[libcxx][nfc] splices non-modifying algorithms into their own headers

[cjdb]

Summary

• Moves all of [alg.nonmodifying] into <__algorithm/${ALGO_NAME}.h>.
• Moves __search from <functional> into <__functional/__search.h> so we can stop including <functional> in <algorithm>.

Depends on D103329.

[ldionne]

LGTM, but can you please keep including <functional> in <algorithm> for now? Add a comment saying // TODO: Remove this include when we're sure it won't break people.

You can then perform the removal immediately after, but in a separate commit. The reason is that I suspect it's going to break a lot of code (which does not include-what-they-use), and so having a separate commit just to toggle that include is going to be helpful for vendors. For example, I might have to temporarily revert that commit for shipping it on Apple platforms until some internal stuff has been fixed - I suspect other vendors will be in the same boat.

[• Quuxplusone]

As usual, I'll leave my for-the-record comment that I really don't like this direction. It makes tons of little headers for no benefit... and I smell the upcoming PR where you add a bunch of C++20 Ranges dependencies into all of these little headers, making compilation slower for C++17 programs and complexifying the dependency graph.

Notice the failing Modules test; that's being discussed in the comments on D102781.

[cjdb]

rebases so Zoe can use this

libcxx/include/CMakeLists.txt

 set(files
+  __algorithm/adjacent_find.h
+  __algorithm/algorithm_functional.h
+  __algorithm/all_of.h
+  __algorithm/any_of.h
+  __algorithm/count.h
+  __algorithm/count_if.h
+  __algorithm/equal.h
+  __algorithm/find.h
+  __algorithm/find_end.h
+  __algorithm/find_if.h
+  __algorithm/find_if_not.h
+  __algorithm/find_first_of.h
+  __algorithm/for_each.h
+  __algorithm/for_each_n.h
+  __algorithm/is_permutation.h
+  __algorithm/mismatch.h
+  __algorithm/none_of.h
+  __algorithm/search.h
+  __algorithm/search_n.h
   __availability
   __bit_reference
   __bits
   __bsd_locale_defaults.h
   __bsd_locale_fallbacks.h
   __config
   __debug
   __errc
   __format/format_error.h
   __format/format_parse_context.h
   __function_like.h
+  __functional/__search.h
   __functional_03
   __functional_base
   __functional_base_03
   __hash_table
   __iterator/advance.h
   __iterator/concepts.h
   __iterator/default_sentinel.h
   __iterator/incrementable_traits.h

libcxx/include/__algorithm/adjacent_find.h

+// -*- 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_ADJACENT_FIND_H
+#define _LIBCPP___ALGORITHM_ADJACENT_FIND_H
+
+#include <__algorithm/algorithm_functional.h>
+#include <__config>
+#include <__iterator/iterator_traits.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _ForwardIterator, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred) {
+  if (__first != __last) {
+    _ForwardIterator __i = __first;
+    while (++__i != __last) {
+      if (__pred(*__first, *__i))
+        return __first;
+      __first = __i;
+    }
+  }
+  return __last;
+}
+
+template <class _ForwardIterator>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+adjacent_find(_ForwardIterator __first, _ForwardIterator __last) {
+  typedef typename iterator_traits<_ForwardIterator>::value_type __v;
+  return _VSTD::adjacent_find(__first, __last, __equal_to<__v>());
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_ADJACENT_FIND_H

libcxx/include/__algorithm/algorithm_functional.h

+// -*- 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_ALGORITHM_FUNCTIONAL_H
+#define _LIBCPP___ALGORITHM_ALGORITHM_FUNCTIONAL_H
+
+#include <__config>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// I'd like to replace these with _VSTD::equal_to<void>, but can't because that only works with C++14 and later.
+template <class _T1, class _T2 = _T1>
+struct __equal_to {
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {
+    return __x == __y;
+  }
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T2& __y) const {
+    return __x == __y;
+  }
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T1& __y) const {
+    return __x == __y;
+  }
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T2& __y) const {
+    return __x == __y;
+  }
+};
+
+template <class _T1>
+struct __equal_to<_T1, _T1> {
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {
+    return __x == __y;
+  }
+};
+
+template <class _T1>
+struct __equal_to<const _T1, _T1> {
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {
+    return __x == __y;
+  }
+};
+
+template <class _T1>
+struct __equal_to<_T1, const _T1> {
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {
+    return __x == __y;
+  }
+};
+
+template <class _T1, class _T2 = _T1>
+struct __less {
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {
+    return __x < __y;
+  }
+
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T2& __y) const {
+    return __x < __y;
+  }
+
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T1& __y) const {
+    return __x < __y;
+  }
+
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T2& __y) const {
+    return __x < __y;
+  }
+};
+
+template <class _T1>
+struct __less<_T1, _T1> {
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {
+    return __x < __y;
+  }
+};
+
+template <class _T1>
+struct __less<const _T1, _T1> {
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {
+    return __x < __y;
+  }
+};
+
+template <class _T1>
+struct __less<_T1, const _T1> {
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {
+    return __x < __y;
+  }
+};
+
+template <class _Predicate>
+class __invert // invert the sense of a comparison
+{
+private:
+  _Predicate __p_;
+
+public:
+  _LIBCPP_INLINE_VISIBILITY __invert() {}
+
+  _LIBCPP_INLINE_VISIBILITY
+  explicit __invert(_Predicate __p) : __p_(__p) {}
+
+  template <class _T1>
+  _LIBCPP_INLINE_VISIBILITY bool operator()(const _T1& __x) {
+    return !__p_(__x);
+  }
+
+  template <class _T1, class _T2>
+  _LIBCPP_INLINE_VISIBILITY bool operator()(const _T1& __x, const _T2& __y) {
+    return __p_(__y, __x);
+  }
+};
+
+// Perform division by two quickly for positive integers (llvm.org/PR39129)
+
+template <typename _Integral>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename enable_if<is_integral<_Integral>::value, _Integral>::type
+__half_positive(_Integral __value) {
+  return static_cast<_Integral>(static_cast<typename make_unsigned<_Integral>::type>(__value) / 2);
+}
+
+template <typename _Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename enable_if<!is_integral<_Tp>::value, _Tp>::type
+__half_positive(_Tp __value) {
+  return __value / 2;
+}
+
+#ifdef _LIBCPP_DEBUG
+
+template <class _Compare>
+struct __debug_less {
+  _Compare& __comp_;
+  _LIBCPP_CONSTEXPR_AFTER_CXX17
+  __debug_less(_Compare& __c) : __comp_(__c) {}
+
+  template <class _Tp, class _Up>
+  _LIBCPP_CONSTEXPR_AFTER_CXX17 bool operator()(const _Tp& __x, const _Up& __y) {
+    bool __r = __comp_(__x, __y);
+    if (__r)
+      __do_compare_assert(0, __y, __x);
+    return __r;
+  }
+
+  template <class _Tp, class _Up>
+  _LIBCPP_CONSTEXPR_AFTER_CXX17 bool operator()(_Tp& __x, _Up& __y) {
+    bool __r = __comp_(__x, __y);
+    if (__r)
+      __do_compare_assert(0, __y, __x);
+    return __r;
+  }
+
+  template <class _LHS, class _RHS>
+  _LIBCPP_CONSTEXPR_AFTER_CXX17 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), "Comparator does not induce a strict weak ordering");
+  }
+
+  template <class _LHS, class _RHS>
+  _LIBCPP_CONSTEXPR_AFTER_CXX17 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 typename add_lvalue_reference<_Comp>::type type;
+#else
+  typedef __debug_less<_Comp> type;
+#endif
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_ALGORITHM_FUNCTIONAL_H

