diff --git a/libcxx/docs/UsingLibcxx.rst b/libcxx/docs/UsingLibcxx.rst
--- a/libcxx/docs/UsingLibcxx.rst
+++ b/libcxx/docs/UsingLibcxx.rst
@@ -271,9 +271,8 @@
 Users who want help diagnosing misuses of STL functions may desire a more
 liberal application of ``[[nodiscard]]``.
 
-For this reason libc++ provides an extension that does just that! The
-extension must be enabled by defining ``_LIBCPP_ENABLE_NODISCARD``. The extended
-applications of ``[[nodiscard]]`` takes two forms:
+For this reason libc++ provides an extension that does just that! The extended
+applications of ``[[nodiscard]]`` take two forms:
 
 1. Backporting ``[[nodiscard]]`` to entities declared as such by the
    standard in newer dialects, but not in the present one.
@@ -281,18 +280,9 @@
 2. Extended applications of ``[[nodiscard]]``, at the library's discretion,
    applied to entities never declared as such by the standard.
 
-Users may also opt-out of additional applications ``[[nodiscard]]`` using
-additional macros.
 
-Applications of the first form, which backport ``[[nodiscard]]`` from a newer
-dialect, may be disabled using macros specific to the dialect in which it was
-added. For example, ``_LIBCPP_DISABLE_NODISCARD_AFTER_CXX17``.
 
-Applications of the second form, which are pure extensions, may be disabled
-by defining ``_LIBCPP_DISABLE_NODISCARD_EXT``.
-
-
-Entities declared with ``_LIBCPP_NODISCARD_EXT``
+Entities declared with ``[[nodiscard]]``
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 This section lists all extended applications of ``[[nodiscard]]`` to entities
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
@@ -24,7 +24,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
 adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred) {
   if (__first != __last) {
     _ForwardIterator __i = __first;
@@ -38,7 +38,7 @@
 }
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
 adjacent_find(_ForwardIterator __first, _ForwardIterator __last) {
   typedef typename iterator_traits<_ForwardIterator>::value_type __v;
   return _VSTD::adjacent_find(__first, __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
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 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
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 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
@@ -34,7 +34,7 @@
 }
 
 template <class _ForwardIterator, class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
@@ -44,7 +44,7 @@
 }
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
diff --git a/libcxx/include/__algorithm/clamp.h b/libcxx/include/__algorithm/clamp.h
--- a/libcxx/include/__algorithm/clamp.h
+++ b/libcxx/include/__algorithm/clamp.h
@@ -25,7 +25,7 @@
 #if _LIBCPP_STD_VER > 14
 // clamp
 template<class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
 const _Tp&
 clamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi, _Compare __comp)
@@ -36,7 +36,7 @@
 }
 
 template<class _Tp>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
 const _Tp&
 clamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi)
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
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     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
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     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
@@ -25,7 +25,7 @@
 _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 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
   for (; __first1 != __last1; ++__first1, (void)++__first2)
     if (!__pred(*__first1, *__first2))
@@ -34,7 +34,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
   typedef typename iterator_traits<_InputIterator1>::value_type __v1;
   typedef typename iterator_traits<_InputIterator2>::value_type __v2;
@@ -64,7 +64,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
       _BinaryPredicate __pred) {
   return _VSTD::__equal<typename add_lvalue_reference<_BinaryPredicate>::type>(
@@ -73,7 +73,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 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
@@ -61,7 +61,7 @@
 }
 
 template <class _ForwardIterator, class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 pair<_ForwardIterator, _ForwardIterator>
 equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
@@ -71,7 +71,7 @@
 }
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 pair<_ForwardIterator, _ForwardIterator>
 equal_range(_ForwardIterator __first, _ForwardIterator __last, 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
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _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
@@ -131,7 +131,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
 find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2,
          _BinaryPredicate __pred) {
   return _VSTD::__find_end<typename add_lvalue_reference<_BinaryPredicate>::type>(
@@ -140,7 +140,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
 find_end(_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_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
@@ -36,14 +36,14 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _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 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _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
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _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
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator
 find_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
   for (; __first != __last; ++__first)
     if (!__pred(*__first))
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
@@ -39,7 +39,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
@@ -50,7 +50,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2)
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
@@ -24,7 +24,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _RandomAccessIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
@@ -33,7 +33,7 @@
 }
 
 template<class _RandomAccessIterator>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 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
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _RandomAccessIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
+_LIBCPP_NODISCARD _LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
 is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
 {
     typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
@@ -50,7 +50,7 @@
 }
 
 template<class _RandomAccessIterator>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 _RandomAccessIterator
 is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last)
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
@@ -21,7 +21,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD _LIBCPP_CONSTEXPR_AFTER_CXX17 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
@@ -26,7 +26,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
                _BinaryPredicate __pred) {
   //  shorten sequences as much as possible by lopping of any equal prefix
@@ -71,7 +71,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2) {
   typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
   typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
@@ -141,7 +141,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
                _ForwardIterator2 __last2, _BinaryPredicate __pred) {
   return _VSTD::__is_permutation<typename add_lvalue_reference<_BinaryPredicate>::type>(
@@ -150,7 +150,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
 is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
                _ForwardIterator2 __last2) {
   typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
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
@@ -24,7 +24,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 is_sorted(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
@@ -33,7 +33,7 @@
 }
 
 template<class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 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
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
 is_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
 {
     if (__first != __last)
@@ -40,7 +40,7 @@
 }
 
 template<class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 _ForwardIterator
 is_sorted_until(_ForwardIterator __first, _ForwardIterator __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
@@ -39,7 +39,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
@@ -50,7 +50,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
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
@@ -46,7 +46,7 @@
 }
 
 template <class _ForwardIterator, class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 _ForwardIterator
 lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
@@ -56,7 +56,7 @@
 }
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 _ForwardIterator
 lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
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
@@ -24,7 +24,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 const _Tp&
 max(const _Tp& __a, const _Tp& __b, _Compare __comp)
@@ -33,7 +33,7 @@
 }
 
 template <class _Tp>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 const _Tp&
 max(const _Tp& __a, const _Tp& __b)
@@ -44,7 +44,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template<class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _Tp
 max(initializer_list<_Tp> __t, _Compare __comp)
@@ -53,7 +53,7 @@
 }
 
 template<class _Tp>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _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
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _ForwardIterator
 max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
@@ -42,7 +42,7 @@
 
