17_input_iterator<_InputIterator>::value>::type*)
     : __begin_(nullptr),
@@ -2640,7 +2640,7 @@
 
 template <class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(_ForwardIterator __first, _ForwardIterator __last,
                                 typename enable_if<__is_cpp17_forward_iterator<_ForwardIterator>::value>::type*)
     : __begin_(nullptr),
@@ -2657,7 +2657,7 @@
 
 template <class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a,
                                 typename enable_if<__is_cpp17_forward_iterator<_ForwardIterator>::value>::type*)
     : __begin_(nullptr),
@@ -2675,7 +2675,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(initializer_list<value_type> __il)
     : __begin_(nullptr),
       __size_(0),
@@ -2690,7 +2690,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(initializer_list<value_type> __il, const allocator_type& __a)
     : __begin_(nullptr),
       __size_(0),
@@ -2707,7 +2707,7 @@
 #endif // _LIBCPP_CXX03_LANG
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::~vector()
 {
     if (__begin_ != nullptr)
@@ -2716,7 +2716,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(const vector& __v)
     : __begin_(nullptr),
       __size_(0),
@@ -2730,7 +2730,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(const vector& __v, const allocator_type& __a)
     : __begin_(nullptr),
       __size_(0),
@@ -2744,7 +2744,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>&
 vector<bool, _Allocator>::operator=(const vector& __v)
 {
@@ -2766,7 +2766,7 @@
 }
 
 template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 vector<bool, _Allocator>::vector(vector&& __v)
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20 vector<bool, _Allocator>::vector(vector&& __v)
 #if _LIBCPP_STD_VER > 14
     _NOEXCEPT
 #else
@@ -2781,7 +2781,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>::vector(vector&& __v, const __type_identity_t<allocator_type>& __a)
     : __begin_(nullptr),
       __size_(0),
@@ -2803,7 +2803,7 @@
 }
 
 template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 vector<bool, _Allocator>&
 vector<bool, _Allocator>::operator=(vector&& __v)
     _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
@@ -2814,7 +2814,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 vector<bool, _Allocator>::__move_assign(vector& __c, false_type)
 {
     if (__alloc() != __c.__alloc())
@@ -2824,7 +2824,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 vector<bool, _Allocator>::__move_assign(vector& __c, true_type)
     _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
 {
@@ -2838,7 +2838,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 vector<bool, _Allocator>::assign(size_type __n, const value_type& __x)
 {
     __size_ = 0;
@@ -2861,7 +2861,7 @@
 
 template <class _Allocator>
 template <class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value,
+_LIBCPP_CONSTEXPR_CXX20 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value,
    void
 >::type
 vector<bool, _Allocator>::assign(_InputIterator __first, _InputIterator __last)
@@ -2873,7 +2873,7 @@
 
 template <class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename enable_if
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -2897,7 +2897,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 vector<bool, _Allocator>::reserve(size_type __n)
 {
     if (__n > capacity())
@@ -2913,7 +2913,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 vector<bool, _Allocator>::shrink_to_fit() _NOEXCEPT
 {
     if (__external_cap_to_internal(size()) > __cap())
@@ -2951,7 +2951,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 vector<bool, _Allocator>::push_back(const value_type& __x)
 {
     if (this->__size_ == this->capacity())
@@ -2961,7 +2961,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 typename vector<bool, _Allocator>::iterator
+_LIBCPP_CONSTEXPR_CXX20 typename vector<bool, _Allocator>::iterator
 vector<bool, _Allocator>::insert(const_iterator __position, const value_type& __x)
 {
     iterator __r;
@@ -2986,7 +2986,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 typename vector<bool, _Allocator>::iterator
+_LIBCPP_CONSTEXPR_CXX20 typename vector<bool, _Allocator>::iterator
 vector<bool, _Allocator>::insert(const_iterator __position, size_type __n, const value_type& __x)
 {
     iterator __r;
@@ -3013,7 +3013,7 @@
 
 template <class _Allocator>
 template <class _InputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value,
+_LIBCPP_CONSTEXPR_CXX20 typename enable_if <__is_exactly_cpp17_input_iterator<_InputIterator>::value,
     typename vector<bool, _Allocator>::iterator
 >::type
 vector<bool, _Allocator>::insert(const_iterator __position, _InputIterator __first, _InputIterator __last)
@@ -3055,7 +3055,7 @@
 
