vendor/llvm-project/llvmorg-15-init-15358-g53dc0f107877

144 files changed, 4660 insertions, 890 deletions

diff --git a/libcxx/include/__algorithm/adjacent_find.h b/libcxx/include/__algorithm/adjacent_find.h
index 29ad83f96810..83d8c260f27a 100644
--- a/libcxx/include/__algorithm/adjacent_find.h
+++ b/libcxx/include/__algorithm/adjacent_find.h
@@ -15,7 +15,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/all_of.h b/libcxx/include/__algorithm/all_of.h
index 817a4bc89ca0..3af32a577504 100644
--- a/libcxx/include/__algorithm/all_of.h
+++ b/libcxx/include/__algorithm/all_of.h
@@ -13,7 +13,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/any_of.h b/libcxx/include/__algorithm/any_of.h
index f4116d913059..6fe6a0b6b3c4 100644
--- a/libcxx/include/__algorithm/any_of.h
+++ b/libcxx/include/__algorithm/any_of.h
@@ -13,7 +13,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/binary_search.h b/libcxx/include/__algorithm/binary_search.h
index 2558dd0b27b9..121a741d070b 100644
--- a/libcxx/include/__algorithm/binary_search.h
+++ b/libcxx/include/__algorithm/binary_search.h
@@ -16,28 +16,20 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-template <class _Compare, class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-__binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    __first = _VSTD::__lower_bound<_Compare>(__first, __last, __value_, __comp);
-    return __first != __last && !__comp(__value_, *__first);
-}
-
 template <class _ForwardIterator, class _Tp, class _Compare>
 _LIBCPP_NODISCARD_EXT inline
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
 {
-    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
-    return _VSTD::__binary_search<_Comp_ref>(__first, __last, __value_, __comp);
+    using _Comp_ref = typename __comp_ref_type<_Compare>::type;
+    __first = std::lower_bound<_ForwardIterator, _Tp, _Comp_ref>(__first, __last, __value_, __comp);
+    return __first != __last && !__comp(__value_, *__first);
 }
 
 template <class _ForwardIterator, class _Tp>
@@ -46,8 +38,8 @@ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
 {
-    return _VSTD::binary_search(__first, __last, __value_,
-                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
+    return std::binary_search(__first, __last, __value_,
+                              __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
 }
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/clamp.h b/libcxx/include/__algorithm/clamp.h
index a51c1015be3f..b3762b85a0bc 100644
--- a/libcxx/include/__algorithm/clamp.h
+++ b/libcxx/include/__algorithm/clamp.h
@@ -10,11 +10,11 @@
 #define _LIBCPP___ALGORITHM_CLAMP_H
 
 #include <__algorithm/comp.h>
+#include <__assert>
 #include <__config>
-#include <__debug>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/comp.h b/libcxx/include/__algorithm/comp.h
index b3f971e4f052..62c06ae57f23 100644
--- a/libcxx/include/__algorithm/comp.h
+++ b/libcxx/include/__algorithm/comp.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/comp_ref_type.h b/libcxx/include/__algorithm/comp_ref_type.h
index 6cc6405686f5..4719871461cf 100644
--- a/libcxx/include/__algorithm/comp_ref_type.h
+++ b/libcxx/include/__algorithm/comp_ref_type.h
@@ -10,29 +10,24 @@
 #define _LIBCPP___ALGORITHM_COMP_REF_TYPE_H
 
 #include <__config>
-
-#ifdef _LIBCPP_DEBUG
-#  include <__debug>
-#  include <__utility/declval.h>
-#endif
+#include <__debug>
+#include <__utility/declval.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#ifdef _LIBCPP_DEBUG
-
 template <class _Compare>
 struct __debug_less
 {
     _Compare &__comp_;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_AFTER_CXX11
     __debug_less(_Compare& __c) : __comp_(__c) {}
 
     template <class _Tp, class _Up>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_AFTER_CXX11
     bool operator()(const _Tp& __x,  const _Up& __y)
     {
         bool __r = __comp_(__x, __y);
@@ -42,7 +37,7 @@ struct __debug_less
     }
 
     template <class _Tp, class _Up>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_AFTER_CXX11
     bool operator()(_Tp& __x,  _Up& __y)
     {
         bool __r = __comp_(__x, __y);
@@ -52,31 +47,31 @@ struct __debug_less
     }
 
     template <class _LHS, class _RHS>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_AFTER_CXX11
     inline _LIBCPP_INLINE_VISIBILITY
     decltype((void)declval<_Compare&>()(
         declval<_LHS &>(), declval<_RHS &>()))
     __do_compare_assert(int, _LHS & __l, _RHS & __r) {
-        _LIBCPP_ASSERT(!__comp_(__l, __r),
+        _LIBCPP_DEBUG_ASSERT(!__comp_(__l, __r),
             "Comparator does not induce a strict weak ordering");
+        (void)__l;
+        (void)__r;
     }
 
     template <class _LHS, class _RHS>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
+    _LIBCPP_CONSTEXPR_AFTER_CXX11
     inline _LIBCPP_INLINE_VISIBILITY
     void __do_compare_assert(long, _LHS &, _RHS &) {}
 };
 
-#endif // _LIBCPP_DEBUG
-
 template <class _Comp>
 struct __comp_ref_type {
   // Pass the comparator by lvalue reference. Or in debug mode, using a
   // debugging wrapper that stores a reference.
-#ifndef _LIBCPP_DEBUG
-  typedef _Comp& type;
-#else
+#ifdef _LIBCPP_ENABLE_DEBUG_MODE
   typedef __debug_less<_Comp> type;
+#else
+  typedef _Comp& type;
 #endif
 };
 
diff --git a/libcxx/include/__algorithm/copy.h b/libcxx/include/__algorithm/copy.h
index 65f0e0b0ef7d..886a1ac6ce3e 100644
--- a/libcxx/include/__algorithm/copy.h
+++ b/libcxx/include/__algorithm/copy.h
@@ -12,64 +12,93 @@
 #include <__algorithm/unwrap_iter.h>
 #include <__config>
 #include <__iterator/iterator_traits.h>
+#include <__iterator/reverse_iterator.h>
+#include <__utility/move.h>
+#include <__utility/pair.h>
 #include <cstring>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 // copy
 
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-__copy_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        *__result = *__first;
-    return __result;
+template <class _InIter, class _Sent, class _OutIter>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_InIter, _OutIter> __copy_impl(_InIter __first, _Sent __last, _OutIter __result) {
+  while (__first != __last) {
+    *__result = *__first;
+    ++__first;
+    ++__result;
+  }
+  return pair<_InIter, _OutIter>(std::move(__first), std::move(__result));
 }
 
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-__copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    return _VSTD::__copy_constexpr(__first, __last, __result);
+template <class _InValueT,
+          class _OutValueT,
+          class = __enable_if_t<is_same<typename remove_const<_InValueT>::type, _OutValueT>::value
+                             && is_trivially_copy_assignable<_OutValueT>::value> >
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_InValueT*, _OutValueT*> __copy_impl(_InValueT* __first, _InValueT* __last, _OutValueT* __result) {
+  if (__libcpp_is_constant_evaluated()
+// TODO: Remove this once GCC supports __builtin_memmove during constant evaluation
+#ifndef _LIBCPP_COMPILER_GCC
+      && !is_trivially_copyable<_InValueT>::value
+#endif
+     )
+    return std::__copy_impl<_InValueT*, _InValueT*, _OutValueT*>(__first, __last, __result);
+  const size_t __n = static_cast<size_t>(__last - __first);
+  if (__n > 0)
+    ::__builtin_memmove(__result, __first, __n * sizeof(_OutValueT));
+  return std::make_pair(__first + __n, __result + __n);
+}
+
+template <class _InIter, class _OutIter,
+          __enable_if_t<is_same<typename remove_const<__iter_value_type<_InIter> >::type, __iter_value_type<_OutIter> >::value
+                      && __is_cpp17_contiguous_iterator<_InIter>::value
+                      && __is_cpp17_contiguous_iterator<_OutIter>::value
+                      && is_trivially_copy_assignable<__iter_value_type<_OutIter> >::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<reverse_iterator<_InIter>, reverse_iterator<_OutIter> >
+__copy_impl(reverse_iterator<_InIter> __first,
+            reverse_iterator<_InIter> __last,
+            reverse_iterator<_OutIter> __result) {
+  auto __first_base = std::__unwrap_iter(__first.base());
+  auto __last_base = std::__unwrap_iter(__last.base());
+  auto __result_base = std::__unwrap_iter(__result.base());
+  auto __result_first = __result_base - (__first_base - __last_base);
+  std::__copy_impl(__last_base, __first_base, __result_first);
+  return std::make_pair(__last, reverse_iterator<_OutIter>(std::__rewrap_iter(__result.base(), __result_first)));
+}
+
+template <class _InIter, class _Sent, class _OutIter,
+          __enable_if_t<!(is_copy_constructible<_InIter>::value
+                       && is_copy_constructible<_Sent>::value
+                       && is_copy_constructible<_OutIter>::value), int> = 0 >
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_InIter, _OutIter> __copy(_InIter __first, _Sent __last, _OutIter __result) {
+  return std::__copy_impl(std::move(__first), std::move(__last), std::move(__result));
 }
 
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_copy_assignable<_Up>::value,
-    _Up*
->::type
-__copy(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    return __result + __n;
+template <class _InIter, class _Sent, class _OutIter,
+          __enable_if_t<is_copy_constructible<_InIter>::value
+                     && is_copy_constructible<_Sent>::value
+                     && is_copy_constructible<_OutIter>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_InIter, _OutIter>
+__copy(_InIter __first, _Sent __last, _OutIter __result) {
+  auto __ret = std::__copy_impl(std::__unwrap_iter(__first), std::__unwrap_iter(__last), std::__unwrap_iter(__result));
+  return std::make_pair(std::__rewrap_iter(__first, __ret.first), std::__rewrap_iter(__result, __ret.second));
 }
 
 template <class _InputIterator, class _OutputIterator>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 _OutputIterator
-copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    if (__libcpp_is_constant_evaluated()) {
-        return _VSTD::__copy_constexpr(__first, __last, __result);
-    } else {
-        return _VSTD::__rewrap_iter(__result,
-            _VSTD::__copy(_VSTD::__unwrap_iter(__first),
-                          _VSTD::__unwrap_iter(__last),
-                          _VSTD::__unwrap_iter(__result)));
-    }
+copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
+  return std::__copy(__first, __last, __result).second;
 }
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/copy_backward.h b/libcxx/include/__algorithm/copy_backward.h
index ac733290abe4..dd43a91ffa87 100644
--- a/libcxx/include/__algorithm/copy_backward.h
+++ b/libcxx/include/__algorithm/copy_backward.h
@@ -9,69 +9,43 @@
 #ifndef _LIBCPP___ALGORITHM_COPY_BACKWARD_H
 #define _LIBCPP___ALGORITHM_COPY_BACKWARD_H
 
+#include <__algorithm/copy.h>
 #include <__algorithm/unwrap_iter.h>
 #include <__config>
 #include <__iterator/iterator_traits.h>
+#include <__iterator/reverse_iterator.h>
 #include <cstring>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-template <class _BidirectionalIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-__copy_backward_constexpr(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
-{
-    while (__first != __last)
-        *--__result = *--__last;
-    return __result;
+template <class _Iter1, class _Sent1, class _Iter2>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_Iter1, _Iter2> __copy_backward_impl(_Iter1 __first, _Sent1 __last, _Iter2 __result) {
+  auto __ret = std::__copy(reverse_iterator<_Iter1>(__last),
+                           reverse_iterator<_Sent1>(__first),
+                           reverse_iterator<_Iter2>(__result));
+  return pair<_Iter1, _Iter2>(__ret.first.base(), __ret.second.base());
 }
 
-template <class _BidirectionalIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-__copy_backward(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
-{
-    return _VSTD::__copy_backward_constexpr(__first, __last, __result);
-}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_copy_assignable<_Up>::value,
-    _Up*
->::type
-__copy_backward(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-    {
-        __result -= __n;
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    }
-    return __result;
+template <class _Iter1, class _Sent1, class _Iter2>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_Iter1, _Iter2> __copy_backward(_Iter1 __first, _Sent1 __last, _Iter2 __result) {
+  auto __ret = std::__copy_backward_impl(std::__unwrap_iter(__first),
+                                         std::__unwrap_iter(__last),
+                                         std::__unwrap_iter(__result));
+  return pair<_Iter1, _Iter2>(std::__rewrap_iter(__first, __ret.first), std::__rewrap_iter(__result, __ret.second));
 }
 
 template <class _BidirectionalIterator1, class _BidirectionalIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
 _BidirectionalIterator2
-copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
-              _BidirectionalIterator2 __result)
-{
-    if (__libcpp_is_constant_evaluated()) {
-        return _VSTD::__copy_backward_constexpr(__first, __last, __result);
-    } else {
-        return _VSTD::__rewrap_iter(__result,
-            _VSTD::__copy_backward(_VSTD::__unwrap_iter(__first),
-                                   _VSTD::__unwrap_iter(__last),
-                                   _VSTD::__unwrap_iter(__result)));
-    }
+copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last, _BidirectionalIterator2 __result) {
+  return std::__copy_backward(__first, __last, __result).second;
 }
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/copy_if.h b/libcxx/include/__algorithm/copy_if.h
index d32514d999b5..9c3cd29e2413 100644
--- a/libcxx/include/__algorithm/copy_if.h
+++ b/libcxx/include/__algorithm/copy_if.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/copy_n.h b/libcxx/include/__algorithm/copy_n.h
index cdcc0d50dbf1..8b915af63c0d 100644
--- a/libcxx/include/__algorithm/copy_n.h
+++ b/libcxx/include/__algorithm/copy_n.h
@@ -15,7 +15,7 @@
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/count.h b/libcxx/include/__algorithm/count.h
index 81a2c186f83b..e18128cae8a8 100644
--- a/libcxx/include/__algorithm/count.h
+++ b/libcxx/include/__algorithm/count.h
@@ -14,7 +14,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/count_if.h b/libcxx/include/__algorithm/count_if.h
index 00f5d671da57..1ec2d83394e1 100644
--- a/libcxx/include/__algorithm/count_if.h
+++ b/libcxx/include/__algorithm/count_if.h
@@ -14,7 +14,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/equal.h b/libcxx/include/__algorithm/equal.h
index 4c9ad05ad6b8..ca1bc6bc5665 100644
--- a/libcxx/include/__algorithm/equal.h
+++ b/libcxx/include/__algorithm/equal.h
@@ -16,7 +16,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/equal_range.h b/libcxx/include/__algorithm/equal_range.h
index e13f0bdd9695..2a07364bb66f 100644
--- a/libcxx/include/__algorithm/equal_range.h
+++ b/libcxx/include/__algorithm/equal_range.h
@@ -12,13 +12,18 @@
 #include <__algorithm/comp.h>
 #include <__algorithm/comp_ref_type.h>
 #include <__algorithm/half_positive.h>
+#include <__algorithm/iterator_operations.h>
 #include <__algorithm/lower_bound.h>
 #include <__algorithm/upper_bound.h>
 #include <__config>
-#include <iterator>
+#include <__functional/identity.h>
+#include <__iterator/advance.h>
+#include <__iterator/distance.h>
+#include <__iterator/iterator_traits.h>
+#include <__utility/pair.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
@@ -46,10 +51,11 @@ __equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __va
         }
         else
         {
+            auto __proj = std::__identity();
             _ForwardIterator __mp1 = __m;
             return pair<_ForwardIterator, _ForwardIterator>
                    (
-                      _VSTD::__lower_bound<_Compare>(__first, __m, __value_, __comp),
+                      _VSTD::__lower_bound_impl<_StdIterOps>(__first, __m, __value_, __comp, __proj),
                       _VSTD::__upper_bound<_Compare>(++__mp1, __last, __value_, __comp)
                    );
         }
diff --git a/libcxx/include/__algorithm/fill.h b/libcxx/include/__algorithm/fill.h
index 0cb36b02c831..be5b4740a52a 100644
--- a/libcxx/include/__algorithm/fill.h
+++ b/libcxx/include/__algorithm/fill.h
@@ -15,7 +15,7 @@
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/fill_n.h b/libcxx/include/__algorithm/fill_n.h
index 857ac1415731..590c8f38f3fd 100644
--- a/libcxx/include/__algorithm/fill_n.h
+++ b/libcxx/include/__algorithm/fill_n.h
@@ -14,7 +14,7 @@
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/find.h b/libcxx/include/__algorithm/find.h
index 2a6dfbe41a94..641b85e2f645 100644
--- a/libcxx/include/__algorithm/find.h
+++ b/libcxx/include/__algorithm/find.h
@@ -13,7 +13,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/find_end.h b/libcxx/include/__algorithm/find_end.h
index dd0f7d7ac03d..0220c0939711 100644
--- a/libcxx/include/__algorithm/find_end.h
+++ b/libcxx/include/__algorithm/find_end.h
@@ -15,7 +15,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/find_first_of.h b/libcxx/include/__algorithm/find_first_of.h
index 69354f61769f..b968329fc318 100644
--- a/libcxx/include/__algorithm/find_first_of.h
+++ b/libcxx/include/__algorithm/find_first_of.h
@@ -15,7 +15,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/find_if.h b/libcxx/include/__algorithm/find_if.h
index a94196a16ac5..aa98171a1f61 100644
--- a/libcxx/include/__algorithm/find_if.h
+++ b/libcxx/include/__algorithm/find_if.h
@@ -13,7 +13,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/find_if_not.h b/libcxx/include/__algorithm/find_if_not.h
index e057db5efa49..61ddab0b9805 100644
--- a/libcxx/include/__algorithm/find_if_not.h
+++ b/libcxx/include/__algorithm/find_if_not.h
@@ -13,7 +13,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/for_each.h b/libcxx/include/__algorithm/for_each.h
index 1612ffa5c002..bfbd37c3a3a4 100644
--- a/libcxx/include/__algorithm/for_each.h
+++ b/libcxx/include/__algorithm/for_each.h
@@ -13,7 +13,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/for_each_n.h b/libcxx/include/__algorithm/for_each_n.h
index 00e3fb9c1db8..2552b40c2781 100644
--- a/libcxx/include/__algorithm/for_each_n.h
+++ b/libcxx/include/__algorithm/for_each_n.h
@@ -14,7 +14,7 @@
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/generate.h b/libcxx/include/__algorithm/generate.h
index 10834cdb7438..dacbd8c68195 100644
--- a/libcxx/include/__algorithm/generate.h
+++ b/libcxx/include/__algorithm/generate.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/generate_n.h b/libcxx/include/__algorithm/generate_n.h
index 595007cdd34b..2650e9e5d8b7 100644
--- a/libcxx/include/__algorithm/generate_n.h
+++ b/libcxx/include/__algorithm/generate_n.h
@@ -13,7 +13,7 @@
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/half_positive.h b/libcxx/include/__algorithm/half_positive.h
index 5d36ff5da985..7666ef1449c6 100644
--- a/libcxx/include/__algorithm/half_positive.h
+++ b/libcxx/include/__algorithm/half_positive.h
@@ -13,7 +13,7 @@
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/in_found_result.h b/libcxx/include/__algorithm/in_found_result.h
new file mode 100644
index 000000000000..d43f45cd80ef
--- /dev/null
+++ b/libcxx/include/__algorithm/in_found_result.h
@@ -0,0 +1,49 @@
+// -*- 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___ALGORITHM_IN_FOUND_RESULT_H
+#define _LIBCPP___ALGORITHM_IN_FOUND_RESULT_H
+
+#include <__concepts/convertible_to.h>
+#include <__config>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+template <class _InIter1>
+struct in_found_result {
+  _LIBCPP_NO_UNIQUE_ADDRESS _InIter1 in;
+  bool found;
+
+  template <class _InIter2>
+    requires convertible_to<const _InIter1&, _InIter2>
+  _LIBCPP_HIDE_FROM_ABI constexpr operator in_found_result<_InIter2>() const & {
+    return {in, found};
+  }
+
+  template <class _InIter2>
+    requires convertible_to<_InIter1, _InIter2>
+  _LIBCPP_HIDE_FROM_ABI constexpr operator in_found_result<_InIter2>() && {
+    return {std::move(in), found};
+  }
+};
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_IN_FOUND_RESULT_H
diff --git a/libcxx/include/__algorithm/in_fun_result.h b/libcxx/include/__algorithm/in_fun_result.h
new file mode 100644
index 000000000000..21efa655063d
--- /dev/null
+++ b/libcxx/include/__algorithm/in_fun_result.h
@@ -0,0 +1,49 @@
+// -*- 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___ALGORITHM_IN_FUN_RESULT_H
+#define _LIBCPP___ALGORITHM_IN_FUN_RESULT_H
+
+#include <__concepts/convertible_to.h>
+#include <__config>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+namespace ranges {
+template <class _InIter1, class _Func1>
+struct in_fun_result {
+  _LIBCPP_NO_UNIQUE_ADDRESS _InIter1 in;
+  _LIBCPP_NO_UNIQUE_ADDRESS _Func1 fun;
+
+  template <class _InIter2, class _Func2>
+    requires convertible_to<const _InIter1&, _InIter2> && convertible_to<const _Func1&, _Func2>
+  _LIBCPP_HIDE_FROM_ABI constexpr operator in_fun_result<_InIter2, _Func2>() const & {
+    return {in, fun};
+  }
+
+  template <class _InIter2, class _Func2>
+    requires convertible_to<_InIter1, _InIter2> && convertible_to<_Func1, _Func2>
+  _LIBCPP_HIDE_FROM_ABI constexpr operator in_fun_result<_InIter2, _Func2>() && {
+    return {std::move(in), std::move(fun)};
+  }
+};
+} // namespace ranges
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___ALGORITHM_IN_FUN_RESULT_H
diff --git a/libcxx/include/__algorithm/in_in_out_result.h b/libcxx/include/__algorithm/in_in_out_result.h
index e365eb58eb62..e45fef187e0d 100644
--- a/libcxx/include/__algorithm/in_in_out_result.h
+++ b/libcxx/include/__algorithm/in_in_out_result.h
@@ -14,35 +14,43 @@
 #include <__config>
 #include <__utility/move.h>
 
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#ifndef _LIBCPP_HAS_NO_CONCEPTS
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
-template <class _I1, class _I2, class _O1>
+
+template <class _InIter1, class _InIter2, class _OutIter1>
 struct in_in_out_result {
-  [[no_unique_address]] _I1 in1;
-  [[no_unique_address]] _I2 in2;
-  [[no_unique_address]] _O1 out;
+  _LIBCPP_NO_UNIQUE_ADDRESS _InIter1 in1;
+  _LIBCPP_NO_UNIQUE_ADDRESS _InIter2 in2;
+  _LIBCPP_NO_UNIQUE_ADDRESS _OutIter1 out;
 
-  template <class _II1, class _II2, class _OO1>
-    requires convertible_to<const _I1&, _II1> && convertible_to<const _I2&, _II2> && convertible_to<const _O1&, _OO1>
+  template <class _InIter3, class _InIter4, class _OutIter2>
+    requires convertible_to<const _InIter1&, _InIter3>
+          && convertible_to<const _InIter2&, _InIter4> && convertible_to<const _OutIter1&, _OutIter2>
   _LIBCPP_HIDE_FROM_ABI constexpr
-  operator in_in_out_result<_II1, _II2, _OO1>() const& {
+  operator in_in_out_result<_InIter3, _InIter4, _OutIter2>() const& {
     return {in1, in2, out};
   }
 