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _ForwardIterator
 max_element(_ForwardIterator __first, _ForwardIterator __last)
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
@@ -24,7 +24,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 const _Tp&
 min(const _Tp& __a, const _Tp& __b, _Compare __comp)
@@ -33,7 +33,7 @@
 }
 
 template <class _Tp>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 const _Tp&
 min(const _Tp& __a, const _Tp& __b)
@@ -44,7 +44,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template<class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _Tp
 min(initializer_list<_Tp> __t, _Compare __comp)
@@ -53,7 +53,7 @@
 }
 
 template<class _Tp>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _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
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _ForwardIterator
 min_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
@@ -41,7 +41,7 @@
 }
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _ForwardIterator
 min_element(_ForwardIterator __first, _ForwardIterator __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 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template<class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 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_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 pair<const _Tp&, const _Tp&>
 minmax(const _Tp& __a, const _Tp& __b)
@@ -46,7 +46,7 @@
 #ifndef _LIBCPP_CXX03_LANG
 
 template<class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 pair<_Tp, _Tp>
 minmax(initializer_list<_Tp> __t, _Compare __comp)
@@ -84,7 +84,7 @@
 }
 
 template<class _Tp>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 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
@@ -24,7 +24,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Compare>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX11
+_LIBCPP_NODISCARD _LIBCPP_CONSTEXPR_AFTER_CXX11
 pair<_ForwardIterator, _ForwardIterator>
 minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
 {
@@ -74,7 +74,7 @@
 }
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 pair<_ForwardIterator, _ForwardIterator>
 minmax_element(_ForwardIterator __first, _ForwardIterator __last)
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
@@ -25,7 +25,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY
     _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
     mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
   for (; __first1 != __last1; ++__first1, (void)++__first2)
@@ -35,7 +35,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY
     _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
     mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
   typedef typename iterator_traits<_InputIterator1>::value_type __v1;
@@ -45,7 +45,7 @@
 
 #if _LIBCPP_STD_VER > 11
 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY
     _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
     mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
              _BinaryPredicate __pred) {
@@ -56,7 +56,7 @@
 }
 
 template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY
     _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
     mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
   typedef typename iterator_traits<_InputIterator1>::value_type __v1;
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
@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
 none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
   for (; __first != __last; ++__first)
     if (__pred(*__first))
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
@@ -24,7 +24,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
 remove(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
 {
     __first = _VSTD::find(__first, __last, __value_);
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
@@ -24,7 +24,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
 remove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
 {
     __first = _VSTD::find_if<_ForwardIterator, typename add_lvalue_reference<_Predicate>::type>
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
@@ -98,7 +98,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2,
        _BinaryPredicate __pred) {
   return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>(
@@ -108,7 +108,7 @@
 }
 
 template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
 search(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2) {
   typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
   typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
@@ -117,7 +117,7 @@
 
 #if _LIBCPP_STD_VER > 14
 template <class _ForwardIterator, class _Searcher>
-_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _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
@@ -95,7 +95,7 @@
 }
 
 template <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator search_n(
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator search_n(
     _ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_, _BinaryPredicate __pred) {
   return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>(
       __first, __last, _VSTD::__convert_to_integral(__count), __value_, __pred,
@@ -103,7 +103,7 @@
 }
 
 template <class _ForwardIterator, class _Size, class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
 search_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_) {
   typedef typename iterator_traits<_ForwardIterator>::value_type __v;
   return _VSTD::search_n(__first, __last, _VSTD::__convert_to_integral(__count), __value_, __equal_to<__v, _Tp>());
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
@@ -28,7 +28,7 @@
 // unique
 
 template <class _ForwardIterator, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+_LIBCPP_NODISCARD _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
 unique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
 {
     __first = _VSTD::adjacent_find<_ForwardIterator, typename add_lvalue_reference<_BinaryPredicate>::type>
@@ -47,7 +47,7 @@
 }
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 _ForwardIterator
 unique(_ForwardIterator __first, _ForwardIterator __last)
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
@@ -46,7 +46,7 @@
 }
 
 template <class _ForwardIterator, class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 _ForwardIterator
 upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
@@ -56,7 +56,7 @@
 }
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 _ForwardIterator
 upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1051,32 +1051,15 @@
 #  define _LIBCPP_CONSTEXPR_AFTER_CXX17
 #endif
 
-// The _LIBCPP_NODISCARD_ATTRIBUTE should only be used to define other
-// NODISCARD macros to the correct attribute.
 #if __has_cpp_attribute(nodiscard) || defined(_LIBCPP_COMPILER_MSVC)
-#  define _LIBCPP_NODISCARD_ATTRIBUTE [[nodiscard]]
+#  define _LIBCPP_NODISCARD [[nodiscard]]
 #elif defined(_LIBCPP_COMPILER_CLANG_BASED) && !defined(_LIBCPP_CXX03_LANG)
-#  define _LIBCPP_NODISCARD_ATTRIBUTE [[clang::warn_unused_result]]
+#  define _LIBCPP_NODISCARD [[clang::warn_unused_result]]
 #else
 // We can't use GCC's [[gnu::warn_unused_result]] and
 // __attribute__((warn_unused_result)), because GCC does not silence them via
 // (void) cast.
-#  define _LIBCPP_NODISCARD_ATTRIBUTE
-#endif
-
-// _LIBCPP_NODISCARD_EXT may be used to apply [[nodiscard]] to entities not
-// specified as such as an extension.
-#if defined(_LIBCPP_ENABLE_NODISCARD) && !defined(_LIBCPP_DISABLE_NODISCARD_EXT)
-#  define _LIBCPP_NODISCARD_EXT _LIBCPP_NODISCARD_ATTRIBUTE
-#else
-#  define _LIBCPP_NODISCARD_EXT
-#endif
-
-#if !defined(_LIBCPP_DISABLE_NODISCARD_AFTER_CXX17) && \
-    (_LIBCPP_STD_VER > 17 || defined(_LIBCPP_ENABLE_NODISCARD))
-#  define _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_NODISCARD_ATTRIBUTE
-#else
-#  define _LIBCPP_NODISCARD_AFTER_CXX17
+#  define _LIBCPP_NODISCARD
 #endif
 