libcxx/include/__algorithm/all_of.h

+// -*- 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_ALL_OF_H
+#define _LIBCPP___ALGORITHM_ALL_OF_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator, class _Predicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
+  for (; __first != __last; ++__first)
+    if (!__pred(*__first))
+      return false;
+  return true;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_ALL_OF_H

libcxx/include/__algorithm/any_of.h

+// -*- 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_ANY_OF_H
+#define _LIBCPP___ALGORITHM_ANY_OF_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator, class _Predicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
+  for (; __first != __last; ++__first)
+    if (__pred(*__first))
+      return true;
+  return false;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_ANY_OF_H

libcxx/include/__algorithm/count.h

+// -*- 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_COUNT_H
+#define _LIBCPP___ALGORITHM_COUNT_H
+
+#include <__config>
+#include <__iterator/iterator_traits.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator, class _Tp>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    typename iterator_traits<_InputIterator>::difference_type
+    count(_InputIterator __first, _InputIterator __last, const _Tp& __value_) {
+  typename iterator_traits<_InputIterator>::difference_type __r(0);
+  for (; __first != __last; ++__first)
+    if (*__first == __value_)
+      ++__r;
+  return __r;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_COUNT_H

libcxx/include/__algorithm/count_if.h

+// -*- 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_COUNT_IF_H
+#define _LIBCPP___ALGORITHM_COUNT_IF_H
+
+#include <__config>
+#include <__iterator/iterator_traits.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator, class _Predicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    typename iterator_traits<_InputIterator>::difference_type
+    count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
+  typename iterator_traits<_InputIterator>::difference_type __r(0);
+  for (; __first != __last; ++__first)
+    if (__pred(*__first))
+      ++__r;
+  return __r;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_COUNT_IF_H

libcxx/include/__algorithm/equal.h

+// -*- 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_EQUAL_H
+#define _LIBCPP___ALGORITHM_EQUAL_H
+
+#include <__algorithm/algorithm_functional.h>
+#include <__config>
+#include <__iterator/iterator_traits.h>
+#include <iterator> // FIXME: replace with <__iterator/distance.h> when it lands
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
+  for (; __first1 != __last1; ++__first1, (void)++__first2)
+    if (!__pred(*__first1, *__first2))
+      return false;
+  return true;
+}
+
+template <class _InputIterator1, class _InputIterator2>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
+  typedef typename iterator_traits<_InputIterator1>::value_type __v1;
+  typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+  return _VSTD::equal(__first1, __last1, __first2, __equal_to<__v1, __v2>());
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+__equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
+        _BinaryPredicate __pred, input_iterator_tag, input_iterator_tag) {
+  for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void)++__first2)
+    if (!__pred(*__first1, *__first2))
+      return false;
+  return __first1 == __last1 && __first2 == __last2;
+}
+
+template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+__equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1, _RandomAccessIterator2 __first2,
+        _RandomAccessIterator2 __last2, _BinaryPredicate __pred, random_access_iterator_tag,
+        random_access_iterator_tag) {
+  if (_VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
+    return false;
+  return _VSTD::equal<_RandomAccessIterator1, _RandomAccessIterator2,
+                      typename add_lvalue_reference<_BinaryPredicate>::type>(__first1, __last1, __first2, __pred);
+}
+
+template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
+      _BinaryPredicate __pred) {
+  return _VSTD::__equal<typename add_lvalue_reference<_BinaryPredicate>::type>(
+      __first1, __last1, __first2, __last2, __pred, typename iterator_traits<_InputIterator1>::iterator_category(),
+      typename iterator_traits<_InputIterator2>::iterator_category());
+}
+
+template <class _InputIterator1, class _InputIterator2>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
+  typedef typename iterator_traits<_InputIterator1>::value_type __v1;
+  typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+  return _VSTD::__equal(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
+                        typename iterator_traits<_InputIterator1>::iterator_category(),
+                        typename iterator_traits<_InputIterator2>::iterator_category());
+}
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_EQUAL_H

libcxx/include/__algorithm/find.h

+// -*- 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_FIND_H
+#define _LIBCPP___ALGORITHM_FIND_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator, class _Tp>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator
+find(_InputIterator __first, _InputIterator __last, const _Tp& __value_) {
+  for (; __first != __last; ++__first)
+    if (*__first == __value_)
+      break;
+  return __first;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_FIND_H

libcxx/include/__algorithm/find_end.h

+// -*- 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_FIND_END_OF_H
+#define _LIBCPP___ALGORITHM_FIND_END_OF_H
+
+#include <__algorithm/algorithm_functional.h>
+#include <__config>
+#include <__iterator/iterator_traits.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
+_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1 __find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+                                                           _ForwardIterator2 __first2, _ForwardIterator2 __last2,
+                                                           _BinaryPredicate __pred, forward_iterator_tag,
+                                                           forward_iterator_tag) {
+  // modeled after search algorithm
+  _ForwardIterator1 __r = __last1; // __last1 is the "default" answer
+  if (__first2 == __last2)
+    return __r;
+  while (true) {
+    while (true) {
+      if (__first1 == __last1) // if source exhausted return last correct answer
+        return __r;            //    (or __last1 if never found)
+      if (__pred(*__first1, *__first2))
+        break;
+      ++__first1;
+    }
+    // *__first1 matches *__first2, now match elements after here
+    _ForwardIterator1 __m1 = __first1;
+    _ForwardIterator2 __m2 = __first2;
+    while (true) {
+      if (++__m2 == __last2) { // Pattern exhaused, record answer and search for another one
+        __r = __first1;
+        ++__first1;
+        break;
+      }
+      if (++__m1 == __last1) // Source exhausted, return last answer
+        return __r;
+      if (!__pred(*__m1, *__m2)) // mismatch, restart with a new __first
+      {
+        ++__first1;
+        break;
+      } // else there is a match, check next elements
+    }
+  }
+}
+
+template <class _BinaryPredicate, class _BidirectionalIterator1, class _BidirectionalIterator2>
+_LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator1 __find_end(
+    _BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1, _BidirectionalIterator2 __first2,
+    _BidirectionalIterator2 __last2, _BinaryPredicate __pred, bidirectional_iterator_tag, bidirectional_iterator_tag) {
+  // modeled after search algorithm (in reverse)
+  if (__first2 == __last2)
+    return __last1; // Everything matches an empty sequence
+  _BidirectionalIterator1 __l1 = __last1;
+  _BidirectionalIterator2 __l2 = __last2;
+  --__l2;
+  while (true) {
+    // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks
+    while (true) {
+      if (__first1 == __l1) // return __last1 if no element matches *__first2
+        return __last1;
+      if (__pred(*--__l1, *__l2))
+        break;
+    }
+    // *__l1 matches *__l2, now match elements before here
+    _BidirectionalIterator1 __m1 = __l1;
+    _BidirectionalIterator2 __m2 = __l2;
+    while (true) {
+      if (__m2 == __first2) // If pattern exhausted, __m1 is the answer (works for 1 element pattern)
+        return __m1;
+      if (__m1 == __first1) // Otherwise if source exhaused, pattern not found
+        return __last1;
+      if (!__pred(*--__m1, *--__m2)) // if there is a mismatch, restart with a new __l1
+      {
+        break;
+      } // else there is a match, check next elements
+    }
+  }
+}
+
+template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
+_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1 __find_end(
+    _RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1, _RandomAccessIterator2 __first2,
+    _RandomAccessIterator2 __last2, _BinaryPredicate __pred, random_access_iterator_tag, random_access_iterator_tag) {
+  // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
+  typename iterator_traits<_RandomAccessIterator2>::difference_type __len2 = __last2 - __first2;
+  if (__len2 == 0)
+    return __last1;
+  typename iterator_traits<_RandomAccessIterator1>::difference_type __len1 = __last1 - __first1;
+  if (__len1 < __len2)
+    return __last1;
+  const _RandomAccessIterator1 __s = __first1 + (__len2 - 1); // End of pattern match can't go before here
+  _RandomAccessIterator1 __l1 = __last1;
+  _RandomAccessIterator2 __l2 = __last2;
+  --__l2;
+  while (true) {
+    while (true) {
+      if (__s == __l1)
+        return __last1;
+      if (__pred(*--__l1, *__l2))
+        break;
+    }
+    _RandomAccessIterator1 __m1 = __l1;
+    _RandomAccessIterator2 __m2 = __l2;
+    while (true) {
+      if (__m2 == __first2)
+        return __m1;
+      // no need to check range on __m1 because __s guarantees we have enough source
+      if (!__pred(*--__m1, *--__m2)) {
+        break;
+      }
+    }
+  }
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2,
+         _BinaryPredicate __pred) {
+  return _VSTD::__find_end<typename add_lvalue_reference<_BinaryPredicate>::type>(
+      __first1, __last1, __first2, __last2, __pred, typename iterator_traits<_ForwardIterator1>::iterator_category(),
+      typename iterator_traits<_ForwardIterator2>::iterator_category());
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2) {
+  typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
+  typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
+  return _VSTD::find_end(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_FIND_END_OF_H

