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_PREV_PERMUTATION_H
10 #define _LIBCPP___ALGORITHM_RANGES_PREV_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/prev_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 #if _LIBCPP_STD_VER >= 20
32 
33 _LIBCPP_BEGIN_NAMESPACE_STD
34 
35 namespace ranges {
36 
37 template <class _InIter>
38 using prev_permutation_result = in_found_result<_InIter>;
39 
40 namespace __prev_permutation {
41 
42 struct __fn {
43   template <bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent, class _Comp = ranges::less, class _Proj = identity>
44     requires sortable<_Iter, _Comp, _Proj>
45   _LIBCPP_HIDE_FROM_ABI constexpr prev_permutation_result<_Iter>
46   operator()(_Iter __first, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {
47     auto __result = std::__prev_permutation<_RangeAlgPolicy>(
48         std::move(__first), std::move(__last), std::__make_projected(__comp, __proj));
49     return {std::move(__result.first), std::move(__result.second)};
50   }
51 
52   template <bidirectional_range _Range, class _Comp = ranges::less, class _Proj = identity>
53     requires sortable<iterator_t<_Range>, _Comp, _Proj>
54   _LIBCPP_HIDE_FROM_ABI constexpr prev_permutation_result<borrowed_iterator_t<_Range>>
55   operator()(_Range&& __range, _Comp __comp = {}, _Proj __proj = {}) const {
56     auto __result = std::__prev_permutation<_RangeAlgPolicy>(
57         ranges::begin(__range), ranges::end(__range), std::__make_projected(__comp, __proj));
58     return {std::move(__result.first), std::move(__result.second)};
59   }
60 };
61 
62 } // namespace __prev_permutation
63 
64 inline namespace __cpo {
65 constexpr inline auto prev_permutation = __prev_permutation::__fn{};
66 } // namespace __cpo
67 } // namespace ranges
68 
69 _LIBCPP_END_NAMESPACE_STD
70 
71 #endif // _LIBCPP_STD_VER >= 20
72 
73 #endif // _LIBCPP___ALGORITHM_RANGES_PREV_PERMUTATION_H
74