-  template <class _II1, class _II2, class _OO1>
-    requires convertible_to<_I1, _II1> && convertible_to<_I2, _II2> && convertible_to<_O1, _OO1>
+  template <class _InIter3, class _InIter4, class _OutIter2>
+    requires convertible_to<_InIter1, _InIter3>
+          && convertible_to<_InIter2, _InIter4> && convertible_to<_OutIter1, _OutIter2>
   _LIBCPP_HIDE_FROM_ABI constexpr
-  operator in_in_out_result<_II1, _II2, _OO1>() && {
-    return {_VSTD::move(in1), _VSTD::move(in2), _VSTD::move(out)};
+  operator in_in_out_result<_InIter3, _InIter4, _OutIter2>() && {
+    return {std::move(in1), std::move(in2), std::move(out)};
   }
 };
+
 } // namespace ranges
 
-#endif // _LIBCPP_HAS_NO_CONCEPTS
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
-#endif // _LIBCPP___ALGORITHM_IN_IN_RESULT_H
+#endif // _LIBCPP___ALGORITHM_IN_IN_OUT_RESULT_H
diff --git a/libcxx/include/__algorithm/in_in_result.h b/libcxx/include/__algorithm/in_in_result.h
index ed14ecedbbdf..39e64ced33b2 100644
--- a/libcxx/include/__algorithm/in_in_result.h
+++ b/libcxx/include/__algorithm/in_in_result.h
@@ -14,31 +14,39 @@
 #include <__config>
 #include <__utility/move.h>
 
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#ifndef _LIBCPP_HAS_NO_CONCEPTS
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
-template <class _I1, class _I2>
+
+template <class _InIter1, class _InIter2>
 struct in_in_result {
-  [[no_unique_address]] _I1 in1;
-  [[no_unique_address]] _I2 in2;
+  _LIBCPP_NO_UNIQUE_ADDRESS _InIter1 in1;
+  _LIBCPP_NO_UNIQUE_ADDRESS _InIter2 in2;
 
-  template <class _II1, class _II2>
-    requires convertible_to<const _I1&, _II1> && convertible_to<const _I2&, _II2>
+  template <class _InIter3, class _InIter4>
+    requires convertible_to<const _InIter1&, _InIter3> && convertible_to<const _InIter2&, _InIter4>
    _LIBCPP_HIDE_FROM_ABI constexpr
-   operator in_in_result<_II1, _II2>() const & {
+   operator in_in_result<_InIter3, _InIter4>() const & {
     return {in1, in2};
   }
 
-  template <class _II1, class _II2>
-    requires convertible_to<_I1, _II1> && convertible_to<_I2, _II2>
+  template <class _InIter3, class _InIter4>
+    requires convertible_to<_InIter1, _InIter3> && convertible_to<_InIter2, _InIter4>
   _LIBCPP_HIDE_FROM_ABI constexpr
-  operator in_in_result<_II1, _II2>() && { return {_VSTD::move(in1), _VSTD::move(in2)}; }
+  operator in_in_result<_InIter3, _InIter4>() && {
+    return {std::move(in1), std::move(in2)};
+  }
 };
+
 } // namespace ranges
 
-#endif // _LIBCPP_HAS_NO_CONCEPTS
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__algorithm/in_out_out_result.h b/libcxx/include/__algorithm/in_out_out_result.h
new file mode 100644
index 000000000000..52a883b17627
--- /dev/null
+++ b/libcxx/include/__algorithm/in_out_out_result.h
@@ -0,0 +1,54 @@
+// -*- 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___ALGORITHM_IN_OUT_OUT_RESULT_H
+#define _LIBCPP___ALGORITHM_IN_OUT_OUT_RESULT_H
+
+#include <__concepts/convertible_to.h>
+#include <__config>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+namespace ranges {
+template <class _InIter1, class _OutIter1, class _OutIter2>
+struct in_out_out_result {
+  _LIBCPP_NO_UNIQUE_ADDRESS _InIter1 in;
+  _LIBCPP_NO_UNIQUE_ADDRESS _OutIter1 out1;
+  _LIBCPP_NO_UNIQUE_ADDRESS _OutIter2 out2;
+
+  template <class _InIter2, class _OutIter3, class _OutIter4>
+    requires convertible_to<const _InIter1&, _InIter2>
+          && convertible_to<const _OutIter1&, _OutIter3> && convertible_to<const _OutIter2&, _OutIter4>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  operator in_out_out_result<_InIter2, _OutIter3, _OutIter4>() const& {
+    return {in, out1, out2};
+  }
+
+  template <class _InIter2, class _OutIter3, class _OutIter4>
+    requires convertible_to<_InIter1, _InIter2>
+          && convertible_to<_OutIter1, _OutIter3> && convertible_to<_OutIter2, _OutIter4>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  operator in_out_out_result<_InIter2, _OutIter3, _OutIter4>() && {
+    return {std::move(in), std::move(out1), std::move(out2)};
+  }
+};
+} // namespace ranges
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___ALGORITHM_IN_OUT_OUT_RESULT_H
diff --git a/libcxx/include/__algorithm/in_out_result.h b/libcxx/include/__algorithm/in_out_result.h
index 8a58d6ada10c..47e6f3907943 100644
--- a/libcxx/include/__algorithm/in_out_result.h
+++ b/libcxx/include/__algorithm/in_out_result.h
@@ -15,37 +15,38 @@
 #include <__utility/move.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
 namespace ranges {
 
-template<class _InputIterator, class _OutputIterator>
+template<class _InIter1, class _OutIter1>
 struct in_out_result {
-  [[no_unique_address]] _InputIterator in;
-  [[no_unique_address]] _OutputIterator out;
+  _LIBCPP_NO_UNIQUE_ADDRESS _InIter1 in;
+  _LIBCPP_NO_UNIQUE_ADDRESS _OutIter1 out;
 
-  template <class _InputIterator2, class _OutputIterator2>
-    requires convertible_to<const _InputIterator&, _InputIterator2> && convertible_to<const _OutputIterator&,
-                           _OutputIterator2>
+  template <class _InIter2, class _OutIter2>
+    requires convertible_to<const _InIter1&, _InIter2> && convertible_to<const _OutIter1&, _OutIter2>
   _LIBCPP_HIDE_FROM_ABI
-  constexpr operator in_out_result<_InputIterator2, _OutputIterator2>() const & {
+  constexpr operator in_out_result<_InIter2, _OutIter2>() const & {
     return {in, out};
   }
 
-  template <class _InputIterator2, class _OutputIterator2>
-    requires convertible_to<_InputIterator, _InputIterator2> && convertible_to<_OutputIterator, _OutputIterator2>
+  template <class _InIter2, class _OutIter2>
+    requires convertible_to<_InIter1, _InIter2> && convertible_to<_OutIter1, _OutIter2>
   _LIBCPP_HIDE_FROM_ABI
-  constexpr operator in_out_result<_InputIterator2, _OutputIterator2>() && {
-    return {_VSTD::move(in), _VSTD::move(out)};
+  constexpr operator in_out_result<_InIter2, _OutIter2>() && {
+    return {std::move(in), std::move(out)};
   }
 };
 
 } // namespace ranges
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__algorithm/includes.h b/libcxx/include/__algorithm/includes.h
index 9d0bc694c0d3..4c87e8d22116 100644
--- a/libcxx/include/__algorithm/includes.h
+++ b/libcxx/include/__algorithm/includes.h
@@ -15,7 +15,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/inplace_merge.h b/libcxx/include/__algorithm/inplace_merge.h
index e6f1efc011b1..58919ddbae76 100644
--- a/libcxx/include/__algorithm/inplace_merge.h
+++ b/libcxx/include/__algorithm/inplace_merge.h
@@ -17,12 +17,15 @@
 #include <__algorithm/rotate.h>
 #include <__algorithm/upper_bound.h>
 #include <__config>
+#include <__iterator/advance.h>
+#include <__iterator/distance.h>
 #include <__iterator/iterator_traits.h>
+#include <__iterator/reverse_iterator.h>
 #include <__utility/swap.h>
 #include <memory>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
@@ -166,7 +169,7 @@ __inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle,
             __len11 = __len1 / 2;
             __m1 = __first;
             _VSTD::advance(__m1, __len11);
-            __m2 = _VSTD::__lower_bound<_Compare>(__middle, __last, *__m1, __comp);
+            __m2 = std::lower_bound(__middle, __last, *__m1, __comp);
             __len21 = _VSTD::distance(__middle, __m2);
         }
         difference_type __len12 = __len1 - __len11;  // distance(__m1, __middle)
@@ -208,7 +211,10 @@ inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _
     difference_type __len1 = _VSTD::distance(__first, __middle);
     difference_type __len2 = _VSTD::distance(__middle, __last);
     difference_type __buf_size = _VSTD::min(__len1, __len2);
+// TODO: Remove the use of std::get_temporary_buffer
+_LIBCPP_SUPPRESS_DEPRECATED_PUSH
     pair<value_type*, ptrdiff_t> __buf = _VSTD::get_temporary_buffer<value_type>(__buf_size);
+_LIBCPP_SUPPRESS_DEPRECATED_POP
     unique_ptr<value_type, __return_temporary_buffer> __h(__buf.first);
     typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
     return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __comp, __len1, __len2,
diff --git a/libcxx/include/__algorithm/is_heap.h b/libcxx/include/__algorithm/is_heap.h
index 925ba8bfb8bd..fe44e634f6dd 100644
--- a/libcxx/include/__algorithm/is_heap.h
+++ b/libcxx/include/__algorithm/is_heap.h
@@ -16,7 +16,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/is_heap_until.h b/libcxx/include/__algorithm/is_heap_until.h
index aa23b6d039d3..39f313eb0d3f 100644
--- a/libcxx/include/__algorithm/is_heap_until.h
+++ b/libcxx/include/__algorithm/is_heap_until.h
@@ -15,7 +15,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/is_partitioned.h b/libcxx/include/__algorithm/is_partitioned.h
index e5b2214aa069..b4f421cfc053 100644
--- a/libcxx/include/__algorithm/is_partitioned.h
+++ b/libcxx/include/__algorithm/is_partitioned.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/is_permutation.h b/libcxx/include/__algorithm/is_permutation.h
index 344aa763ad0e..cdd742048412 100644
--- a/libcxx/include/__algorithm/is_permutation.h
+++ b/libcxx/include/__algorithm/is_permutation.h
@@ -17,7 +17,7 @@
 #include <__iterator/next.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/is_sorted.h b/libcxx/include/__algorithm/is_sorted.h
index 57953295a888..56de95bb31b7 100644
--- a/libcxx/include/__algorithm/is_sorted.h
+++ b/libcxx/include/__algorithm/is_sorted.h
@@ -16,7 +16,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/is_sorted_until.h b/libcxx/include/__algorithm/is_sorted_until.h
index 57cad47761d9..338d28508c17 100644
--- a/libcxx/include/__algorithm/is_sorted_until.h
+++ b/libcxx/include/__algorithm/is_sorted_until.h
@@ -15,7 +15,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/iter_swap.h b/libcxx/include/__algorithm/iter_swap.h
index 9f7d0d77630c..038859e1361d 100644
--- a/libcxx/include/__algorithm/iter_swap.h
+++ b/libcxx/include/__algorithm/iter_swap.h
@@ -14,7 +14,7 @@
 #include <__utility/swap.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/iterator_operations.h b/libcxx/include/__algorithm/iterator_operations.h
new file mode 100644
index 000000000000..c02f9bf649df
--- /dev/null
+++ b/libcxx/include/__algorithm/iterator_operations.h
@@ -0,0 +1,47 @@
+//===----------------------------------------------------------------------===//
+//
+// 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___ALGORIHTM_ITERATOR_OPERATIONS_H
+#define _LIBCPP___ALGORIHTM_ITERATOR_OPERATIONS_H
+
+#include <__config>
+#include <__iterator/advance.h>
+#include <__iterator/distance.h>
+#include <__iterator/iterator_traits.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+struct _RangesIterOps {
+  static constexpr auto advance = ranges::advance;
+  static constexpr auto distance = ranges::distance;
+};
+#endif
+
+struct _StdIterOps {
+
+  template <class _Iterator, class _Distance>
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11 void advance(_Iterator& __iter, _Distance __count) {
+    return std::advance(__iter, __count);
+  }
+
+  template <class _Iterator>
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11
+  typename iterator_traits<_Iterator>::difference_type distance(_Iterator __first, _Iterator __last) {
+    return std::distance(__first, __last);
+  }
+
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___ALGORIHTM_ITERATOR_OPERATIONS_H
diff --git a/libcxx/include/__algorithm/lexicographical_compare.h b/libcxx/include/__algorithm/lexicographical_compare.h
index 55a1da620125..30ddf2408120 100644
--- a/libcxx/include/__algorithm/lexicographical_compare.h
+++ b/libcxx/include/__algorithm/lexicographical_compare.h
@@ -15,7 +15,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/lower_bound.h b/libcxx/include/__algorithm/lower_bound.h
index 663a0b16228e..fbcd5c7e908a 100644
--- a/libcxx/include/__algorithm/lower_bound.h
+++ b/libcxx/include/__algorithm/lower_bound.h
@@ -11,54 +11,55 @@
 
 #include <__algorithm/comp.h>
 #include <__algorithm/half_positive.h>
+#include <__algorithm/iterator_operations.h>
 #include <__config>
-#include <iterator>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/advance.h>
+#include <__iterator/distance.h>
+#include <__iterator/iterator_traits.h>
+#include <__type_traits/is_callable.h>
+#include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-template <class _Compare, class _ForwardIterator, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    while (__len != 0)
-    {
-        difference_type __l2 = _VSTD::__half_positive(__len);
-        _ForwardIterator __m = __first;
-        _VSTD::advance(__m, __l2);
-        if (__comp(*__m, __value_))
-        {
-            __first = ++__m;
-            __len -= __l2 + 1;
-        }
-        else
-            __len = __l2;
+template <class _IterOps, class _Iter, class _Sent, class _Type, class _Proj, class _Comp>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_Iter __lower_bound_impl(_Iter __first, _Sent __last, const _Type& __value, _Comp& __comp, _Proj& __proj) {
+  auto __len = _IterOps::distance(__first, __last);
+
+  while (__len != 0) {
+    auto __l2 = std::__half_positive(__len);
+    _Iter __m = __first;
+    _IterOps::advance(__m, __l2);
+    if (std::__invoke(__comp, std::__invoke(__proj, *__m), __value)) {
+      __first = ++__m;
+      __len -= __l2 + 1;
+    } else {
+      __len = __l2;
     }
-    return __first;
+  }
+  return __first;
 }
 
 template <class _ForwardIterator, class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    return _VSTD::__lower_bound<_Compare&>(__first, __last, __value_, __comp);
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_ForwardIterator lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp) {
+  static_assert(__is_callable<_Compare, decltype(*__first), const _Tp&>::value,
+                "The comparator has to be callable");
+  auto __proj = std::__identity();
+  return std::__lower_bound_impl<_StdIterOps>(__first, __last, __value_, __comp, __proj);
 }
 
 template <class _ForwardIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    return _VSTD::lower_bound(__first, __last, __value_,
-                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_ForwardIterator lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_) {
+  return std::lower_bound(__first, __last, __value_,
+                          __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
 }
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/make_heap.h b/libcxx/include/__algorithm/make_heap.h
index f489addaf5cc..acac0aabf1e4 100644
--- a/libcxx/include/__algorithm/make_heap.h
+++ b/libcxx/include/__algorithm/make_heap.h
@@ -16,7 +16,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/make_projected.h b/libcxx/include/__algorithm/make_projected.h
new file mode 100644
index 000000000000..8141c4ed176f
--- /dev/null
+++ b/libcxx/include/__algorithm/make_projected.h
@@ -0,0 +1,51 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_MAKE_PROJECTED_H
+#define _LIBCPP___ALGORITHM_MAKE_PROJECTED_H
+
+#include <__concepts/same_as.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__utility/forward.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _Comp, class _Proj>
+_LIBCPP_HIDE_FROM_ABI constexpr static
+decltype(auto) __make_projected_comp(_Comp& __comp, _Proj& __proj) {
+  if constexpr (same_as<_Proj, identity>) {
+    // Avoid creating the lambda and just use the pristine comparator -- for certain algorithms, this would enable
+    // optimizations that rely on the type of the comparator.
+    return __comp;
+
+  } else {
+    return [&](auto&& __lhs, auto&& __rhs) {
+      return std::invoke(__comp,
+                        std::invoke(__proj, std::forward<decltype(__lhs)>(__lhs)),
+                        std::invoke(__proj, std::forward<decltype(__rhs)>(__rhs)));
+    };
+  }
+}
+
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_MAKE_PROJECTED_H
diff --git a/libcxx/include/__algorithm/max.h b/libcxx/include/__algorithm/max.h
index 0bbc971e0a9c..345b235a2193 100644
--- a/libcxx/include/__algorithm/max.h
+++ b/libcxx/include/__algorithm/max.h
@@ -16,7 +16,7 @@
 #include <initializer_list>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
diff --git a/libcxx/include/__algorithm/max_element.h b/libcxx/include/__algorithm/max_element.h
index db2937260582..795ec8e1ddc1 100644
--- a/libcxx/include/__algorithm/max_element.h
+++ b/libcxx/include/__algorithm/max_element.h
@@ -15,7 +15,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/merge.h b/libcxx/include/__algorithm/merge.h
index 91826493771a..48360ed5b445 100644
--- a/libcxx/include/__algorithm/merge.h
+++ b/libcxx/include/__algorithm/merge.h
@@ -16,7 +16,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/min.h b/libcxx/include/__algorithm/min.h
index ed2d3b87828a..3d8c73d78f11 100644
--- a/libcxx/include/__algorithm/min.h
+++ b/libcxx/include/__algorithm/min.h
@@ -16,7 +16,7 @@
 #include <initializer_list>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
diff --git a/libcxx/include/__algorithm/min_element.h b/libcxx/include/__algorithm/min_element.h
index 407c7f93336d..129833d42bda 100644
--- a/libcxx/include/__algorithm/min_element.h
+++ b/libcxx/include/__algorithm/min_element.h
@@ -15,7 +15,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/min_max_result.h b/libcxx/include/__algorithm/min_max_result.h
new file mode 100644
index 000000000000..ca77dcc5725a
--- /dev/null
+++ b/libcxx/include/__algorithm/min_max_result.h
@@ -0,0 +1,56 @@
+// -*- 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___ALGORITHM_MIN_MAX_RESULT_H
+#define _LIBCPP___ALGORITHM_MIN_MAX_RESULT_H
+
+#include <__concepts/convertible_to.h>
+#include <__config>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+namespace ranges {
+
+template <class _T1>
+struct min_max_result {
+  _LIBCPP_NO_UNIQUE_ADDRESS _T1 min;
+  _LIBCPP_NO_UNIQUE_ADDRESS _T1 max;
+
+  template <class _T2>
+    requires convertible_to<const _T1&, _T2>
+  _LIBCPP_HIDE_FROM_ABI constexpr operator min_max_result<_T2>() const & {
+    return {min, max};
+  }
+
+  template <class _T2>
+    requires convertible_to<_T1, _T2>
+  _LIBCPP_HIDE_FROM_ABI constexpr operator min_max_result<_T2>() && {
+    return {std::move(min), std::move(max)};
+  }
+};
+
+} // namespace ranges
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_MIN_MAX_RESULT_H
diff --git a/libcxx/include/__algorithm/minmax.h b/libcxx/include/__algorithm/minmax.h
index 0bf88a70b8aa..7e10b8b8350c 100644
--- a/libcxx/include/__algorithm/minmax.h
+++ b/libcxx/include/__algorithm/minmax.h
@@ -10,12 +10,15 @@
 #define _LIBCPP___ALGORITHM_MINMAX_H
 
 #include <__algorithm/comp.h>
+#include <__algorithm/minmax_element.h>
 #include <__config>
+#include <__functional/identity.h>
+#include <__type_traits/is_callable.h>
+#include <__utility/pair.h>
 #include <initializer_list>
-#include <utility>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
@@ -36,47 +39,18 @@ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 pair<const _Tp&, const _Tp&>
 minmax(const _Tp& __a, const _Tp& __b)
 {
-    return _VSTD::minmax(__a, __b, __less<_Tp>());
+    return std::minmax(__a, __b, __less<_Tp>());
 }
 
 #ifndef _LIBCPP_CXX03_LANG
 
 template<class _Tp, class _Compare>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<_Tp, _Tp>
-minmax(initializer_list<_Tp> __t, _Compare __comp)
-{
-    typedef typename initializer_list<_Tp>::const_iterator _Iter;
-    _Iter __first = __t.begin();
-    _Iter __last  = __t.end();
-    pair<_Tp, _Tp> __result(*__first, *__first);
-
-    ++__first;
-    if (__t.size() % 2 == 0)
-    {
-        if (__comp(*__first,  __result.first))
-            __result.first  = *__first;
-        else
-            __result.second = *__first;
-        ++__first;
-    }
-
-    while (__first != __last)
-    {
-        _Tp __prev = *__first++;
-        if (__comp(*__first, __prev)) {
-            if ( __comp(*__first, __result.first)) __result.first  = *__first;
-            if (!__comp(__prev, __result.second))  __result.second = __prev;
-            }
-        else {
-            if ( __comp(__prev, __result.first))    __result.first  = __prev;
-            if (!__comp(*__first, __result.second)) __result.second = *__first;
-            }
-
-        __first++;
-    }
-    return __result;
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_Tp, _Tp> minmax(initializer_list<_Tp> __t, _Compare __comp) {
+    static_assert(__is_callable<_Compare, _Tp, _Tp>::value, "The comparator has to be callable");
+    __identity __proj;
+    auto __ret = std::__minmax_element_impl(__t.begin(), __t.end(), __comp, __proj);
+    return pair<_Tp, _Tp>(*__ret.first, *__ret.second);
 }
 
 template<class _Tp>
@@ -85,7 +59,7 @@ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 pair<_Tp, _Tp>
 minmax(initializer_list<_Tp> __t)
 {
-    return _VSTD::minmax(__t, __less<_Tp>());
+    return std::minmax(__t, __less<_Tp>());
 }
 
 #endif // _LIBCPP_CXX03_LANG
diff --git a/libcxx/include/__algorithm/minmax_element.h b/libcxx/include/__algorithm/minmax_element.h
index 5d768603843b..fe5f20bf1c7f 100644
--- a/libcxx/include/__algorithm/minmax_element.h
+++ b/libcxx/include/__algorithm/minmax_element.h
@@ -11,73 +11,89 @@
 
