diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -28,6 +28,7 @@
   __algorithm/is_partitioned.h
   __algorithm/is_permutation.h
   __algorithm/is_sorted.h
+  __algorithm/iter_swap.h
   __algorithm/lexicographical_compare.h
   __algorithm/lower_bound.h
   __algorithm/make_heap.h
@@ -67,6 +68,7 @@
   __algorithm/sort_heap.h
   __algorithm/stable_partition.h
   __algorithm/stable_sort.h
+  __algorithm/swap_ranges.h
   __algorithm/transform.h
   __algorithm/uniform_int_distribution.h
   __algorithm/unique.h
@@ -79,6 +81,7 @@
   __bsd_locale_fallbacks.h
   __config
   __debug
+  __decay_copy.h
   __errc
   __format/format_error.h
   __format/format_parse_context.h
@@ -133,7 +136,15 @@
   __threading_support
   __tree
   __tuple
+  __type_traits/integral_constant.h
+  __type_traits/is_same.h
+  __type_traits/references.h
   __undef_macros
+  __utility/declval.h
+  __utility/forward.h
+  __utility/move_if_noexcept.h
+  __utility/move.h
+  __utility/swap.h
   __utility/to_underlying.h
   algorithm
   any
diff --git a/libcxx/include/__algorithm/iter_swap.h b/libcxx/include/__algorithm/iter_swap.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__algorithm/iter_swap.h
@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___ALGORITHM_ITER_SWAP_H
+#define _LIBCPP___ALGORITHM_ITER_SWAP_H
+
+#include <__config>
+#include <__utility/declval.h>
+#include <__utility/swap.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 void iter_swap(_ForwardIterator1 __a,
+                                                                              _ForwardIterator2 __b)
+    //                                  _NOEXCEPT_(_NOEXCEPT_(swap(*__a, *__b)))
+    _NOEXCEPT_(_NOEXCEPT_(swap(*declval<_ForwardIterator1>(), *declval<_ForwardIterator2>()))) {
+  swap(*__a, *__b);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_ITER_SWAP_H
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
@@ -11,6 +11,7 @@
 
 #include <__config>
 #include <__algorithm/unwrap_iter.h>
+#include <__utility/move.h>
 #include <cstring>
 #include <type_traits>
 
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
@@ -12,6 +12,7 @@
 #include <__config>
 #include <__algorithm/comp_ref_type.h>
 #include <__iterator/iterator_traits.h>
+#include <__utility/move.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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
@@ -12,6 +12,7 @@
 #include <__config>
 #include <__algorithm/find.h>
 #include <__algorithm/find_if.h>
+#include <__utility/move.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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
@@ -10,8 +10,8 @@
 #define _LIBCPP___ALGORITHM_REVERSE_H
 
 #include <__config>
+#include <__algorithm/iter_swap.h>
 #include <__iterator/iterator_traits.h>
-#include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
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
@@ -11,6 +11,7 @@
 
 #include <__config>
 #include <__iterator/iterator_traits.h>
+#include <__utility/move.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
diff --git a/libcxx/include/__algorithm/swap_ranges.h b/libcxx/include/__algorithm/swap_ranges.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__algorithm/swap_ranges.h
@@ -0,0 +1,52 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___ALGORITHM_SWAP_RANGES_H
+#define _LIBCPP___ALGORITHM_SWAP_RANGES_H
+
+#include <__config>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+#ifndef _LIBCPP_CXX03_LANG
+    typename enable_if<is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value>::type
+#else
+    void
+#endif
+        _LIBCPP_CONSTEXPR_AFTER_CXX17
+        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
+    typename enable_if<__is_swappable<_Tp>::value>::type swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np])
+        _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value);
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator2
+swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2) {
+  for (; __first1 != __last1; ++__first1, (void)++__first2)
+    swap(*__first1, *__first2);
+  return __first2;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_SWAP_RANGES_H
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
@@ -12,6 +12,7 @@
 #include <__config>
 #include <__algorithm/adjacent_find.h>
 #include <__iterator/iterator_traits.h>
+#include <__utility/move.h>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
diff --git a/libcxx/include/__decay_copy.h b/libcxx/include/__decay_copy.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__decay_copy.h
@@ -0,0 +1,39 @@
+// -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___DECAY_COPY_H
+#define _LIBCPP___DECAY_COPY_H
+
+#include <__config>
+#include <__utility/forward.h>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY typename decay<_Tp>::type __decay_copy(_Tp&& __t)
+#if _LIBCPP_STD_VER > 17
+    noexcept(is_nothrow_convertible_v<_Tp, remove_reference_t<_Tp> >)
+#endif
+{
+  return _VSTD::forward<_Tp>(__t);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___DECAY_COPY_H
diff --git a/libcxx/include/__ranges/access.h b/libcxx/include/__ranges/access.h
--- a/libcxx/include/__ranges/access.h
+++ b/libcxx/include/__ranges/access.h
@@ -10,6 +10,7 @@
 #define _LIBCPP___RANGES_ACCESS_H
 