 template <class _Allocator>
 template <class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename enable_if
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value,
@@ -3089,7 +3089,7 @@
 }
 
 template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
 typename vector<bool, _Allocator>::iterator
 vector<bool, _Allocator>::erase(const_iterator __position)
 {
@@ -3100,7 +3100,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 typename vector<bool, _Allocator>::iterator
 vector<bool, _Allocator>::erase(const_iterator __first, const_iterator __last)
 {
@@ -3112,7 +3112,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 vector<bool, _Allocator>::swap(vector& __x)
 #if _LIBCPP_STD_VER >= 14
     _NOEXCEPT
@@ -3129,7 +3129,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 vector<bool, _Allocator>::resize(size_type __sz, value_type __x)
 {
     size_type __cs = size();
@@ -3158,7 +3158,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 void
+_LIBCPP_CONSTEXPR_CXX20 void
 vector<bool, _Allocator>::flip() _NOEXCEPT
 {
     // do middle whole words
@@ -3177,7 +3177,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_CONSTEXPR_CXX20 bool
 vector<bool, _Allocator>::__invariants() const
 {
     if (this->__begin_ == nullptr)
@@ -3196,7 +3196,7 @@
 }
 
 template <class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 size_t
+_LIBCPP_CONSTEXPR_CXX20 size_t
 vector<bool, _Allocator>::__hash_code() const _NOEXCEPT
 {
     size_t __h = 0;
@@ -3218,13 +3218,13 @@
 struct _LIBCPP_TEMPLATE_VIS hash<vector<bool, _Allocator> >
     : public __unary_function<vector<bool, _Allocator>, size_t>
 {
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_CXX20
     size_t operator()(const vector<bool, _Allocator>& __vec) const _NOEXCEPT
         {return __vec.__hash_code();}
 };
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 bool
 operator==(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
@@ -3234,7 +3234,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 bool
 operator!=(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
@@ -3243,7 +3243,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 bool
 operator< (const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
@@ -3252,7 +3252,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 bool
 operator> (const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
@@ -3261,7 +3261,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 bool
 operator>=(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
@@ -3270,7 +3270,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 bool
 operator<=(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
@@ -3279,7 +3279,7 @@
 }
 
 template <class _Tp, class _Allocator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY
 void
 swap(vector<_Tp, _Allocator>& __x, vector<_Tp, _Allocator>& __y)
@@ -3290,7 +3290,7 @@
 
 #if _LIBCPP_STD_VER > 17
 template <class _Tp, class _Allocator, class _Up>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY typename vector<_Tp, _Allocator>::size_type
 erase(vector<_Tp, _Allocator>& __c, const _Up& __v) {
   auto __old_size = __c.size();
@@ -3299,7 +3299,7 @@
 }
 
 template <class _Tp, class _Allocator, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_CONSTEXPR_CXX20
 inline _LIBCPP_INLINE_VISIBILITY typename vector<_Tp, _Allocator>::size_type
 erase_if(vector<_Tp, _Allocator>& __c, _Predicate __pred) {
   auto __old_size = __c.size();
diff --git a/libcxx/src/experimental/memory_resource.cpp b/libcxx/src/experimental/memory_resource.cpp
--- a/libcxx/src/experimental/memory_resource.cpp
+++ b/libcxx/src/experimental/memory_resource.cpp
@@ -72,7 +72,7 @@
     __null_memory_resource_imp       null_res;
   } resources;
   char dummy;
-  _LIBCPP_CONSTEXPR_AFTER_CXX11 ResourceInitHelper() : resources() {}
+  _LIBCPP_CONSTEXPR_CXX14 ResourceInitHelper() : resources() {}
   ~ResourceInitHelper() {}
 };
 
diff --git a/libcxx/src/filesystem/filesystem_common.h b/libcxx/src/filesystem/filesystem_common.h
--- a/libcxx/src/filesystem/filesystem_common.h
+++ b/libcxx/src/filesystem/filesystem_common.h
@@ -124,7 +124,7 @@
 template <class T>
 T error_value();
 template <>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 void error_value<void>() {}
+_LIBCPP_CONSTEXPR_CXX14 void error_value<void>() {}
 template <>
 bool error_value<bool>() {
   return false;
@@ -140,7 +140,7 @@
   return uintmax_t(-1);
 }
 template <>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 file_time_type error_value<file_time_type>() {
+_LIBCPP_CONSTEXPR_CXX14 file_time_type error_value<file_time_type>() {
   return file_time_type::min();
 }
 template <>
@@ -309,7 +309,7 @@
           .count();
 