 #include <__algorithm/comp.h>
 #include <__config>
+#include <__functional/identity.h>
 #include <__iterator/iterator_traits.h>
-#include <utility>
+#include <__utility/pair.h>
+#include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+template <class _Comp, class _Proj>
+class _MinmaxElementLessFunc {
+  _Comp& __comp;
+  _Proj& __proj;
+
+public:
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
+  _MinmaxElementLessFunc(_Comp& __comp_, _Proj& __proj_) : __comp(__comp_), __proj(__proj_) {}
+
+  template <class _Iter>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+  bool operator()(_Iter& __it1, _Iter& __it2) {
+    return std::__invoke(__comp, std::__invoke(__proj, *__it1), std::__invoke(__proj, *__it2));
+  }
+};
+
+template <class _Iter, class _Sent, class _Proj, class _Comp>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_Iter, _Iter> __minmax_element_impl(_Iter __first, _Sent __last, _Comp& __comp, _Proj& __proj) {
+  auto __less = _MinmaxElementLessFunc<_Comp, _Proj>(__comp, __proj);
+
+  pair<_Iter, _Iter> __result(__first, __first);
+  if (__first == __last || ++__first == __last)
+    return __result;
+
+  if (__less(__first, __result.first))
+    __result.first = __first;
+  else
+    __result.second = __first;
+
+  while (++__first != __last) {
+    _Iter __i = __first;
+    if (++__first == __last) {
+      if (__less(__i, __result.first))
+        __result.first = __i;
+      else if (!__less(__i, __result.second))
+        __result.second = __i;
+      return __result;
+    }
+
+    if (__less(__first, __i)) {
+      if (__less(__first, __result.first))
+        __result.first = __first;
+    if (!__less(__i, __result.second))
+      __result.second = __i;
+    } else {
+      if (__less(__i, __result.first))
+        __result.first = __i;
+      if (!__less(__first, __result.second))
+        __result.second = __first;
+    }
+  }
+
+  return __result;
+}
+
 template <class _ForwardIterator, class _Compare>
 _LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX11
 pair<_ForwardIterator, _ForwardIterator>
-minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
+minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) {
   static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
-        "std::minmax_element requires a ForwardIterator");
-  pair<_ForwardIterator, _ForwardIterator> __result(__first, __first);
-  if (__first != __last)
-  {
-      if (++__first != __last)
-      {
-          if (__comp(*__first, *__result.first))
-              __result.first = __first;
-          else
-              __result.second = __first;
-          while (++__first != __last)
-          {
-              _ForwardIterator __i = __first;
-              if (++__first == __last)
-              {
-                  if (__comp(*__i, *__result.first))
-                      __result.first = __i;
-                  else if (!__comp(*__i, *__result.second))
-                      __result.second = __i;
-                  break;
-              }
-              else
-              {
-                  if (__comp(*__first, *__i))
-                  {
-                      if (__comp(*__first, *__result.first))
-                          __result.first = __first;
-                      if (!__comp(*__i, *__result.second))
-                          __result.second = __i;
-                  }
-                  else
-                  {
-                      if (__comp(*__i, *__result.first))
-                          __result.first = __i;
-                      if (!__comp(*__first, *__result.second))
-                          __result.second = __first;
-                  }
-              }
-          }
-      }
-  }
-  return __result;
+                "std::minmax_element requires a ForwardIterator");
+  static_assert(__is_callable<_Compare, decltype(*__first), decltype(*__first)>::value,
+                "The comparator has to be callable");
+  auto __proj = __identity();
+  return std::__minmax_element_impl(__first, __last, __comp, __proj);
 }
 
 template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<_ForwardIterator, _ForwardIterator>
-minmax_element(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::minmax_element(__first, __last,
-              __less<typename iterator_traits<_ForwardIterator>::value_type>());
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_ForwardIterator, _ForwardIterator> minmax_element(_ForwardIterator __first, _ForwardIterator __last) {
+    return std::minmax_element(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
 }
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/mismatch.h b/libcxx/include/__algorithm/mismatch.h
index 230ade03df19..f2011faf2f9a 100644
--- a/libcxx/include/__algorithm/mismatch.h
+++ b/libcxx/include/__algorithm/mismatch.h
@@ -13,10 +13,10 @@
 #include <__algorithm/comp.h>
 #include <__config>
 #include <__iterator/iterator_traits.h>
-#include <utility>
+#include <__utility/pair.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/move.h b/libcxx/include/__algorithm/move.h
index fa118f471669..0b08d31c176e 100644
--- a/libcxx/include/__algorithm/move.h
+++ b/libcxx/include/__algorithm/move.h
@@ -11,66 +11,103 @@
 
 #include <__algorithm/unwrap_iter.h>
 #include <__config>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/reverse_iterator.h>
 #include <__utility/move.h>
+#include <__utility/pair.h>
 #include <cstring>
 #include <type_traits>
-#include <utility>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 // move
 
-template <class _InputIterator, class _OutputIterator>
+template <class _InIter, class _Sent, class _OutIter>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-_OutputIterator
-__move_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        *__result = _VSTD::move(*__first);
-    return __result;
+pair<_InIter, _OutIter> __move_impl(_InIter __first, _Sent __last, _OutIter __result) {
+  while (__first != __last) {
+    *__result = std::move(*__first);
+    ++__first;
+    ++__result;
+  }
+  return std::make_pair(std::move(__first), std::move(__result));
 }
 
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-_OutputIterator
-__move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    return _VSTD::__move_constexpr(__first, __last, __result);
+template <class _InType,
+          class _OutType,
+          class = __enable_if_t<is_same<typename remove_const<_InType>::type, _OutType>::value
+                             && is_trivially_move_assignable<_OutType>::value> >
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_InType*, _OutType*> __move_impl(_InType* __first, _InType* __last, _OutType* __result) {
+  if (__libcpp_is_constant_evaluated()
+// TODO: Remove this once GCC supports __builtin_memmove during constant evaluation
+#ifndef _LIBCPP_COMPILER_GCC
+   && !is_trivially_copyable<_InType>::value
+#endif
+     )
+    return std::__move_impl<_InType*, _InType*, _OutType*>(__first, __last, __result);
+  const size_t __n = static_cast<size_t>(__last - __first);
+  ::__builtin_memmove(__result, __first, __n * sizeof(_OutType));
+  return std::make_pair(__first + __n, __result + __n);
 }
 
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_move_assignable<_Up>::value,
-    _Up*
->::type
-__move(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    return __result + __n;
+template <class>
+struct __is_trivially_move_assignable_unwrapped_impl : false_type {};
+
+template <class _Type>
+struct __is_trivially_move_assignable_unwrapped_impl<_Type*> : is_trivially_move_assignable<_Type> {};
+
+template <class _Iter>
+struct __is_trivially_move_assignable_unwrapped
+    : __is_trivially_move_assignable_unwrapped_impl<decltype(std::__unwrap_iter<_Iter>(std::declval<_Iter>()))> {};
+
+template <class _InIter,
+          class _OutIter,
+          __enable_if_t<is_same<typename remove_const<typename iterator_traits<_InIter>::value_type>::type,
+                                typename iterator_traits<_OutIter>::value_type>::value
+                     && __is_cpp17_contiguous_iterator<_InIter>::value
+                     && __is_cpp17_contiguous_iterator<_OutIter>::value
+                     && is_trivially_move_assignable<__iter_value_type<_OutIter> >::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX14
+pair<reverse_iterator<_InIter>, reverse_iterator<_OutIter> >
+__move_impl(reverse_iterator<_InIter> __first,
+            reverse_iterator<_InIter> __last,
+            reverse_iterator<_OutIter> __result) {
+  auto __first_base = std::__unwrap_iter(__first.base());
+  auto __last_base = std::__unwrap_iter(__last.base());
+  auto __result_base = std::__unwrap_iter(__result.base());
+  auto __result_first = __result_base - (__first_base - __last_base);
+  std::__move_impl(__last_base, __first_base, __result_first);
+  return std::make_pair(__last, reverse_iterator<_OutIter>(std::__rewrap_iter(__result.base(), __result_first)));
+}
+
+template <class _InIter, class _Sent, class _OutIter>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+__enable_if_t<is_copy_constructible<_InIter>::value
+           && is_copy_constructible<_Sent>::value
+           && is_copy_constructible<_OutIter>::value, pair<_InIter, _OutIter> >
+__move(_InIter __first, _Sent __last, _OutIter __result) {
+  auto __ret = std::__move_impl(std::__unwrap_iter(__first), std::__unwrap_iter(__last), std::__unwrap_iter(__result));
+  return std::make_pair(std::__rewrap_iter(__first, __ret.first), std::__rewrap_iter(__result, __ret.second));
+}
+
+template <class _InIter, class _Sent, class _OutIter>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+__enable_if_t<!is_copy_constructible<_InIter>::value
+           || !is_copy_constructible<_Sent>::value
+           || !is_copy_constructible<_OutIter>::value, pair<_InIter, _OutIter> >
+__move(_InIter __first, _Sent __last, _OutIter __result) {
+  return std::__move_impl(std::move(__first), std::move(__last), std::move(__result));
 }
 
 template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    if (__libcpp_is_constant_evaluated()) {
-        return _VSTD::__move_constexpr(__first, __last, __result);
-    } else {
-        return _VSTD::__rewrap_iter(__result,
-            _VSTD::__move(_VSTD::__unwrap_iter(__first),
-                          _VSTD::__unwrap_iter(__last),
-                          _VSTD::__unwrap_iter(__result)));
-    }
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+_OutputIterator move(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
+  return std::__move(__first, __last, __result).second;
 }
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/move_backward.h b/libcxx/include/__algorithm/move_backward.h
index a4e3828b6069..a56f6b826ce3 100644
--- a/libcxx/include/__algorithm/move_backward.h
+++ b/libcxx/include/__algorithm/move_backward.h
@@ -11,12 +11,12 @@
 
 #include <__algorithm/unwrap_iter.h>
 #include <__config>
+#include <__utility/move.h>
 #include <cstring>
 #include <type_traits>
-#include <utility>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/next_permutation.h b/libcxx/include/__algorithm/next_permutation.h
index eb81cceb7bbc..05e56f4a17ff 100644
--- a/libcxx/include/__algorithm/next_permutation.h
+++ b/libcxx/include/__algorithm/next_permutation.h
@@ -17,7 +17,7 @@
 #include <__utility/swap.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/none_of.h b/libcxx/include/__algorithm/none_of.h
index 10339e2418c8..b34b1e00ddb8 100644
--- a/libcxx/include/__algorithm/none_of.h
+++ b/libcxx/include/__algorithm/none_of.h
@@ -13,7 +13,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/nth_element.h b/libcxx/include/__algorithm/nth_element.h
index 3afbd6c61846..60b9280f75f0 100644
--- a/libcxx/include/__algorithm/nth_element.h
+++ b/libcxx/include/__algorithm/nth_element.h
@@ -13,6 +13,7 @@
 #include <__algorithm/comp_ref_type.h>
 #include <__algorithm/sort.h>
 #include <__config>
+#include <__debug>
 #include <__iterator/iterator_traits.h>
 #include <__utility/swap.h>
 
@@ -21,7 +22,7 @@
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/partial_sort.h b/libcxx/include/__algorithm/partial_sort.h
index a92a7e56610a..3870c0cc9335 100644
--- a/libcxx/include/__algorithm/partial_sort.h
+++ b/libcxx/include/__algorithm/partial_sort.h
@@ -15,6 +15,7 @@
 #include <__algorithm/sift_down.h>
 #include <__algorithm/sort_heap.h>
 #include <__config>
+#include <__debug>
 #include <__iterator/iterator_traits.h>
 #include <__utility/swap.h>
 
@@ -23,7 +24,7 @@
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/partial_sort_copy.h b/libcxx/include/__algorithm/partial_sort_copy.h
index 67a62bae1f5a..7ed1e538e9b8 100644
--- a/libcxx/include/__algorithm/partial_sort_copy.h
+++ b/libcxx/include/__algorithm/partial_sort_copy.h
@@ -18,7 +18,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/partition.h b/libcxx/include/__algorithm/partition.h
index 131c5d3735d5..73d94831ed87 100644
--- a/libcxx/include/__algorithm/partition.h
+++ b/libcxx/include/__algorithm/partition.h
@@ -14,7 +14,7 @@
 #include <__utility/swap.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/partition_copy.h b/libcxx/include/__algorithm/partition_copy.h
index d34944589b9e..cacde0bfd47b 100644
--- a/libcxx/include/__algorithm/partition_copy.h
+++ b/libcxx/include/__algorithm/partition_copy.h
@@ -11,10 +11,10 @@
 
 #include <__config>
 #include <__iterator/iterator_traits.h>
-#include <utility> // pair
+#include <__utility/pair.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/partition_point.h b/libcxx/include/__algorithm/partition_point.h
index 18e6e6f6812f..1675534e60d5 100644
--- a/libcxx/include/__algorithm/partition_point.h
+++ b/libcxx/include/__algorithm/partition_point.h
@@ -11,10 +11,12 @@
 
 #include <__algorithm/half_positive.h>
 #include <__config>
-#include <iterator>
+#include <__iterator/advance.h>
+#include <__iterator/distance.h>
+#include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/pop_heap.h b/libcxx/include/__algorithm/pop_heap.h
index c1cc8016ac91..2932a5e31dbc 100644
--- a/libcxx/include/__algorithm/pop_heap.h
+++ b/libcxx/include/__algorithm/pop_heap.h
@@ -11,13 +11,14 @@
 
 #include <__algorithm/comp.h>
 #include <__algorithm/comp_ref_type.h>
+#include <__algorithm/push_heap.h>
 #include <__algorithm/sift_down.h>
 #include <__config>
 #include <__iterator/iterator_traits.h>
-#include <__utility/swap.h>
+#include <__utility/move.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
@@ -28,10 +29,21 @@ void
 __pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
            typename iterator_traits<_RandomAccessIterator>::difference_type __len)
 {
+    using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
+
     if (__len > 1)
     {
-        swap(*__first, *--__last);
-        _VSTD::__sift_down<_Compare>(__first, __comp, __len - 1, __first);
+        value_type __top = std::move(*__first);  // create a hole at __first
+        _RandomAccessIterator __hole = std::__floyd_sift_down<_Compare>(__first, __comp, __len);
+        --__last;
+        if (__hole == __last) {
+            *__hole = std::move(__top);
+        } else {
+            *__hole = std::move(*__last);
+            ++__hole;
+            *__last = std::move(__top);
+            std::__sift_up<_Compare>(__first, __hole, __comp, __hole - __first);
+        }
     }
 }
 