 #include <__config>
+#include <__decay_copy.h>
 #include <__iterator/concepts.h>
 #include <__ranges/enable_borrowed_range.h>
 #include <type_traits>
diff --git a/libcxx/include/__ranges/size.h b/libcxx/include/__ranges/size.h
--- a/libcxx/include/__ranges/size.h
+++ b/libcxx/include/__ranges/size.h
@@ -10,6 +10,7 @@
 #define _LIBCPP___RANGES_SIZE_H
 
 #include <__config>
+#include <__decay_copy.h>
 #include <__iterator/concepts.h>
 #include <__iterator/iterator_traits.h>
 #include <__ranges/access.h>
diff --git a/libcxx/include/__type_traits/integral_constant.h b/libcxx/include/__type_traits/integral_constant.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__type_traits/integral_constant.h
@@ -0,0 +1,58 @@
+// -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___TYPE_TRAITS_INTEGRAL_CONSTANT_H
+#define _LIBCPP___TYPE_TRAITS_INTEGRAL_CONSTANT_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, _Tp __v>
+struct _LIBCPP_TEMPLATE_VIS integral_constant {
+  static _LIBCPP_CONSTEXPR const _Tp value = __v;
+  typedef _Tp value_type;
+  typedef integral_constant type;
+  _LIBCPP_INLINE_VISIBILITY
+  _LIBCPP_CONSTEXPR operator value_type() const _NOEXCEPT { return value; }
+#if _LIBCPP_STD_VER > 11
+  _LIBCPP_INLINE_VISIBILITY
+  constexpr value_type operator()() const _NOEXCEPT { return value; }
+#endif
+};
+
+template <class _Tp, _Tp __v>
+_LIBCPP_CONSTEXPR const _Tp integral_constant<_Tp, __v>::value;
+
+#if _LIBCPP_STD_VER > 14
+template <bool __b>
+using bool_constant = integral_constant<bool, __b>;
+#define _LIBCPP_BOOL_CONSTANT(__b) bool_constant<(__b)>
+#else
+#define _LIBCPP_BOOL_CONSTANT(__b) integral_constant<bool, (__b)>
+#endif
+
+typedef _LIBCPP_BOOL_CONSTANT(true) true_type;
+typedef _LIBCPP_BOOL_CONSTANT(false) false_type;
+
+template <bool _Val>
+using _BoolConstant _LIBCPP_NODEBUG_TYPE = integral_constant<bool, _Val>;
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___TYPE_TRAITS_INTEGRAL_CONSTANT_H
diff --git a/libcxx/include/__type_traits/is_same.h b/libcxx/include/__type_traits/is_same.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__type_traits/is_same.h
@@ -0,0 +1,73 @@
+// -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___TYPE_TRAITS_IS_SAME_H
+#define _LIBCPP___TYPE_TRAITS_IS_SAME_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// is_same
+
+#if __has_keyword(__is_same)
+
+template <class _Tp, class _Up>
+struct _LIBCPP_TEMPLATE_VIS is_same : _BoolConstant<__is_same(_Tp, _Up)> {};
+
+#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
+template <class _Tp, class _Up>
+_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_same_v = __is_same(_Tp, _Up);
+#endif
+
+#else
+
+template <class _Tp, class _Up>
+struct _LIBCPP_TEMPLATE_VIS is_same : public false_type {};
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_same<_Tp, _Tp> : public true_type {};
+
+#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
+template <class _Tp, class _Up>
+_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_same_v = is_same<_Tp, _Up>::value;
+#endif
+
+#endif // __is_same
+
+template <class _Tp, class _Up>
+using _IsSame = _BoolConstant<
+#ifdef __clang__
+    __is_same(_Tp, _Up)
+#else
+    is_same<_Tp, _Up>::value
+#endif
+    >;
+
+template <class _Tp, class _Up>
+using _IsNotSame = _BoolConstant<
+#ifdef __clang__
+    !__is_same(_Tp, _Up)
+#else
+    !is_same<_Tp, _Up>::value
+#endif
+    >;
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___TYPE_TRAITS_IS_SAME_H
diff --git a/libcxx/include/__type_traits/references.h b/libcxx/include/__type_traits/references.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__type_traits/references.h
@@ -0,0 +1,174 @@
+// -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___TYPE_TRAITS_REFERENCES_H
+#define _LIBCPP___TYPE_TRAITS_REFERENCES_H
+
+#include <__config>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_same.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// is_reference
+
+#if __has_keyword(__is_lvalue_reference) && __has_keyword(__is_rvalue_reference) && __has_keyword(__is_reference)
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_lvalue_reference : _BoolConstant<__is_lvalue_reference(_Tp)> {};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_rvalue_reference : _BoolConstant<__is_rvalue_reference(_Tp)> {};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_reference : _BoolConstant<__is_reference(_Tp)> {};
+
+#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
+template <class _Tp>
+_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_reference_v = __is_reference(_Tp);
