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 
26 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
27 #  pragma GCC system_header
28 #endif
29 
30 #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
31 
32 _LIBCPP_BEGIN_NAMESPACE_STD
33 
34 namespace ranges {
35 
36 template <class _InIter>
37 using next_permutation_result = in_found_result<_InIter>;
38 
39 namespace __next_permutation {
40 
41 struct __fn {
42   template <bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent, class _Comp = ranges::less, class _Proj = identity>
43     requires sortable<_Iter, _Comp, _Proj>
44   _LIBCPP_HIDE_FROM_ABI constexpr next_permutation_result<_Iter>
45   operator()(_Iter __first, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {
46     auto __result = std::__next_permutation<_RangeAlgPolicy>(
47         std::move(__first), std::move(__last), std::__make_projected(__comp, __proj));
48     return {std::move(__result.first), std::move(__result.second)};
49   }
50 
51   template <bidirectional_range _Range, class _Comp = ranges::less, class _Proj = identity>
52     requires sortable<iterator_t<_Range>, _Comp, _Proj>
53   _LIBCPP_HIDE_FROM_ABI constexpr next_permutation_result<borrowed_iterator_t<_Range>>
54   operator()(_Range&& __range, _Comp __comp = {}, _Proj __proj = {}) const {
55     auto __result = std::__next_permutation<_RangeAlgPolicy>(
56         ranges::begin(__range), ranges::end(__range), std::__make_projected(__comp, __proj));
57     return {std::move(__result.first), std::move(__result.second)};
58   }
59 };
60 
61 } // namespace __next_permutation
62 
63 inline namespace __cpo {
64 constexpr inline auto next_permutation = __next_permutation::__fn{};
65 } // namespace __cpo
66 } // namespace ranges
67 
68 _LIBCPP_END_NAMESPACE_STD
69 
70 #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
71 
72 #endif // _LIBCPP___ALGORITHM_RANGES_NEXT_PERMUTATION_H
73