diff --git a/libcxx/include/__algorithm/prev_permutation.h b/libcxx/include/__algorithm/prev_permutation.h
index 457c2695b324..9dbc1dad0124 100644
--- a/libcxx/include/__algorithm/prev_permutation.h
+++ b/libcxx/include/__algorithm/prev_permutation.h
@@ -17,7 +17,7 @@
 #include <__utility/swap.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/push_heap.h b/libcxx/include/__algorithm/push_heap.h
index 864d419fa203..66973e082f14 100644
--- a/libcxx/include/__algorithm/push_heap.h
+++ b/libcxx/include/__algorithm/push_heap.h
@@ -16,7 +16,7 @@
 #include <__utility/move.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/ranges_adjacent_find.h b/libcxx/include/__algorithm/ranges_adjacent_find.h
new file mode 100644
index 000000000000..e798d568299d
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_adjacent_find.h
@@ -0,0 +1,78 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_ADJACENT_FIND_H
+#define _LIBCPP___ALGORITHM_RANGES_ADJACENT_FIND_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __adjacent_find {
+struct __fn {
+
+  template <class _Iter, class _Sent, class _Proj, class _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  _Iter __adjacent_find_impl(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) {
+    if (__first == __last)
+      return __first;
+
+    auto __i = __first;
+    while (++__i != __last) {
+      if (std::invoke(__pred, std::invoke(__proj, *__first), std::invoke(__proj, *__i)))
+        return __first;
+      __first = __i;
+    }
+    return __i;
+  }
+
+  template <forward_iterator _Iter, sentinel_for<_Iter> _Sent,
+            class _Proj = identity,
+            indirect_binary_predicate<projected<_Iter, _Proj>, projected<_Iter, _Proj>> _Pred = ranges::equal_to>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last, _Pred __pred = {}, _Proj __proj = {}) const {
+    return __adjacent_find_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <forward_range _Range,
+            class _Proj = identity,
+            indirect_binary_predicate<projected<iterator_t<_Range>, _Proj>,
+                                      projected<iterator_t<_Range>, _Proj>> _Pred = ranges::equal_to>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range> operator()(_Range&& __range, _Pred __pred = {}, _Proj __proj = {}) const {
+    return __adjacent_find_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
+  }
+};
+} // namespace __adjacent_find
+
+inline namespace __cpo {
+  inline constexpr auto adjacent_find = __adjacent_find::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_ADJACENT_FIND_H
diff --git a/libcxx/include/__algorithm/ranges_all_of.h b/libcxx/include/__algorithm/ranges_all_of.h
new file mode 100644
index 000000000000..a146865652a7
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_all_of.h
@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_ALL_OF_H
+#define _LIBCPP___ALGORITHM_RANGES_ALL_OF_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __all_of {
+struct __fn {
+
+  template <class _Iter, class _Sent, class _Proj, class _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  bool __all_of_impl(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) {
+    for (; __first != __last; ++__first) {
+      if (!std::invoke(__pred, std::invoke(__proj, *__first)))
+        return false;
+    }
+    return true;
+  }
+
+  template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Proj = identity,
+            indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) const {
+    return __all_of_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <input_range _Range, class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
+    return __all_of_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
+  }
+};
+} // namespace __all_of
+
+inline namespace __cpo {
+  inline constexpr auto all_of = __all_of::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_ALL_OF_H
diff --git a/libcxx/include/__algorithm/ranges_any_of.h b/libcxx/include/__algorithm/ranges_any_of.h
new file mode 100644
index 000000000000..11c52cbe21ea
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_any_of.h
@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_ANY_OF_H
+#define _LIBCPP___ALGORITHM_RANGES_ANY_OF_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __any_of {
+struct __fn {
+
+  template <class _Iter, class _Sent, class _Proj, class _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  bool __any_of_impl(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) {
+    for (; __first != __last; ++__first) {
+      if (std::invoke(__pred, std::invoke(__proj, *__first)))
+        return true;
+    }
+    return false;
+  }
+
+  template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Proj = identity,
+            indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Iter __first, _Sent __last, _Pred __pred = {}, _Proj __proj = {}) const {
+    return __any_of_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <input_range _Range, class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
+    return __any_of_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
+  }
+};
+} // namespace __any_of
+
+inline namespace __cpo {
+  inline constexpr auto any_of = __any_of::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_ANY_OF_H
diff --git a/libcxx/include/__algorithm/ranges_binary_search.h b/libcxx/include/__algorithm/ranges_binary_search.h
new file mode 100644
index 000000000000..68359fb1388f
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_binary_search.h
@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_BINARY_SEARCH_H
+#define _LIBCPP___ALGORITHM_RANGES_BINARY_SEARCH_H
+
+#include <__algorithm/iterator_operations.h>
+#include <__algorithm/lower_bound.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __binary_search {
+struct __fn {
+  template <forward_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<_Iter, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Iter __first, _Sent __last, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __ret = std::__lower_bound_impl<_RangesIterOps>(__first, __last, __value, __comp, __proj);
+    return __ret != __last && !std::invoke(__comp, __value, std::invoke(__proj, *__first));
+  }
+
+  template <forward_range _Range, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Range&& __r, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __first = ranges::begin(__r);
+    auto __last = ranges::end(__r);
+    auto __ret = std::__lower_bound_impl<_RangesIterOps>(__first, __last, __value, __comp, __proj);
+    return __ret != __last && !std::invoke(__comp, __value, std::invoke(__proj, *__first));
+  }
+};
+} // namespace __binary_search
+
+inline namespace __cpo {
+  inline constexpr auto binary_search = __binary_search::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_BINARY_SEARCH_H
diff --git a/libcxx/include/__algorithm/ranges_copy.h b/libcxx/include/__algorithm/ranges_copy.h
new file mode 100644
index 000000000000..f5d6d5cd139a
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_copy.h
@@ -0,0 +1,65 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_COPY_H
+#define _LIBCPP___ALGORITHM_RANGES_COPY_H
+
+#include <__algorithm/copy.h>
+#include <__algorithm/in_out_result.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__iterator/concepts.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _InIter, class _OutIter>
+using copy_result = in_out_result<_InIter, _OutIter>;
+
+namespace __copy {
+struct __fn {
+
+  template <input_iterator _InIter, sentinel_for<_InIter> _Sent, weakly_incrementable _OutIter>
+    requires indirectly_copyable<_InIter, _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  copy_result<_InIter, _OutIter> operator()(_InIter __first, _Sent __last, _OutIter __result) const {
+    auto __ret = std::__copy(std::move(__first), std::move(__last), std::move(__result));
+    return {std::move(__ret.first), std::move(__ret.second)};
+  }
+
+  template <input_range _Range, weakly_incrementable _OutIter>
+    requires indirectly_copyable<iterator_t<_Range>, _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  copy_result<borrowed_iterator_t<_Range>, _OutIter> operator()(_Range&& __r, _OutIter __result) const {
+    auto __ret = std::__copy(ranges::begin(__r), ranges::end(__r), std::move(__result));
+    return {std::move(__ret.first), std::move(__ret.second)};
+  }
+};
+} // namespace __copy
+
+inline namespace __cpo {
+  inline constexpr auto copy = __copy::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_COPY_H
diff --git a/libcxx/include/__algorithm/ranges_copy_backward.h b/libcxx/include/__algorithm/ranges_copy_backward.h
new file mode 100644
index 000000000000..49c1b26add6d
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_copy_backward.h
@@ -0,0 +1,67 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_COPY_BACKWARD_H
+#define _LIBCPP___ALGORITHM_RANGES_COPY_BACKWARD_H
+
+#include <__algorithm/copy_backward.h>
+#include <__algorithm/in_out_result.h>
+#include <__config>
+#include <__iterator/concepts.h>
+#include <__iterator/reverse_iterator.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template<class _Ip, class _Op>
+using copy_backward_result = in_out_result<_Ip, _Op>;
+
+namespace __copy_backward {
+struct __fn {
+
+  template <bidirectional_iterator _InIter1, sentinel_for<_InIter1> _Sent1, bidirectional_iterator _InIter2>
+    requires indirectly_copyable<_InIter1, _InIter2>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  copy_backward_result<_InIter1, _InIter2> operator()(_InIter1 __first, _Sent1 __last, _InIter2 __result) const {
+    auto __ret = std::__copy_backward(std::move(__first), std::move(__last), std::move(__result));
+    return {std::move(__ret.first), std::move(__ret.second)};
+  }
+
+  template <bidirectional_range _Range, bidirectional_iterator _Iter>
+    requires indirectly_copyable<iterator_t<_Range>, _Iter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  copy_backward_result<borrowed_iterator_t<_Range>, _Iter> operator()(_Range&& __r, _Iter __result) const {
+    auto __ret = std::__copy_backward(ranges::begin(__r),
+                                      ranges::end(__r),
+                                      std::move(__result));
+    return {std::move(__ret.first), std::move(__ret.second)};
+  }
+};
+} // namespace __copy_backward
+
+inline namespace __cpo {
+  inline constexpr auto copy_backward = __copy_backward::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_COPY_BACKWARD_H
diff --git a/libcxx/include/__algorithm/ranges_copy_if.h b/libcxx/include/__algorithm/ranges_copy_if.h
new file mode 100644
index 000000000000..492104fbbfba
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_copy_if.h
@@ -0,0 +1,81 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_COPY_IF_H
+#define _LIBCPP___ALGORITHM_RANGES_COPY_IF_H
+
+#include <__algorithm/in_out_result.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template<class _Ip, class _Op>
+using copy_if_result = in_out_result<_Ip, _Op>;
+
+namespace __copy_if {
+struct __fn {
+
+  template <class _InIter, class _Sent, class _OutIter, class _Proj, class _Pred>
+  _LIBCPP_HIDE_FROM_ABI static constexpr
+  copy_if_result <_InIter, _OutIter>
+  __copy_if_impl(_InIter __first, _Sent __last, _OutIter __result, _Pred& __pred, _Proj& __proj) {
+    for (; __first != __last; ++__first) {
+      if (std::invoke(__pred, std::invoke(__proj, *__first))) {
+        *__result = *__first;
+        ++__result;
+      }
+    }
+    return {std::move(__first), std::move(__result)};
+  }
+
+  template <input_iterator _Iter, sentinel_for<_Iter> _Sent, weakly_incrementable _OutIter, class _Proj = identity,
+            indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
+    requires indirectly_copyable<_Iter, _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  copy_if_result<_Iter, _OutIter>
+  operator()(_Iter __first, _Sent __last, _OutIter __result, _Pred __pred, _Proj __proj = {}) const {
+    return __copy_if_impl(std::move(__first), std::move(__last), std::move(__result), __pred, __proj);
+  }
+
+  template <input_range _Range, weakly_incrementable _OutIter, class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
+    requires indirectly_copyable<iterator_t<_Range>, _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  copy_if_result<borrowed_iterator_t<_Range>, _OutIter>
+  operator()(_Range&& __r, _OutIter __result, _Pred __pred, _Proj __proj = {}) const {
+    return __copy_if_impl(ranges::begin(__r), ranges::end(__r), std::move(__result), __pred, __proj);
+  }
+};
+} // namespace __copy_if
+
+inline namespace __cpo {
+  inline constexpr auto copy_if = __copy_if::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_COPY_IF_H
diff --git a/libcxx/include/__algorithm/ranges_copy_n.h b/libcxx/include/__algorithm/ranges_copy_n.h
new file mode 100644
index 000000000000..eaa05c954686
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_copy_n.h
@@ -0,0 +1,76 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_COPY_N_H
+#define _LIBCPP___ALGORITHM_RANGES_COPY_N_H
+
+#include <__algorithm/copy.h>
+#include <__algorithm/in_out_result.h>
+#include <__algorithm/ranges_copy.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__iterator/concepts.h>
+#include <__iterator/incrementable_traits.h>
+#include <__iterator/unreachable_sentinel.h>
+#include <__iterator/wrap_iter.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+namespace ranges {
+
+template <class _Ip, class _Op>
+using copy_n_result = in_out_result<_Ip, _Op>;
+
+namespace __copy_n {
+struct __fn {
+
+  template <class _InIter, class _DiffType, class _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  copy_n_result<_InIter, _OutIter> __go(_InIter __first, _DiffType __n, _OutIter __result) {
+    while (__n != 0) {
+      *__result = *__first;
+      ++__first;
+      ++__result;
+      --__n;
+    }
+    return {std::move(__first), std::move(__result)};
+  }
+
+  template <random_access_iterator _InIter, class _DiffType, random_access_iterator _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  copy_n_result<_InIter, _OutIter> __go(_InIter __first, _DiffType __n, _OutIter __result) {
+    auto __ret = std::__copy(__first, __first + __n, __result);
+    return {__ret.first, __ret.second};
+  }
+
+  template <input_iterator _Ip, weakly_incrementable _Op>
+    requires indirectly_copyable<_Ip, _Op>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  copy_n_result<_Ip, _Op> operator()(_Ip __first, iter_difference_t<_Ip> __n, _Op __result) const {
+    return __go(std::move(__first), __n, std::move(__result));
+  }
+};
+} // namespace __copy_n
+
+inline namespace __cpo {
+  inline constexpr auto copy_n = __copy_n::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___ALGORITHM_RANGES_COPY_N_H
diff --git a/libcxx/include/__algorithm/ranges_count.h b/libcxx/include/__algorithm/ranges_count.h
new file mode 100644
index 000000000000..670df26911d0
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_count.h
@@ -0,0 +1,62 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_COUNT_H
+#define _LIBCPP___ALGORITHM_RANGES_COUNT_H
+
+#include <__algorithm/ranges_count_if.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/incrementable_traits.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __count {
+struct __fn {
+  template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity>
+    requires indirect_binary_predicate<ranges::equal_to, projected<_Iter, _Proj>, const _Type*>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  iter_difference_t<_Iter> operator()(_Iter __first, _Sent __last, const _Type& __value, _Proj __proj = {}) const {
+    auto __pred = [&](auto&& __e) { return __e == __value; };
+    return ranges::__count_if_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <input_range _Range, class _Type, class _Proj = identity>
+    requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<_Range>, _Proj>, const _Type*>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  range_difference_t<_Range> operator()(_Range&& __r, const _Type& __value, _Proj __proj = {}) const {
+    auto __pred = [&](auto&& __e) { return __e == __value; };
+    return ranges::__count_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj);
+  }
+};
+} // namespace __count
+
+inline namespace __cpo {
+  inline constexpr auto count = __count::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_COUNT_H
diff --git a/libcxx/include/__algorithm/ranges_count_if.h b/libcxx/include/__algorithm/ranges_count_if.h
new file mode 100644
index 000000000000..0f34ee9f2b1b
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_count_if.h
@@ -0,0 +1,72 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_COUNT_IF_H
+#define _LIBCPP___ALGORITHM_RANGES_COUNT_IF_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/incrementable_traits.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+template <class _Iter, class _Sent, class _Proj, class _Pred>
+_LIBCPP_HIDE_FROM_ABI constexpr
+iter_difference_t<_Iter> __count_if_impl(_Iter __first, _Sent __last,
+                                             _Pred& __pred, _Proj& __proj) {
+  iter_difference_t<_Iter> __counter(0);
+  for (; __first != __last; ++__first) {
+    if (std::invoke(__pred, std::invoke(__proj, *__first)))
+      ++__counter;
+  }
+  return __counter;
+}
+
+namespace __count_if {
+struct __fn {
+  template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Proj = identity,
+            indirect_unary_predicate<projected<_Iter, _Proj>> _Predicate>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  iter_difference_t<_Iter> operator()(_Iter __first, _Sent __last, _Predicate __pred, _Proj __proj = {}) const {
+    return ranges::__count_if_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <input_range _Range, class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Predicate>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  range_difference_t<_Range> operator()(_Range&& __r, _Predicate __pred, _Proj __proj = {}) const {
+    return ranges::__count_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj);
+  }
+};
+} // namespace __count_if
+
+inline namespace __cpo {
+  inline constexpr auto count_if = __count_if::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_COUNT_IF_H
diff --git a/libcxx/include/__algorithm/ranges_equal.h b/libcxx/include/__algorithm/ranges_equal.h
new file mode 100644
index 000000000000..c5f2d2332216
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_equal.h
@@ -0,0 +1,115 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_EQUAL_H
+#define _LIBCPP___ALGORITHM_RANGES_EQUAL_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/distance.h>
+#include <__iterator/indirectly_comparable.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __equal {
+struct __fn {
+private:
+  template <class _Iter1, class _Sent1,
+            class _Iter2, class _Sent2,
+            class _Pred,
+            class _Proj1,
+            class _Proj2>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  bool __equal_impl(_Iter1 __first1, _Sent1 __last1,
+                    _Iter2 __first2, _Sent2 __last2,
+                    _Pred& __pred,
+                    _Proj1& __proj1,
+                    _Proj2& __proj2) {
+    while (__first1 != __last1 && __first2 != __last2) {
+      if (!std::invoke(__pred, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__first2)))
+        return false;
+      ++__first1;
+      ++__first2;
+    }
+    return __first1 == __last1 && __first2 == __last2;
+  }
+
+public:
+
+  template <input_iterator _Iter1, sentinel_for<_Iter1> _Sent1,
+            input_iterator _Iter2, sentinel_for<_Iter2> _Sent2,
+            class _Pred = ranges::equal_to,
+            class _Proj1 = identity,
+            class _Proj2 = identity>
+    requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Iter1 __first1, _Sent1 __last1,
+                  _Iter2 __first2, _Sent2 __last2,
+                  _Pred __pred = {},
+                  _Proj1 __proj1 = {},
+                  _Proj2 __proj2 = {}) const {
+    if constexpr (sized_sentinel_for<_Sent1, _Iter1> && sized_sentinel_for<_Sent2, _Iter2>) {
+      if (__last1 - __first1 != __last2 - __first2)
+        return false;
+    }
+    return __equal_impl(std::move(__first1), std::move(__last1),
+                        std::move(__first2), std::move(__last2),
+                        __pred,
+                        __proj1,
+                        __proj2);
+  }
+
+  template <input_range _Range1,
+            input_range _Range2,
+            class _Pred = ranges::equal_to,
+            class _Proj1 = identity,
+            class _Proj2 = identity>
+    requires indirectly_comparable<iterator_t<_Range1>, iterator_t<_Range2>, _Pred, _Proj1, _Proj2>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Range1&& __range1,
+                  _Range2&& __range2,
+                  _Pred __pred = {},
+                  _Proj1 __proj1 = {},
+                  _Proj2 __proj2 = {}) const {
+    if constexpr (sized_range<_Range1> && sized_range<_Range2>) {
+      if (ranges::distance(__range1) != ranges::distance(__range2))
+        return false;
+    }
+    return __equal_impl(ranges::begin(__range1), ranges::end(__range1),
+                        ranges::begin(__range2), ranges::end(__range2),
+                        __pred,
+                        __proj1,
+                        __proj2);
+    return false;
+  }
+};
+} // namespace __equal
+
+inline namespace __cpo {
+  inline constexpr auto equal = __equal::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_EQUAL_H
diff --git a/libcxx/include/__algorithm/ranges_fill.h b/libcxx/include/__algorithm/ranges_fill.h
new file mode 100644
index 000000000000..846e31885141
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_fill.h
@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_FILL_H
+#define _LIBCPP___ALGORITHM_RANGES_FILL_H
+
+#include <__algorithm/ranges_fill_n.h>
+#include <__config>
+#include <__iterator/concepts.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __fill {
+struct __fn {
+  template <class _Type, output_iterator<const _Type&> _Iter, sentinel_for<_Iter> _Sent>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last, const _Type& __value) const {
+    if constexpr(random_access_iterator<_Iter>) {
+      return ranges::fill_n(__first, __last - __first, __value);
+    } else {
+      for (; __first != __last; ++__first)
+        *__first = __value;
+      return __first;
+    }
+  }
+
+  template <class _Type, output_range<const _Type&> _Range>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range> operator()(_Range&& __range, const _Type& __value) const {
+    return (*this)(ranges::begin(__range), ranges::end(__range), __value);
+  }
+};
+} // namespace __fill
+
+inline namespace __cpo {
+  inline constexpr auto fill = __fill::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_FILL_H
diff --git a/libcxx/include/__algorithm/ranges_fill_n.h b/libcxx/include/__algorithm/ranges_fill_n.h
new file mode 100644
index 000000000000..d93c573406ec
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_fill_n.h
@@ -0,0 +1,48 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_FILL_N_H
+#define _LIBCPP___ALGORITHM_RANGES_FILL_N_H
+
+#include <__config>
+#include <__iterator/concepts.h>
+#include <__iterator/incrementable_traits.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __fill_n {
+struct __fn {
+  template <class _Type, output_iterator<const _Type&> _Iter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, iter_difference_t<_Iter> __n, const _Type& __value) const {
+    for (; __n != 0; --__n) {
+      *__first = __value;
+      ++__first;
+    }
+    return __first;
+  }
+};
+} // namespace __fill_n
+
+inline namespace __cpo {
+  inline constexpr auto fill_n = __fill_n::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_FILL_N_H
diff --git a/libcxx/include/__algorithm/ranges_find.h b/libcxx/include/__algorithm/ranges_find.h
new file mode 100644
index 000000000000..ca6d2f438295
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_find.h
@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_FIND_H
+#define _LIBCPP___ALGORITHM_RANGES_FIND_H
+
+#include <__algorithm/ranges_find_if.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/forward.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __find {
+struct __fn {
+  template <input_iterator _Ip, sentinel_for<_Ip> _Sp, class _Tp, class _Proj = identity>
+    requires indirect_binary_predicate<ranges::equal_to, projected<_Ip, _Proj>, const _Tp*>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Ip operator()(_Ip __first, _Sp __last, const _Tp& __value, _Proj __proj = {}) const {
+    auto __pred = [&](auto&& __e) { return std::forward<decltype(__e)>(__e) == __value; };
+    return ranges::__find_if_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <input_range _Rp, class _Tp, class _Proj = identity>
+    requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<_Rp>, _Proj>, const _Tp*>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Rp> operator()(_Rp&& __r, const _Tp& __value, _Proj __proj = {}) const {
+    auto __pred = [&](auto&& __e) { return std::forward<decltype(__e)>(__e) == __value; };
+    return ranges::__find_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj);
+  }
+};
+} // namespace __find
+
+inline namespace __cpo {
+  inline constexpr auto find = __find::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_FIND_H
diff --git a/libcxx/include/__algorithm/ranges_find_first_of.h b/libcxx/include/__algorithm/ranges_find_first_of.h
new file mode 100644
index 000000000000..ae31d38e6a95
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_find_first_of.h
@@ -0,0 +1,101 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_FIND_FIRST_OF_H
+#define _LIBCPP___ALGORITHM_RANGES_FIND_FIRST_OF_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/indirectly_comparable.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __find_first_of {
+struct __fn {
+
+  template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _Proj2>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  _Iter1 __find_first_of_impl(_Iter1 __first1, _Sent1 __last1,
+                              _Iter2 __first2, _Sent2 __last2,
+                              _Pred& __pred,
+                              _Proj1& __proj1,
+                              _Proj2& __proj2) {
+    for (; __first1 != __last1; ++__first1) {
+      for (auto __j = __first2; __j != __last2; ++__j) {
+        if (std::invoke(__pred, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__j)))
+          return __first1;
+      }
+    }
+    return __first1;
+  }
+
+  template <input_iterator _Iter1, sentinel_for<_Iter1> _Sent1,
+            forward_iterator _Iter2, sentinel_for<_Iter2> _Sent2,
+            class _Pred = ranges::equal_to,
+            class _Proj1 = identity,
+            class _Proj2 = identity>
+    requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter1 operator()(_Iter1 __first1, _Sent1 __last1,
+                    _Iter2 __first2, _Sent2 __last2,
+                    _Pred __pred = {},
+                    _Proj1 __proj1 = {},
+                    _Proj2 __proj2 = {}) const {
+    return __find_first_of_impl(std::move(__first1), std::move(__last1),
+                                std::move(__first2), std::move(__last2),
+                                __pred,
+                                __proj1,
+                                __proj2);
+  }
+
+  template <input_range _Range1,
+            forward_range _Range2,
+            class _Pred = ranges::equal_to,
+            class _Proj1 = identity,
+            class _Proj2 = identity>
+    requires indirectly_comparable<iterator_t<_Range1>, iterator_t<_Range2>, _Pred, _Proj1, _Proj2>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range1> operator()(_Range1&& __range1,
+                                          _Range2&& __range2,
+                                          _Pred __pred = {},
+                                          _Proj1 __proj1 = {},
+                                          _Proj2 __proj2 = {}) const {
+    return __find_first_of_impl(ranges::begin(__range1), ranges::end(__range1),
+                                ranges::begin(__range2), ranges::end(__range2),
+                                __pred,
+                                __proj1,
+                                __proj2);
+  }
+
+};
+} // namespace __find_first_of
+
+inline namespace __cpo {
+  inline constexpr auto find_first_of = __find_first_of::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_FIND_FIRST_OF_H
diff --git a/libcxx/include/__algorithm/ranges_find_if.h b/libcxx/include/__algorithm/ranges_find_if.h
new file mode 100644
index 000000000000..65ac122f6677
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_find_if.h
@@ -0,0 +1,71 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_FIND_IF_H
+#define _LIBCPP___ALGORITHM_RANGES_FIND_IF_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _Ip, class _Sp, class _Pred, class _Proj>
+_LIBCPP_HIDE_FROM_ABI static constexpr
+_Ip __find_if_impl(_Ip __first, _Sp __last, _Pred& __pred, _Proj& __proj) {
+  for (; __first != __last; ++__first) {
+    if (std::invoke(__pred, std::invoke(__proj, *__first)))
+      break;
+  }
+  return __first;
+}
+
+namespace __find_if {
+struct __fn {
+
+  template <input_iterator _Ip, sentinel_for<_Ip> _Sp, class _Proj = identity,
+            indirect_unary_predicate<projected<_Ip, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Ip operator()(_Ip __first, _Sp __last, _Pred __pred, _Proj __proj = {}) const {
+    return ranges::__find_if_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <input_range _Rp, class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Rp>, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Rp> operator()(_Rp&& __r, _Pred __pred, _Proj __proj = {}) const {
+    return ranges::__find_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj);
+  }
+};
+} // namespace __find_if
+
+inline namespace __cpo {
+  inline constexpr auto find_if = __find_if::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_FIND_IF_H
diff --git a/libcxx/include/__algorithm/ranges_find_if_not.h b/libcxx/include/__algorithm/ranges_find_if_not.h
new file mode 100644
index 000000000000..9a1adf71fc58
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_find_if_not.h
@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_FIND_IF_NOT_H
+#define _LIBCPP___ALGORITHM_RANGES_FIND_IF_NOT_H
+
+#include <__algorithm/ranges_find_if.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/forward.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __find_if_not {
+struct __fn {
+  template <input_iterator _Ip, sentinel_for<_Ip> _Sp, class _Proj = identity,
+            indirect_unary_predicate<projected<_Ip, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Ip operator()(_Ip __first, _Sp __last, _Pred __pred, _Proj __proj = {}) const {
+    auto __pred2 = [&](auto&& __e) { return !std::invoke(__pred, std::forward<decltype(__e)>(__e)); };
+    return ranges::__find_if_impl(std::move(__first), std::move(__last), __pred2, __proj);
+  }
+
+  template <input_range _Rp, class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Rp>, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Rp> operator()(_Rp&& __r, _Pred __pred, _Proj __proj = {}) const {
+    auto __pred2 = [&](auto&& __e) { return !std::invoke(__pred, std::forward<decltype(__e)>(__e)); };
+    return ranges::__find_if_impl(ranges::begin(__r), ranges::end(__r), __pred2, __proj);
+  }
+};
+} // namespace __find_if_not
+
+inline namespace __cpo {
+  inline constexpr auto find_if_not = __find_if_not::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_FIND_IF_NOT_H
diff --git a/libcxx/include/__algorithm/ranges_for_each.h b/libcxx/include/__algorithm/ranges_for_each.h
new file mode 100644
index 000000000000..f284c0ee3ad4
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_for_each.h
@@ -0,0 +1,78 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_FOR_EACH_H
+#define _LIBCPP___ALGORITHM_RANGES_FOR_EACH_H
+
+#include <__algorithm/in_fun_result.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _Iter, class _Func>
+using for_each_result = in_fun_result<_Iter, _Func>;
+
+namespace __for_each {
+struct __fn {
+private:
+  template <class _Iter, class _Sent, class _Proj, class _Func>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  for_each_result<_Iter, _Func> __for_each_impl(_Iter __first, _Sent __last, _Func& __func, _Proj& __proj) {
+    for (; __first != __last; ++__first)
+      std::invoke(__func, std::invoke(__proj, *__first));
+    return {std::move(__first), std::move(__func)};
+  }
+
+public:
+  template <input_iterator _Iter, sentinel_for<_Iter> _Sent,
+            class _Proj = identity,
+            indirectly_unary_invocable<projected<_Iter, _Proj>> _Func>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  for_each_result<_Iter, _Func> operator()(_Iter __first, _Sent __last, _Func __func, _Proj __proj = {}) const {
+    return __for_each_impl(std::move(__first), std::move(__last), __func, __proj);
+  }
+
+  template <input_range _Range,
+            class _Proj = identity,
+            indirectly_unary_invocable<projected<iterator_t<_Range>, _Proj>> _Func>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  for_each_result<borrowed_iterator_t<_Range>, _Func> operator()(_Range&& __range,
+                                                                 _Func __func,
+                                                                 _Proj __proj = {}) const {
+    return __for_each_impl(ranges::begin(__range), ranges::end(__range), __func, __proj);
+  }
+
+};
+} // namespace __for_each
+
+inline namespace __cpo {
+  inline constexpr auto for_each = __for_each::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_FOR_EACH_H
diff --git a/libcxx/include/__algorithm/ranges_for_each_n.h b/libcxx/include/__algorithm/ranges_for_each_n.h
new file mode 100644
index 000000000000..ddf8b047cdb2
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_for_each_n.h
@@ -0,0 +1,67 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_FOR_EACH_N_H
+#define _LIBCPP___ALGORITHM_RANGES_FOR_EACH_N_H
+
+#include <__algorithm/in_fun_result.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/incrementable_traits.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/projected.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _Iter, class _Func>
+using for_each_n_result = in_fun_result<_Iter, _Func>;
+
+namespace __for_each_n {
+struct __fn {
+
+  template <input_iterator _Iter,
+            class _Proj = identity,
+            indirectly_unary_invocable<projected<_Iter, _Proj>> _Func>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  for_each_n_result<_Iter, _Func> operator()(_Iter __first,
+                                             iter_difference_t<_Iter> __count,
+                                             _Func __func,
+                                             _Proj __proj = {}) const {
+    while (__count-- > 0) {
+      std::invoke(__func, std::invoke(__proj, *__first));
+      ++__first;
+    }
+    return {std::move(__first), std::move(__func)};
+  }
+
+};
+} // namespace __for_each_n
+
+inline namespace __cpo {
+  inline constexpr auto for_each_n = __for_each_n::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_FOR_EACH_N_H
diff --git a/libcxx/include/__algorithm/ranges_is_partitioned.h b/libcxx/include/__algorithm/ranges_is_partitioned.h
new file mode 100644
index 000000000000..3d572895ebe1
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_is_partitioned.h
@@ -0,0 +1,81 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_IS_PARTITIONED_H
+#define _LIBCPP___ALGORITHM_RANGES_IS_PARTITIONED_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/indirectly_comparable.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __is_partitioned {
+struct __fn {
+
+  template <class _Iter, class _Sent, class _Proj, class _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  bool __is_parititioned_impl(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) {
+    for (; __first != __last; ++__first) {
+      if (!std::invoke(__pred, std::invoke(__proj, *__first)))
+        break;
+    }
+
+    if (__first == __last)
+      return true;
+    ++__first;
+
+    for (; __first != __last; ++__first) {
+      if (std::invoke(__pred, std::invoke(__proj, *__first)))
+        return false;
+    }
+
+    return true;
+  }
+
+  template <input_iterator _Iter, sentinel_for<_Iter> _Sent,
+            class _Proj = identity,
+            indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) const {
+    return __is_parititioned_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <input_range _Range,
+            class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
+    return __is_parititioned_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
+  }
+};
+} // namespace __is_partitioned
+
+inline namespace __cpo {
+  inline constexpr auto is_partitioned = __is_partitioned::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_IS_PARTITIONED_H
diff --git a/libcxx/include/__algorithm/ranges_is_sorted.h b/libcxx/include/__algorithm/ranges_is_sorted.h
new file mode 100644
index 000000000000..938e69afba8d
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_is_sorted.h
@@ -0,0 +1,61 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_IS_SORTED_H
+#define _LIBCPP__ALGORITHM_RANGES_IS_SORTED_H
+
+#include <__algorithm/ranges_is_sorted_until.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __is_sorted {
+struct __fn {
+  template <forward_iterator _Iter, sentinel_for<_Iter> _Sent,
+            class _Proj = identity,
+            indirect_strict_weak_order<projected<_Iter, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Iter __first, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {
+    return ranges::__is_sorted_until_impl(std::move(__first), __last, __comp, __proj) == __last;
+  }
+
+  template <forward_range _Range,
+            class _Proj = identity,
+            indirect_strict_weak_order<projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Range&& __range, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __last = ranges::end(__range);
+    return ranges::__is_sorted_until_impl(ranges::begin(__range), __last, __comp, __proj) == __last;
+  }
+};
+} // namespace __is_sorted
+
+inline namespace __cpo {
+  inline constexpr auto is_sorted = __is_sorted::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP__ALGORITHM_RANGES_IS_SORTED_H
diff --git a/libcxx/include/__algorithm/ranges_is_sorted_until.h b/libcxx/include/__algorithm/ranges_is_sorted_until.h
new file mode 100644
index 000000000000..c8f0608e1255
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_is_sorted_until.h
@@ -0,0 +1,76 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_IS_SORTED_UNTIL_H
+#define _LIBCPP__ALGORITHM_RANGES_IS_SORTED_UNTIL_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _Iter, class _Sent, class _Proj, class _Comp>
+_LIBCPP_HIDE_FROM_ABI constexpr
+_Iter __is_sorted_until_impl(_Iter __first, _Sent __last, _Comp& __comp, _Proj& __proj) {
+  if (__first == __last)
+    return __first;
+  auto __i = __first;
+  while (++__i != __last) {
+    if (std::invoke(__comp, std::invoke(__proj, *__i), std::invoke(__proj, *__first)))
+      return __i;
+    __first = __i;
+  }
+  return __i;
+}
+
+namespace __is_sorted_until {
+struct __fn {
+  template <forward_iterator _Iter, sentinel_for<_Iter> _Sent,
+            class _Proj = identity,
+            indirect_strict_weak_order<projected<_Iter, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {
+    return ranges::__is_sorted_until_impl(std::move(__first), std::move(__last), __comp, __proj);
+  }
+
+  template <forward_range _Range,
+            class _Proj = identity,
+            indirect_strict_weak_order<projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range> operator()(_Range&& __range, _Comp __comp = {}, _Proj __proj = {}) const {
+    return ranges::__is_sorted_until_impl(ranges::begin(__range), ranges::end(__range), __comp, __proj);
+  }
+};
+} // namespace __is_sorted_until
+
+inline namespace __cpo {
+  inline constexpr auto is_sorted_until = __is_sorted_until::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP__ALGORITHM_RANGES_IS_SORTED_UNTIL_H
diff --git a/libcxx/include/__algorithm/ranges_lexicographical_compare.h b/libcxx/include/__algorithm/ranges_lexicographical_compare.h
new file mode 100644
index 000000000000..fe709f7a7f70
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_lexicographical_compare.h
@@ -0,0 +1,98 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_LEXICOGRAPHICAL_COMPARE_H
+#define _LIBCPP___ALGORITHM_RANGES_LEXICOGRAPHICAL_COMPARE_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __lexicographical_compare {
+struct __fn {
+
+  template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Proj1, class _Proj2, class _Comp>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  bool __lexicographical_compare_impl(_Iter1 __first1, _Sent1 __last1,
+                                      _Iter2 __first2, _Sent2 __last2,
+                                      _Comp& __comp,
+                                      _Proj1& __proj1,
+                                      _Proj2& __proj2) {
+    while (__first2 != __last2) {
+      if (__first1 == __last1
+       || std::invoke(__comp, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__first2)))
+        return true;
+      if (std::invoke(__comp, std::invoke(__proj2, *__first2), std::invoke(__proj1, *__first1)))
+        return false;
+      ++__first1;
+      ++__first2;
+    }
+    return false;
+  }
+
+  template <input_iterator _Iter1, sentinel_for<_Iter1> _Sent1,
+            input_iterator _Iter2, sentinel_for<_Iter2> _Sent2,
+            class _Proj1 = identity,
+            class _Proj2 = identity,
+            indirect_strict_weak_order<projected<_Iter1, _Proj1>, projected<_Iter2, _Proj2>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Iter1 __first1, _Sent1 __last1,
+                  _Iter2 __first2, _Sent2 __last2,
+                  _Comp __comp = {},
+                  _Proj1 __proj1 = {},
+                  _Proj2 __proj2 = {}) const {
+    return __lexicographical_compare_impl(std::move(__first1), std::move(__last1),
+                                          std::move(__first2), std::move(__last2),
+                                          __comp,
+                                          __proj1,
+                                          __proj2);
+  }
+
+  template <input_range _Range1,
+            input_range _Range2,
+            class _Proj1 = identity,
+            class _Proj2 = identity,
+            indirect_strict_weak_order<projected<iterator_t<_Range1>, _Proj1>,
+                                       projected<iterator_t<_Range2>, _Proj2>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Range1&& __range1, _Range2&& __range2, _Comp __comp = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
+    return __lexicographical_compare_impl(ranges::begin(__range1), ranges::end(__range1),
+                                          ranges::begin(__range2), ranges::end(__range2),
+                                          __comp,
+                                          __proj1,
+                                          __proj2);
+  }
+
+};
+} // namespace __lexicographical_compare
+
+inline namespace __cpo {
+  inline constexpr auto lexicographical_compare = __lexicographical_compare::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_LEXICOGRAPHICAL_COMPARE_H
diff --git a/libcxx/include/__algorithm/ranges_lower_bound.h b/libcxx/include/__algorithm/ranges_lower_bound.h
new file mode 100644
index 000000000000..a73470465cfd
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_lower_bound.h
@@ -0,0 +1,66 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_LOWER_BOUND_H
+#define _LIBCPP___ALGORITHM_RANGES_LOWER_BOUND_H
+
+#include <__algorithm/iterator_operations.h>
+#include <__algorithm/lower_bound.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/advance.h>
+#include <__iterator/concepts.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+namespace __lower_bound {
+struct __fn {
+  template <forward_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<_Iter, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
+    return std::__lower_bound_impl<_RangesIterOps>(__first, __last, __value, __comp, __proj);
+  }
+
+  template <forward_range _Range, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range> operator()(_Range&& __r,
+                                         const _Type& __value,
+                                         _Comp __comp = {},
+                                         _Proj __proj = {}) const {
+    return std::__lower_bound_impl<_RangesIterOps>(ranges::begin(__r), ranges::end(__r), __value, __comp, __proj);
+  }
+};
+} // namespace __lower_bound
+
+inline namespace __cpo {
+  inline constexpr auto lower_bound = __lower_bound::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_LOWER_BOUND_H
diff --git a/libcxx/include/__algorithm/ranges_max.h b/libcxx/include/__algorithm/ranges_max.h
new file mode 100644
index 000000000000..f48bc3ececa2
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_max.h
@@ -0,0 +1,93 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_MAX_H
+#define _LIBCPP___ALGORITHM_RANGES_MAX_H
+
+#include <__algorithm/ranges_min_element.h>
+#include <__assert>
+#include <__concepts/copyable.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/move.h>
+#include <initializer_list>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __max {
+struct __fn {
+  template <class _Tp, class _Proj = identity,
+            indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  const _Tp& operator()(const _Tp& __a, const _Tp& __b, _Comp __comp = {}, _Proj __proj = {}) const {
+    return std::invoke(__comp, std::invoke(__proj, __a), std::invoke(__proj, __b)) ? __b : __a;
+  }
+
+  template <copyable _Tp, class _Proj = identity,
+            indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Tp operator()(initializer_list<_Tp> __il, _Comp __comp = {}, _Proj __proj = {}) const {
+    _LIBCPP_ASSERT(__il.begin() != __il.end(), "initializer_list must contain at least one element");
+
+    auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return std::invoke(__comp, __rhs, __lhs); };
+    return *ranges::__min_element_impl(__il.begin(), __il.end(), __comp_lhs_rhs_swapped, __proj);
+  }
+
+  template <input_range _Rp, class _Proj = identity,
+            indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
+    requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  range_value_t<_Rp> operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __first = ranges::begin(__r);
+    auto __last = ranges::end(__r);
+
+    _LIBCPP_ASSERT(__first != __last, "range must contain at least one element");
+
+    if constexpr (forward_range<_Rp>) {
+      auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return std::invoke(__comp, __rhs, __lhs); };
+      return *ranges::__min_element_impl(std::move(__first), std::move(__last), __comp_lhs_rhs_swapped, __proj);
+    } else {
+      range_value_t<_Rp> __result = *__first;
+      while (++__first != __last) {
+        if (std::invoke(__comp, std::invoke(__proj, __result), std::invoke(__proj, *__first)))
+          __result = *__first;
+      }
+      return __result;
+    }
+  }
+};
+} // namespace __max
+
+inline namespace __cpo {
+  inline constexpr auto max = __max::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP_STD_VER > 17 && && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_MAX_H
diff --git a/libcxx/include/__algorithm/ranges_max_element.h b/libcxx/include/__algorithm/ranges_max_element.h
new file mode 100644
index 000000000000..d8d7242e176b
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_max_element.h
@@ -0,0 +1,61 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_MAX_ELEMENT_H
+#define _LIBCPP___ALGORITHM_RANGES_MAX_ELEMENT_H
+
+#include <__algorithm/ranges_min_element.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __max_element {
+struct __fn {
+  template <forward_iterator _Ip, sentinel_for<_Ip> _Sp, class _Proj = identity,
+            indirect_strict_weak_order<projected<_Ip, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Ip operator()(_Ip __first, _Sp __last, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return std::invoke(__comp, __rhs, __lhs); };
+    return ranges::__min_element_impl(__first, __last, __comp_lhs_rhs_swapped, __proj);
+  }
+
+  template <forward_range _Rp, class _Proj = identity,
+            indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Rp> operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __comp_lhs_rhs_swapped = [&](auto&& __lhs, auto&& __rhs) { return std::invoke(__comp, __rhs, __lhs); };
+    return ranges::__min_element_impl(ranges::begin(__r), ranges::end(__r), __comp_lhs_rhs_swapped, __proj);
+  }
+};
+} // namespace __max_element
+
+inline namespace __cpo {
+  inline constexpr auto max_element = __max_element::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_MAX_ELEMENT_H
diff --git a/libcxx/include/__algorithm/ranges_min.h b/libcxx/include/__algorithm/ranges_min.h
new file mode 100644
index 000000000000..0bb1e72ac5ac
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_min.h
@@ -0,0 +1,89 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_MIN_H
+#define _LIBCPP___ALGORITHM_RANGES_MIN_H
+
+#include <__algorithm/ranges_min_element.h>
+#include <__assert>
+#include <__concepts/copyable.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <initializer_list>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __min {
+struct __fn {
+  template <class _Tp, class _Proj = identity,
+            indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  const _Tp& operator()(const _Tp& __a, const _Tp& __b, _Comp __comp = {}, _Proj __proj = {}) const {
+    return std::invoke(__comp, std::invoke(__proj, __b), std::invoke(__proj, __a)) ? __b : __a;
+  }
+
+  template <copyable _Tp, class _Proj = identity,
+            indirect_strict_weak_order<projected<const _Tp*, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Tp operator()(initializer_list<_Tp> __il, _Comp __comp = {}, _Proj __proj = {}) const {
+    _LIBCPP_ASSERT(__il.begin() != __il.end(), "initializer_list must contain at least one element");
+    return *ranges::__min_element_impl(__il.begin(), __il.end(), __comp, __proj);
+  }
+
+  template <input_range _Rp, class _Proj = identity,
+            indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
+    requires indirectly_copyable_storable<iterator_t<_Rp>, range_value_t<_Rp>*>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  range_value_t<_Rp> operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __first = ranges::begin(__r);
+    auto __last = ranges::end(__r);
+
+    _LIBCPP_ASSERT(__first != __last, "range must contain at least one element");
+
+    if constexpr (forward_range<_Rp>) {
+      return *ranges::__min_element_impl(__first, __last, __comp, __proj);
+    } else {
+      range_value_t<_Rp> __result = *__first;
+      while (++__first != __last) {
+        if (std::invoke(__comp, std::invoke(__proj, *__first), std::invoke(__proj, __result)))
+          __result = *__first;
+      }
+      return __result;
+    }
+  }
+};
+} // namespace __min
+
+inline namespace __cpo {
+  inline constexpr auto min = __min::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP_STD_VER > 17 && && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_MIN_H
diff --git a/libcxx/include/__algorithm/ranges_min_element.h b/libcxx/include/__algorithm/ranges_min_element.h
new file mode 100644
index 000000000000..ae82dceb9ad8
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_min_element.h
@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_MIN_ELEMENT_H
+#define _LIBCPP___ALGORITHM_RANGES_MIN_ELEMENT_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/forward.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _Ip, class _Sp, class _Proj, class _Comp>
+_LIBCPP_HIDE_FROM_ABI static constexpr
+_Ip __min_element_impl(_Ip __first, _Sp __last, _Comp& __comp, _Proj& __proj) {
+  if (__first == __last)
+    return __first;
+
+  _Ip __i = __first;
+  while (++__i != __last)
+    if (std::invoke(__comp, std::invoke(__proj, *__i), std::invoke(__proj, *__first)))
+      __first = __i;
+  return __first;
+}
+
+namespace __min_element {
+struct __fn {
+  template <forward_iterator _Ip, sentinel_for<_Ip> _Sp, class _Proj = identity,
+            indirect_strict_weak_order<projected<_Ip, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Ip operator()(_Ip __first, _Sp __last, _Comp __comp = {}, _Proj __proj = {}) const {
+    return ranges::__min_element_impl(__first, __last, __comp, __proj);
+  }
+
+  template <forward_range _Rp, class _Proj = identity,
+            indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Rp> operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
+    return ranges::__min_element_impl(ranges::begin(__r), ranges::end(__r), __comp, __proj);
+  }
+};
+} // namespace __min_element
+
+inline namespace __cpo {
+  inline constexpr auto min_element = __min_element::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_MIN_ELEMENT_H
diff --git a/libcxx/include/__algorithm/ranges_minmax.h b/libcxx/include/__algorithm/ranges_minmax.h
new file mode 100644
index 000000000000..2f4bba0e7cc0
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_minmax.h
@@ -0,0 +1,133 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_MINMAX_H
+#define _LIBCPP___ALGORITHM_RANGES_MINMAX_H
+
+#include <__algorithm/min_max_result.h>
+#include <__algorithm/minmax_element.h>
+#include <__assert>
+#include <__concepts/copyable.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/forward.h>
+#include <__utility/move.h>
+#include <initializer_list>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+template <class _T1>
+using minmax_result = min_max_result<_T1>;
+
+namespace __minmax {
+struct __fn {
+  template <class _Type, class _Proj = identity,
+            indirect_strict_weak_order<projected<const _Type*, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr ranges::minmax_result<const _Type&>
+  operator()(const _Type& __a, const _Type& __b, _Comp __comp = {}, _Proj __proj = {}) const {
+    if (std::invoke(__comp, std::invoke(__proj, __b), std::invoke(__proj, __a)))
+      return {__b, __a};
+    return {__a, __b};
+  }
+
+  template <copyable _Type, class _Proj = identity,
+            indirect_strict_weak_order<projected<const _Type*, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  ranges::minmax_result<_Type> operator()(initializer_list<_Type> __il, _Comp __comp = {}, _Proj __proj = {}) const {
+    _LIBCPP_ASSERT(__il.begin() != __il.end(), "initializer_list has to contain at least one element");
+    auto __iters = std::__minmax_element_impl(__il.begin(), __il.end(), __comp, __proj);
+    return ranges::minmax_result<_Type> { *__iters.first, *__iters.second };
+  }
+
+  template <input_range _Range, class _Proj = identity,
+            indirect_strict_weak_order<projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
+    requires indirectly_copyable_storable<iterator_t<_Range>, range_value_t<_Range>*>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  ranges::minmax_result<range_value_t<_Range>> operator()(_Range&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __first = ranges::begin(__r);
+    auto __last = ranges::end(__r);
+    using _ValueT = range_value_t<_Range>;
+
+    _LIBCPP_ASSERT(__first != __last, "range has to contain at least one element");
+
+    if constexpr (forward_range<_Range>) {
+      auto __result = std::__minmax_element_impl(__first, __last, __comp, __proj);
+      return {*__result.first, *__result.second};
+    } else {
+      // input_iterators can't be copied, so the implementation for input_iterators has to store
+      // the values instead of a pointer to the correct values
+      auto __less = [&](auto&& __a, auto&& __b) -> bool {
+        return std::invoke(__comp, std::invoke(__proj, std::forward<decltype(__a)>(__a)),
+                                   std::invoke(__proj, std::forward<decltype(__b)>(__b)));
+      };
+
+      ranges::minmax_result<_ValueT> __result = {*__first, __result.min};
+      if (__first == __last || ++__first == __last)
+        return __result;
+
+      if (__less(*__first, __result.min))
+        __result.min = *__first;
+      else
+        __result.max = *__first;
+
+      while (++__first != __last) {
+        _ValueT __i = *__first;
+        if (++__first == __last) {
+          if (__less(__i, __result.min))
+            __result.min = __i;
+          else if (!__less(__i, __result.max))
+            __result.max = __i;
+          return __result;
+        }
+
+        if (__less(*__first, __i)) {
+          if (__less(*__first, __result.min))
+            __result.min = *__first;
+          if (!__less(__i, __result.max))
+            __result.max = std::move(__i);
+        } else {
+          if (__less(__i, __result.min))
+            __result.min = std::move(__i);
+          if (!__less(*__first, __result.max))
+            __result.max = *__first;
+        }
+      }
+      return __result;
+    }
+  }
+};
+} // namespace __minmax
+
+inline namespace __cpo {
+  inline constexpr auto minmax = __minmax::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_MINMAX_H
diff --git a/libcxx/include/__algorithm/ranges_minmax_element.h b/libcxx/include/__algorithm/ranges_minmax_element.h
new file mode 100644
index 000000000000..b7bb26cefe95
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_minmax_element.h
@@ -0,0 +1,72 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_MINMAX_ELEMENT_H
+#define _LIBCPP___ALGORITHM_RANGES_MINMAX_ELEMENT_H
+
+#include <__algorithm/min_max_result.h>
+#include <__algorithm/minmax_element.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/forward.h>
+#include <__utility/move.h>
+#include <__utility/pair.h>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _T1>
+using minmax_element_result = min_max_result<_T1>;
+
+namespace __minmax_element {
+struct __fn {
+  template <forward_iterator _Ip, sentinel_for<_Ip> _Sp, class _Proj = identity,
+            indirect_strict_weak_order<projected<_Ip, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  ranges::minmax_element_result<_Ip> operator()(_Ip __first, _Sp __last, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __ret = std::__minmax_element_impl(std::move(__first), std::move(__last), __comp, __proj);
+    return {__ret.first, __ret.second};
+  }
+
+  template <forward_range _Rp, class _Proj = identity,
+            indirect_strict_weak_order<projected<iterator_t<_Rp>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  ranges::minmax_element_result<borrowed_iterator_t<_Rp>>
+  operator()(_Rp&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __ret = std::__minmax_element_impl(ranges::begin(__r), ranges::end(__r), __comp, __proj);
+    return {__ret.first, __ret.second};
+  }
+};
+} // namespace __minmax_element
+
+inline namespace __cpo {
+  inline constexpr auto minmax_element = __minmax_element::__fn{};
+} // namespace __cpo
+
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_MINMAX_H
diff --git a/libcxx/include/__algorithm/ranges_mismatch.h b/libcxx/include/__algorithm/ranges_mismatch.h
new file mode 100644
index 000000000000..4c1440b5da06
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_mismatch.h
@@ -0,0 +1,85 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_MISMATCH_H
+#define _LIBCPP___ALGORITHM_RANGES_MISMATCH_H
+
+#include <__algorithm/in_in_result.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/indirectly_comparable.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+namespace ranges {
+
+template <class _I1, class _I2>
+using mismatch_result = in_in_result<_I1, _I2>;
+
+namespace __mismatch {
+struct __fn {
+  template <class _I1, class _S1, class _I2, class _S2,
+            class _Pred, class _Proj1, class _Proj2>
+  static _LIBCPP_HIDE_FROM_ABI constexpr
+  mismatch_result<_I1, _I2>
+  __go(_I1 __first1, _S1 __last1, _I2 __first2, _S2 __last2,
+       _Pred& __pred, _Proj1& __proj1, _Proj2& __proj2) {
+    while (__first1 != __last1 && __first2 != __last2) {
+      if (!std::invoke(__pred, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__first2)))
+        break;
+      ++__first1;
+      ++__first2;
+    }
+    return {std::move(__first1), std::move(__first2)};
+  }
+
+  template <input_iterator _I1, sentinel_for<_I1> _S1,
+            input_iterator _I2, sentinel_for<_I2> _S2,
+            class _Pred = ranges::equal_to, class _Proj1 = identity, class _Proj2 = identity>
+    requires indirectly_comparable<_I1, _I2, _Pred, _Proj1, _Proj2>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  mismatch_result<_I1, _I2> operator()(_I1 __first1, _S1 __last1, _I2 __first2, _S2 __last2,
+                                       _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
+    return __go(std::move(__first1), __last1, std::move(__first2), __last2, __pred, __proj1, __proj2);
+  }
+
+  template <input_range _R1, input_range _R2,
+            class _Pred = ranges::equal_to, class _Proj1 = identity, class _Proj2 = identity>
+    requires indirectly_comparable<iterator_t<_R1>, iterator_t<_R2>, _Pred, _Proj1, _Proj2>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  mismatch_result<borrowed_iterator_t<_R1>, borrowed_iterator_t<_R2>>
+  operator()(_R1&& __r1, _R2&& __r2, _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
+    return __go(ranges::begin(__r1), ranges::end(__r1), ranges::begin(__r2), ranges::end(__r2),
+                __pred, __proj1, __proj2);
+  }
+};
+} // namespace __mismatch
+
+inline namespace __cpo {
+  constexpr inline auto mismatch = __mismatch::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___ALGORITHM_RANGES_MISMATCH_H
diff --git a/libcxx/include/__algorithm/ranges_move.h b/libcxx/include/__algorithm/ranges_move.h
new file mode 100644
index 000000000000..ad4342d7c989
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_move.h
@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_MOVE_H
+#define _LIBCPP___ALGORITHM_RANGES_MOVE_H
+
+#include <__algorithm/in_out_result.h>
+#include <__algorithm/move.h>
+#include <__config>
+#include <__iterator/concepts.h>
+#include <__iterator/iter_move.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _InIter, class _OutIter>
+using move_result = in_out_result<_InIter, _OutIter>;
+
+namespace __move {
+struct __fn {
+
+  template <class _InIter, class _Sent, class _OutIter>
+    requires __iter_move::__move_deref<_InIter> // check that we are allowed to std::move() the value
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  move_result<_InIter, _OutIter> __move_impl(_InIter __first, _Sent __last, _OutIter __result) {
+    auto __ret = std::__move(std::move(__first), std::move(__last), std::move(__result));
+    return {std::move(__ret.first), std::move(__ret.second)};
+  }
+
+  template <class _InIter, class _Sent, class _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  move_result<_InIter, _OutIter> __move_impl(_InIter __first, _Sent __last, _OutIter __result) {
+    while (__first != __last) {
+      *__result = ranges::iter_move(__first);
+      ++__first;
+      ++__result;
+    }
+    return {std::move(__first), std::move(__result)};
+  }
+
+  template <input_iterator _InIter, sentinel_for<_InIter> _Sent, weakly_incrementable _OutIter>
+    requires indirectly_movable<_InIter, _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  move_result<_InIter, _OutIter> operator()(_InIter __first, _Sent __last, _OutIter __result) const {
+    return __move_impl(std::move(__first), std::move(__last), std::move(__result));
+  }
+
+  template <input_range _Range, weakly_incrementable _OutIter>
+    requires indirectly_movable<iterator_t<_Range>, _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  move_result<borrowed_iterator_t<_Range>, _OutIter> operator()(_Range&& __range, _OutIter __result) const {
+    return __move_impl(ranges::begin(__range), ranges::end(__range), std::move(__result));
+  }
+
+};
+} // namespace __move
+
+inline namespace __cpo {
+  inline constexpr auto move = __move::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_MOVE_H
diff --git a/libcxx/include/__algorithm/ranges_move_backward.h b/libcxx/include/__algorithm/ranges_move_backward.h
new file mode 100644
index 000000000000..b3dfa7139603
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_move_backward.h
@@ -0,0 +1,75 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_MOVE_BACKWARD_H
+#define _LIBCPP___ALGORITHM_RANGES_MOVE_BACKWARD_H
+
+#include <__algorithm/in_out_result.h>
+#include <__algorithm/ranges_move.h>
+#include <__config>
+#include <__iterator/concepts.h>
+#include <__iterator/iter_move.h>
+#include <__iterator/next.h>
+#include <__iterator/reverse_iterator.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _InIter, class _OutIter>
+using move_backward_result = in_out_result<_InIter, _OutIter>;
+
+namespace __move_backward {
+struct __fn {
+
+  template <class _InIter, class _Sent, class _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  move_backward_result<_InIter, _OutIter> __move_backward_impl(_InIter __first, _Sent __last, _OutIter __result) {
+    auto __ret = ranges::move(std::make_reverse_iterator(ranges::next(__first, __last)),
+                              std::make_reverse_iterator(__first),
+                              std::make_reverse_iterator(__result));
+    return {std::move(__ret.in.base()), std::move(__ret.out.base())};
+  }
+
+  template <bidirectional_iterator _InIter, sentinel_for<_InIter> _Sent, bidirectional_iterator _OutIter>
+    requires indirectly_movable<_InIter, _OutIter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  move_backward_result<_InIter, _OutIter> operator()(_InIter __first, _Sent __last, _OutIter __result) const {
+    return __move_backward_impl(std::move(__first), std::move(__last), std::move(__result));
+  }
+
+  template <bidirectional_range _Range, bidirectional_iterator _Iter>
+    requires indirectly_movable<iterator_t<_Range>, _Iter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  move_backward_result<borrowed_iterator_t<_Range>, _Iter> operator()(_Range&& __range, _Iter __result) const {
+    return __move_backward_impl(ranges::begin(__range), ranges::end(__range), std::move(__result));
+  }
+
+};
+} // namespace __move_backward
+
+inline namespace __cpo {
+  inline constexpr auto move_backward = __move_backward::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_MOVE_BACKWARD_H
diff --git a/libcxx/include/__algorithm/ranges_none_of.h b/libcxx/include/__algorithm/ranges_none_of.h
new file mode 100644
index 000000000000..706ff5cd741d
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_none_of.h
@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_NONE_OF_H
+#define _LIBCPP___ALGORITHM_RANGES_NONE_OF_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __none_of {
+struct __fn {
+
+  template <class _Iter, class _Sent, class _Proj, class _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  bool __none_of_impl(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) {
+    for (; __first != __last; ++__first) {
+      if (std::invoke(__pred, std::invoke(__proj, *__first)))
+        return false;
+    }
+    return true;
+  }
+
+  template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Proj = identity,
+            indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Iter __first, _Sent __last, _Pred __pred = {}, _Proj __proj = {}) const {
+    return __none_of_impl(std::move(__first), std::move(__last), __pred, __proj);
+  }
+
+  template <input_range _Range, class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  bool operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
+    return __none_of_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
+  }
+};
+} // namespace __none_of
+
+inline namespace __cpo {
+  inline constexpr auto none_of = __none_of::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_NONE_OF_H
diff --git a/libcxx/include/__algorithm/ranges_replace.h b/libcxx/include/__algorithm/ranges_replace.h
new file mode 100644
index 000000000000..5e74c3ff80cb
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_replace.h
@@ -0,0 +1,74 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_REPLACE_H
+#define _LIBCPP___ALGORITHM_RANGES_REPLACE_H
+
+#include <__algorithm/ranges_replace_if.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined (_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __replace {
+struct __fn {
+
+  template <input_iterator _Iter, sentinel_for<_Iter> _Sent,
+            class _Type1,
+            class _Type2,
+            class _Proj = identity>
+    requires indirectly_writable<_Iter, const _Type2&>
+          && indirect_binary_predicate<ranges::equal_to, projected<_Iter, _Proj>, const _Type1*>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last,
+                   const _Type1& __old_value,
+                   const _Type2& __new_value,
+                   _Proj __proj = {}) const {
+    auto __pred = [&](const auto& __val) { return __val == __old_value; };
+    return ranges::__replace_if_impl(std::move(__first), std::move(__last), __pred, __new_value, __proj);
+  }
+
+  template <input_range _Range,
+            class _Type1,
+            class _Type2,
+            class _Proj = identity>
+    requires indirectly_writable<iterator_t<_Range>, const _Type2&>
+          && indirect_binary_predicate<ranges::equal_to, projected<iterator_t<_Range>, _Proj>, const _Type1*>
+  _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Range>
+  operator()(_Range&& __range, const _Type1& __old_value, const _Type2& __new_value, _Proj __proj = {}) const {
+    auto __pred = [&](auto&& __val) { return __val == __old_value; };
+    return ranges::__replace_if_impl(ranges::begin(__range), ranges::end(__range), __pred, __new_value, __proj);
+  }
+
+};
+} // namespace __replace
+
+inline namespace __cpo {
+  inline constexpr auto replace = __replace::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined (_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_REPLACE_H
diff --git a/libcxx/include/__algorithm/ranges_replace_if.h b/libcxx/include/__algorithm/ranges_replace_if.h
new file mode 100644
index 000000000000..0f9555fc35c2
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_replace_if.h
@@ -0,0 +1,77 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_REPLACE_IF_H
+#define _LIBCPP___ALGORITHM_RANGES_REPLACE_IF_H
+
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined (_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _Iter, class _Sent, class _Type, class _Proj, class _Pred>
+_LIBCPP_HIDE_FROM_ABI constexpr
+_Iter __replace_if_impl(_Iter __first, _Sent __last, _Pred& __pred, const _Type& __new_value, _Proj& __proj) {
+  for (; __first != __last; ++__first) {
+    if (std::invoke(__pred, std::invoke(__proj, *__first)))
+      *__first = __new_value;
+  }
+  return __first;
+}
+
+namespace __replace_if {
+struct __fn {
+
+  template <input_iterator _Iter, sentinel_for<_Iter> _Sent,
+            class _Type,
+            class _Proj = identity,
+            indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
+    requires indirectly_writable<_Iter, const _Type&>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last, _Pred __pred, const _Type& __new_value, _Proj __proj = {}) const {
+    return ranges::__replace_if_impl(std::move(__first), std::move(__last), __pred, __new_value, __proj);
+  }
+
+  template <input_range _Range,
+            class _Type,
+            class _Proj = identity,
+            indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
+    requires indirectly_writable<iterator_t<_Range>, const _Type&>
+  _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Range>
+  operator()(_Range&& __range, _Pred __pred, const _Type& __new_value, _Proj __proj = {}) const {
+    return ranges::__replace_if_impl(ranges::begin(__range), ranges::end(__range), __pred, __new_value, __proj);
+  }
+
+};
+} // namespace __replace_if
+
+inline namespace __cpo {
+  inline constexpr auto replace_if = __replace_if::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined (_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_REPLACE_IF_H
diff --git a/libcxx/include/__algorithm/ranges_reverse.h b/libcxx/include/__algorithm/ranges_reverse.h
new file mode 100644
index 000000000000..e7555d0f9acd
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_reverse.h
@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_REVERSE_H
+#define _LIBCPP___ALGORITHM_RANGES_REVERSE_H
+
+#include <__config>
+#include <__iterator/concepts.h>
+#include <__iterator/iter_swap.h>
+#include <__iterator/next.h>
+#include <__iterator/permutable.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __reverse {
+struct __fn {
+
+  template <bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent>
+    requires permutable<_Iter>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last) const {
+    if constexpr (random_access_iterator<_Iter>) {
+      if (__first == __last)
+        return __first;
+
+      auto __end = ranges::next(__first, __last);
+      auto __ret = __end;
+
+      while (__first < --__end) {
+        ranges::iter_swap(__first, __end);
+        ++__first;
+      }
+      return __ret;
+    } else {
+      auto __end = ranges::next(__first, __last);
+      auto __ret = __end;
+
+      while (__first != __end) {
+        if (__first == --__end)
+          break;
+
+        ranges::iter_swap(__first, __end);
+        ++__first;
+      }
+      return __ret;
+    }
+  }
+
+  template <bidirectional_range _Range>
+    requires permutable<iterator_t<_Range>>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range> operator()(_Range&& __range) const {
+    return (*this)(ranges::begin(__range), ranges::end(__range));
+  }
+
+};
+} // namespace __reverse
+
+inline namespace __cpo {
+  inline constexpr auto reverse = __reverse::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_REVERSE_H
diff --git a/libcxx/include/__algorithm/ranges_sort.h b/libcxx/include/__algorithm/ranges_sort.h
new file mode 100644
index 000000000000..8297940df237
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_sort.h
@@ -0,0 +1,78 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_SORT_H
+#define _LIBCPP___ALGORITHM_RANGES_SORT_H
+
+#include <__algorithm/make_projected.h>
+#include <__algorithm/sort.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/next.h>
+#include <__iterator/projected.h>
+#include <__iterator/sortable.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/forward.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __sort {
+
+struct __fn {
+  template <class _Iter, class _Sent, class _Comp, class _Proj>
+  _LIBCPP_HIDE_FROM_ABI constexpr static
+  _Iter __sort_fn_impl(_Iter __first, _Sent __last, _Comp& __comp, _Proj& __proj) {
+    auto __last_iter = ranges::next(__first, __last);
+
+    auto&& __projected_comp = ranges::__make_projected_comp(__comp, __proj);
+    std::__sort_impl(std::move(__first), __last_iter, __projected_comp);
+
+    return __last_iter;
+  }
+
+  template <random_access_iterator _Iter, sentinel_for<_Iter> _Sent, class _Comp = ranges::less, class _Proj = identity>
+    requires sortable<_Iter, _Comp, _Proj>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {
+    return __sort_fn_impl(std::move(__first), std::move(__last), __comp, __proj);
+  }
+
+  template <random_access_range _Range, class _Comp = ranges::less, class _Proj = identity>
+    requires sortable<iterator_t<_Range>, _Comp, _Proj>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range> operator()(_Range&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
+    return __sort_fn_impl(ranges::begin(__r), ranges::end(__r), __comp, __proj);
+  }
+};
+
+} // namespace __sort
+
+inline namespace __cpo {
+  inline constexpr auto sort = __sort::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_SORT_H
diff --git a/libcxx/include/__algorithm/ranges_stable_sort.h b/libcxx/include/__algorithm/ranges_stable_sort.h
new file mode 100644
index 000000000000..20e840426434
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_stable_sort.h
@@ -0,0 +1,78 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_STABLE_SORT_H
+#define _LIBCPP___ALGORITHM_RANGES_STABLE_SORT_H
+
+#include <__algorithm/make_projected.h>
+#include <__algorithm/stable_sort.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/next.h>
+#include <__iterator/projected.h>
+#include <__iterator/sortable.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/forward.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __stable_sort {
+
+struct __fn {
+  template <class _Iter, class _Sent, class _Comp, class _Proj>
+  _LIBCPP_HIDE_FROM_ABI
+  static _Iter __stable_sort_fn_impl(_Iter __first, _Sent __last, _Comp& __comp, _Proj& __proj) {
+    auto __last_iter = ranges::next(__first, __last);
+
+    auto&& __projected_comp = ranges::__make_projected_comp(__comp, __proj);
+    std::__stable_sort_impl(std::move(__first), __last_iter, __projected_comp);
+
+    return __last_iter;
+  }
+
+  template <random_access_iterator _Iter, sentinel_for<_Iter> _Sent, class _Comp = ranges::less, class _Proj = identity>
+    requires sortable<_Iter, _Comp, _Proj>
+  _LIBCPP_HIDE_FROM_ABI
+  _Iter operator()(_Iter __first, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {
+    return __stable_sort_fn_impl(std::move(__first), std::move(__last), __comp, __proj);
+  }
+
+  template <random_access_range _Range, class _Comp = ranges::less, class _Proj = identity>
+    requires sortable<iterator_t<_Range>, _Comp, _Proj>
+  _LIBCPP_HIDE_FROM_ABI
+  borrowed_iterator_t<_Range> operator()(_Range&& __r, _Comp __comp = {}, _Proj __proj = {}) const {
+    return __stable_sort_fn_impl(ranges::begin(__r), ranges::end(__r), __comp, __proj);
+  }
+};
+
+} // namespace __stable_sort
+
+inline namespace __cpo {
+  inline constexpr auto stable_sort = __stable_sort::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_STABLE_SORT_H
diff --git a/libcxx/include/__algorithm/ranges_swap_ranges.h b/libcxx/include/__algorithm/ranges_swap_ranges.h
new file mode 100644
index 000000000000..3254e1c60abb
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_swap_ranges.h
@@ -0,0 +1,69 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_SWAP_RANGES_H
+#define _LIBCPP___ALGORITHM_RANGES_SWAP_RANGES_H
+
+#include <__algorithm/in_in_result.h>
+#include <__config>
+#include <__iterator/concepts.h>
+#include <__iterator/iter_swap.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _I1, class _I2>
+using swap_ranges_result = in_in_result<_I1, _I2>;
+
+namespace __swap_ranges {
+struct __fn {
+  template <input_iterator _I1, sentinel_for<_I1> _S1,
+            input_iterator _I2, sentinel_for<_I2> _S2>
+    requires indirectly_swappable<_I1, _I2>
+  _LIBCPP_HIDE_FROM_ABI constexpr swap_ranges_result<_I1, _I2>
+  operator()(_I1 __first1, _S1 __last1, _I2 __first2, _S2 __last2) const {
+    while (__first1 != __last1 && __first2 != __last2) {
+      ranges::iter_swap(__first1, __first2);
+      ++__first1;
+      ++__first2;
+    }
+    return {_VSTD::move(__first1), _VSTD::move(__first2)};
+  }
+
+  template <input_range _R1, input_range _R2>
+    requires indirectly_swappable<iterator_t<_R1>, iterator_t<_R2>>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  swap_ranges_result<borrowed_iterator_t<_R1>, borrowed_iterator_t<_R2>>
+  operator()(_R1&& __r1, _R2&& __r2) const {
+    return operator()(ranges::begin(__r1), ranges::end(__r1),
+                      ranges::begin(__r2), ranges::end(__r2));
+  }
+};
+} // namespace __swap_ranges
+
+inline namespace __cpo {
+  inline constexpr auto swap_ranges = __swap_ranges::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_SWAP_RANGES_H
diff --git a/libcxx/include/__algorithm/ranges_transform.h b/libcxx/include/__algorithm/ranges_transform.h
new file mode 100644
index 000000000000..3c13b1b79ff3
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_transform.h
@@ -0,0 +1,170 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_TRANSFORM_H
+#define _LIBCPP___ALGORITHM_RANGES_TRANSFORM_H
+
+#include <__algorithm/in_in_out_result.h>
+#include <__algorithm/in_out_result.h>
+#include <__concepts/constructible.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _Ip, class _Op>
+using unary_transform_result = in_out_result<_Ip, _Op>;
+
+template <class _I1, class _I2, class _O1>
+using binary_transform_result = in_in_out_result<_I1, _I2, _O1>;
+
+namespace __transform {
+struct __fn {
+private:
+  template <class _InIter, class _Sent,
+            class _OutIter,
+            class _Func,
+            class _Proj>
+  _LIBCPP_HIDE_FROM_ABI static constexpr
+  unary_transform_result<_InIter, _OutIter> __unary(_InIter __first, _Sent __last,
+                                                    _OutIter __result,
+                                                    _Func& __operation,
+                                                    _Proj& __projection) {
+    while (__first != __last) {
+      *__result = std::invoke(__operation, std::invoke(__projection, *__first));
+      ++__first;
+      ++__result;
+    }
+
+    return {std::move(__first), std::move(__result)};
+  }
+
+  template <class _InIter1, class _Sent1,
+            class _InIter2, class _Sent2,
+            class _OutIter,
+            class _Func,
+            class _Proj1,
+            class _Proj2>
+  _LIBCPP_HIDE_FROM_ABI static constexpr binary_transform_result<_InIter1, _InIter2, _OutIter>
+  __binary(_InIter1 __first1, _Sent1 __last1,
+           _InIter2 __first2, _Sent2 __last2,
+           _OutIter __result,
+           _Func& __binary_operation,
+           _Proj1& __projection1,
+           _Proj2& __projection2) {
+    while (__first1 != __last1 && __first2 != __last2) {
+      *__result = std::invoke(__binary_operation, std::invoke(__projection1, *__first1),
+                                                  std::invoke(__projection2, *__first2));
+      ++__first1;
+      ++__first2;
+      ++__result;
+    }
+    return {std::move(__first1), std::move(__first2), std::move(__result)};
+  }
+public:
+  template <input_iterator _InIter, sentinel_for<_InIter> _Sent,
+            weakly_incrementable _OutIter,
+            copy_constructible _Func,
+            class _Proj = identity>
+    requires indirectly_writable<_OutIter, indirect_result_t<_Func&, projected<_InIter, _Proj>>>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  unary_transform_result<_InIter, _OutIter> operator()(_InIter __first, _Sent __last,
+                                                       _OutIter __result,
+                                                       _Func __operation,
+                                                       _Proj __proj = {}) const {
+    return __unary(std::move(__first), std::move(__last), std::move(__result), __operation, __proj);
+  }
+
+  template <input_range _Range,
+            weakly_incrementable _OutIter,
+            copy_constructible _Func,
+            class _Proj = identity>
+    requires indirectly_writable<_OutIter, indirect_result_t<_Func, projected<iterator_t<_Range>, _Proj>>>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  unary_transform_result<borrowed_iterator_t<_Range>, _OutIter> operator()(_Range&& __range,
+                                                                           _OutIter __result,
+                                                                           _Func __operation,
+                                                                           _Proj __projection = {}) const {
+    return __unary(ranges::begin(__range), ranges::end(__range), std::move(__result), __operation, __projection);
+  }
+
+  template <input_iterator _InIter1, sentinel_for<_InIter1> _Sent1,
+            input_iterator _InIter2, sentinel_for<_InIter2> _Sent2,
+            weakly_incrementable _OutIter,
+            copy_constructible _Func,
+            class _Proj1 = identity,
+            class _Proj2 = identity>
+    requires indirectly_writable<_OutIter, indirect_result_t<_Func&, projected<_InIter1, _Proj1>,
+                                                                     projected<_InIter2, _Proj2>>>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  binary_transform_result<_InIter1, _InIter2, _OutIter> operator()(_InIter1 __first1, _Sent1 __last1,
+                                                                   _InIter2 __first2, _Sent2 __last2,
+                                                                   _OutIter __result,
+                                                                   _Func __binary_operation,
+                                                                   _Proj1 __projection1 = {},
+                                                                   _Proj2 __projection2 = {}) const {
+    return __binary(std::move(__first1), std::move(__last1),
+                    std::move(__first2), std::move(__last2),
+                    std::move(__result),
+                    __binary_operation,
+                    __projection1,
+                    __projection2);
+  }
+
+  template <input_range _Range1,
+            input_range _Range2,
+            weakly_incrementable _OutIter,
+            copy_constructible _Func,
+            class _Proj1 = identity,
+            class _Proj2 = identity>
+    requires indirectly_writable<_OutIter, indirect_result_t<_Func&, projected<iterator_t<_Range1>, _Proj1>,
+                                                                     projected<iterator_t<_Range2>, _Proj2>>>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  binary_transform_result<borrowed_iterator_t<_Range1>, borrowed_iterator_t<_Range2>, _OutIter>
+  operator()(_Range1&& __range1,
+             _Range2&& __range2,
+             _OutIter __result,
+             _Func __binary_operation,
+             _Proj1 __projection1 = {},
+             _Proj2 __projection2 = {}) const {
+    return __binary(ranges::begin(__range1), ranges::end(__range1),
+                    ranges::begin(__range2), ranges::end(__range2),
+                    std::move(__result),
+                    __binary_operation,
+                    __projection1,
+                    __projection2);
+  }
+
+};
+} // namespace __transform
+
+inline namespace __cpo {
+  inline constexpr auto transform = __transform::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_TRANSFORM_H
diff --git a/libcxx/include/__algorithm/ranges_upper_bound.h b/libcxx/include/__algorithm/ranges_upper_bound.h
new file mode 100644
index 000000000000..94b5269c86af
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_upper_bound.h
@@ -0,0 +1,75 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_UPPER_BOUND_H
+#define _LIBCPP___ALGORITHM_RANGES_UPPER_BOUND_H
+
+#include <__algorithm/iterator_operations.h>
+#include <__algorithm/lower_bound.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __upper_bound {
+struct __fn {
+  template <forward_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<_Iter, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  _Iter operator()(_Iter __first, _Sent __last, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
+    auto __comp_lhs_rhs_swapped = [&](const auto& __lhs, const auto& __rhs) {
+      return !std::invoke(__comp, __rhs, __lhs);
+    };
+
+    return std::__lower_bound_impl<_RangesIterOps>(__first, __last, __value, __comp_lhs_rhs_swapped, __proj);
+  }
+
+  template <forward_range _Range, class _Type, class _Proj = identity,
+            indirect_strict_weak_order<const _Type*, projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
+  _LIBCPP_HIDE_FROM_ABI constexpr
+  borrowed_iterator_t<_Range> operator()(_Range&& __r,
+                                         const _Type& __value,
+                                         _Comp __comp = {},
+                                         _Proj __proj = {}) const {
+    auto __comp_lhs_rhs_swapped = [&](const auto& __lhs, const auto& __rhs) {
+      return !std::invoke(__comp, __rhs, __lhs);
+    };
+
+    return std::__lower_bound_impl<_RangesIterOps>(ranges::begin(__r),
+                                                   ranges::end(__r),
+                                                   __value,
+                                                   __comp_lhs_rhs_swapped,
+                                                   __proj);
+  }
+};
+} // namespace __upper_bound
+
+inline namespace __cpo {
+  inline constexpr auto upper_bound = __upper_bound::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_UPPER_BOUND_H
diff --git a/libcxx/include/__algorithm/remove.h b/libcxx/include/__algorithm/remove.h
index 681b9cc768d9..c00f96f78a63 100644
--- a/libcxx/include/__algorithm/remove.h
+++ b/libcxx/include/__algorithm/remove.h
@@ -15,7 +15,7 @@
 #include <__utility/move.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/remove_copy.h b/libcxx/include/__algorithm/remove_copy.h
index 338ca94300bb..a29a385af9ac 100644
--- a/libcxx/include/__algorithm/remove_copy.h
+++ b/libcxx/include/__algorithm/remove_copy.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/remove_copy_if.h b/libcxx/include/__algorithm/remove_copy_if.h
index a55638722074..36ddba4883ab 100644
--- a/libcxx/include/__algorithm/remove_copy_if.h
+++ b/libcxx/include/__algorithm/remove_copy_if.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/remove_if.h b/libcxx/include/__algorithm/remove_if.h
index 36f817cfa6e1..0ae131498d22 100644
--- a/libcxx/include/__algorithm/remove_if.h
+++ b/libcxx/include/__algorithm/remove_if.h
@@ -11,10 +11,10 @@
 