 #if _LIBCPP_STD_VER > 14 && defined(__cpp_inline_variables) && (__cpp_inline_variables >= 201606L)
diff --git a/libcxx/include/__functional/identity.h b/libcxx/include/__functional/identity.h
--- a/libcxx/include/__functional/identity.h
+++ b/libcxx/include/__functional/identity.h
@@ -23,7 +23,7 @@
 
 struct identity {
     template<class _Tp>
-    _LIBCPP_NODISCARD_EXT constexpr _Tp&& operator()(_Tp&& __t) const noexcept
+    _LIBCPP_NODISCARD constexpr _Tp&& operator()(_Tp&& __t) const noexcept
     {
         return _VSTD::forward<_Tp>(__t);
     }
diff --git a/libcxx/include/__iterator/empty.h b/libcxx/include/__iterator/empty.h
--- a/libcxx/include/__iterator/empty.h
+++ b/libcxx/include/__iterator/empty.h
@@ -26,18 +26,18 @@
 #if _LIBCPP_STD_VER > 14
 
 template <class _Cont>
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
 constexpr auto empty(const _Cont& __c)
 _NOEXCEPT_(noexcept(__c.empty()))
 -> decltype        (__c.empty())
 { return            __c.empty(); }
 
 template <class _Tp, size_t _Sz>
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
 constexpr bool empty(const _Tp (&)[_Sz]) noexcept { return false; }
 
 template <class _Ep>
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
 constexpr bool empty(initializer_list<_Ep> __il) noexcept { return __il.size() == 0; }
 
 #endif // _LIBCPP_STD_VER > 14
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
@@ -97,7 +97,7 @@
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     allocator(const allocator<_Up>&) _NOEXCEPT { }
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     _Tp* allocate(size_t __n) {
         if (__n > allocator_traits<allocator>::max_size(*this))
             __throw_length_error("allocator<T>::allocate(size_t n)"
@@ -139,7 +139,7 @@
         return _VSTD::addressof(__x);
     }
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_DEPRECATED_IN_CXX17
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY _LIBCPP_DEPRECATED_IN_CXX17
     _Tp* allocate(size_t __n, const void*) {
         return allocate(__n);
     }
@@ -179,7 +179,7 @@
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     allocator(const allocator<_Up>&) _NOEXCEPT { }
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     const _Tp* allocate(size_t __n) {
         if (__n > allocator_traits<allocator>::max_size(*this))
             __throw_length_error("allocator<const T>::allocate(size_t n)"
@@ -217,7 +217,7 @@
         return _VSTD::addressof(__x);
     }
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_DEPRECATED_IN_CXX17
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY _LIBCPP_DEPRECATED_IN_CXX17
     const _Tp* allocate(size_t __n, const void*) {
         return allocate(__n);
     }
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 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     static pointer allocate(allocator_type& __a, size_type __n) {
         return __a.allocate(__n);
     }
 
     template <class _Ap = _Alloc, class =
         _EnableIf<__has_allocate_hint<_Ap, size_type, const_void_pointer>::value> >
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint) {
         _LIBCPP_SUPPRESS_DEPRECATED_PUSH
         return __a.allocate(__n, __hint);
@@ -272,7 +272,7 @@
     }
     template <class _Ap = _Alloc, class = void, class =
         _EnableIf<!__has_allocate_hint<_Ap, size_type, const_void_pointer>::value> >
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer) {
         return __a.allocate(__n);
     }
diff --git a/libcxx/include/__memory/temporary_buffer.h b/libcxx/include/__memory/temporary_buffer.h
--- a/libcxx/include/__memory/temporary_buffer.h
+++ b/libcxx/include/__memory/temporary_buffer.h
@@ -25,7 +25,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp>
-_LIBCPP_NODISCARD_EXT _LIBCPP_NO_CFI
+_LIBCPP_NODISCARD _LIBCPP_NO_CFI
 pair<_Tp*, ptrdiff_t>
 get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
 {
diff --git a/libcxx/include/__mutex_base b/libcxx/include/__mutex_base
--- a/libcxx/include/__mutex_base
+++ b/libcxx/include/__mutex_base
@@ -85,11 +85,11 @@
     mutex_type& __m_;
 public:
 
-    _LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     explicit lock_guard(mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
         : __m_(__m) {__m_.lock();}
 
-    _LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     lock_guard(mutex_type& __m, adopt_lock_t) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
         : __m_(__m) {}
     _LIBCPP_INLINE_VISIBILITY
diff --git a/libcxx/include/__node_handle b/libcxx/include/__node_handle
--- a/libcxx/include/__node_handle
+++ b/libcxx/include/__node_handle
@@ -126,7 +126,7 @@
     _LIBCPP_INLINE_VISIBILITY
     explicit operator bool() const { return __ptr_ != nullptr; }
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const { return __ptr_ == nullptr; }
 
     _LIBCPP_INLINE_VISIBILITY
diff --git a/libcxx/include/__utility/as_const.h b/libcxx/include/__utility/as_const.h
--- a/libcxx/include/__utility/as_const.h
+++ b/libcxx/include/__utility/as_const.h
@@ -25,7 +25,7 @@
 
 #if _LIBCPP_STD_VER > 14
 template <class _Tp>
-_LIBCPP_NODISCARD_EXT constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
+_LIBCPP_NODISCARD constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
 
 template <class _Tp>
 void as_const(const _Tp&&) = delete;
diff --git a/libcxx/include/__utility/forward.h b/libcxx/include/__utility/forward.h
--- a/libcxx/include/__utility/forward.h
+++ b/libcxx/include/__utility/forward.h
@@ -23,13 +23,13 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR _Tp&&
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR _Tp&&
 forward(typename remove_reference<_Tp>::type& __t) _NOEXCEPT {
   return static_cast<_Tp&&>(__t);
 }
 
 template <class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR _Tp&&
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR _Tp&&
 forward(typename remove_reference<_Tp>::type&& __t) _NOEXCEPT {
   static_assert(!is_lvalue_reference<_Tp>::value, "cannot forward an rvalue as an lvalue");
   return static_cast<_Tp&&>(__t);
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
@@ -23,7 +23,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename remove_reference<_Tp>::type&&
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename remove_reference<_Tp>::type&&
 move(_Tp&& __t) _NOEXCEPT {
   typedef _LIBCPP_NODEBUG_TYPE typename remove_reference<_Tp>::type _Up;
   return static_cast<_Up&&>(__t);
@@ -40,7 +40,7 @@
 #endif
 
 template <class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 __move_if_noexcept_result_t<_Tp>
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 __move_if_noexcept_result_t<_Tp>
 move_if_noexcept(_Tp& __x) _NOEXCEPT {
   return _VSTD::move(__x);
 }
diff --git a/libcxx/include/__utility/to_underlying.h b/libcxx/include/__utility/to_underlying.h
--- a/libcxx/include/__utility/to_underlying.h
+++ b/libcxx/include/__utility/to_underlying.h
@@ -32,7 +32,7 @@
 