+
+template <class _Tp>
+_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_lvalue_reference_v = __is_lvalue_reference(_Tp);
+
+template <class _Tp>
+_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_rvalue_reference_v = __is_rvalue_reference(_Tp);
+#endif
+
+#else // __has_keyword(__is_lvalue_reference) && etc...
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_lvalue_reference : public false_type {};
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_lvalue_reference<_Tp&> : public true_type {};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_rvalue_reference : public false_type {};
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_rvalue_reference<_Tp&&> : public true_type {};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_reference : public false_type {};
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_reference<_Tp&> : public true_type {};
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_reference<_Tp&&> : public true_type {};
+
+#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
+template <class _Tp>
+_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_reference_v = is_reference<_Tp>::value;
+
+template <class _Tp>
+_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_lvalue_reference_v = is_lvalue_reference<_Tp>::value;
+
+template <class _Tp>
+_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_rvalue_reference_v = is_rvalue_reference<_Tp>::value;
+#endif
+
+#endif // __has_keyword(__is_lvalue_reference) && etc...
+
+// remove_reference
+
+#if __has_keyword(__remove_reference)
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS remove_reference {
+  typedef __remove_reference(_Tp) type;
+};
+
+#else // __has_keyword(__remove_reference)
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS remove_reference {
+  typedef _LIBCPP_NODEBUG_TYPE _Tp type;
+};
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS remove_reference<_Tp&> {
+  typedef _LIBCPP_NODEBUG_TYPE _Tp type;
+};
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS remove_reference<_Tp&&> {
+  typedef _LIBCPP_NODEBUG_TYPE _Tp type;
+};
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp>
+using remove_reference_t = typename remove_reference<_Tp>::type;
+#endif
+
+#endif // __has_keyword(__remove_reference)
+
+struct __two {
+  char __lx[2];
+};
+
+// __is_referenceable  [defns.referenceable]
+
+struct __is_referenceable_impl {
+  template <class _Tp>
+  static _Tp& __test(int);
+  template <class _Tp>
+  static __two __test(...);
+};
+
+template <class _Tp>
+struct __is_referenceable
+    : integral_constant<bool, _IsNotSame<decltype(__is_referenceable_impl::__test<_Tp>(0)), __two>::value> {};
+
+// add_lvalue_reference
+
+template <class _Tp, bool = __is_referenceable<_Tp>::value>
+struct __add_lvalue_reference_impl {
+  typedef _LIBCPP_NODEBUG_TYPE _Tp type;
+};
+template <class _Tp>
+struct __add_lvalue_reference_impl<_Tp, true> {
+  typedef _LIBCPP_NODEBUG_TYPE _Tp& type;
+};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS add_lvalue_reference {
+  typedef _LIBCPP_NODEBUG_TYPE typename __add_lvalue_reference_impl<_Tp>::type type;
+};
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp>
+using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
+#endif
+
+template <class _Tp, bool = __is_referenceable<_Tp>::value>
+struct __add_rvalue_reference_impl {
+  typedef _LIBCPP_NODEBUG_TYPE _Tp type;
+};
+template <class _Tp>
+struct __add_rvalue_reference_impl<_Tp, true> {
+  typedef _LIBCPP_NODEBUG_TYPE _Tp&& type;
+};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS add_rvalue_reference {
+  typedef _LIBCPP_NODEBUG_TYPE typename __add_rvalue_reference_impl<_Tp>::type type;
+};
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp>
+using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___TYPE_TRAITS_REFERENCES_H
diff --git a/libcxx/include/__utility/declval.h b/libcxx/include/__utility/declval.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__utility/declval.h
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___UTILITY_DECLVAL_H
+#define _LIBCPP___UTILITY_DECLVAL_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// Suppress deprecation notice for volatile-qualified return type resulting
+// from volatile-qualified types _Tp.
+_LIBCPP_SUPPRESS_DEPRECATED_PUSH
+template <class _Tp>
+_Tp&& __declval(int);
+template <class _Tp>
+_Tp __declval(long);
+_LIBCPP_SUPPRESS_DEPRECATED_POP
+
+template <class _Tp>
+decltype(__declval<_Tp>(0)) declval() _NOEXCEPT;
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___UTILITY_DECLVAL_H
diff --git a/libcxx/include/__utility/forward.h b/libcxx/include/__utility/forward.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__utility/forward.h
@@ -0,0 +1,42 @@
+// -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___UTILITY_FORWARD_H
+#define _LIBCPP___UTILITY_FORWARD_H
+
+#include <__config>
+#include <__type_traits/references.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp>
+_LIBCPP_NODISCARD_EXT 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&&
+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);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___UTILITY_FORWARD_H
diff --git a/libcxx/include/__utility/move.h b/libcxx/include/__utility/move.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__utility/move.h
@@ -0,0 +1,36 @@
+// -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___UTILITY_MOVE_H
+#define _LIBCPP___UTILITY_MOVE_H
+
+#include <__config>
+#include <__type_traits/references.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp>
+_LIBCPP_NODISCARD_EXT 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);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___UTILITY_MOVE_H
diff --git a/libcxx/include/__utility/move_if_noexcept.h b/libcxx/include/__utility/move_if_noexcept.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__utility/move_if_noexcept.h
@@ -0,0 +1,42 @@
+// -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___UTILITY_MOVE_IF_NOEXCEPT_H
+#define _LIBCPP___UTILITY_MOVE_IF_NOEXCEPT_H
+
+#include <__config>
+#include <__utility/move.h>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+#ifndef _LIBCPP_CXX03_LANG
+    typename conditional<!is_nothrow_move_constructible<_Tp>::value && is_copy_constructible<_Tp>::value, const _Tp&,
+                         _Tp&&>::type
+#else // _LIBCPP_CXX03_LANG
+    const _Tp&
+#endif
+    move_if_noexcept(_Tp& __x) _NOEXCEPT {
+  return _VSTD::move(__x);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___UTILITY_MOVE_IF_NOEXCEPT_H
diff --git a/libcxx/include/__utility/swap.h b/libcxx/include/__utility/swap.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/__utility/swap.h
@@ -0,0 +1,54 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___UTILITY_SWAP_H
+#define _LIBCPP___UTILITY_SWAP_H
+
+#include <__config>
+#include <__utility/move.h>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator2
+swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2);
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+#ifndef _LIBCPP_CXX03_LANG
+    typename enable_if<is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value>::type
+#else
+    void
+#endif
+        _LIBCPP_CONSTEXPR_AFTER_CXX17
+        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);
+  __y = _VSTD::move(__t);
+}
+
+template <class _Tp, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 typename enable_if<__is_swappable<_Tp>::value>::type
+swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
+  _VSTD::swap_ranges(__a, __a + _Np, __b);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___UTILITY_SWAP_H
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -689,6 +689,7 @@
 #include <__algorithm/is_partitioned.h>
 #include <__algorithm/is_permutation.h>
 #include <__algorithm/is_sorted.h>
+#include <__algorithm/iter_swap.h>
 #include <__algorithm/lexicographical_compare.h>
 #include <__algorithm/lower_bound.h>
 #include <__algorithm/make_heap.h>
@@ -728,6 +729,7 @@
 #include <__algorithm/sort_heap.h>
 #include <__algorithm/stable_partition.h>
 #include <__algorithm/stable_sort.h>
+#include <__algorithm/swap_ranges.h>
 #include <__algorithm/transform.h>
 #include <__algorithm/uniform_int_distribution.h>
 #include <__algorithm/unique.h>
diff --git a/libcxx/include/future b/libcxx/include/future
--- a/libcxx/include/future
+++ b/libcxx/include/future
@@ -364,6 +364,7 @@
 #include <__availability>
 #include <__config>
 #include <__debug>
+#include <__decay_copy.h>
 #include <chrono>
 #include <exception>
 #include <memory>
diff --git a/libcxx/include/module.modulemap b/libcxx/include/module.modulemap
--- a/libcxx/include/module.modulemap
+++ b/libcxx/include/module.modulemap
@@ -619,6 +619,12 @@
   module type_traits {
     header "type_traits"
     export *
+
+    module __type_traits {
+      module integral_constant { header "__type_traits/integral_constant.h" }
+      module is_same           { header "__type_traits/is_same.h"           }
+      module references        { header "__type_traits/references.h"        }
+    }
   }
   module typeindex {
     header "typeindex"
@@ -644,9 +650,12 @@
     export *
 