 #include <__algorithm/find_if.h>
 #include <__config>
-#include <utility>
+#include <__utility/move.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/replace.h b/libcxx/include/__algorithm/replace.h
index 2bc96ffc87dc..d0ae8f65d4a2 100644
--- a/libcxx/include/__algorithm/replace.h
+++ b/libcxx/include/__algorithm/replace.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/replace_copy.h b/libcxx/include/__algorithm/replace_copy.h
index c6c5fe32e81c..7c8a5a0b93cb 100644
--- a/libcxx/include/__algorithm/replace_copy.h
+++ b/libcxx/include/__algorithm/replace_copy.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/replace_copy_if.h b/libcxx/include/__algorithm/replace_copy_if.h
index 274d8e630ef1..9d8a68fdc0f3 100644
--- a/libcxx/include/__algorithm/replace_copy_if.h
+++ b/libcxx/include/__algorithm/replace_copy_if.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/replace_if.h b/libcxx/include/__algorithm/replace_if.h
index bcc3feb2f507..37c719a34c84 100644
--- a/libcxx/include/__algorithm/replace_if.h
+++ b/libcxx/include/__algorithm/replace_if.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/reverse.h b/libcxx/include/__algorithm/reverse.h
index 1198aeaf41f4..0202cd740833 100644
--- a/libcxx/include/__algorithm/reverse.h
+++ b/libcxx/include/__algorithm/reverse.h
@@ -14,7 +14,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/reverse_copy.h b/libcxx/include/__algorithm/reverse_copy.h
index 002c0344a794..158390707803 100644
--- a/libcxx/include/__algorithm/reverse_copy.h
+++ b/libcxx/include/__algorithm/reverse_copy.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/rotate.h b/libcxx/include/__algorithm/rotate.h
index fd6d3e9c114f..c9ea5bad4c5a 100644
--- a/libcxx/include/__algorithm/rotate.h
+++ b/libcxx/include/__algorithm/rotate.h
@@ -16,11 +16,12 @@
 #include <__iterator/iterator_traits.h>
 #include <__iterator/next.h>
 #include <__iterator/prev.h>
+#include <__utility/move.h>
 #include <__utility/swap.h>
-#include <iterator>
+#include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/rotate_copy.h b/libcxx/include/__algorithm/rotate_copy.h
index f9e644c88d0e..ab569ef7c6be 100644
--- a/libcxx/include/__algorithm/rotate_copy.h
+++ b/libcxx/include/__algorithm/rotate_copy.h
@@ -13,7 +13,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/sample.h b/libcxx/include/__algorithm/sample.h
index 33264c4ea3a7..e04466a08d5a 100644
--- a/libcxx/include/__algorithm/sample.h
+++ b/libcxx/include/__algorithm/sample.h
@@ -10,13 +10,15 @@
 #define _LIBCPP___ALGORITHM_SAMPLE_H
 