libcxx/include/__algorithm/find_first_of.h

+// -*- 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_FIND_FIRST_OF_H
+#define _LIBCPP___ALGORITHM_FIND_FIRST_OF_H
+
+#include <__algorithm/algorithm_functional.h>
+#include <__config>
+#include <__iterator/iterator_traits.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator1 __find_first_of_ce(_ForwardIterator1 __first1,
+                                                                   _ForwardIterator1 __last1,
+                                                                   _ForwardIterator2 __first2,
+                                                                   _ForwardIterator2 __last2, _BinaryPredicate __pred) {
+  for (; __first1 != __last1; ++__first1)
+    for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
+      if (__pred(*__first1, *__j))
+        return __first1;
+  return __last1;
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+find_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
+              _ForwardIterator2 __last2, _BinaryPredicate __pred) {
+  return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __pred);
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1 find_first_of(
+    _ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2) {
+  typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
+  typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
+  return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_FIND_FIRST_OF_H

libcxx/include/__algorithm/find_if.h

+// -*- 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_FIND_IF_H
+#define _LIBCPP___ALGORITHM_FIND_IF_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator, class _Predicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator
+find_if(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
+  for (; __first != __last; ++__first)
+    if (__pred(*__first))
+      break;
+  return __first;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_FIND_IF_H

libcxx/include/__algorithm/find_if_not.h

+// -*- 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_FIND_IF_NOT_H
+#define _LIBCPP___ALGORITHM_FIND_IF_NOT_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator, class _Predicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator
+find_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
+  for (; __first != __last; ++__first)
+    if (!__pred(*__first))
+      break;
+  return __first;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_FIND_IF_NOT_H

libcxx/include/__algorithm/for_each.h

+// -*- 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_FOR_EACH_H
+#define _LIBCPP___ALGORITHM_FOR_EACH_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator, class _Function>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _Function for_each(_InputIterator __first,
+                                                                                  _InputIterator __last,
+                                                                                  _Function __f) {
+  for (; __first != __last; ++__first)
+    __f(*__first);
+  return __f;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_FOR_EACH_H

libcxx/include/__algorithm/for_each_n.h

+// -*- 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_FOR_EACH_N_H
+#define _LIBCPP___ALGORITHM_FOR_EACH_N_H
+
+#include <__config>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER > 14
+
+template <class _InputIterator, class _Size, class _Function>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _InputIterator for_each_n(_InputIterator __first,
+                                                                                         _Size __orig_n,
+                                                                                         _Function __f) {
+  typedef decltype(_VSTD::__convert_to_integral(__orig_n)) _IntegralSize;
+  _IntegralSize __n = __orig_n;
+  while (__n > 0) {
+    __f(*__first);
+    ++__first;
+    --__n;
+  }
+  return __first;
+}
+
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_FOR_EACH_N_H

libcxx/include/__algorithm/is_permutation.h

+// -*- 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_IS_PERMUTATION_H
+#define _LIBCPP___ALGORITHM_IS_PERMUTATION_H
+
+#include <__algorithm/algorithm_functional.h>
+#include <__config>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/next.h>
+#include <iterator> // FIXME: replace with <__iterator/distance.h> when it lands
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
+               _BinaryPredicate __pred) {
+  //  shorten sequences as much as possible by lopping of any equal prefix
+  for (; __first1 != __last1; ++__first1, (void)++__first2)
+    if (!__pred(*__first1, *__first2))
+      break;
+  if (__first1 == __last1)
+    return true;
+
+  //  __first1 != __last1 && *__first1 != *__first2
+  typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
+  _D1 __l1 = _VSTD::distance(__first1, __last1);
+  if (__l1 == _D1(1))
+    return false;
+  _ForwardIterator2 __last2 = _VSTD::next(__first2, __l1);
+  // For each element in [f1, l1) see if there are the same number of
+  //    equal elements in [f2, l2)
+  for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i) {
+    //  Have we already counted the number of *__i in [f1, l1)?
+    _ForwardIterator1 __match = __first1;
+    for (; __match != __i; ++__match)
+      if (__pred(*__match, *__i))
+        break;
+    if (__match == __i) {
+      // Count number of *__i in [f2, l2)
+      _D1 __c2 = 0;
+      for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
+        if (__pred(*__i, *__j))
+          ++__c2;
+      if (__c2 == 0)
+        return false;
+      // Count number of *__i in [__i, l1) (we can start with 1)
+      _D1 __c1 = 1;
+      for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
+        if (__pred(*__i, *__j))
+          ++__c1;
+      if (__c1 != __c2)
+        return false;
+    }
+  }
+  return true;
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2) {
+  typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
+  typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
+  return _VSTD::is_permutation(__first1, __last1, __first2, __equal_to<__v1, __v2>());
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
+_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+__is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
+                 _ForwardIterator2 __last2, _BinaryPredicate __pred, forward_iterator_tag, forward_iterator_tag) {
+  //  shorten sequences as much as possible by lopping of any equal prefix
+  for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void)++__first2)
+    if (!__pred(*__first1, *__first2))
+      break;
+  if (__first1 == __last1)
+    return __first2 == __last2;
+  else if (__first2 == __last2)
+    return false;
+
+  typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
+  _D1 __l1 = _VSTD::distance(__first1, __last1);
+
+  typedef typename iterator_traits<_ForwardIterator2>::difference_type _D2;
+  _D2 __l2 = _VSTD::distance(__first2, __last2);
+  if (__l1 != __l2)
+    return false;
+
+  // For each element in [f1, l1) see if there are the same number of
+  //    equal elements in [f2, l2)
+  for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i) {
+    //  Have we already counted the number of *__i in [f1, l1)?
+    _ForwardIterator1 __match = __first1;
+    for (; __match != __i; ++__match)
+      if (__pred(*__match, *__i))
+        break;
+    if (__match == __i) {
+      // Count number of *__i in [f2, l2)
+      _D1 __c2 = 0;
+      for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
+        if (__pred(*__i, *__j))
+          ++__c2;
+      if (__c2 == 0)
+        return false;
+      // Count number of *__i in [__i, l1) (we can start with 1)
+      _D1 __c1 = 1;
+      for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
+        if (__pred(*__i, *__j))
+          ++__c1;
+      if (__c1 != __c2)
+        return false;
+    }
+  }
+  return true;
+}
+
+template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
+_LIBCPP_CONSTEXPR_AFTER_CXX17 bool __is_permutation(_RandomAccessIterator1 __first1, _RandomAccessIterator2 __last1,
+                                                    _RandomAccessIterator1 __first2, _RandomAccessIterator2 __last2,
+                                                    _BinaryPredicate __pred, random_access_iterator_tag,
+                                                    random_access_iterator_tag) {
+  if (_VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
+    return false;
+  return _VSTD::is_permutation<_RandomAccessIterator1, _RandomAccessIterator2,
+                               typename add_lvalue_reference<_BinaryPredicate>::type>(__first1, __last1, __first2,
+                                                                                      __pred);
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
+               _ForwardIterator2 __last2, _BinaryPredicate __pred) {
+  return _VSTD::__is_permutation<typename add_lvalue_reference<_BinaryPredicate>::type>(
+      __first1, __last1, __first2, __last2, __pred, typename iterator_traits<_ForwardIterator1>::iterator_category(),
+      typename iterator_traits<_ForwardIterator2>::iterator_category());
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
+               _ForwardIterator2 __last2) {
+  typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
+  typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
+  return _VSTD::__is_permutation(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
+                                 typename iterator_traits<_ForwardIterator1>::iterator_category(),
+                                 typename iterator_traits<_ForwardIterator2>::iterator_category());
+}
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_IS_PERMUTATION_H