 #if _LIBCPP_STD_VER > 20
 template <class _Tp>
-_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY constexpr underlying_type_t<_Tp>
+_LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY constexpr underlying_type_t<_Tp>
 to_underlying(_Tp __val) noexcept {
   return _VSTD::__to_underlying(__val);
 }
diff --git a/libcxx/include/array b/libcxx/include/array
--- a/libcxx/include/array
+++ b/libcxx/include/array
@@ -188,7 +188,7 @@
     _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return _Size;}
     _LIBCPP_INLINE_VISIBILITY
     _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return _Size;}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return _Size == 0;}
 
     // element access:
@@ -302,7 +302,7 @@
     _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return 0; }
     _LIBCPP_INLINE_VISIBILITY
     _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return 0;}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
 
     // element access:
diff --git a/libcxx/include/cstddef b/libcxx/include/cstddef
--- a/libcxx/include/cstddef
+++ b/libcxx/include/cstddef
@@ -152,7 +152,7 @@
   { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) >> __shift)); }
 
 template <class _Integer, class = _EnableByteOverload<_Integer> >
-  _LIBCPP_NODISCARD_EXT constexpr _Integer
+  _LIBCPP_NODISCARD constexpr _Integer
   to_integer(byte __b) noexcept { return static_cast<_Integer>(__b); }
 }
 
diff --git a/libcxx/include/deque b/libcxx/include/deque
--- a/libcxx/include/deque
+++ b/libcxx/include/deque
@@ -1403,7 +1403,7 @@
     void resize(size_type __n);
     void resize(size_type __n, const value_type& __v);
     void shrink_to_fit() _NOEXCEPT;
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT {return __base::size() == 0;}
 
     // element access:
diff --git a/libcxx/include/filesystem b/libcxx/include/filesystem
--- a/libcxx/include/filesystem
+++ b/libcxx/include/filesystem
@@ -1371,7 +1371,7 @@
   }
 
   // query
-  _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY bool
+  _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY bool
   empty() const noexcept {
     return __pn_.empty();
   }
diff --git a/libcxx/include/forward_list b/libcxx/include/forward_list
--- a/libcxx/include/forward_list
+++ b/libcxx/include/forward_list
@@ -754,7 +754,7 @@
     const_iterator cbefore_begin() const _NOEXCEPT
         {return const_iterator(base::__before_begin());}
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT
         {return base::__before_begin()->__next_ == nullptr;}
     _LIBCPP_INLINE_VISIBILITY
diff --git a/libcxx/include/future b/libcxx/include/future
--- a/libcxx/include/future
+++ b/libcxx/include/future
@@ -2195,7 +2195,7 @@
 { return (int(__policy) & int(__value)) != 0; }
 
 template <class _Fp, class... _Args>
-_LIBCPP_NODISCARD_AFTER_CXX17
+_LIBCPP_NODISCARD
 future<typename __invoke_of<typename decay<_Fp>::type, typename decay<_Args>::type...>::type>
 async(launch __policy, _Fp&& __f, _Args&&... __args)
 {
@@ -2221,7 +2221,7 @@
 }
 
 template <class _Fp, class... _Args>
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY
 future<typename __invoke_of<typename decay<_Fp>::type, typename decay<_Args>::type...>::type>
 async(_Fp&& __f, _Args&&... __args)
 {
diff --git a/libcxx/include/list b/libcxx/include/list
--- a/libcxx/include/list
+++ b/libcxx/include/list
@@ -931,7 +931,7 @@
 
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT     {return base::__sz();}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT         {return base::empty();}
     _LIBCPP_INLINE_VISIBILITY
     size_type max_size() const _NOEXCEPT
diff --git a/libcxx/include/map b/libcxx/include/map
--- a/libcxx/include/map
+++ b/libcxx/include/map
@@ -1146,7 +1146,7 @@
     _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator crend() const _NOEXCEPT {return rend();}
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool      empty() const _NOEXCEPT {return __tree_.size() == 0;}
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT {return __tree_.size();}
@@ -1929,7 +1929,7 @@
     _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator crend() const _NOEXCEPT {return rend();}
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT {return __tree_.size() == 0;}
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT {return __tree_.size();}
diff --git a/libcxx/include/new b/libcxx/include/new
--- a/libcxx/include/new
+++ b/libcxx/include/new
@@ -177,16 +177,16 @@
 
 #if !defined(_LIBCPP_ABI_VCRUNTIME)
 
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz) _THROW_BAD_ALLOC;
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
+_LIBCPP_NODISCARD _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz) _THROW_BAD_ALLOC;
+_LIBCPP_NODISCARD _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p) _NOEXCEPT;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
 #ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
 _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void  operator delete(void* __p, std::size_t __sz) _NOEXCEPT;
 #endif
 
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz) _THROW_BAD_ALLOC;
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
+_LIBCPP_NODISCARD _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz) _THROW_BAD_ALLOC;
+_LIBCPP_NODISCARD _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete[](void* __p) _NOEXCEPT;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
 #ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
@@ -194,16 +194,16 @@
 #endif
 
 #ifndef _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
+_LIBCPP_NODISCARD _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
+_LIBCPP_NODISCARD _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p, std::align_val_t) _NOEXCEPT;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
 #ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
 _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void  operator delete(void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
 #endif
 
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
+_LIBCPP_NODISCARD _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
+_LIBCPP_NODISCARD _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete[](void* __p, std::align_val_t) _NOEXCEPT;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete[](void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
 #ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
@@ -211,8 +211,8 @@
 #endif
 #endif
 
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new  (std::size_t, void* __p) _NOEXCEPT {return __p;}
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new[](std::size_t, void* __p) _NOEXCEPT {return __p;}
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY void* operator new  (std::size_t, void* __p) _NOEXCEPT {return __p;}
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY void* operator new[](std::size_t, void* __p) _NOEXCEPT {return __p;}
 inline _LIBCPP_INLINE_VISIBILITY void  operator delete  (void*, void*) _NOEXCEPT {}
 inline _LIBCPP_INLINE_VISIBILITY void  operator delete[](void*, void*) _NOEXCEPT {}
 