 #include <__algorithm/min.h>
+#include <__assert>
 #include <__config>
-#include <__debug>
+#include <__iterator/distance.h>
+#include <__iterator/iterator_traits.h>
 #include <__random/uniform_int_distribution.h>
-#include <iterator>
+#include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
diff --git a/libcxx/include/__algorithm/search.h b/libcxx/include/__algorithm/search.h
index cfaec0ed1e17..d89ec2b1c5bc 100644
--- a/libcxx/include/__algorithm/search.h
+++ b/libcxx/include/__algorithm/search.h
@@ -13,10 +13,10 @@
 #include <__algorithm/comp.h>
 #include <__config>
 #include <__iterator/iterator_traits.h>
-#include <utility>
+#include <__utility/pair.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/search_n.h b/libcxx/include/__algorithm/search_n.h
index e4576cc76ac4..4c083de65ee2 100644
--- a/libcxx/include/__algorithm/search_n.h
+++ b/libcxx/include/__algorithm/search_n.h
@@ -16,7 +16,7 @@
 #include <type_traits>  // __convert_to_integral
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/set_difference.h b/libcxx/include/__algorithm/set_difference.h
index 00f61e070b4b..5e2dca24e446 100644
--- a/libcxx/include/__algorithm/set_difference.h
+++ b/libcxx/include/__algorithm/set_difference.h
@@ -16,7 +16,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/set_intersection.h b/libcxx/include/__algorithm/set_intersection.h
index f6aa38217d95..c4163fcd4c3c 100644
--- a/libcxx/include/__algorithm/set_intersection.h
+++ b/libcxx/include/__algorithm/set_intersection.h
@@ -15,7 +15,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/set_symmetric_difference.h b/libcxx/include/__algorithm/set_symmetric_difference.h
index 5b5c2acff773..2dbfb35d7be6 100644
--- a/libcxx/include/__algorithm/set_symmetric_difference.h
+++ b/libcxx/include/__algorithm/set_symmetric_difference.h
@@ -16,7 +16,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/set_union.h b/libcxx/include/__algorithm/set_union.h
index 5b3e3af79b4f..0ec6b09380ed 100644
--- a/libcxx/include/__algorithm/set_union.h
+++ b/libcxx/include/__algorithm/set_union.h
@@ -16,7 +16,7 @@
 #include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/shift_left.h b/libcxx/include/__algorithm/shift_left.h
index 0466a3188a75..33f06d57e23a 100644
--- a/libcxx/include/__algorithm/shift_left.h
+++ b/libcxx/include/__algorithm/shift_left.h
@@ -15,7 +15,7 @@
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/shift_right.h b/libcxx/include/__algorithm/shift_right.h
index 121712e85532..14bc761598b2 100644
--- a/libcxx/include/__algorithm/shift_right.h
+++ b/libcxx/include/__algorithm/shift_right.h
@@ -18,7 +18,7 @@
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/shuffle.h b/libcxx/include/__algorithm/shuffle.h
index 7f6ad50e241e..6c6ff5675dad 100644
--- a/libcxx/include/__algorithm/shuffle.h
+++ b/libcxx/include/__algorithm/shuffle.h
@@ -10,6 +10,7 @@
 #define _LIBCPP___ALGORITHM_SHUFFLE_H
 