libcxx/include/__algorithm/mismatch.h

+// -*- 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_MISMATCH_H
+#define _LIBCPP___ALGORITHM_MISMATCH_H
+
+#include <__algorithm/algorithm_functional.h>
+#include <__config>
+#include <__iterator/iterator_traits.h>
+#include <utility>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
+    mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
+  for (; __first1 != __last1; ++__first1, (void)++__first2)
+    if (!__pred(*__first1, *__first2))
+      break;
+  return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
+}
+
+template <class _InputIterator1, class _InputIterator2>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
+    mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
+  typedef typename iterator_traits<_InputIterator1>::value_type __v1;
+  typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+  return _VSTD::mismatch(__first1, __last1, __first2, __equal_to<__v1, __v2>());
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
+    mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
+             _BinaryPredicate __pred) {
+  for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void)++__first2)
+    if (!__pred(*__first1, *__first2))
+      break;
+  return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
+}
+
+template <class _InputIterator1, class _InputIterator2>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_InputIterator1, _InputIterator2>
+    mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
+  typedef typename iterator_traits<_InputIterator1>::value_type __v1;
+  typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+  return _VSTD::mismatch(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
+}
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_MISMATCH_H

libcxx/include/__algorithm/none_of.h

+// -*- 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_NONE_OF_H
+#define _LIBCPP___ALGORITHM_NONE_OF_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator, class _Predicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
+none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred) {
+  for (; __first != __last; ++__first)
+    if (__pred(*__first))
+      return false;
+  return true;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_NONE_OF_H

libcxx/include/__algorithm/search.h

+// -*- 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_SEARCH_H
+#define _LIBCPP___ALGORITHM_SEARCH_H
+
+#include <__config>
+#include <__functional/__search.h>
+#include <__iterator/iterator_traits.h>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+search(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2,
+       _BinaryPredicate __pred) {
+  return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>(
+             __first1, __last1, __first2, __last2, __pred,
+             typename iterator_traits<_ForwardIterator1>::iterator_category(),
+             typename iterator_traits<_ForwardIterator2>::iterator_category())
+      .first;
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
+search(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _ForwardIterator2 __last2) {
+  typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
+  typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
+  return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
+}
+
+#if _LIBCPP_STD_VER > 14
+template <class _ForwardIterator, class _Searcher>
+_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher& __s) {
+  return __s(__f, __l).first;
+}
+
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_SEARCH_H

libcxx/include/__algorithm/search_n.h

+// -*- 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_SEARCH_N_H
+#define _LIBCPP___ALGORITHM_SEARCH_N_H
+
+#include <__config>
+#include <__iterator/iterator_traits.h>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _BinaryPredicate, class _ForwardIterator, class _Size, class _Tp>
+_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator __search_n(_ForwardIterator __first, _ForwardIterator __last,
+                                                          _Size __count, const _Tp& __value_, _BinaryPredicate __pred,
+                                                          forward_iterator_tag) {
+  if (__count <= 0)
+    return __first;
+  while (true) {
+    // Find first element in sequence that matchs __value_, with a mininum of loop checks
+    while (true) {
+      if (__first == __last) // return __last if no element matches __value_
+        return __last;
+      if (__pred(*__first, __value_))
+        break;
+      ++__first;
+    }
+    // *__first matches __value_, now match elements after here
+    _ForwardIterator __m = __first;
+    _Size __c(0);
+    while (true) {
+      if (++__c == __count) // If pattern exhausted, __first is the answer (works for 1 element pattern)
+        return __first;
+      if (++__m == __last) // Otherwise if source exhaused, pattern not found
+        return __last;
+      if (!__pred(*__m, __value_)) // if there is a mismatch, restart with a new __first
+      {
+        __first = __m;
+        ++__first;
+        break;
+      } // else there is a match, check next elements
+    }
+  }
+}
+
+template <class _BinaryPredicate, class _RandomAccessIterator, class _Size, class _Tp>
+_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator __search_n(_RandomAccessIterator __first,
+                                                               _RandomAccessIterator __last, _Size __count,
+                                                               const _Tp& __value_, _BinaryPredicate __pred,
+                                                               random_access_iterator_tag) {
+  if (__count <= 0)
+    return __first;
+  _Size __len = static_cast<_Size>(__last - __first);
+  if (__len < __count)
+    return __last;
+  const _RandomAccessIterator __s = __last - (__count - 1); // Start of pattern match can't go beyond here
+  while (true) {
+    // Find first element in sequence that matchs __value_, with a mininum of loop checks
+    while (true) {
+      if (__first >= __s) // return __last if no element matches __value_
+        return __last;
+      if (__pred(*__first, __value_))
+        break;
+      ++__first;
+    }
+    // *__first matches __value_, now match elements after here
+    _RandomAccessIterator __m = __first;
+    _Size __c(0);
+    while (true) {
+      if (++__c == __count) // If pattern exhausted, __first is the answer (works for 1 element pattern)
+        return __first;
+      ++__m;                       // no need to check range on __m because __s guarantees we have enough source
+      if (!__pred(*__m, __value_)) // if there is a mismatch, restart with a new __first
+      {
+        __first = __m;
+        ++__first;
+        break;
+      } // else there is a match, check next elements
+    }
+  }
+}
+
+template <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator search_n(
+    _ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_, _BinaryPredicate __pred) {
+  return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>(
+      __first, __last, _VSTD::__convert_to_integral(__count), __value_, __pred,
+      typename iterator_traits<_ForwardIterator>::iterator_category());
+}
+
+template <class _ForwardIterator, class _Size, class _Tp>
+_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
+search_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_) {
+  typedef typename iterator_traits<_ForwardIterator>::value_type __v;
+  return _VSTD::search_n(__first, __last, _VSTD::__convert_to_integral(__count), __value_, __equal_to<__v, _Tp>());
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_SEARCH_N_H

