--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libcxx/include/__algorithm/iterator_operations.h	Wed Nov 09 17:45:10 2022 +0900
@@ -0,0 +1,172 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_ITERATOR_OPERATIONS_H
+#define _LIBCPP___ALGORITHM_ITERATOR_OPERATIONS_H
+
+#include <__algorithm/iter_swap.h>
+#include <__algorithm/ranges_iterator_concept.h>
+#include <__config>
+#include <__iterator/advance.h>
+#include <__iterator/distance.h>
+#include <__iterator/incrementable_traits.h>
+#include <__iterator/iter_move.h>
+#include <__iterator/iter_swap.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/next.h>
+#include <__iterator/prev.h>
+#include <__iterator/readable_traits.h>
+#include <__utility/declval.h>
+#include <__utility/forward.h>
+#include <__utility/move.h>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _AlgPolicy> struct _IterOps;
+
+#if _LIBCPP_STD_VER > 17
+struct _RangeAlgPolicy {};
+
+template <>
+struct _IterOps<_RangeAlgPolicy> {
+
+  template <class _Iter>
+  using __value_type = iter_value_t<_Iter>;
+
+  template <class _Iter>
+  using __iterator_category = ranges::__iterator_concept<_Iter>;
+
+  template <class _Iter>
+  using __difference_type = iter_difference_t<_Iter>;
+
+  static constexpr auto advance = ranges::advance;
+  static constexpr auto distance = ranges::distance;
+  static constexpr auto __iter_move = ranges::iter_move;
+  static constexpr auto iter_swap = ranges::iter_swap;
+  static constexpr auto next = ranges::next;
+  static constexpr auto prev = ranges::prev;
+  static constexpr auto __advance_to = ranges::advance;
+};
+
+#endif
+
+struct _ClassicAlgPolicy {};
+
+template <>
+struct _IterOps<_ClassicAlgPolicy> {
+
+  template <class _Iter>
+  using __value_type = typename iterator_traits<_Iter>::value_type;
+
+  template <class _Iter>
+  using __iterator_category = typename iterator_traits<_Iter>::iterator_category;
+
+  template <class _Iter>
+  using __difference_type = typename iterator_traits<_Iter>::difference_type;
+
+  // advance
+  template <class _Iter, class _Distance>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
+  static void advance(_Iter& __iter, _Distance __count) {
+    std::advance(__iter, __count);
+  }
+
+  // distance
+  template <class _Iter>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
+  static typename iterator_traits<_Iter>::difference_type distance(_Iter __first, _Iter __last) {
+    return std::distance(__first, __last);
+  }
+
+  template <class _Iter>
+  using __deref_t = decltype(*std::declval<_Iter&>());
+
+  template <class _Iter>
+  using __move_t = decltype(std::move(*std::declval<_Iter&>()));
+
+  template <class _Iter>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
+  static void __validate_iter_reference() {
+    static_assert(is_same<__deref_t<_Iter>, typename iterator_traits<__remove_cvref_t<_Iter> >::reference>::value,
+        "It looks like your iterator's `iterator_traits<It>::reference` does not match the return type of "
+        "dereferencing the iterator, i.e., calling `*it`. This is undefined behavior according to [input.iterators] "
+        "and can lead to dangling reference issues at runtime, so we are flagging this.");
+  }
+
+  // iter_move
+  template <class _Iter>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static
+  // If the result of dereferencing `_Iter` is a reference type, deduce the result of calling `std::move` on it. Note
+  // that the C++03 mode doesn't support `decltype(auto)` as the return type.
+  __enable_if_t<
+      is_reference<__deref_t<_Iter> >::value,
+      __move_t<_Iter> >
+  __iter_move(_Iter&& __i) {
+    __validate_iter_reference<_Iter>();
+
+    return std::move(*std::forward<_Iter>(__i));
+  }
+
+  template <class _Iter>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static
+  // If the result of dereferencing `_Iter` is a value type, deduce the return value of this function to also be a
+  // value -- otherwise, after `operator*` returns a temporary, this function would return a dangling reference to that
+  // temporary. Note that the C++03 mode doesn't support `auto` as the return type.
+  __enable_if_t<
+      !is_reference<__deref_t<_Iter> >::value,
+      __deref_t<_Iter> >
+  __iter_move(_Iter&& __i) {
+    __validate_iter_reference<_Iter>();
+
+    return *std::forward<_Iter>(__i);
+  }
+
+  // iter_swap
+  template <class _Iter1, class _Iter2>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
+  static void iter_swap(_Iter1&& __a, _Iter2&& __b) {
+    std::iter_swap(std::forward<_Iter1>(__a), std::forward<_Iter2>(__b));
+  }
+
+  // next
+  template <class _Iterator>
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14
+  _Iterator next(_Iterator, _Iterator __last) {
+    return __last;
+  }
+
+  template <class _Iter>
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14
+  __remove_cvref_t<_Iter> next(_Iter&& __it,
+                          typename iterator_traits<__remove_cvref_t<_Iter> >::difference_type __n = 1) {
+    return std::next(std::forward<_Iter>(__it), __n);
+  }
+
+  // prev
+  template <class _Iter>
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14
+  __remove_cvref_t<_Iter> prev(_Iter&& __iter,
+                 typename iterator_traits<__remove_cvref_t<_Iter> >::difference_type __n = 1) {
+    return std::prev(std::forward<_Iter>(__iter), __n);
+  }
+
+  template <class _Iter>
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14
+  void __advance_to(_Iter& __first, _Iter __last) {
+    __first = __last;
+  }
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___ALGORITHM_ITERATOR_OPERATIONS_H