 #include <__config>
+#include <__debug>
 #include <__iterator/iterator_traits.h>
 #include <__random/uniform_int_distribution.h>
 #include <__utility/swap.h>
@@ -17,7 +18,7 @@
 #include <cstdint>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
diff --git a/libcxx/include/__algorithm/sift_down.h b/libcxx/include/__algorithm/sift_down.h
index bf5447698cd6..0351a1c578b0 100644
--- a/libcxx/include/__algorithm/sift_down.h
+++ b/libcxx/include/__algorithm/sift_down.h
@@ -9,12 +9,13 @@
 #ifndef _LIBCPP___ALGORITHM_SIFT_DOWN_H
 #define _LIBCPP___ALGORITHM_SIFT_DOWN_H
 
+#include <__assert>
 #include <__config>
 #include <__iterator/iterator_traits.h>
 #include <__utility/move.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
@@ -73,6 +74,38 @@ __sift_down(_RandomAccessIterator __first, _Compare __comp,
     *__start = _VSTD::move(__top);
 }
 
+template <class _Compare, class _RandomAccessIterator>
+_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator
+__floyd_sift_down(_RandomAccessIterator __first, _Compare __comp,
+                  typename iterator_traits<_RandomAccessIterator>::difference_type __len)
+{
+    using difference_type = typename iterator_traits<_RandomAccessIterator>::difference_type;
+    _LIBCPP_ASSERT(__len >= 2, "shouldn't be called unless __len >= 2");
+
+    _RandomAccessIterator __hole = __first;
+    _RandomAccessIterator __child_i = __first;
+    difference_type __child = 0;
+
+    while (true) {
+        __child_i += difference_type(__child + 1);
+        __child = 2 * __child + 1;
+
+        if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + difference_type(1)))) {
+            // right-child exists and is greater than left-child
+            ++__child_i;
+            ++__child;
+        }
+
+        // swap __hole with its largest child
+        *__hole = std::move(*__child_i);
+        __hole = __child_i;
+
+        // if __hole is now a leaf, we're done
+        if (__child > (__len - 2) / 2)
+            return __hole;
+    }
+}
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___ALGORITHM_SIFT_DOWN_H
diff --git a/libcxx/include/__algorithm/sort.h b/libcxx/include/__algorithm/sort.h
index 5e09b280080a..f7406a5170e1 100644
--- a/libcxx/include/__algorithm/sort.h
+++ b/libcxx/include/__algorithm/sort.h
@@ -14,8 +14,14 @@
 #include <__algorithm/min_element.h>
 #include <__algorithm/partial_sort.h>
 #include <__algorithm/unwrap_iter.h>
+#include <__bits>
 #include <__config>
+#include <__debug>
+#include <__functional/operations.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/iterator_traits.h>
 #include <__utility/swap.h>
+#include <climits>
 #include <memory>
 
 #if defined(_LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY)
@@ -23,7 +29,7 @@
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
@@ -31,442 +37,489 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 // stable, 2-3 compares, 0-2 swaps
 
 template <class _Compare, class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 unsigned
-__sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z, _Compare __c)
-{
-    unsigned __r = 0;
-    if (!__c(*__y, *__x))          // if x <= y
+_LIBCPP_CONSTEXPR_AFTER_CXX11 unsigned __sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z,
+                                               _Compare __c) {
+  unsigned __r = 0;
+  if (!__c(*__y, *__x))   // if x <= y
+  {
+    if (!__c(*__z, *__y)) // if y <= z
+      return __r;         // x <= y && y <= z
+                          // x <= y && y > z
+    swap(*__y, *__z);     // x <= z && y < z
+    __r = 1;
+    if (__c(*__y, *__x))  // if x > y
     {
-        if (!__c(*__z, *__y))      // if y <= z
-            return __r;            // x <= y && y <= z
-                                   // x <= y && y > z
-        swap(*__y, *__z);          // x <= z && y < z
-        __r = 1;
-        if (__c(*__y, *__x))       // if x > y
-        {
-            swap(*__x, *__y);      // x < y && y <= z
-            __r = 2;
-        }
-        return __r;                // x <= y && y < z
-    }
-    if (__c(*__z, *__y))           // x > y, if y > z
-    {
-        swap(*__x, *__z);          // x < y && y < z
-        __r = 1;
-        return __r;
-    }
-    swap(*__x, *__y);              // x > y && y <= z
-    __r = 1;                       // x < y && x <= z
-    if (__c(*__z, *__y))           // if y > z
-    {
-        swap(*__y, *__z);          // x <= y && y < z
-        __r = 2;
+      swap(*__x, *__y);   // x < y && y <= z
+      __r = 2;
     }
+    return __r;           // x <= y && y < z
+  }
+  if (__c(*__z, *__y))    // x > y, if y > z
+  {
+    swap(*__x, *__z);     // x < y && y < z
+    __r = 1;
     return __r;
-}                                  // x <= y && y <= z
+  }
+  swap(*__x, *__y);       // x > y && y <= z
+  __r = 1;                // x < y && x <= z
+  if (__c(*__z, *__y))    // if y > z
+  {
+    swap(*__y, *__z);     // x <= y && y < z
+    __r = 2;
+  }
+  return __r;
+}                         // x <= y && y <= z
 
 // stable, 3-6 compares, 0-5 swaps
 
 template <class _Compare, class _ForwardIterator>
-unsigned
-__sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
-            _ForwardIterator __x4, _Compare __c)
-{
-    unsigned __r = _VSTD::__sort3<_Compare>(__x1, __x2, __x3, __c);
-    if (__c(*__x4, *__x3))
-    {
-        swap(*__x3, *__x4);
+unsigned __sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3, _ForwardIterator __x4,
+                 _Compare __c) {
+  unsigned __r = _VSTD::__sort3<_Compare>(__x1, __x2, __x3, __c);
+  if (__c(*__x4, *__x3)) {
+    swap(*__x3, *__x4);
+    ++__r;
+    if (__c(*__x3, *__x2)) {
+      swap(*__x2, *__x3);
+      ++__r;
+      if (__c(*__x2, *__x1)) {
+        swap(*__x1, *__x2);
         ++__r;
-        if (__c(*__x3, *__x2))
-        {
-            swap(*__x2, *__x3);
-            ++__r;
-            if (__c(*__x2, *__x1))
-            {
-                swap(*__x1, *__x2);
-                ++__r;
-            }
-        }
+      }
     }
-    return __r;
+  }
+  return __r;
 }
 
 // stable, 4-10 compares, 0-9 swaps
 
 template <class _Compare, class _ForwardIterator>
-_LIBCPP_HIDDEN
-unsigned
-__sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
-            _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c)
-{
-    unsigned __r = _VSTD::__sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
-    if (__c(*__x5, *__x4))
-    {
-        swap(*__x4, *__x5);
+_LIBCPP_HIDDEN unsigned __sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
+                                _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c) {
+  unsigned __r = _VSTD::__sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
+  if (__c(*__x5, *__x4)) {
+    swap(*__x4, *__x5);
+    ++__r;
+    if (__c(*__x4, *__x3)) {
+      swap(*__x3, *__x4);
+      ++__r;
+      if (__c(*__x3, *__x2)) {
+        swap(*__x2, *__x3);
         ++__r;
-        if (__c(*__x4, *__x3))
-        {
-            swap(*__x3, *__x4);
-            ++__r;
-            if (__c(*__x3, *__x2))
-            {
-                swap(*__x2, *__x3);
-                ++__r;
-                if (__c(*__x2, *__x1))
-                {
-                    swap(*__x1, *__x2);
-                    ++__r;
-                }
-            }
+        if (__c(*__x2, *__x1)) {
+          swap(*__x1, *__x2);
+          ++__r;
         }
+      }
     }
-    return __r;
+  }
+  return __r;
+}
+
+// The comparator being simple is a prerequisite for using the branchless optimization.
+template <class _Tp>
+struct __is_simple_comparator : false_type {};
+template <class _Tp>
+struct __is_simple_comparator<__less<_Tp>&> : true_type {};
+template <class _Tp>
+struct __is_simple_comparator<less<_Tp>&> : true_type {};
+template <class _Tp>
+struct __is_simple_comparator<greater<_Tp>&> : true_type {};
+#if _LIBCPP_STD_VER > 17
+template <>
+struct __is_simple_comparator<ranges::less&> : true_type {};
+template <>
+struct __is_simple_comparator<ranges::greater&> : true_type {};
+#endif
+
+template <class _Compare, class _Iter, class _Tp = typename iterator_traits<_Iter>::value_type>
+using __use_branchless_sort =
+    integral_constant<bool, __is_cpp17_contiguous_iterator<_Iter>::value && sizeof(_Tp) <= sizeof(void*) &&
+                                is_arithmetic<_Tp>::value && __is_simple_comparator<_Compare>::value>;
+
+// Ensures that __c(*__x, *__y) is true by swapping *__x and *__y if necessary.
+template <class _Compare, class _RandomAccessIterator>
+inline _LIBCPP_HIDE_FROM_ABI void __cond_swap(_RandomAccessIterator __x, _RandomAccessIterator __y, _Compare __c) {
+  using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
+  bool __r = __c(*__x, *__y);
+  value_type __tmp = __r ? *__x : *__y;
+  *__y = __r ? *__y : *__x;
+  *__x = __tmp;
+}
+
+// Ensures that *__x, *__y and *__z are ordered according to the comparator __c,
+// under the assumption that *__y and *__z are already ordered.
+template <class _Compare, class _RandomAccessIterator>
+inline _LIBCPP_HIDE_FROM_ABI void __partially_sorted_swap(_RandomAccessIterator __x, _RandomAccessIterator __y,
+                                                          _RandomAccessIterator __z, _Compare __c) {
+  using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
+  bool __r = __c(*__z, *__x);
+  value_type __tmp = __r ? *__z : *__x;
+  *__z = __r ? *__x : *__z;
+  __r = __c(__tmp, *__y);
+  *__x = __r ? *__x : *__y;
+  *__y = __r ? *__y : __tmp;
+}
+
+template <class _Compare, class _RandomAccessIterator>
+inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
+__sort3_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
+                         _Compare __c) {
+  _VSTD::__cond_swap<_Compare>(__x2, __x3, __c);
+  _VSTD::__partially_sorted_swap<_Compare>(__x1, __x2, __x3, __c);
+}
+
+template <class _Compare, class _RandomAccessIterator>
+inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<!__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
+__sort3_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
+                         _Compare __c) {
+  _VSTD::__sort3<_Compare>(__x1, __x2, __x3, __c);
+}
+
+template <class _Compare, class _RandomAccessIterator>
+inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
+__sort4_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
+                         _RandomAccessIterator __x4, _Compare __c) {
+  _VSTD::__cond_swap<_Compare>(__x1, __x3, __c);
+  _VSTD::__cond_swap<_Compare>(__x2, __x4, __c);
+  _VSTD::__cond_swap<_Compare>(__x1, __x2, __c);
+  _VSTD::__cond_swap<_Compare>(__x3, __x4, __c);
+  _VSTD::__cond_swap<_Compare>(__x2, __x3, __c);
+}
+
+template <class _Compare, class _RandomAccessIterator>
+inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<!__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
+__sort4_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
+                         _RandomAccessIterator __x4, _Compare __c) {
+  _VSTD::__sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
+}
+
+template <class _Compare, class _RandomAccessIterator>
+inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
+__sort5_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
+                         _RandomAccessIterator __x4, _RandomAccessIterator __x5, _Compare __c) {
+  _VSTD::__cond_swap<_Compare>(__x1, __x2, __c);
+  _VSTD::__cond_swap<_Compare>(__x4, __x5, __c);
+  _VSTD::__partially_sorted_swap<_Compare>(__x3, __x4, __x5, __c);
+  _VSTD::__cond_swap<_Compare>(__x2, __x5, __c);
+  _VSTD::__partially_sorted_swap<_Compare>(__x1, __x3, __x4, __c);
+  _VSTD::__partially_sorted_swap<_Compare>(__x2, __x3, __x4, __c);
+}
+
+template <class _Compare, class _RandomAccessIterator>
+inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<!__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
+__sort5_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
+                         _RandomAccessIterator __x4, _RandomAccessIterator __x5, _Compare __c) {
+  _VSTD::__sort5<_Compare>(__x1, __x2, __x3, __x4, __x5, __c);
 }
 
 // Assumes size > 0
 template <class _Compare, class _BidirectionalIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 void
-__selection_sort(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
-{
-    _BidirectionalIterator __lm1 = __last;
-    for (--__lm1; __first != __lm1; ++__first)
-    {
-        _BidirectionalIterator __i = _VSTD::min_element(__first, __last, __comp);
-        if (__i != __first)
-            swap(*__first, *__i);
-    }
+_LIBCPP_CONSTEXPR_AFTER_CXX11 void __selection_sort(_BidirectionalIterator __first, _BidirectionalIterator __last,
+                                                    _Compare __comp) {
+  _BidirectionalIterator __lm1 = __last;
+  for (--__lm1; __first != __lm1; ++__first) {
+    _BidirectionalIterator __i = _VSTD::min_element(__first, __last, __comp);
+    if (__i != __first)
+      swap(*__first, *__i);
+  }
 }
 
 template <class _Compare, class _BidirectionalIterator>
-void
-__insertion_sort(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-    if (__first != __last)
-    {
-        _BidirectionalIterator __i = __first;
-        for (++__i; __i != __last; ++__i)
-        {
-            _BidirectionalIterator __j = __i;
-            value_type __t(_VSTD::move(*__j));
-            for (_BidirectionalIterator __k = __i; __k != __first && __comp(__t,  *--__k); --__j)
-                *__j = _VSTD::move(*__k);
-            *__j = _VSTD::move(__t);
-        }
+void __insertion_sort(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp) {
+  typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
+  if (__first != __last) {
+    _BidirectionalIterator __i = __first;
+    for (++__i; __i != __last; ++__i) {
+      _BidirectionalIterator __j = __i;
+      value_type __t(_VSTD::move(*__j));
+      for (_BidirectionalIterator __k = __i; __k != __first && __comp(__t, *--__k); --__j)
+        *__j = _VSTD::move(*__k);
+      *__j = _VSTD::move(__t);
     }
+  }
 }
 
 template <class _Compare, class _RandomAccessIterator>
-void
-__insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    _RandomAccessIterator __j = __first+difference_type(2);
-    _VSTD::__sort3<_Compare>(__first, __first+difference_type(1), __j, __comp);
-    for (_RandomAccessIterator __i = __j+difference_type(1); __i != __last; ++__i)
-    {
-        if (__comp(*__i, *__j))
-        {
-            value_type __t(_VSTD::move(*__i));
-            _RandomAccessIterator __k = __j;
-            __j = __i;
-            do
-            {
-                *__j = _VSTD::move(*__k);
-                __j = __k;
-            } while (__j != __first && __comp(__t, *--__k));
-            *__j = _VSTD::move(__t);
-        }
-        __j = __i;
+void __insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
+  typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+  typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+  _RandomAccessIterator __j = __first + difference_type(2);
+  _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), __j, __comp);
+  for (_RandomAccessIterator __i = __j + difference_type(1); __i != __last; ++__i) {
+    if (__comp(*__i, *__j)) {
+      value_type __t(_VSTD::move(*__i));
+      _RandomAccessIterator __k = __j;
+      __j = __i;
+      do {
+        *__j = _VSTD::move(*__k);
+        __j = __k;
+      } while (__j != __first && __comp(__t, *--__k));
+      *__j = _VSTD::move(__t);
     }
+    __j = __i;
+  }
 }
 