libcxx/include/__functional/__search.h

+// -*- 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___FUNCTIONAL___SEARCH_H
+#define _LIBCPP___FUNCTIONAL___SEARCH_H
+
+#include <__config>
+#include <__iterator/iterator_traits.h>
+#include <utility>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
+pair<_ForwardIterator1, _ForwardIterator1>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 __search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+                                           _ForwardIterator2 __first2, _ForwardIterator2 __last2,
+                                           _BinaryPredicate __pred, forward_iterator_tag, forward_iterator_tag) {
+  if (__first2 == __last2)
+    return _VSTD::make_pair(__first1, __first1); // Everything matches an empty sequence
+  while (true) {
+    // Find first element in sequence 1 that matchs *__first2, with a mininum of loop checks
+    while (true) {
+      if (__first1 == __last1) // return __last1 if no element matches *__first2
+        return _VSTD::make_pair(__last1, __last1);
+      if (__pred(*__first1, *__first2))
+        break;
+      ++__first1;
+    }
+    // *__first1 matches *__first2, now match elements after here
+    _ForwardIterator1 __m1 = __first1;
+    _ForwardIterator2 __m2 = __first2;
+    while (true) {
+      if (++__m2 == __last2) // If pattern exhausted, __first1 is the answer (works for 1 element pattern)
+        return _VSTD::make_pair(__first1, __m1);
+      if (++__m1 == __last1) // Otherwise if source exhaused, pattern not found
+        return _VSTD::make_pair(__last1, __last1);
+      if (!__pred(*__m1, *__m2)) // if there is a mismatch, restart with a new __first1
+      {
+        ++__first1;
+        break;
+      } // else there is a match, check next elements
+    }
+  }
+}
+
+template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
+_LIBCPP_CONSTEXPR_AFTER_CXX11 pair<_RandomAccessIterator1, _RandomAccessIterator1>
+__search(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1, _RandomAccessIterator2 __first2,
+         _RandomAccessIterator2 __last2, _BinaryPredicate __pred, random_access_iterator_tag,
+         random_access_iterator_tag) {
+  typedef typename iterator_traits<_RandomAccessIterator1>::difference_type _D1;
+  typedef typename iterator_traits<_RandomAccessIterator2>::difference_type _D2;
+  // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
+  const _D2 __len2 = __last2 - __first2;
+  if (__len2 == 0)
+    return _VSTD::make_pair(__first1, __first1);
+  const _D1 __len1 = __last1 - __first1;
+  if (__len1 < __len2)
+    return _VSTD::make_pair(__last1, __last1);
+  const _RandomAccessIterator1 __s = __last1 - (__len2 - 1); // Start of pattern match can't go beyond here
+
+  while (true) {
+    while (true) {
+      if (__first1 == __s)
+        return _VSTD::make_pair(__last1, __last1);
+      if (__pred(*__first1, *__first2))
+        break;
+      ++__first1;
+    }
+
+    _RandomAccessIterator1 __m1 = __first1;
+    _RandomAccessIterator2 __m2 = __first2;
+    while (true) {
+      if (++__m2 == __last2)
+        return _VSTD::make_pair(__first1, __first1 + __len2);
+      ++__m1; // no need to check range on __m1 because __s guarantees we have enough source
+      if (!__pred(*__m1, *__m2)) {
+        ++__first1;
+        break;
+      }
+    }
+  }
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___FUNCTIONAL___SEARCH_H

libcxx/include/algorithm

 template <class BidirectionalIterator, class Compare>
     constexpr bool     // constexpr in C++20
     prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
 
 }  // std
 
 */
 
+#include <__algorithm/adjacent_find.h>
+#include <__algorithm/all_of.h>
+#include <__algorithm/any_of.h>
+#include <__algorithm/count.h>
+#include <__algorithm/count_if.h>
+#include <__algorithm/equal.h>
+#include <__algorithm/find.h>
+#include <__algorithm/find_end.h>
+#include <__algorithm/find_if.h>
+#include <__algorithm/find_if_not.h>
+#include <__algorithm/find_first_of.h>
+#include <__algorithm/for_each.h>
+#include <__algorithm/for_each_n.h>
+#include <__algorithm/is_permutation.h>
+#include <__algorithm/mismatch.h>
+#include <__algorithm/none_of.h>
+#include <__algorithm/search.h>
+#include <__algorithm/search_n.h>
 #include <__config>
 #include <__bits> // __libcpp_clz
 #include <cstddef>
 #include <cstring>
 #include <functional>
 #include <initializer_list>
+#include <utility> // needed to provide swap_ranges.
+#include <memory>
 #include <iterator>
 #include <memory>
 #include <type_traits>
 #include <utility> // swap_ranges
 #include <version>
 