@@ -332,7 +332,7 @@
 
 
 template <class _Tp>
-_LIBCPP_NODISCARD_AFTER_CXX17 inline
+_LIBCPP_NODISCARD inline
 _LIBCPP_CONSTEXPR _Tp* __launder(_Tp* __p) _NOEXCEPT
 {
     static_assert (!(is_function<_Tp>::value), "can't launder functions" );
@@ -347,7 +347,7 @@
 
 #if _LIBCPP_STD_VER > 14
 template <class _Tp>
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NODISCARD inline _LIBCPP_INLINE_VISIBILITY
 constexpr _Tp* launder(_Tp* __p) noexcept
 {
     return _VSTD::__launder(__p);
diff --git a/libcxx/include/queue b/libcxx/include/queue
--- a/libcxx/include/queue
+++ b/libcxx/include/queue
@@ -305,7 +305,7 @@
 
 #endif // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool      empty() const {return c.empty();}
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const  {return c.size();}
@@ -559,7 +559,7 @@
                        _EnableIf<uses_allocator<container_type, _Alloc>::value>* = 0);
 #endif  // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool            empty() const {return c.empty();}
     _LIBCPP_INLINE_VISIBILITY
     size_type       size() const  {return c.size();}
diff --git a/libcxx/include/regex b/libcxx/include/regex
--- a/libcxx/include/regex
+++ b/libcxx/include/regex
@@ -5383,7 +5383,7 @@
     size_type size() const _NOEXCEPT {return __matches_.size();}
     _LIBCPP_INLINE_VISIBILITY
     size_type max_size() const _NOEXCEPT {return __matches_.max_size();}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT {return size() == 0;}
 
     // element access:
diff --git a/libcxx/include/scoped_allocator b/libcxx/include/scoped_allocator
--- a/libcxx/include/scoped_allocator
+++ b/libcxx/include/scoped_allocator
@@ -478,11 +478,11 @@
     const outer_allocator_type& outer_allocator() const _NOEXCEPT
         {return base::outer_allocator();}
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     pointer allocate(size_type __n)
         {return allocator_traits<outer_allocator_type>::
             allocate(outer_allocator(), __n);}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     pointer allocate(size_type __n, const_void_pointer __hint)
         {return allocator_traits<outer_allocator_type>::
             allocate(outer_allocator(), __n, __hint);}
diff --git a/libcxx/include/set b/libcxx/include/set
--- a/libcxx/include/set
+++ b/libcxx/include/set
@@ -649,7 +649,7 @@
     _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator crend() const _NOEXCEPT {return rend();}
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT {return __tree_.size() == 0;}
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT {return __tree_.size();}
@@ -1180,7 +1180,7 @@
     _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator crend() const _NOEXCEPT {return rend();}
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT {return __tree_.size() == 0;}
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT {return __tree_.size();}
diff --git a/libcxx/include/stack b/libcxx/include/stack
--- a/libcxx/include/stack
+++ b/libcxx/include/stack
@@ -183,7 +183,7 @@
             : c(_VSTD::move(__s.c), __a) {}
 #endif // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty()     const      {return c.empty();}
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const      {return c.size();}
diff --git a/libcxx/include/string b/libcxx/include/string
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -990,7 +990,7 @@
     void shrink_to_fit() _NOEXCEPT;
     _LIBCPP_INLINE_VISIBILITY
     void clear() _NOEXCEPT;
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT {return size() == 0;}
 
     _LIBCPP_INLINE_VISIBILITY const_reference operator[](size_type __pos) const _NOEXCEPT;
diff --git a/libcxx/include/string_view b/libcxx/include/string_view
--- a/libcxx/include/string_view
+++ b/libcxx/include/string_view
@@ -313,7 +313,7 @@
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max(); }
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     bool empty()         const _NOEXCEPT { return __size == 0; }
 
     // [string.view.access], element access
diff --git a/libcxx/include/type_traits b/libcxx/include/type_traits
--- a/libcxx/include/type_traits
+++ b/libcxx/include/type_traits
@@ -2340,7 +2340,7 @@
 
 #ifndef _LIBCPP_CXX03_LANG
 template <class _Tp>
-_LIBCPP_NODISCARD_ATTRIBUTE _LIBCPP_INLINE_VISIBILITY constexpr
+_LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY constexpr
 typename make_unsigned<_Tp>::type __to_unsigned_like(_Tp __x) noexcept {
     return static_cast<typename make_unsigned<_Tp>::type>(__x);
 }
diff --git a/libcxx/include/unordered_map b/libcxx/include/unordered_map
--- a/libcxx/include/unordered_map
+++ b/libcxx/include/unordered_map
@@ -1075,7 +1075,7 @@
     allocator_type get_allocator() const _NOEXCEPT
         {return allocator_type(__table_.__node_alloc());}
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool      empty() const _NOEXCEPT {return __table_.size() == 0;}
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT  {return __table_.size();}
@@ -2010,7 +2010,7 @@
     allocator_type get_allocator() const _NOEXCEPT
         {return allocator_type(__table_.__node_alloc());}
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool      empty() const _NOEXCEPT {return __table_.size() == 0;}
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT  {return __table_.size();}
diff --git a/libcxx/include/unordered_set b/libcxx/include/unordered_set
--- a/libcxx/include/unordered_set
+++ b/libcxx/include/unordered_set
@@ -539,7 +539,7 @@
     allocator_type get_allocator() const _NOEXCEPT
         {return allocator_type(__table_.__node_alloc());}
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool      empty() const _NOEXCEPT {return __table_.size() == 0;}
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT  {return __table_.size();}
@@ -1234,7 +1234,7 @@
     allocator_type get_allocator() const _NOEXCEPT
         {return allocator_type(__table_.__node_alloc());}
 
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool      empty() const _NOEXCEPT {return __table_.size() == 0;}
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT  {return __table_.size();}
diff --git a/libcxx/include/vector b/libcxx/include/vector
--- a/libcxx/include/vector
+++ b/libcxx/include/vector
@@ -661,7 +661,7 @@
     _LIBCPP_INLINE_VISIBILITY
     size_type capacity() const _NOEXCEPT
         {return __base::capacity();}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT
         {return this->__begin_ == this->__end_;}
     size_type max_size() const _NOEXCEPT;
@@ -2308,7 +2308,7 @@
     _LIBCPP_INLINE_VISIBILITY
     size_type size() const _NOEXCEPT
         {return __size_;}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_NODISCARD _LIBCPP_INLINE_VISIBILITY
     bool empty() const _NOEXCEPT
         {return __size_ == 0;}
     void reserve(size_type __n);
diff --git a/libcxx/test/libcxx/diagnostics/enable_nodiscard.verify.cpp b/libcxx/test/libcxx/diagnostics/enable_nodiscard.verify.cpp
deleted file mode 100644
--- a/libcxx/test/libcxx/diagnostics/enable_nodiscard.verify.cpp
+++ /dev/null
@@ -1,30 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// Test that _LIBCPP_NODISCARD_EXT and _LIBCPP_NODISCARD_AFTER_CXX17 are defined
-// to the appropriate warning-generating attribute when _LIBCPP_ENABLE_NODISCARD
-// is explicitly provided.
-
-// UNSUPPORTED: c++03
-
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_NODISCARD
-
-#include <__config>
-
-_LIBCPP_NODISCARD_EXT int foo() { return 42; }
-_LIBCPP_NODISCARD_AFTER_CXX17 int bar() { return 42; }
-
-int main(int, char**) {
-  foo(); // expected-warning-re {{ignoring return value of function declared with {{'nodiscard'|warn_unused_result}} attribute}}
-  bar(); // expected-warning-re {{ignoring return value of function declared with {{'nodiscard'|warn_unused_result}} attribute}}
-  (void)foo(); // OK. void casts disable the diagnostic.
-  (void)bar();
-
-  return 0;
-}
diff --git a/libcxx/test/libcxx/diagnostics/enable_nodiscard_disable_after_cxx17.verify.cpp b/libcxx/test/libcxx/diagnostics/enable_nodiscard_disable_after_cxx17.verify.cpp
deleted file mode 100644
--- a/libcxx/test/libcxx/diagnostics/enable_nodiscard_disable_after_cxx17.verify.cpp
+++ /dev/null
@@ -1,29 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03
-
-// Test that _LIBCPP_DISABLE_NODISCARD_EXT only disables _LIBCPP_NODISCARD_EXT
-// and not _LIBCPP_NODISCARD_AFTER_CXX17.
-
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_NODISCARD
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_NODISCARD_AFTER_CXX17
-#include <__config>
-
-
-_LIBCPP_NODISCARD_EXT int foo() { return 42; }
-_LIBCPP_NODISCARD_AFTER_CXX17 int bar() { return 42; }
-
-int main(int, char**) {
-  foo(); // expected-warning-re{{ignoring return value of function declared with {{'nodiscard'|warn_unused_result}} attribute}}
-  bar(); // OK.
-  (void)foo(); // OK.
-
-  return 0;
-}
diff --git a/libcxx/test/libcxx/diagnostics/enable_nodiscard_disable_nodiscard_ext.verify.cpp b/libcxx/test/libcxx/diagnostics/enable_nodiscard_disable_nodiscard_ext.verify.cpp
deleted file mode 100644
--- a/libcxx/test/libcxx/diagnostics/enable_nodiscard_disable_nodiscard_ext.verify.cpp
+++ /dev/null
@@ -1,26 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03
-
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_NODISCARD
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_NODISCARD_EXT
-#include <__config>
-
-
-_LIBCPP_NODISCARD_EXT int foo() { return 42; }
-_LIBCPP_NODISCARD_AFTER_CXX17 int bar() { return 42; }
-
-int main(int, char**) {
-  bar(); // expected-warning-re{{ignoring return value of function declared with {{'nodiscard'|warn_unused_result}} attribute}}
-  foo(); // OK.
-  (void)bar(); // OK.
-
-  return 0;
-}
diff --git a/libcxx/test/libcxx/diagnostics/nodiscard.pass.cpp b/libcxx/test/libcxx/diagnostics/nodiscard.pass.cpp
deleted file mode 100644
--- a/libcxx/test/libcxx/diagnostics/nodiscard.pass.cpp
+++ /dev/null
@@ -1,23 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// Test that _LIBCPP_NODISCARD_EXT is not defined to [[nodiscard]] unless
-// explicitly enabled by _LIBCPP_ENABLE_NODISCARD
-
-#include <__config>
-
-#include "test_macros.h"
-
-_LIBCPP_NODISCARD_EXT int foo() { return 42; }
-
-int main(int, char**) {
-  foo(); // OK.
-
-  return 0;
-}
diff --git a/libcxx/test/libcxx/diagnostics/nodiscard_aftercxx17.pass.cpp b/libcxx/test/libcxx/diagnostics/nodiscard_aftercxx17.pass.cpp
deleted file mode 100644
--- a/libcxx/test/libcxx/diagnostics/nodiscard_aftercxx17.pass.cpp
+++ /dev/null
@@ -1,26 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// Test that _LIBCPP_NODISCARD_AFTER_CXX17 is disabled whenever
-// _LIBCPP_DISABLE_NODISCARD_AFTER_CXX17 is defined by the user.
-
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_NODISCARD_AFTER_CXX17
-
-#include <__config>
-
-#include "test_macros.h"
-
-_LIBCPP_NODISCARD_AFTER_CXX17 int foo() { return 6; }
-
-int main(int, char**)
-{
-	foo();	// no error here!
-
-  return 0;
-}
diff --git a/libcxx/test/libcxx/diagnostics/nodiscard_aftercxx17.verify.cpp b/libcxx/test/libcxx/diagnostics/nodiscard_aftercxx17.verify.cpp
deleted file mode 100644
--- a/libcxx/test/libcxx/diagnostics/nodiscard_aftercxx17.verify.cpp
+++ /dev/null
@@ -1,24 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// Test that _LIBCPP_NODISCARD_AFTER_CXX17 works
-//	#define _LIBCPP_NODISCARD_AFTER_CXX17 [[nodiscard]]
-
-// UNSUPPORTED: c++03, c++11, c++14, c++17
-
-#include <__config>
-
-_LIBCPP_NODISCARD_AFTER_CXX17 int foo() { return 6; }
-
-int main(int, char**)
-{
-    foo(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
-
-    return 0;
-}
diff --git a/libcxx/test/libcxx/diagnostics/nodiscard_extensions.pass.cpp b/libcxx/test/libcxx/diagnostics/nodiscard_extensions.pass.cpp
deleted file mode 100644
--- a/libcxx/test/libcxx/diagnostics/nodiscard_extensions.pass.cpp
+++ /dev/null
@@ -1,195 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// Test that entities declared [[nodiscard]] as at extension by libc++, are
-// only actually declared such when _LIBCPP_ENABLE_NODISCARD is specified.
-
-// This test intentionally leaks memory, so it is unsupported under ASAN.
-// UNSUPPORTED: asan
-
-// AppleClang9 and GCC 5 don't support C++17's implicitly synthesized
-// deduction guides from existing ctors, needed by default_searcher() below.
-// UNSUPPORTED: apple-clang-9
-
-// All entities to which libc++ applies [[nodiscard]] as an extension should
-// be tested here and in nodiscard_extensions.fail.cpp. They should also
-// be listed in `UsingLibcxx.rst` in the documentation for the extension.
-
-#include <algorithm>
-#include <cstddef> // to_integer
-#include <functional> // identity
-#include <iterator>
-#include <memory>
-#include <utility> // to_underlying
-
-#include "test_macros.h"
-
-struct P {
-  bool operator()(int) const { return false; }