     module __utility {
-      module to_underlying {
-        header "__utility/to_underlying.h"
-      }
+      module declval          { header "__utility/declval.h"          }
+      module forward          { header "__utility/forward.h"          }
+      module move_if_noexcept { header "__utility/move_if_noexcept.h" }
+      module move             { header "__utility/move.h"             }
+      module swap             { header "__utility/swap.h"             }
+      module to_underlying    { header "__utility/to_underlying.h"    }
     }
   }
   module valarray {
@@ -674,6 +683,7 @@
   module __bits               { header "__bits"               export * }
   module __config             { header "__config"             export * }
   module __debug              { header "__debug"              export * }
+  module __decay_copy         { header "__decay_copy.h"       export * }
   module __errc               { header "__errc"               export * }
   module __function_like      { header "__function_like.h"    export * }
   module __functional_base    { header "__functional_base" export * }
diff --git a/libcxx/include/thread b/libcxx/include/thread
--- a/libcxx/include/thread
+++ b/libcxx/include/thread
@@ -84,6 +84,7 @@
 
 #include <__config>
 #include <__debug>
+#include <__decay_copy.h>
 #include <__functional_base>
 #include <__mutex_base>
 #include <__threading_support>
diff --git a/libcxx/include/tuple b/libcxx/include/tuple
--- a/libcxx/include/tuple
+++ b/libcxx/include/tuple
@@ -151,6 +151,7 @@
 
 #include <__config>
 #include <__functional_base>
+#include <__utility/move.h>
 #include <__tuple>
 #include <compare>
 #include <cstddef>
diff --git a/libcxx/include/type_traits b/libcxx/include/type_traits
--- a/libcxx/include/type_traits
+++ b/libcxx/include/type_traits
@@ -417,6 +417,12 @@
 
 */
 #include <__config>
+#include <__type_traits/integral_constant.h>
+#include <__type_traits/is_same.h>
+#include <__type_traits/references.h>
+#include <__utility/declval.h>
+#include <__utility/forward.h>
+#include <__utility/move.h> // TODO: remove
 #include <cstddef>
 #include <version>
 
@@ -430,37 +436,6 @@
 template <class _Tp> class _LIBCPP_TEMPLATE_VIS reference_wrapper;
 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS hash;
 