 private:
-  static _LIBCPP_CONSTEXPR_AFTER_CXX11 fs_duration get_min_nsecs() {
+  static _LIBCPP_CONSTEXPR_CXX14 fs_duration get_min_nsecs() {
     return duration_cast<fs_duration>(
         fs_nanoseconds(min_nsec_timespec) -
         duration_cast<fs_nanoseconds>(fs_seconds(1)));
@@ -319,7 +319,7 @@
                     FileTimeT::duration::min(),
                 "value doesn't roundtrip");
 
-  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool check_range() {
+  static _LIBCPP_CONSTEXPR_CXX14 bool check_range() {
     // This kinda sucks, but it's what happens when we don't have __int128_t.
     if (sizeof(TimeT) == sizeof(rep)) {
       typedef duration<long long, ratio<3600 * 24 * 365> > Years;
@@ -385,7 +385,7 @@
 
 public:
   template <class CType, class ChronoType>
-  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool checked_set(CType* out,
+  static _LIBCPP_CONSTEXPR_CXX14 bool checked_set(CType* out,
                                                         ChronoType time) {
     using Lim = numeric_limits<CType>;
     if (time > Lim::max() || time < Lim::min())
@@ -394,7 +394,7 @@
     return true;
   }
 
-  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool is_representable(TimeSpecT tm) {
+  static _LIBCPP_CONSTEXPR_CXX14 bool is_representable(TimeSpecT tm) {
     if (tm.tv_sec >= 0) {
       return tm.tv_sec < max_seconds ||
              (tm.tv_sec == max_seconds && tm.tv_nsec <= max_nsec);
@@ -405,7 +405,7 @@
     }
   }
 
-  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool is_representable(FileTimeT tm) {
+  static _LIBCPP_CONSTEXPR_CXX14 bool is_representable(FileTimeT tm) {
     auto secs = duration_cast<fs_seconds>(tm.time_since_epoch());
     auto nsecs = duration_cast<fs_nanoseconds>(tm.time_since_epoch() - secs);
     if (nsecs.count() < 0) {
@@ -418,7 +418,7 @@
     return secs.count() >= TLim::min();
   }
 
-  static _LIBCPP_CONSTEXPR_AFTER_CXX11 FileTimeT
+  static _LIBCPP_CONSTEXPR_CXX14 FileTimeT
   convert_from_timespec(TimeSpecT tm) {
     if (tm.tv_sec >= 0 || tm.tv_nsec == 0) {
       return FileTimeT(fs_seconds(tm.tv_sec) +
@@ -432,7 +432,7 @@
   }
 
   template <class SubSecT>
-  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool
+  static _LIBCPP_CONSTEXPR_CXX14 bool
   set_times_checked(TimeT* sec_out, SubSecT* subsec_out, FileTimeT tp) {
     auto dur = tp.time_since_epoch();
     auto sec_dur = duration_cast<fs_seconds>(dur);
@@ -449,7 +449,7 @@
     return checked_set(sec_out, sec_dur.count()) &&
            checked_set(subsec_out, subsec_dur.count());
   }
-  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool convert_to_timespec(TimeSpecT& dest,
+  static _LIBCPP_CONSTEXPR_CXX14 bool convert_to_timespec(TimeSpecT& dest,
                                                                 FileTimeT tp) {
     if (!is_representable(tp))
       return false;
diff --git a/libcxx/test/libcxx/nasty_macros.compile.pass.cpp b/libcxx/test/libcxx/nasty_macros.compile.pass.cpp
--- a/libcxx/test/libcxx/nasty_macros.compile.pass.cpp
+++ b/libcxx/test/libcxx/nasty_macros.compile.pass.cpp
@@ -140,6 +140,11 @@
 #define min NASTY_MACRO
 #define max NASTY_MACRO
 
+// Old constexpr macros
+#define _LIBCPP_CONSTEXPR_AFTER_CXX11 NASTY_MACRO
+#define _LIBCPP_CONSTEXPR_AFTER_CXX14 NASTY_MACRO
+#define _LIBCPP_CONSTEXPR_AFTER_CXX17 NASTY_MACRO
+
 /*
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