 template <class _Compare, class _RandomAccessIterator>
-bool
-__insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    switch (__last - __first)
-    {
+bool __insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
+  typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+  switch (__last - __first) {
+  case 0:
+  case 1:
+    return true;
+  case 2:
+    if (__comp(*--__last, *__first))
+      swap(*__first, *__last);
+    return true;
+  case 3:
+    _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), --__last, __comp);
+    return true;
+  case 4:
+    _VSTD::__sort4_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
+                                              --__last, __comp);
+    return true;
+  case 5:
+    _VSTD::__sort5_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
+                                              __first + difference_type(3), --__last, __comp);
+    return true;
+  }
+  typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+  _RandomAccessIterator __j = __first + difference_type(2);
+  _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), __j, __comp);
+  const unsigned __limit = 8;
+  unsigned __count = 0;
+  for (_RandomAccessIterator __i = __j + difference_type(1); __i != __last; ++__i) {
+    if (__comp(*__i, *__j)) {
+      value_type __t(_VSTD::move(*__i));
+      _RandomAccessIterator __k = __j;
+      __j = __i;
+      do {
+        *__j = _VSTD::move(*__k);
+        __j = __k;
+      } while (__j != __first && __comp(__t, *--__k));
+      *__j = _VSTD::move(__t);
+      if (++__count == __limit)
+        return ++__i == __last;
+    }
+    __j = __i;
+  }
+  return true;
+}
+
+template <class _Compare, class _BidirectionalIterator>
+void __insertion_sort_move(_BidirectionalIterator __first1, _BidirectionalIterator __last1,
+                           typename iterator_traits<_BidirectionalIterator>::value_type* __first2, _Compare __comp) {
+  typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
+  if (__first1 != __last1) {
+    __destruct_n __d(0);
+    unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
+    value_type* __last2 = __first2;
+    ::new ((void*)__last2) value_type(_VSTD::move(*__first1));
+    __d.template __incr<value_type>();
+    for (++__last2; ++__first1 != __last1; ++__last2) {
+      value_type* __j2 = __last2;
+      value_type* __i2 = __j2;
+      if (__comp(*__first1, *--__i2)) {
+        ::new ((void*)__j2) value_type(_VSTD::move(*__i2));
+        __d.template __incr<value_type>();
+        for (--__j2; __i2 != __first2 && __comp(*__first1, *--__i2); --__j2)
+          *__j2 = _VSTD::move(*__i2);
+        *__j2 = _VSTD::move(*__first1);
+      } else {
+        ::new ((void*)__j2) value_type(_VSTD::move(*__first1));
+        __d.template __incr<value_type>();
+      }
+    }
+    __h.release();
+  }
+}
+
+template <class _Compare, class _RandomAccessIterator>
+void __introsort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
+                 typename iterator_traits<_RandomAccessIterator>::difference_type __depth) {
+  typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+  typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+  const difference_type __limit =
+      is_trivially_copy_constructible<value_type>::value && is_trivially_copy_assignable<value_type>::value ? 30 : 6;
+  while (true) {
+  __restart:
+    difference_type __len = __last - __first;
+    switch (__len) {
     case 0:
     case 1:
-        return true;
+      return;
     case 2:
-        if (__comp(*--__last, *__first))
-            swap(*__first, *__last);
-        return true;
+      if (__comp(*--__last, *__first))
+        swap(*__first, *__last);
+      return;
     case 3:
-        _VSTD::__sort3<_Compare>(__first, __first+difference_type(1), --__last, __comp);
-        return true;
+      _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), --__last, __comp);
+      return;
     case 4:
-        _VSTD::__sort4<_Compare>(__first, __first+difference_type(1), __first+difference_type(2), --__last, __comp);
-        return true;
+      _VSTD::__sort4_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
+                                                --__last, __comp);
+      return;
     case 5:
-        _VSTD::__sort5<_Compare>(__first, __first+difference_type(1), __first+difference_type(2), __first+difference_type(3), --__last, __comp);
-        return true;
+      _VSTD::__sort5_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
+                                                __first + difference_type(3), --__last, __comp);
+      return;
     }
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    _RandomAccessIterator __j = __first+difference_type(2);
-    _VSTD::__sort3<_Compare>(__first, __first+difference_type(1), __j, __comp);
-    const unsigned __limit = 8;
-    unsigned __count = 0;
-    for (_RandomAccessIterator __i = __j+difference_type(1); __i != __last; ++__i)
-    {
-        if (__comp(*__i, *__j))
-        {
-            value_type __t(_VSTD::move(*__i));
-            _RandomAccessIterator __k = __j;
-            __j = __i;
-            do
-            {
-                *__j = _VSTD::move(*__k);
-                __j = __k;
-            } while (__j != __first && __comp(__t, *--__k));
-            *__j = _VSTD::move(__t);
-            if (++__count == __limit)
-                return ++__i == __last;
-        }
-        __j = __i;
+    if (__len <= __limit) {
+      _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
+      return;
     }
-    return true;
-}
-
-template <class _Compare, class _BidirectionalIterator>
-void
-__insertion_sort_move(_BidirectionalIterator __first1, _BidirectionalIterator __last1,
-                      typename iterator_traits<_BidirectionalIterator>::value_type* __first2, _Compare __comp)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-    if (__first1 != __last1)
+    // __len > 5
+    if (__depth == 0) {
+      // Fallback to heap sort as Introsort suggests.
+      _VSTD::__partial_sort<_Compare>(__first, __last, __last, __comp);
+      return;
+    }
+    --__depth;
+    _RandomAccessIterator __m = __first;
+    _RandomAccessIterator __lm1 = __last;
+    --__lm1;
+    unsigned __n_swaps;
     {
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
-        value_type* __last2 = __first2;
-        ::new ((void*)__last2) value_type(_VSTD::move(*__first1));
-        __d.template __incr<value_type>();
-        for (++__last2; ++__first1 != __last1; ++__last2)
-        {
-            value_type* __j2 = __last2;
-            value_type* __i2 = __j2;
-            if (__comp(*__first1, *--__i2))
-            {
-                ::new ((void*)__j2) value_type(_VSTD::move(*__i2));
-                __d.template __incr<value_type>();
-                for (--__j2; __i2 != __first2 && __comp(*__first1,  *--__i2); --__j2)
-                    *__j2 = _VSTD::move(*__i2);
-                *__j2 = _VSTD::move(*__first1);
-            }
-            else
-            {
-                ::new ((void*)__j2) value_type(_VSTD::move(*__first1));
-                __d.template __incr<value_type>();
-            }
-        }
-        __h.release();
+      difference_type __delta;
+      if (__len >= 1000) {
+        __delta = __len / 2;
+        __m += __delta;
+        __delta /= 2;
+        __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m + __delta, __lm1, __comp);
+      } else {
+        __delta = __len / 2;
+        __m += __delta;
+        __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
+      }
     }
-}
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__introsort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
-            typename iterator_traits<_RandomAccessIterator>::difference_type __depth)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    const difference_type __limit = is_trivially_copy_constructible<value_type>::value &&
-                                    is_trivially_copy_assignable<value_type>::value ? 30 : 6;
-    while (true)
+    // *__m is median
+    // partition [__first, __m) < *__m and *__m <= [__m, __last)
+    // (this inhibits tossing elements equivalent to __m around unnecessarily)
+    _RandomAccessIterator __i = __first;
+    _RandomAccessIterator __j = __lm1;
+    // j points beyond range to be tested, *__m is known to be <= *__lm1
+    // The search going up is known to be guarded but the search coming down isn't.
+    // Prime the downward search with a guard.
+    if (!__comp(*__i, *__m)) // if *__first == *__m
     {
-    __restart:
-        difference_type __len = __last - __first;
-        switch (__len)
-        {
-        case 0:
-        case 1:
-            return;
-        case 2:
-            if (__comp(*--__last, *__first))
-                swap(*__first, *__last);
-            return;
-        case 3:
-            _VSTD::__sort3<_Compare>(__first, __first+difference_type(1), --__last, __comp);
-            return;
-        case 4:
-            _VSTD::__sort4<_Compare>(__first, __first+difference_type(1), __first+difference_type(2), --__last, __comp);
-            return;
-        case 5:
-            _VSTD::__sort5<_Compare>(__first, __first+difference_type(1), __first+difference_type(2), __first+difference_type(3), --__last, __comp);
-            return;
-        }
-        if (__len <= __limit)
-        {
-            _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
-            return;
-        }
-        // __len > 5
-        if (__depth == 0)
-        {
-          // Fallback to heap sort as Introsort suggests.
-          _VSTD::__partial_sort<_Compare>(__first, __last, __last, __comp);
-          return;
-        }
-        --__depth;
-        _RandomAccessIterator __m = __first;
-        _RandomAccessIterator __lm1 = __last;
-        --__lm1;
-        unsigned __n_swaps;
-        {
-        difference_type __delta;
-        if (__len >= 1000)
-        {
-            __delta = __len/2;
-            __m += __delta;
-            __delta /= 2;
-            __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m+__delta, __lm1, __comp);
-        }
-        else
-        {
-            __delta = __len/2;
-            __m += __delta;
-            __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
-        }
-        }
-        // *__m is median
-        // partition [__first, __m) < *__m and *__m <= [__m, __last)
-        // (this inhibits tossing elements equivalent to __m around unnecessarily)
-        _RandomAccessIterator __i = __first;
-        _RandomAccessIterator __j = __lm1;
-        // j points beyond range to be tested, *__m is known to be <= *__lm1
-        // The search going up is known to be guarded but the search coming down isn't.
-        // Prime the downward search with a guard.
-        if (!__comp(*__i, *__m))  // if *__first == *__m
-        {
-            // *__first == *__m, *__first doesn't go in first part
-            // manually guard downward moving __j against __i
-            while (true)
-            {
-                if (__i == --__j)
-                {
-                    // *__first == *__m, *__m <= all other elements
-                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
-                    ++__i;  // __first + 1
-                    __j = __last;
-                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
-                    {
-                        while (true)
-                        {
-                            if (__i == __j)
-                                return;  // [__first, __last) all equivalent elements
-                            if (__comp(*__first, *__i))
-                            {
-                                swap(*__i, *__j);
-                                ++__n_swaps;
-                                ++__i;
-                                break;
-                            }
-                            ++__i;
-                        }
-                    }
-                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
-                    if (__i == __j)
-                        return;
-                    while (true)
-                    {
-                        while (!__comp(*__first, *__i))
-                            ++__i;
-                        while (__comp(*__first, *--__j))
-                            ;
-                        if (__i >= __j)
-                            break;
-                        swap(*__i, *__j);
-                        ++__n_swaps;
-                        ++__i;
-                    }
-                    // [__first, __i) == *__first and *__first < [__i, __last)
-                    // The first part is sorted, sort the second part
-                    // _VSTD::__sort<_Compare>(__i, __last, __comp);
-                    __first = __i;
-                    goto __restart;
-                }
-                if (__comp(*__j, *__m))
-                {
-                    swap(*__i, *__j);
-                    ++__n_swaps;
-                    break;  // found guard for downward moving __j, now use unguarded partition
-                }
-            }
-        }
-        // It is known that *__i < *__m
-        ++__i;
-        // j points beyond range to be tested, *__m is known to be <= *__lm1
-        // if not yet partitioned...
-        if (__i < __j)
-        {
-            // known that *(__i - 1) < *__m
-            // known that __i <= __m
-            while (true)
-            {
-                // __m still guards upward moving __i
-                while (__comp(*__i, *__m))
-                    ++__i;
-                // It is now known that a guard exists for downward moving __j
-                while (!__comp(*--__j, *__m))
-                    ;
-                if (__i > __j)
-                    break;
+      // *__first == *__m, *__first doesn't go in first part
+      // manually guard downward moving __j against __i
+      while (true) {
+        if (__i == --__j) {
+          // *__first == *__m, *__m <= all other elements
+          // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
+          ++__i; // __first + 1
+          __j = __last;
+          if (!__comp(*__first, *--__j)) // we need a guard if *__first == *(__last-1)
+          {
+            while (true) {
+              if (__i == __j)
+                return; // [__first, __last) all equivalent elements
+              if (__comp(*__first, *__i)) {
                 swap(*__i, *__j);
                 ++__n_swaps;
-                // It is known that __m != __j
-                // If __m just moved, follow it
-                if (__m == __i)
-                    __m = __j;
                 ++__i;
+                break;
+              }
+              ++__i;
             }
-        }
-        // [__first, __i) < *__m and *__m <= [__i, __last)
-        if (__i != __m && __comp(*__m, *__i))
-        {
-            swap(*__i, *__m);
+          }
+          // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
+          if (__i == __j)
+            return;
+          while (true) {
+            while (!__comp(*__first, *__i))
+              ++__i;
+            while (__comp(*__first, *--__j))
+              ;
+            if (__i >= __j)
+              break;
+            swap(*__i, *__j);
             ++__n_swaps;
+            ++__i;
+          }
+          // [__first, __i) == *__first and *__first < [__i, __last)
+          // The first part is sorted, sort the second part
+          // _VSTD::__sort<_Compare>(__i, __last, __comp);
+          __first = __i;
+          goto __restart;
         }
-        // [__first, __i) < *__i and *__i <= [__i+1, __last)
-        // If we were given a perfect partition, see if insertion sort is quick...
-        if (__n_swaps == 0)
-        {
-            bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
-            if (_VSTD::__insertion_sort_incomplete<_Compare>(__i+difference_type(1), __last, __comp))
-            {
-                if (__fs)
-                    return;
-                __last = __i;
-                continue;
-            }
-            else
-            {
-                if (__fs)
-                {
-                    __first = ++__i;
-                    continue;
-                }
-            }
+        if (__comp(*__j, *__m)) {
+          swap(*__i, *__j);
+          ++__n_swaps;
+          break; // found guard for downward moving __j, now use unguarded partition
         }
-        // sort smaller range with recursive call and larger with tail recursion elimination
-        if (__i - __first < __last - __i)
-        {
-          _VSTD::__introsort<_Compare>(__first, __i, __comp, __depth);
+      }
+    }
+    // It is known that *__i < *__m
+    ++__i;
+    // j points beyond range to be tested, *__m is known to be <= *__lm1
+    // if not yet partitioned...
+    if (__i < __j) {
+      // known that *(__i - 1) < *__m
+      // known that __i <= __m
+      while (true) {
+        // __m still guards upward moving __i
+        while (__comp(*__i, *__m))
+          ++__i;
+        // It is now known that a guard exists for downward moving __j
+        while (!__comp(*--__j, *__m))
+          ;
+        if (__i > __j)
+          break;
+        swap(*__i, *__j);
+        ++__n_swaps;
+        // It is known that __m != __j
+        // If __m just moved, follow it
+        if (__m == __i)
+          __m = __j;
+        ++__i;
+      }
+    }
+    // [__first, __i) < *__m and *__m <= [__i, __last)
+    if (__i != __m && __comp(*__m, *__i)) {
+      swap(*__i, *__m);
+      ++__n_swaps;
+    }
+    // [__first, __i) < *__i and *__i <= [__i+1, __last)
+    // If we were given a perfect partition, see if insertion sort is quick...
+    if (__n_swaps == 0) {
+      bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
+      if (_VSTD::__insertion_sort_incomplete<_Compare>(__i + difference_type(1), __last, __comp)) {
+        if (__fs)
+          return;
+        __last = __i;
+        continue;
+      } else {
+        if (__fs) {
           __first = ++__i;
+          continue;
         }
-        else
-        {
-          _VSTD::__introsort<_Compare>(__i + difference_type(1), __last, __comp, __depth);
-          __last = __i;
-        }
+      }
+    }
+    // sort smaller range with recursive call and larger with tail recursion elimination
+    if (__i - __first < __last - __i) {
+      _VSTD::__introsort<_Compare>(__first, __i, __comp, __depth);
+      __first = ++__i;
+    } else {
+      _VSTD::__introsort<_Compare>(__i + difference_type(1), __last, __comp, __depth);
+      __last = __i;
     }
+  }
 }
 
 template <typename _Number>
 inline _LIBCPP_HIDE_FROM_ABI _Number __log2i(_Number __n) {
+  if (__n == 0)
+    return 0;
+  if (sizeof(__n) <= sizeof(unsigned))
+    return sizeof(unsigned) * CHAR_BIT - 1 - __libcpp_clz(static_cast<unsigned>(__n));
+  if (sizeof(__n) <= sizeof(unsigned long))
+    return sizeof(unsigned long) * CHAR_BIT - 1 - __libcpp_clz(static_cast<unsigned long>(__n));
+  if (sizeof(__n) <= sizeof(unsigned long long))
+    return sizeof(unsigned long long) * CHAR_BIT - 1 - __libcpp_clz(static_cast<unsigned long long>(__n));
+
   _Number __log2 = 0;
   while (__n > 1) {
     __log2++;
@@ -483,72 +536,71 @@ void __sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compar
 }
 
 template <class _Compare, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__sort(_Tp** __first, _Tp** __last, __less<_Tp*>&)
-{
-    __less<uintptr_t> __comp;
-    _VSTD::__sort<__less<uintptr_t>&, uintptr_t*>((uintptr_t*)__first, (uintptr_t*)__last, __comp);
+inline _LIBCPP_INLINE_VISIBILITY void __sort(_Tp** __first, _Tp** __last, __less<_Tp*>&) {
+  __less<uintptr_t> __comp;
+  _VSTD::__sort<__less<uintptr_t>&, uintptr_t*>((uintptr_t*)__first, (uintptr_t*)__last, __comp);
 }
 
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&))
+extern template _LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&);
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
+extern template _LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&);
 #endif
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
-
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&))
+extern template _LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&);
+extern template _LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&);
+
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&);
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&);
 #endif
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
-
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS unsigned __sort5<__less<long double>&, long double*>(long double*, long double*, long double*, long double*, long double*, __less<long double>&))
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&);
+extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&);
+
+extern template _LIBCPP_FUNC_VIS unsigned __sort5<__less<long double>&, long double*>(long double*, long double*, long double*, long double*, long double*, __less<long double>&);
+
+template <class _RandomAccessIterator, class _Comp>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+void __sort_impl(_RandomAccessIterator __first, _RandomAccessIterator __last, _Comp& __comp) {
   _LIBCPP_DEBUG_RANDOMIZE_RANGE(__first, __last);
-  typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
+  using _Comp_ref = typename __comp_ref_type<_Comp>::type;
   if (__libcpp_is_constant_evaluated()) {
-    _VSTD::__partial_sort<_Comp_ref>(__first, __last, __last, _Comp_ref(__comp));
+    std::__partial_sort<_Comp_ref>(__first, __last, __last, _Comp_ref(__comp));
   } else {
-    _VSTD::__sort<_Comp_ref>(_VSTD::__unwrap_iter(__first), _VSTD::__unwrap_iter(__last), _Comp_ref(__comp));
+    std::__sort<_Comp_ref>(std::__unwrap_iter(__first), std::__unwrap_iter(__last), _Comp_ref(__comp));
   }
 }
 
+template <class _RandomAccessIterator, class _Comp>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+void sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Comp __comp) {
+  std::__sort_impl(std::move(__first), std::move(__last), __comp);
+}
+
 template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17
+void sort(_RandomAccessIterator __first, _RandomAccessIterator __last) {
+  std::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
 }
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/sort_heap.h b/libcxx/include/__algorithm/sort_heap.h
index 64291ff2e8c9..3a63d744fc1c 100644
--- a/libcxx/include/__algorithm/sort_heap.h
+++ b/libcxx/include/__algorithm/sort_heap.h
@@ -17,7 +17,7 @@
 #include <type_traits> // swap
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/stable_partition.h b/libcxx/include/__algorithm/stable_partition.h
index 331f0fde77dc..969ac7a6173e 100644
--- a/libcxx/include/__algorithm/stable_partition.h
+++ b/libcxx/include/__algorithm/stable_partition.h
@@ -11,12 +11,14 @@
 
 #include <__algorithm/rotate.h>
 #include <__config>
+#include <__iterator/advance.h>
+#include <__iterator/distance.h>
 #include <__iterator/iterator_traits.h>
 #include <__utility/swap.h>
 #include <memory>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
@@ -130,7 +132,10 @@ __stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate
     unique_ptr<value_type, __return_temporary_buffer> __h;
     if (__len >= __alloc_limit)
     {
+// TODO: Remove the use of std::get_temporary_buffer
+_LIBCPP_SUPPRESS_DEPRECATED_PUSH
         __p = _VSTD::get_temporary_buffer<value_type>(__len);
+_LIBCPP_SUPPRESS_DEPRECATED_POP
         __h.reset(__p.first);
     }
     return _VSTD::__stable_partition<_Predicate&>(__first, __last, __pred, __len, __p, forward_iterator_tag());
@@ -276,7 +281,10 @@ __stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last
     unique_ptr<value_type, __return_temporary_buffer> __h;
     if (__len >= __alloc_limit)
     {
+// TODO: Remove the use of std::get_temporary_buffer
+_LIBCPP_SUPPRESS_DEPRECATED_PUSH
         __p = _VSTD::get_temporary_buffer<value_type>(__len);
+_LIBCPP_SUPPRESS_DEPRECATED_POP
         __h.reset(__p.first);
     }
     return _VSTD::__stable_partition<_Predicate&>(__first, __last, __pred, __len, __p, bidirectional_iterator_tag());
diff --git a/libcxx/include/__algorithm/stable_sort.h b/libcxx/include/__algorithm/stable_sort.h
index 4ae17e0e4d94..e3479aad62e6 100644
--- a/libcxx/include/__algorithm/stable_sort.h
+++ b/libcxx/include/__algorithm/stable_sort.h
@@ -15,12 +15,13 @@
 #include <__algorithm/sort.h>
 #include <__config>
 #include <__iterator/iterator_traits.h>
+#include <__utility/move.h>
 #include <__utility/swap.h>
 #include <memory>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
@@ -199,30 +200,36 @@ __stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Comp
 }
 
 template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    difference_type __len = __last - __first;
-    pair<value_type*, ptrdiff_t> __buf(0, 0);
-    unique_ptr<value_type, __return_temporary_buffer> __h;
-    if (__len > static_cast<difference_type>(__stable_sort_switch<value_type>::value))
-    {
-        __buf = _VSTD::get_temporary_buffer<value_type>(__len);
-        __h.reset(__buf.first);
-    }
-    typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
-    _VSTD::__stable_sort<_Comp_ref>(__first, __last, __comp, __len, __buf.first, __buf.second);
+inline _LIBCPP_HIDE_FROM_ABI
+void __stable_sort_impl(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare& __comp) {
+  using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
+  using difference_type = typename iterator_traits<_RandomAccessIterator>::difference_type;
+
+  difference_type __len = __last - __first;
+  pair<value_type*, ptrdiff_t> __buf(0, 0);
+  unique_ptr<value_type, __return_temporary_buffer> __h;
+  if (__len > static_cast<difference_type>(__stable_sort_switch<value_type>::value)) {
+// TODO: Remove the use of std::get_temporary_buffer
+_LIBCPP_SUPPRESS_DEPRECATED_PUSH
+      __buf = std::get_temporary_buffer<value_type>(__len);
+_LIBCPP_SUPPRESS_DEPRECATED_POP
+      __h.reset(__buf.first);
+  }
+
+  using _Comp_ref = typename __comp_ref_type<_Compare>::type;
+  std::__stable_sort<_Comp_ref>(__first, __last, __comp, __len, __buf.first, __buf.second);
+}
+
+template <class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_HIDE_FROM_ABI
+void stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
+  std::__stable_sort_impl(std::move(__first), std::move(__last), __comp);
 }
 
 template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::stable_sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+inline _LIBCPP_HIDE_FROM_ABI
+void stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last) {
+  std::stable_sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
 }
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/swap_ranges.h b/libcxx/include/__algorithm/swap_ranges.h
index 2b099c7361f1..0422265bb4be 100644
--- a/libcxx/include/__algorithm/swap_ranges.h
+++ b/libcxx/include/__algorithm/swap_ranges.h
@@ -11,10 +11,9 @@
 
 #include <__config>
 #include <__utility/swap.h>
-#include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/transform.h b/libcxx/include/__algorithm/transform.h
index 494cb7128d29..f9db806f5b94 100644
--- a/libcxx/include/__algorithm/transform.h
+++ b/libcxx/include/__algorithm/transform.h
@@ -12,7 +12,7 @@
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/unique.h b/libcxx/include/__algorithm/unique.h
index e17ff1567fa9..264d727d93c8 100644
--- a/libcxx/include/__algorithm/unique.h
+++ b/libcxx/include/__algorithm/unique.h
@@ -16,7 +16,7 @@
 #include <__utility/move.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/unique_copy.h b/libcxx/include/__algorithm/unique_copy.h
index 4833ae9b59f5..f58517749f51 100644
--- a/libcxx/include/__algorithm/unique_copy.h
+++ b/libcxx/include/__algorithm/unique_copy.h
@@ -12,10 +12,9 @@
 #include <__algorithm/comp.h>
 #include <__config>
 #include <__iterator/iterator_traits.h>
-#include <utility>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/unwrap_iter.h b/libcxx/include/__algorithm/unwrap_iter.h
index 35765330bb7f..7d1807b7bbf9 100644
--- a/libcxx/include/__algorithm/unwrap_iter.h
+++ b/libcxx/include/__algorithm/unwrap_iter.h
@@ -10,12 +10,12 @@
 #define _LIBCPP___ALGORITHM_UNWRAP_ITER_H
 
 #include <__config>
+#include <__iterator/iterator_traits.h>
 #include <__memory/pointer_traits.h>
-#include <iterator>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
@@ -43,7 +43,7 @@ struct __unwrap_iter_impl {
     }
 };
 
-#if _LIBCPP_DEBUG_LEVEL < 2
+#ifndef _LIBCPP_ENABLE_DEBUG_MODE
 
 template <class _Iter>
 struct __unwrap_iter_impl<_Iter, true> {
@@ -53,7 +53,7 @@ struct __unwrap_iter_impl<_Iter, true> {
     }
 };
 
-#endif // _LIBCPP_DEBUG_LEVEL < 2
+#endif // !_LIBCPP_ENABLE_DEBUG_MODE
 
 template<class _Iter, class _Impl = __unwrap_iter_impl<_Iter> >
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
@@ -63,20 +63,34 @@ __unwrap_iter(_Iter __i) _NOEXCEPT
     return _Impl::__apply(__i);
 }
 
+template <class _OrigIter, class _UnwrappedIter>
+struct __rewrap_iter_impl {
+  static _LIBCPP_CONSTEXPR _OrigIter __apply(_OrigIter __first, _UnwrappedIter __result) {
+    // Precondition: __result is reachable from __first
+    // Precondition: _OrigIter is a contiguous iterator
+    return __first + (__result - std::__unwrap_iter(__first));
+  }
+};
+
+template <class _OrigIter>
+struct __rewrap_iter_impl<_OrigIter, _OrigIter> {
+  static _LIBCPP_CONSTEXPR _OrigIter __apply(_OrigIter, _OrigIter __result) {
+    return __result;
+  }
+};
+
 template<class _OrigIter>
-_LIBCPP_HIDE_FROM_ABI
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
 _OrigIter __rewrap_iter(_OrigIter, _OrigIter __result)
 {
     return __result;
 }
 
-template<class _OrigIter, class _UnwrappedIter>
-_LIBCPP_HIDE_FROM_ABI
+template<class _OrigIter, class _UnwrappedIter, class _Impl = __rewrap_iter_impl<_OrigIter, _UnwrappedIter> >
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
 _OrigIter __rewrap_iter(_OrigIter __first, _UnwrappedIter __result)
 {
-    // Precondition: __result is reachable from __first
-    // Precondition: _OrigIter is a contiguous iterator
-    return __first + (__result - _VSTD::__unwrap_iter(__first));
+  return _Impl::__apply(__first, __result);
 }
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/upper_bound.h b/libcxx/include/__algorithm/upper_bound.h
index c064f1e35b9a..c6483607e3c6 100644
--- a/libcxx/include/__algorithm/upper_bound.h
+++ b/libcxx/include/__algorithm/upper_bound.h
@@ -12,10 +12,12 @@
 #include <__algorithm/comp.h>
 #include <__algorithm/half_positive.h>
 #include <__config>
-#include <iterator>
+#include <__iterator/advance.h>
+#include <__iterator/distance.h>
+#include <__iterator/iterator_traits.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
+#  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD