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 _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 prev_permutation_result = in_found_result<_InIter>;
42 
43 namespace __prev_permutation {
44 
45 struct __fn {
46   template <bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent, class _Comp = ranges::less, class _Proj = identity>
47     requires sortable<_Iter, _Comp, _Proj>
48   _LIBCPP_HIDE_FROM_ABI constexpr prev_permutation_result<_Iter>
49   operator()(_Iter __first, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {
50     auto __result = std::__prev_permutation<_RangeAlgPolicy>(
51         std::move(__first), std::move(__last), std::__make_projected(__comp, __proj));
52     return {std::move(__result.first), std::move(__result.second)};
53   }
54 
55   template <bidirectional_range _Range, 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>>
58   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 } // namespace __prev_permutation
66 
67 inline namespace __cpo {
68 constexpr inline auto prev_permutation = __prev_permutation::__fn{};
69 } // namespace __cpo
70 } // namespace ranges
71 
72 _LIBCPP_END_NAMESPACE_STD
73 
74 #endif // _LIBCPP_STD_VER >= 20
75 
76 _LIBCPP_POP_MACROS
77 
78 #endif // _LIBCPP___ALGORITHM_RANGES_PREV_PERMUTATION_H
79