 #include <__debug>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-// I'd like to replace these with _VSTD::equal_to<void>, but can't because:
-//   * That only works with C++14 and later, and
-//   * We haven't included <functional> here.
-template <class _T1, class _T2 = _T1>
-struct __equal_to
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T2& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T1& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T2& __y) const {return __x == __y;}
-};
-
-template <class _T1>
-struct __equal_to<_T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-};
-
-template <class _T1>
-struct __equal_to<const _T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-};
-
-template <class _T1>
-struct __equal_to<_T1, const _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-};
-
-template <class _T1, class _T2 = _T1>
-struct __less
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T2& __y) const {return __x < __y;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T2& __x, const _T1& __y) const {return __x < __y;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T2& __x, const _T2& __y) const {return __x < __y;}
-};
-
-template <class _T1>
-struct __less<_T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-};
-
-template <class _T1>
-struct __less<const _T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-};
-
-template <class _T1>
-struct __less<_T1, const _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-};
-
-template <class _Predicate>
-class __invert // invert the sense of a comparison
-{
-private:
-    _Predicate __p_;
-public:
-    _LIBCPP_INLINE_VISIBILITY __invert() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __invert(_Predicate __p) : __p_(__p) {}
-
-    template <class _T1>
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _T1& __x) {return !__p_(__x);}
-
-    template <class _T1, class _T2>
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _T1& __x, const _T2& __y) {return __p_(__y, __x);}
-};
-
-// Perform division by two quickly for positive integers (llvm.org/PR39129)
-
-template <typename _Integral>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    is_integral<_Integral>::value,
-    _Integral
->::type
-__half_positive(_Integral __value)
-{
-    return static_cast<_Integral>(static_cast<typename make_unsigned<_Integral>::type>(__value) / 2);
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    !is_integral<_Tp>::value,
-    _Tp
->::type
-__half_positive(_Tp __value)
-{
-    return __value / 2;
-}
-
-#ifdef _LIBCPP_DEBUG
-
-template <class _Compare>
-struct __debug_less
-{
-    _Compare &__comp_;
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
-    __debug_less(_Compare& __c) : __comp_(__c) {}
-
-    template <class _Tp, class _Up>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
-    bool operator()(const _Tp& __x,  const _Up& __y)
-    {
-        bool __r = __comp_(__x, __y);
-        if (__r)
-            __do_compare_assert(0, __y, __x);
-        return __r;
-    }
-
-    template <class _Tp, class _Up>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
-    bool operator()(_Tp& __x,  _Up& __y)
-    {
-        bool __r = __comp_(__x, __y);
-        if (__r)
-            __do_compare_assert(0, __y, __x);
-        return __r;
-    }
-
-    template <class _LHS, class _RHS>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
-    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),
-            "Comparator does not induce a strict weak ordering");
-    }
-
-    template <class _LHS, class _RHS>
-    _LIBCPP_CONSTEXPR_AFTER_CXX17
-    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 typename add_lvalue_reference<_Comp>::type type;
-#else
-  typedef __debug_less<_Comp> type;
-#endif
-};
-
-// all_of
-
-template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (!__pred(*__first))
-            return false;
-    return true;
-}
-
-// any_of
-
-template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            return true;
-    return false;
-}
-
-// none_of
-
-template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            return false;
-    return true;
-}
-
-// for_each
-
-template <class _InputIterator, class _Function>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_Function
-for_each(_InputIterator __first, _InputIterator __last, _Function __f)
-{
-    for (; __first != __last; ++__first)
-        __f(*__first);
-    return __f;
-}
-
-#if _LIBCPP_STD_VER > 14
-// for_each_n
-
-template <class _InputIterator, class _Size, class _Function>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-for_each_n(_InputIterator __first, _Size __orig_n, _Function __f)
-{
-    typedef decltype(_VSTD::__convert_to_integral(__orig_n)) _IntegralSize;
-    _IntegralSize __n = __orig_n;
-    while (__n > 0)
-    {
-         __f(*__first);
-         ++__first;
-         --__n;
-    }
-    return __first;
-}
-#endif
-
-// find
-
-template <class _InputIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-find(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
-{
-    for (; __first != __last; ++__first)
-        if (*__first == __value_)
-            break;
-    return __first;
-}
-
-// find_if
-
-template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-find_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            break;
-    return __first;
-}
-
-// find_if_not
-
-template<class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-find_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (!__pred(*__first))
-            break;
-    return __first;
-}
-
-// find_end
-
-template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
-__find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-           _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
-           forward_iterator_tag, forward_iterator_tag)
-{
-    // modeled after search algorithm
-    _ForwardIterator1 __r = __last1;  // __last1 is the "default" answer
-    if (__first2 == __last2)
-        return __r;
-    while (true)
-    {
-        while (true)
-        {
-            if (__first1 == __last1)         // if source exhausted return last correct answer
-                return __r;                  //    (or __last1 if never found)
-            if (__pred(*__first1, *__first2))
-                break;
-            ++__first1;
-        }
-        // *__first1 matches *__first2, now match elements after here
-        _ForwardIterator1 __m1 = __first1;
-        _ForwardIterator2 __m2 = __first2;
-        while (true)
-        {
-            if (++__m2 == __last2)
-            {                         // Pattern exhaused, record answer and search for another one
-                __r = __first1;
-                ++__first1;
-                break;
-            }
-            if (++__m1 == __last1)     // Source exhausted, return last answer
-                return __r;
-            if (!__pred(*__m1, *__m2))  // mismatch, restart with a new __first
-            {
-                ++__first1;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _BidirectionalIterator1, class _BidirectionalIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator1
-__find_end(_BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1,
-           _BidirectionalIterator2 __first2, _BidirectionalIterator2 __last2, _BinaryPredicate __pred,
-           bidirectional_iterator_tag, bidirectional_iterator_tag)
-{
-    // modeled after search algorithm (in reverse)
-    if (__first2 == __last2)
-        return __last1;  // Everything matches an empty sequence
-    _BidirectionalIterator1 __l1 = __last1;
-    _BidirectionalIterator2 __l2 = __last2;
-    --__l2;
-    while (true)
-    {
-        // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks
-        while (true)
-        {
-            if (__first1 == __l1)  // return __last1 if no element matches *__first2
-                return __last1;
-            if (__pred(*--__l1, *__l2))
-                break;
-        }
-        // *__l1 matches *__l2, now match elements before here
-        _BidirectionalIterator1 __m1 = __l1;
-        _BidirectionalIterator2 __m2 = __l2;
-        while (true)
-        {
-            if (__m2 == __first2)  // If pattern exhausted, __m1 is the answer (works for 1 element pattern)
-                return __m1;
-            if (__m1 == __first1)  // Otherwise if source exhaused, pattern not found
-                return __last1;
-            if (!__pred(*--__m1, *--__m2))  // if there is a mismatch, restart with a new __l1
-            {
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1
-__find_end(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
-           _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
-           random_access_iterator_tag, random_access_iterator_tag)
-{
-    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
-    typename iterator_traits<_RandomAccessIterator2>::difference_type __len2 = __last2 - __first2;
-    if (__len2 == 0)
-        return __last1;
-    typename iterator_traits<_RandomAccessIterator1>::difference_type __len1 = __last1 - __first1;
-    if (__len1 < __len2)
-        return __last1;
-    const _RandomAccessIterator1 __s = __first1 + (__len2 - 1);  // End of pattern match can't go before here
-    _RandomAccessIterator1 __l1 = __last1;
-    _RandomAccessIterator2 __l2 = __last2;
-    --__l2;
-    while (true)
-    {
-        while (true)
-        {
-            if (__s == __l1)
-                return __last1;
-            if (__pred(*--__l1, *__l2))
-                break;
-        }
-        _RandomAccessIterator1 __m1 = __l1;
-        _RandomAccessIterator2 __m2 = __l2;
-        while (true)
-        {
-            if (__m2 == __first2)
-                return __m1;
-                                 // no need to check range on __m1 because __s guarantees we have enough source
-            if (!__pred(*--__m1, *--__m2))
-            {
-                break;
-            }
-        }
-    }
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    return _VSTD::__find_end<typename add_lvalue_reference<_BinaryPredicate>::type>
-                         (__first1, __last1, __first2, __last2, __pred,
-                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
-                          typename iterator_traits<_ForwardIterator2>::iterator_category());
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-         _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::find_end(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-
-// find_first_of
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator1
-__find_first_of_ce(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1; ++__first1)
-        for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
-            if (__pred(*__first1, *__j))
-                return __first1;
-    return __last1;
-}
-
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __pred);
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-              _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-
-// adjacent_find
-
-template <class _ForwardIterator, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (__pred(*__first, *__i))
-                return __first;
-            __first = __i;
-        }
-    }
-    return __last;
-}
-
-template <class _ForwardIterator>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-adjacent_find(_ForwardIterator __first, _ForwardIterator __last)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
-    return _VSTD::adjacent_find(__first, __last, __equal_to<__v>());
-}
-
-// count
-
-template <class _InputIterator, class _Tp>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-typename iterator_traits<_InputIterator>::difference_type
-count(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
-{
-    typename iterator_traits<_InputIterator>::difference_type __r(0);
-    for (; __first != __last; ++__first)
-        if (*__first == __value_)
-            ++__r;
-    return __r;
-}
-
-// count_if
-
-template <class _InputIterator, class _Predicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-typename iterator_traits<_InputIterator>::difference_type