-template <class _Tp, _Tp __v>
-struct _LIBCPP_TEMPLATE_VIS integral_constant
-{
-  static _LIBCPP_CONSTEXPR const _Tp      value = __v;
-  typedef _Tp               value_type;
-  typedef integral_constant type;
-  _LIBCPP_INLINE_VISIBILITY
-  _LIBCPP_CONSTEXPR operator value_type() const _NOEXCEPT {return value;}
-#if _LIBCPP_STD_VER > 11
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr value_type operator ()() const _NOEXCEPT {return value;}
-#endif
-};
-
-template <class _Tp, _Tp __v>
-_LIBCPP_CONSTEXPR const _Tp integral_constant<_Tp, __v>::value;
-
-#if _LIBCPP_STD_VER > 14
-template <bool __b>
-using bool_constant = integral_constant<bool, __b>;
-#define _LIBCPP_BOOL_CONSTANT(__b) bool_constant<(__b)>
-#else
-#define _LIBCPP_BOOL_CONSTANT(__b) integral_constant<bool,(__b)>
-#endif
-
-typedef _LIBCPP_BOOL_CONSTANT(true)  true_type;
-typedef _LIBCPP_BOOL_CONSTANT(false) false_type;
-
-template <bool _Val>
-using _BoolConstant _LIBCPP_NODEBUG_TYPE = integral_constant<bool, _Val>;
-
 template <bool> struct _MetaBase;
 template <>
 struct _MetaBase<true> {
@@ -550,50 +525,6 @@
 template <bool _Bp, class _Tp = void> using enable_if_t = typename enable_if<_Bp, _Tp>::type;
 #endif
 
-// is_same
-
-#if __has_keyword(__is_same)
-
-template <class _Tp, class _Up>
-struct _LIBCPP_TEMPLATE_VIS is_same : _BoolConstant<__is_same(_Tp, _Up)> { };
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_same_v = __is_same(_Tp, _Up);
-#endif
-
-#else
-
-template <class _Tp, class _Up> struct _LIBCPP_TEMPLATE_VIS is_same           : public false_type {};
-template <class _Tp>            struct _LIBCPP_TEMPLATE_VIS is_same<_Tp, _Tp> : public true_type {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_same_v
-    = is_same<_Tp, _Up>::value;
-#endif
-
-#endif // __is_same
-
-template <class _Tp, class _Up>
-using _IsSame = _BoolConstant<
-#ifdef __clang__
-    __is_same(_Tp, _Up)
-#else
-    is_same<_Tp, _Up>::value
-#endif
->;
-
-template <class _Tp, class _Up>
-using _IsNotSame = _BoolConstant<
-#ifdef __clang__
-    !__is_same(_Tp, _Up)
-#else
-    !is_same<_Tp, _Up>::value
-#endif
->;
-
-
 template <class _Tp>
 using __test_for_primary_template = _EnableIf<
     _IsSame<_Tp, typename _Tp::__primary_template>::value
@@ -603,8 +534,6 @@
     __test_for_primary_template, _Tp
   >;
 
-struct __two {char __lx[2];};
-
 // helper class:
 
 // is_const
@@ -900,60 +829,6 @@
 
 #endif // __has_keyword(__is_pointer)
 
-// is_reference
-
-#if __has_keyword(__is_lvalue_reference) && \
-    __has_keyword(__is_rvalue_reference) && \
-    __has_keyword(__is_reference)
-
-template<class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_lvalue_reference : _BoolConstant<__is_lvalue_reference(_Tp)> { };
-
-template<class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_rvalue_reference : _BoolConstant<__is_rvalue_reference(_Tp)> { };
-
-template<class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_reference : _BoolConstant<__is_reference(_Tp)> { };
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_reference_v = __is_reference(_Tp);
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_lvalue_reference_v = __is_lvalue_reference(_Tp);
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_rvalue_reference_v = __is_rvalue_reference(_Tp);
-#endif
-
-#else // __has_keyword(__is_lvalue_reference) && etc...
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_lvalue_reference       : public false_type {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_lvalue_reference<_Tp&> : public true_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_rvalue_reference        : public false_type {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_rvalue_reference<_Tp&&> : public true_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_reference        : public false_type {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_reference<_Tp&>  : public true_type {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_reference<_Tp&&> : public true_type {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_reference_v
-    = is_reference<_Tp>::value;
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_lvalue_reference_v
-    = is_lvalue_reference<_Tp>::value;
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_rvalue_reference_v
-    = is_rvalue_reference<_Tp>::value;
-#endif
-
-#endif // __has_keyword(__is_lvalue_reference) && etc...
-
 // is_union
 
 #if __has_feature(is_union) || defined(_LIBCPP_COMPILER_GCC)
@@ -1281,18 +1156,6 @@
 
 #endif // __has_keyword(__is_compound)
 
-// __is_referenceable  [defns.referenceable]
-
-struct __is_referenceable_impl {
-    template <class _Tp> static _Tp& __test(int);
-    template <class _Tp> static __two __test(...);
-};
-
-template <class _Tp>
-struct __is_referenceable : integral_constant<bool,
-    _IsNotSame<decltype(__is_referenceable_impl::__test<_Tp>(0)), __two>::value> {};
-
-
 // add_const
 
 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS add_const {
@@ -1322,58 +1185,6 @@
 template <class _Tp> using add_cv_t = typename add_cv<_Tp>::type;
 #endif
 
-// remove_reference
-
-#if __has_keyword(__remove_reference)
-
-template<class _Tp>
-struct _LIBCPP_TEMPLATE_VIS remove_reference { typedef __remove_reference(_Tp) type; };
-
-#else // __has_keyword(__remove_reference)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_reference        {typedef _LIBCPP_NODEBUG_TYPE _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_reference<_Tp&>  {typedef _LIBCPP_NODEBUG_TYPE _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_reference<_Tp&&> {typedef _LIBCPP_NODEBUG_TYPE _Tp type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using remove_reference_t = typename remove_reference<_Tp>::type;
-#endif
-
-#endif // __has_keyword(__remove_reference)
-
-// add_lvalue_reference
-
-template <class _Tp, bool = __is_referenceable<_Tp>::value> struct __add_lvalue_reference_impl            { typedef _LIBCPP_NODEBUG_TYPE _Tp  type; };
-template <class _Tp                                       > struct __add_lvalue_reference_impl<_Tp, true> { typedef _LIBCPP_NODEBUG_TYPE _Tp& type; };
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS add_lvalue_reference
-{typedef _LIBCPP_NODEBUG_TYPE typename  __add_lvalue_reference_impl<_Tp>::type type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
-#endif
-
-template <class _Tp, bool = __is_referenceable<_Tp>::value> struct __add_rvalue_reference_impl            { typedef _LIBCPP_NODEBUG_TYPE  _Tp   type; };
-template <class _Tp                                       > struct __add_rvalue_reference_impl<_Tp, true> { typedef _LIBCPP_NODEBUG_TYPE  _Tp&& type; };
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS add_rvalue_reference
-{typedef _LIBCPP_NODEBUG_TYPE  typename __add_rvalue_reference_impl<_Tp>::type type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
-#endif
-
-// Suppress deprecation notice for volatile-qualified return type resulting
-// from volatile-qualified types _Tp.
-_LIBCPP_SUPPRESS_DEPRECATED_PUSH
-template <class _Tp> _Tp&& __declval(int);
-template <class _Tp> _Tp   __declval(long);
-_LIBCPP_SUPPRESS_DEPRECATED_POP
-
-template <class _Tp>
-decltype(__declval<_Tp>(0))
-declval() _NOEXCEPT;
-
 // __uncvref
 
 template <class _Tp>
@@ -2818,46 +2629,6 @@
 
 #endif // __has_keyword(__is_destructible)
 
-// move
-
-template <class _Tp>
-_LIBCPP_NODISCARD_EXT 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);
-}
-
-template <class _Tp>
-_LIBCPP_NODISCARD_EXT 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&&
-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);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename decay<_Tp>::type
-__decay_copy(_Tp&& __t)
-#if _LIBCPP_STD_VER > 17
-noexcept(is_nothrow_convertible_v<_Tp, remove_reference_t<_Tp>>)
-#endif
-{
-    return _VSTD::forward<_Tp>(__t);
-}
-
 template <class _MP, bool _IsMemberFunctionPtr, bool _IsMemberObjectPtr>
 struct __member_pointer_traits_imp
 {
@@ -4188,13 +3959,7 @@
 template <class _Tp> struct __is_swappable;
 template <class _Tp> struct __is_nothrow_swappable;
 