-};
-
-void test_algorithms() {
-  int arr[1] = { 1 };
-
-  std::adjacent_find(std::begin(arr), std::end(arr));
-  std::adjacent_find(std::begin(arr), std::end(arr), std::greater<int>());
-  std::all_of(std::begin(arr), std::end(arr), P());
-  std::any_of(std::begin(arr), std::end(arr), P());
-  std::binary_search(std::begin(arr), std::end(arr), 1);
-  std::binary_search(std::begin(arr), std::end(arr), 1, std::greater<int>());
-#if TEST_STD_VER >= 17
-  std::clamp(2, 1, 3);
-  std::clamp(2, 3, 1, std::greater<int>());
-#endif
-  std::count_if(std::begin(arr), std::end(arr), P());
-  std::count(std::begin(arr), std::end(arr), 1);
-  std::equal_range(std::begin(arr), std::end(arr), 1);
-  std::equal_range(std::begin(arr), std::end(arr), 1, std::greater<int>());
-  std::equal(std::begin(arr), std::end(arr), std::begin(arr));
-  std::equal(std::begin(arr), std::end(arr), std::begin(arr),
-             std::greater<int>());
-#if TEST_STD_VER >= 14
-  std::equal(std::begin(arr), std::end(arr), std::begin(arr), std::end(arr));
-  std::equal(std::begin(arr), std::end(arr), std::begin(arr), std::end(arr),
-             std::greater<int>());
-#endif
-  std::find_end(std::begin(arr), std::end(arr), std::begin(arr), std::end(arr));
-  std::find_end(std::begin(arr), std::end(arr), std::begin(arr), std::end(arr),
-                std::greater<int>());
-  std::find_first_of(std::begin(arr), std::end(arr), std::begin(arr),
-                     std::end(arr));
-  std::find_first_of(std::begin(arr), std::end(arr), std::begin(arr),
-                     std::end(arr), std::greater<int>());
-  std::find_if_not(std::begin(arr), std::end(arr), P());
-  std::find_if(std::begin(arr), std::end(arr), P());
-  std::find(std::begin(arr), std::end(arr), 1);
-  std::get_temporary_buffer<int>(1); // intentional memory leak.
-  std::includes(std::begin(arr), std::end(arr), std::begin(arr), std::end(arr));
-  std::includes(std::begin(arr), std::end(arr), std::begin(arr), std::end(arr),
-                std::greater<int>());
-  std::is_heap_until(std::begin(arr), std::end(arr));
-  std::is_heap_until(std::begin(arr), std::end(arr), std::greater<int>());
-  std::is_heap(std::begin(arr), std::end(arr));
-  std::is_heap(std::begin(arr), std::end(arr), std::greater<int>());
-  std::is_partitioned(std::begin(arr), std::end(arr), P());
-  std::is_permutation(std::begin(arr), std::end(arr), std::begin(arr));
-  std::is_permutation(std::begin(arr), std::end(arr), std::begin(arr),
-                      std::greater<int>());
-#if TEST_STD_VER >= 14
-  std::is_permutation(std::begin(arr), std::end(arr), std::begin(arr),
-                      std::end(arr));
-  std::is_permutation(std::begin(arr), std::end(arr), std::begin(arr),
-                      std::end(arr), std::greater<int>());
-#endif
-  std::is_sorted_until(std::begin(arr), std::end(arr));
-  std::is_sorted_until(std::begin(arr), std::end(arr), std::greater<int>());
-  std::is_sorted(std::begin(arr), std::end(arr));
-  std::is_sorted(std::begin(arr), std::end(arr), std::greater<int>());
-  std::lexicographical_compare(std::begin(arr), std::end(arr), std::begin(arr),
-                               std::end(arr));
-  std::lexicographical_compare(std::begin(arr), std::end(arr), std::begin(arr),
-                               std::end(arr), std::greater<int>());
-  std::lower_bound(std::begin(arr), std::end(arr), 1);
-  std::lower_bound(std::begin(arr), std::end(arr), 1, std::greater<int>());
-  std::max_element(std::begin(arr), std::end(arr));
-  std::max_element(std::begin(arr), std::end(arr), std::greater<int>());
-  std::max(1, 2);
-  std::max(1, 2, std::greater<int>());
-#if TEST_STD_VER >= 11
-  std::max({1, 2, 3});
-  std::max({1, 2, 3}, std::greater<int>());
-#endif
-  std::min_element(std::begin(arr), std::end(arr));
-  std::min_element(std::begin(arr), std::end(arr), std::greater<int>());
-  std::min(1, 2);
-  std::min(1, 2, std::greater<int>());
-#if TEST_STD_VER >= 11
-  std::min({1, 2, 3});
-  std::min({1, 2, 3}, std::greater<int>());
-#endif
-  std::minmax_element(std::begin(arr), std::end(arr));
-  std::minmax_element(std::begin(arr), std::end(arr), std::greater<int>());
-  std::minmax(1, 2);
-  std::minmax(1, 2, std::greater<int>());
-#if TEST_STD_VER >= 11
-  std::minmax({1, 2, 3});
-  std::minmax({1, 2, 3}, std::greater<int>());
-#endif
-  std::mismatch(std::begin(arr), std::end(arr), std::begin(arr));
-  std::mismatch(std::begin(arr), std::end(arr), std::begin(arr),
-                std::greater<int>());
-#if TEST_STD_VER >= 14
-  std::mismatch(std::begin(arr), std::end(arr), std::begin(arr), std::end(arr));
-  std::mismatch(std::begin(arr), std::end(arr), std::begin(arr), std::end(arr),
-                std::greater<int>());
-#endif
-  std::none_of(std::begin(arr), std::end(arr), P());
-  std::remove_if(std::begin(arr), std::end(arr), P());
-  std::remove(std::begin(arr), std::end(arr), 1);
-  std::search_n(std::begin(arr), std::end(arr), 1, 1);
-  std::search_n(std::begin(arr), std::end(arr), 1, 1, std::greater<int>());
-  std::search(std::begin(arr), std::end(arr), std::begin(arr), std::end(arr));
-  std::search(std::begin(arr), std::end(arr), std::begin(arr), std::end(arr),
-              std::greater<int>());
-#if TEST_STD_VER >= 17
-  std::search(std::begin(arr), std::end(arr),
-              std::default_searcher(std::begin(arr), std::end(arr)));
-#endif
-  std::unique(std::begin(arr), std::end(arr));
-  std::unique(std::begin(arr), std::end(arr), std::greater<int>());
-  std::upper_bound(std::begin(arr), std::end(arr), 1);
-  std::upper_bound(std::begin(arr), std::end(arr), 1, std::greater<int>());
-}
-
-template<class LV, class RV>
-void test_template_cast_wrappers(LV&& lv, RV&& rv) {
-  std::forward<LV>(lv);
-  std::forward<RV>(rv);
-  std::move(lv);
-  std::move(rv);
-  std::move_if_noexcept(lv);
-  std::move_if_noexcept(rv);
-
-#if TEST_STD_VER >= 17
-  std::as_const(lv);
-  std::as_const(rv);
-#endif
-
-#if TEST_STD_VER >= 20
-  std::identity()(lv);
-  std::identity()(rv);
-#endif
-}
-
-void test_nontemplate_cast_wrappers()
-{
-#if TEST_STD_VER >= 17
-  std::byte b{42};
-  std::to_integer<int>(b);
-#endif
-
-#if TEST_STD_VER >= 20
-  // std::bit_cast<unsigned int>(42);
-#endif
-
-#if TEST_STD_VER > 20
-  enum E { Apple, Orange } e = Apple;
-  std::to_underlying(e);
-#endif
-}
-
-int main(int, char**) {
-  test_algorithms();
-
-  int i = 42;
-  test_template_cast_wrappers(i, std::move(i));
-  test_nontemplate_cast_wrappers();
-
-  return 0;
-}
diff --git a/libcxx/test/libcxx/diagnostics/nodiscard_extensions.verify.cpp b/libcxx/test/libcxx/diagnostics/nodiscard_extensions.verify.cpp
--- a/libcxx/test/libcxx/diagnostics/nodiscard_extensions.verify.cpp
+++ b/libcxx/test/libcxx/diagnostics/nodiscard_extensions.verify.cpp
@@ -13,15 +13,12 @@
 // guides from existing ctors, needed by default_searcher() below.
 // UNSUPPORTED: apple-clang-9
 
