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 > 17
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 
44   template <bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent,
45             class _Comp = ranges::less, class _Proj = identity>
46     requires sortable<_Iter, _Comp, _Proj>
47   _LIBCPP_HIDE_FROM_ABI constexpr prev_permutation_result<_Iter>
operator__fn48   operator()(_Iter __first, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {
49     auto __result = std::__prev_permutation<_RangeAlgPolicy>(
50         std::move(__first), std::move(__last), std::__make_projected(__comp, __proj));
51     return {std::move(__result.first), std::move(__result.second)};
52   }
53 
54   template <bidirectional_range _Range,
55             class _Comp = ranges::less, class _Proj = identity>
56     requires sortable<iterator_t<_Range>, _Comp, _Proj>
57   _LIBCPP_HIDE_FROM_ABI constexpr prev_permutation_result<borrowed_iterator_t<_Range>>
operator__fn58   operator()(_Range&& __range, _Comp __comp = {}, _Proj __proj = {}) const {
59     auto __result = std::__prev_permutation<_RangeAlgPolicy>(
60         ranges::begin(__range), ranges::end(__range), std::__make_projected(__comp, __proj));
61     return {std::move(__result.first), std::move(__result.second)};
62   }
63 
64 };
65 
66 } // namespace __prev_permutation
67 
68 inline namespace __cpo {
69 constexpr inline auto prev_permutation = __prev_permutation::__fn{};
70 } // namespace __cpo
71 } // namespace ranges
72 
73 _LIBCPP_END_NAMESPACE_STD
74 
75 #endif // _LIBCPP_STD_VER > 17
76 
77 #endif // _LIBCPP___ALGORITHM_RANGES_PREV_PERMUTATION_H
78