-// swap, swap_ranges
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator2
-swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2);
-
+// __swappable
 template <class _Tp>
 inline _LIBCPP_INLINE_VISIBILITY
 #ifndef _LIBCPP_CXX03_LANG
@@ -4208,47 +3973,14 @@
 #endif
 _LIBCPP_CONSTEXPR_AFTER_CXX17
 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);
-    __y = _VSTD::move(__t);
-}
+                                    is_nothrow_move_assignable<_Tp>::value);
 
 template<class _Tp, size_t _Np>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 typename enable_if<
     __is_swappable<_Tp>::value
 >::type
-swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value)
-{
-    _VSTD::swap_ranges(__a, __a + _Np, __b);
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator2
-swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2)
-{
-    for(; __first1 != __last1; ++__first1, (void) ++__first2)
-        swap(*__first1, *__first2);
-    return __first2;
-}
-
-// iter_swap
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
-    //                                  _NOEXCEPT_(_NOEXCEPT_(swap(*__a, *__b)))
-               _NOEXCEPT_(_NOEXCEPT_(swap(*declval<_ForwardIterator1>(),
-                                          *declval<_ForwardIterator2>())))
-{
-    swap(*__a, *__b);
-}
-
-// __swappable
+swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value);
 
 namespace __detail
 {
diff --git a/libcxx/include/utility b/libcxx/include/utility
--- a/libcxx/include/utility
+++ b/libcxx/include/utility
@@ -210,6 +210,11 @@
 #include <__config>
 #include <__debug>
 #include <__tuple>
+#include <__utility/declval.h>
+#include <__utility/forward.h>
+#include <__utility/move_if_noexcept.h>
+#include <__utility/move.h>
+#include <__utility/swap.h>
 #include <__utility/to_underlying.h>
 #include <compare>
 #include <cstddef>
@@ -266,29 +271,6 @@
 
 }  // rel_ops
 
-// swap_ranges is defined in <type_traits>`
-
-// swap is defined in <type_traits>
-
-// move_if_noexcept
-
-template <class _Tp>
-_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-#ifndef _LIBCPP_CXX03_LANG
-typename conditional
-<
-    !is_nothrow_move_constructible<_Tp>::value && is_copy_constructible<_Tp>::value,
-    const _Tp&,
-    _Tp&&
->::type
-#else  // _LIBCPP_CXX03_LANG
-const _Tp&
-#endif
-move_if_noexcept(_Tp& __x) _NOEXCEPT
-{
-    return _VSTD::move(__x);
-}
-
 #if _LIBCPP_STD_VER > 14
 template <class _Tp>
 _LIBCPP_NODISCARD_EXT constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
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
@@ -23,7 +23,7 @@
 {
     {
         std::forward<A&>(source());  // expected-note {{requested here}}
-        // expected-error-re@type_traits:* 1 {{static_assert failed{{.*}} "cannot forward an rvalue as an lvalue"}}
+        // expected-error-re@*:* 1 {{static_assert failed{{.*}} "cannot forward an rvalue as an lvalue"}}
     }
     {
         const A ca = A();
diff --git a/libcxx/test/std/utilities/utility/utility.swap/swap_array.pass.cpp b/libcxx/test/std/utilities/utility/utility.swap/swap_array.pass.cpp
--- a/libcxx/test/std/utilities/utility/utility.swap/swap_array.pass.cpp
+++ b/libcxx/test/std/utilities/utility/utility.swap/swap_array.pass.cpp
@@ -13,9 +13,10 @@
 //   void
 //   swap(T (&a)[N], T (&b)[N]);
 
-#include <utility>
+#include <algorithm>
 #include <cassert>
 #include <memory>
+#include <utility>
 
 #include "test_macros.h"