-count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    typename iterator_traits<_InputIterator>::difference_type __r(0);
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            ++__r;
-    return __r;
-}
-
-// mismatch
-
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
-         _InputIterator2 __first2, _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
-}
-
-template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::mismatch(__first1, __last1, __first2, __equal_to<__v1, __v2>());
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
-         _InputIterator2 __first2, _InputIterator2 __last2,
-         _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
-}
-
-template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
-         _InputIterator2 __first2, _InputIterator2 __last2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::mismatch(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-#endif
-
-// equal
-
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            return false;
-    return true;
-}
-
-template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::equal(__first1, __last1, __first2, __equal_to<__v1, __v2>());
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-__equal(_InputIterator1 __first1, _InputIterator1 __last1,
-        _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred,
-        input_iterator_tag, input_iterator_tag )
-{
-    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            return false;
-    return __first1 == __last1 && __first2 == __last2;
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-__equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
-        _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
-      random_access_iterator_tag, random_access_iterator_tag )
-{
-    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
-        return false;
-    return _VSTD::equal<_RandomAccessIterator1, _RandomAccessIterator2,
-                        typename add_lvalue_reference<_BinaryPredicate>::type>
-                       (__first1, __last1, __first2, __pred );
-}
-
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1,
-      _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred )
-{
-    return _VSTD::__equal<typename add_lvalue_reference<_BinaryPredicate>::type>
-       (__first1, __last1, __first2, __last2, __pred,
-        typename iterator_traits<_InputIterator1>::iterator_category(),
-        typename iterator_traits<_InputIterator2>::iterator_category());
-}
-
-template <class _InputIterator1, class _InputIterator2>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1,
-      _InputIterator2 __first2, _InputIterator2 __last2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::__equal(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
-        typename iterator_traits<_InputIterator1>::iterator_category(),
-        typename iterator_traits<_InputIterator2>::iterator_category());
-}
-#endif
-
-// is_permutation
-
-template<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT _LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2, _BinaryPredicate __pred)
-{
-//  shorten sequences as much as possible by lopping of any equal prefix
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    if (__first1 == __last1)
-        return true;
-
-//  __first1 != __last1 && *__first1 != *__first2
-    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
-    _D1 __l1 = _VSTD::distance(__first1, __last1);
-    if (__l1 == _D1(1))
-        return false;
-    _ForwardIterator2 __last2 = _VSTD::next(__first2, __l1);
-    // For each element in [f1, l1) see if there are the same number of
-    //    equal elements in [f2, l2)
-    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
-    {
-    //  Have we already counted the number of *__i in [f1, l1)?
-        _ForwardIterator1 __match = __first1;
-        for (; __match != __i; ++__match)
-            if (__pred(*__match, *__i))
-                break;
-        if (__match == __i) {
-            // Count number of *__i in [f2, l2)
-            _D1 __c2 = 0;
-            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c2;
-            if (__c2 == 0)
-                return false;
-            // Count number of *__i in [__i, l1) (we can start with 1)
-            _D1 __c1 = 1;
-            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c1;
-            if (__c1 != __c2)
-                return false;
-        }
-    }
-    return true;
-}
-
-template<class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::is_permutation(__first1, __last1, __first2, __equal_to<__v1, __v2>());
-}
-
-#if _LIBCPP_STD_VER > 11
-template<class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-__is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-                 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
-                 _BinaryPredicate __pred,
-                 forward_iterator_tag, forward_iterator_tag )
-{
-//  shorten sequences as much as possible by lopping of any equal prefix
-    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    if (__first1 == __last1)
-        return __first2 == __last2;
-    else if (__first2 == __last2)
-        return false;
-
-    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
-    _D1 __l1 = _VSTD::distance(__first1, __last1);
-
-    typedef typename iterator_traits<_ForwardIterator2>::difference_type _D2;
-    _D2 __l2 = _VSTD::distance(__first2, __last2);
-    if (__l1 != __l2)
-        return false;
-
-    // For each element in [f1, l1) see if there are the same number of
-    //    equal elements in [f2, l2)
-    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
-    {
-    //  Have we already counted the number of *__i in [f1, l1)?
-        _ForwardIterator1 __match = __first1;
-        for (; __match != __i; ++__match)
-            if (__pred(*__match, *__i))
-                break;
-        if (__match == __i) {
-            // Count number of *__i in [f2, l2)
-            _D1 __c2 = 0;
-            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c2;
-            if (__c2 == 0)
-                return false;
-            // Count number of *__i in [__i, l1) (we can start with 1)
-            _D1 __c1 = 1;
-            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c1;
-            if (__c1 != __c2)
-                return false;
-        }
-    }
-    return true;
-}
-
-template<class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-__is_permutation(_RandomAccessIterator1 __first1, _RandomAccessIterator2 __last1,
-               _RandomAccessIterator1 __first2, _RandomAccessIterator2 __last2,
-               _BinaryPredicate __pred,
-               random_access_iterator_tag, random_access_iterator_tag )
-{
-    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
-        return false;
-    return _VSTD::is_permutation<_RandomAccessIterator1, _RandomAccessIterator2,
-                                 typename add_lvalue_reference<_BinaryPredicate>::type>
-                                (__first1, __last1, __first2, __pred );
-}
-
-template<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2, _ForwardIterator2 __last2,
-               _BinaryPredicate __pred )
-{
-    return _VSTD::__is_permutation<typename add_lvalue_reference<_BinaryPredicate>::type>
-       (__first1, __last1, __first2, __last2, __pred,
-        typename iterator_traits<_ForwardIterator1>::iterator_category(),
-        typename iterator_traits<_ForwardIterator2>::iterator_category());
-}
-
-template<class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::__is_permutation(__first1, __last1, __first2, __last2,
-        __equal_to<__v1, __v2>(),
-        typename iterator_traits<_ForwardIterator1>::iterator_category(),
-        typename iterator_traits<_ForwardIterator2>::iterator_category());
-}
-#endif
-
-// search
-// __search is in <functional>
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-       _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>
-                         (__first1, __last1, __first2, __last2, __pred,
-                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
-                          typename iterator_traits<_ForwardIterator2>::iterator_category())
-            .first;
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-       _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-
-
-#if _LIBCPP_STD_VER > 14
-template <class _ForwardIterator, class _Searcher>
-_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
-{ return __s(__f, __l).first; }
-#endif
-
-// search_n
-
-template <class _BinaryPredicate, class _ForwardIterator, class _Size, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__search_n(_ForwardIterator __first, _ForwardIterator __last,
-           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, forward_iterator_tag)
-{
-    if (__count <= 0)
-        return __first;
-    while (true)
-    {
-        // Find first element in sequence that matchs __value_, with a mininum of loop checks
-        while (true)
-        {
-            if (__first == __last)  // return __last if no element matches __value_
-                return __last;
-            if (__pred(*__first, __value_))
-                break;
-            ++__first;
-        }
-        // *__first matches __value_, now match elements after here
-        _ForwardIterator __m = __first;
-        _Size __c(0);
-        while (true)
-        {
-            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
-                return __first;
-            if (++__m == __last)  // Otherwise if source exhaused, pattern not found
-                return __last;
-            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
-            {
-                __first = __m;
-                ++__first;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator, class _Size, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
-__search_n(_RandomAccessIterator __first, _RandomAccessIterator __last,
-           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, random_access_iterator_tag)
-{
-    if (__count <= 0)
-        return __first;
-    _Size __len = static_cast<_Size>(__last - __first);
-    if (__len < __count)
-        return __last;
-    const _RandomAccessIterator __s = __last - (__count - 1);  // Start of pattern match can't go beyond here
-    while (true)
-    {
-        // Find first element in sequence that matchs __value_, with a mininum of loop checks
-        while (true)
-        {
-            if (__first >= __s)  // return __last if no element matches __value_
-                return __last;
-            if (__pred(*__first, __value_))
-                break;
-            ++__first;
-        }
-        // *__first matches __value_, now match elements after here
-        _RandomAccessIterator __m = __first;
-        _Size __c(0);
-        while (true)
-        {
-            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
-                return __first;
-             ++__m;          // no need to check range on __m because __s guarantees we have enough source
-            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
-            {
-                __first = __m;
-                ++__first;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-search_n(_ForwardIterator __first, _ForwardIterator __last,
-         _Size __count, const _Tp& __value_, _BinaryPredicate __pred)
-{
-    return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>
-           (__first, __last, _VSTD::__convert_to_integral(__count), __value_, __pred,
-           typename iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-template <class _ForwardIterator, class _Size, class _Tp>
-_LIBCPP_NODISCARD_EXT inline
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-search_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
-    return _VSTD::search_n(__first, __last, _VSTD::__convert_to_integral(__count),
-                           __value_, __equal_to<__v, _Tp>());
-}
-
 // __unwrap_iter, __rewrap_iter
 
