libcxx/include/__algorithm/ranges_next_permutation.h

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef _LIBCPP___ALGORITHM_RANGES_NEXT_PERMUTATION_H
  10 #define _LIBCPP___ALGORITHM_RANGES_NEXT_PERMUTATION_H
  11
  12 #include <__algorithm/in_found_result.h>
  13 #include <__algorithm/iterator_operations.h>
  14 #include <__algorithm/make_projected.h>
  15 #include <__algorithm/next_permutation.h>
  16 #include <__config>
  17 #include <__functional/identity.h>
  18 #include <__functional/ranges_operations.h>
  19 #include <__iterator/concepts.h>
  20 #include <__iterator/sortable.h>
  21 #include <__ranges/access.h>
  22 #include <__ranges/concepts.h>
  23 #include <__ranges/dangling.h>
  24 #include <__utility/move.h>
  25 #include <__utility/pair.h>
  26
  27 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  28 #  pragma GCC system_header
  29 #endif
  30
  31 _LIBCPP_PUSH_MACROS
  32 #include <__undef_macros>
  33
  34 #if _LIBCPP_STD_VER >= 20
  35
  36 _LIBCPP_BEGIN_NAMESPACE_STD
  37
  38 namespace ranges {
  39
  40 template <class _InIter>
  41 using next_permutation_result = in_found_result<_InIter>;
  42
  43 struct __next_permutation {
  44   template <bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent, class _Comp = ranges::less, class _Proj = identity>
  45     requires sortable<_Iter, _Comp, _Proj>
  46   _LIBCPP_HIDE_FROM_ABI constexpr next_permutation_result<_Iter>
  47   operator()(_Iter __first, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {
  48     auto __result = std::__next_permutation<_RangeAlgPolicy>(
  49         std::move(__first), std::move(__last), std::__make_projected(__comp, __proj));
  50     return {std::move(__result.first), std::move(__result.second)};
  51   }
  52
  53   template <bidirectional_range _Range, class _Comp = ranges::less, class _Proj = identity>
  54     requires sortable<iterator_t<_Range>, _Comp, _Proj>
  55   _LIBCPP_HIDE_FROM_ABI constexpr next_permutation_result<borrowed_iterator_t<_Range>>
  56   operator()(_Range&& __range, _Comp __comp = {}, _Proj __proj = {}) const {
  57     auto __result = std::__next_permutation<_RangeAlgPolicy>(
  58         ranges::begin(__range), ranges::end(__range), std::__make_projected(__comp, __proj));
  59     return {std::move(__result.first), std::move(__result.second)};
  60   }
  61 };
  62
  63 inline namespace __cpo {
  64 constexpr inline auto next_permutation = __next_permutation{};
  65 } // namespace __cpo
  66 } // namespace ranges
  67
  68 _LIBCPP_END_NAMESPACE_STD
  69
  70 #endif // _LIBCPP_STD_VER >= 20
  71
  72 _LIBCPP_POP_MACROS
  73
  74 #endif // _LIBCPP___ALGORITHM_RANGES_NEXT_PERMUTATION_H