-// Test that entities declared [[nodiscard]] as an extension by libc++, are
-// only actually declared such when _LIBCPP_ENABLE_NODISCARD is specified.
+// Test that entities declared [[nodiscard]] as an extension by libc++.
 
 // All entities to which libc++ applies [[nodiscard]] as an extension should
 // be tested here and in nodiscard_extensions.pass.cpp. They should also
 // be listed in `UsingLibcxx.rst` in the documentation for the extension.
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_NODISCARD
-
 #include <algorithm>
 #include <cstddef> // to_integer
 #include <functional> // identity
diff --git a/libcxx/test/std/algorithms/alg.sorting/alg.min.max/requires_forward_iterator.fail.cpp b/libcxx/test/std/algorithms/alg.sorting/alg.min.max/requires_forward_iterator.fail.cpp
--- a/libcxx/test/std/algorithms/alg.sorting/alg.min.max/requires_forward_iterator.fail.cpp
+++ b/libcxx/test/std/algorithms/alg.sorting/alg.min.max/requires_forward_iterator.fail.cpp
@@ -22,15 +22,15 @@
   typedef cpp17_input_iterator<const int*> Iter;
   {
     // expected-error@*:* {{"std::min_element requires a ForwardIterator"}}
-    std::min_element(Iter(b), Iter(e));
+    (void)std::min_element(Iter(b), Iter(e));
   }
   {
     // expected-error@*:* {{"std::max_element requires a ForwardIterator"}}
-    std::max_element(Iter(b), Iter(e));
+    (void)std::max_element(Iter(b), Iter(e));
   }
   {
     // expected-error@*:* {{"std::minmax_element requires a ForwardIterator"}}
-    std::minmax_element(Iter(b), Iter(e));
+    (void)std::minmax_element(Iter(b), Iter(e));
   }
 
 
diff --git a/libcxx/test/std/utilities/utility/forward/forward.fail.cpp b/libcxx/test/std/utilities/utility/forward/forward.fail.cpp
--- a/libcxx/test/std/utilities/utility/forward/forward.fail.cpp
+++ b/libcxx/test/std/utilities/utility/forward/forward.fail.cpp
@@ -22,26 +22,26 @@
 int main(int, char**)
 {
     {
-        std::forward<A&>(source());  // expected-note {{requested here}}
+        (void)std::forward<A&>(source());  // expected-note {{requested here}}
         // expected-error-re@*:* 1 {{static_assert failed{{.*}} "cannot forward an rvalue as an lvalue"}}
     }
     {
         const A ca = A();
-        std::forward<A&>(ca); // expected-error {{no matching function for call to 'forward'}}
+        (void)std::forward<A&>(ca); // expected-error {{no matching function for call to 'forward'}}
     }
     {
-        std::forward<A&>(csource());  // expected-error {{no matching function for call to 'forward'}}
+        (void)std::forward<A&>(csource());  // expected-error {{no matching function for call to 'forward'}}
     }
     {
         const A ca = A();
-        std::forward<A>(ca); // expected-error {{no matching function for call to 'forward'}}
+        (void)std::forward<A>(ca); // expected-error {{no matching function for call to 'forward'}}
     }
     {
-        std::forward<A>(csource()); // expected-error {{no matching function for call to 'forward'}}
+        (void)std::forward<A>(csource()); // expected-error {{no matching function for call to 'forward'}}
     }
     {
         A a;
-        std::forward(a); // expected-error {{no matching function for call to 'forward'}}
+        (void)std::forward(a); // expected-error {{no matching function for call to 'forward'}}
     }
 
   return 0;