 // The job of __unwrap_iter is to lower contiguous iterators (such as
 // vector<T>::iterator) into pointers, to reduce the number of template
 // instantiations and to enable pointer-based optimizations e.g. in std::copy.
 // For iterators that are not contiguous, it must be a no-op.
 // In debug mode, we don't do this.
 //

libcxx/include/experimental/functional

inline namespace fundamentals_v1 {
 
   template<class R, class... ArgTypes, class Alloc>
   struct uses_allocator<experimental::function<R(ArgTypes...)>, Alloc>;
 
 } // namespace std
 
 */
 
+#include <__functional/__search.h>
 #include <experimental/__config>
 #include <functional>
 #include <algorithm>
 #include <type_traits>
 #include <vector>
 #include <array>
 #include <unordered_map>
 

libcxx/include/functional

POLICY:  For non-variadic implementations, the number of arguments is limited
          to 3.  It is hoped that the need for non-variadic implementations
          will be minimal.
 
 */
 
 #include <__config>
 #include <__debug>
 #include <__functional_base>
+#include <__functional/__search.h>
 #include <concepts>
 #include <exception>
 #include <memory>
 #include <tuple>
 #include <type_traits>
 #include <typeinfo>
 #include <utility>
 #include <version>
constexpr auto bind_front(_Fn&& __f, _Args&&... __args)
     return __perfect_forward<__bind_front_op, _Fn, _Args...>(_VSTD::forward<_Fn>(__f),
                                                              _VSTD::forward<_Args>(__args)...);
 }
 
 #endif // _LIBCPP_STD_VER > 17
 
 // struct hash<T*> in <memory>
 
-template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
-pair<_ForwardIterator1, _ForwardIterator1> _LIBCPP_CONSTEXPR_AFTER_CXX11
-__search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
-         forward_iterator_tag, forward_iterator_tag)
-{
-    if (__first2 == __last2)
-        return _VSTD::make_pair(__first1, __first1);  // Everything matches an empty sequence
-    while (true)
-    {
-        // Find first element in sequence 1 that matchs *__first2, with a mininum of loop checks
-        while (true)
-        {
-            if (__first1 == __last1)  // return __last1 if no element matches *__first2
-                return _VSTD::make_pair(__last1, __last1);
-            if (__pred(*__first1, *__first2))
-                break;
-            ++__first1;
-        }
-        // *__first1 matches *__first2, now match elements after here
-        _ForwardIterator1 __m1 = __first1;
-        _ForwardIterator2 __m2 = __first2;
-        while (true)
-        {
-            if (++__m2 == __last2)  // If pattern exhausted, __first1 is the answer (works for 1 element pattern)
-                return _VSTD::make_pair(__first1, __m1);
-            if (++__m1 == __last1)  // Otherwise if source exhaused, pattern not found
-                return _VSTD::make_pair(__last1, __last1);
-            if (!__pred(*__m1, *__m2))  // if there is a mismatch, restart with a new __first1
-            {
-                ++__first1;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<_RandomAccessIterator1, _RandomAccessIterator1>
-__search(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
-         _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
-           random_access_iterator_tag, random_access_iterator_tag)
-{
-    typedef typename iterator_traits<_RandomAccessIterator1>::difference_type _D1;
-    typedef typename iterator_traits<_RandomAccessIterator2>::difference_type _D2;
-    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
-    const _D2 __len2 = __last2 - __first2;
-    if (__len2 == 0)
-        return _VSTD::make_pair(__first1, __first1);
-    const _D1 __len1 = __last1 - __first1;
-    if (__len1 < __len2)
-        return _VSTD::make_pair(__last1, __last1);
-    const _RandomAccessIterator1 __s = __last1 - (__len2 - 1);  // Start of pattern match can't go beyond here
-
-    while (true)
-    {
-        while (true)
-        {
-            if (__first1 == __s)
-                return _VSTD::make_pair(__last1, __last1);
-            if (__pred(*__first1, *__first2))
-                break;
-            ++__first1;
-        }
-
-        _RandomAccessIterator1 __m1 = __first1;
-        _RandomAccessIterator2 __m2 = __first2;
-         while (true)
-         {
-             if (++__m2 == __last2)
-                 return _VSTD::make_pair(__first1, __first1 + __len2);
-             ++__m1;          // no need to check range on __m1 because __s guarantees we have enough source
-             if (!__pred(*__m1, *__m2))
-             {
-                 ++__first1;
-                 break;
-             }
-         }
-    }
-}
-
 #if _LIBCPP_STD_VER > 14
 
 // default searcher
 template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
 class _LIBCPP_TEMPLATE_VIS default_searcher {
 public:
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     default_searcher(_ForwardIterator __f, _ForwardIterator __l,

libcxx/include/module.modulemap

module cwctype {
       export *
     }
   }
 
   module algorithm {
     header "algorithm"
     export initializer_list
     export *
+    umbrella "__algorithm"
+    explicit module * {
+      export *
+    }
   }
   module any {
     header "any"
     export *
   }
   module array {
     header "array"
     export initializer_list
module forward_list {
     export *
   }
   module fstream {
     header "fstream"
     export *
   }
   module functional {
     header "functional"
+    umbrella "__functional"
     export *
   }
   module future {
     header "future"
     export *
   }
   module initializer_list {
     header "initializer_list"
module std [system] {
   module istream {
     header "istream"
     // FIXME: should re-export ios, streambuf?
     export *
   }
   module iterator {
     header "iterator"
     export *
+    umbrella "__iterator"
+    explicit module * {
+      export *
+    }
   }
   module latch {
     requires cplusplus14
     header "latch"
     export *
   }
   module limits {
     header "limits"
module random {
     export *
   }
   module ranges {
     header "ranges"
     export compare
     export initializer_list
     export iterator
     export *
+    umbrella "__ranges"
+    explicit module * {
+      export *
+    }
   }
   module ratio {
     header "ratio"
     export *
   }
   module regex {
     header "regex"
     export initializer_list

libcxx/include/regex

 typedef regex_token_iterator<string::const_iterator>  sregex_token_iterator;
 typedef regex_token_iterator<wstring::const_iterator> wsregex_token_iterator;
 
 } // std
 */
 
 #include <__config>
 #include <__debug>
+#include <__functional/__search.h>
 #include <__locale>
 #include <compare>
 #include <deque>
 #include <initializer_list>
 #include <iterator>
 #include <memory>
 #include <stdexcept>
 #include <string>

libcxx/test/std/containers/sequences/array/compare.fail.cpp

 template <int Dummy> struct NoCompare {};
 
 int main(int, char**)
 {
   {
     typedef NoCompare<0> T;
     typedef std::array<T, 3> C;
     C c1 = {{}};
-    // expected-error@algorithm:* 2 {{invalid operands to binary expression}}
+    // expected-error@*:* 2 {{invalid operands to binary expression}}
     TEST_IGNORE_NODISCARD (c1 == c1);
     TEST_IGNORE_NODISCARD (c1 < c1);
   }
   {
     typedef NoCompare<1> T;
     typedef std::array<T, 3> C;
     C c1 = {{}};
-    // expected-error@algorithm:* 2 {{invalid operands to binary expression}}
+    // expected-error@*:* 2 {{invalid operands to binary expression}}
     TEST_IGNORE_NODISCARD (c1 != c1);
     TEST_IGNORE_NODISCARD (c1 > c1);
   }
   {
     typedef NoCompare<2> T;
     typedef std::array<T, 0> C;
     C c1 = {{}};
-    // expected-error@algorithm:* 2 {{invalid operands to binary expression}}
+    // expected-error@*:* 2 {{invalid operands to binary expression}}
     TEST_IGNORE_NODISCARD (c1 == c1);
     TEST_IGNORE_NODISCARD (c1 < c1);
   }
 
   return 0;
 }