xref: /llvm-project/libcxx/include/__algorithm/ranges_lexicographical_compare.h (revision d07fdf9779f7dead2828cfb18bafbd9a2c085920)
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_LEXICOGRAPHICAL_COMPARE_H
10 #define _LIBCPP___ALGORITHM_RANGES_LEXICOGRAPHICAL_COMPARE_H
11 
12 #include <__algorithm/lexicographical_compare.h>
13 #include <__algorithm/unwrap_range.h>
14 #include <__config>
15 #include <__functional/identity.h>
16 #include <__functional/invoke.h>
17 #include <__functional/ranges_operations.h>
18 #include <__iterator/concepts.h>
19 #include <__iterator/projected.h>
20 #include <__ranges/access.h>
21 #include <__ranges/concepts.h>
22 #include <__utility/move.h>
23 
24 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
25 #  pragma GCC system_header
26 #endif
27 
28 _LIBCPP_PUSH_MACROS
29 #include <__undef_macros>
30 
31 #if _LIBCPP_STD_VER >= 20
32 
33 _LIBCPP_BEGIN_NAMESPACE_STD
34 
35 namespace ranges {
36 struct __lexicographical_compare {
37   template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Proj1, class _Proj2, class _Comp>
38   static _LIBCPP_HIDE_FROM_ABI constexpr bool __lexicographical_compare_unwrap(
39       _Iter1 __first1,
40       _Sent1 __last1,
41       _Iter2 __first2,
42       _Sent2 __last2,
43       _Comp& __comp,
44       _Proj1& __proj1,
45       _Proj2& __proj2) {
46     auto [__first1_un, __last1_un] = std::__unwrap_range(std::move(__first1), std::move(__last1));
47     auto [__first2_un, __last2_un] = std::__unwrap_range(std::move(__first2), std::move(__last2));
48     return std::__lexicographical_compare(
49         std::move(__first1_un),
50         std::move(__last1_un),
51         std::move(__first2_un),
52         std::move(__last2_un),
53         __comp,
54         __proj1,
55         __proj2);
56   }
57 
58   template <input_iterator _Iter1,
59             sentinel_for<_Iter1> _Sent1,
60             input_iterator _Iter2,
61             sentinel_for<_Iter2> _Sent2,
62             class _Proj1                                                                           = identity,
63             class _Proj2                                                                           = identity,
64             indirect_strict_weak_order<projected<_Iter1, _Proj1>, projected<_Iter2, _Proj2>> _Comp = ranges::less>
65   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(
66       _Iter1 __first1,
67       _Sent1 __last1,
68       _Iter2 __first2,
69       _Sent2 __last2,
70       _Comp __comp   = {},
71       _Proj1 __proj1 = {},
72       _Proj2 __proj2 = {}) const {
73     return __lexicographical_compare_unwrap(
74         std::move(__first1), std::move(__last1), std::move(__first2), std::move(__last2), __comp, __proj1, __proj2);
75   }
76 
77   template <input_range _Range1,
78             input_range _Range2,
79             class _Proj1 = identity,
80             class _Proj2 = identity,
81             indirect_strict_weak_order<projected<iterator_t<_Range1>, _Proj1>, projected<iterator_t<_Range2>, _Proj2>>
82                 _Comp = ranges::less>
83   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(
84       _Range1&& __range1, _Range2&& __range2, _Comp __comp = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
85     return __lexicographical_compare_unwrap(
86         ranges::begin(__range1),
87         ranges::end(__range1),
88         ranges::begin(__range2),
89         ranges::end(__range2),
90         __comp,
91         __proj1,
92         __proj2);
93   }
94 };
95 
96 inline namespace __cpo {
97 inline constexpr auto lexicographical_compare = __lexicographical_compare{};
98 } // namespace __cpo
99 } // namespace ranges
100 
101 _LIBCPP_END_NAMESPACE_STD
102 
103 #endif // _LIBCPP_STD_VER >= 20
104 
105 _LIBCPP_POP_MACROS
106 
107 #endif // _LIBCPP___ALGORITHM_RANGES_LEXICOGRAPHICAL_COMPARE_H
108