xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/ranges_lexicographical_compare.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
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 <__config>
13 #include <__functional/identity.h>
14 #include <__functional/invoke.h>
15 #include <__functional/ranges_operations.h>
16 #include <__iterator/concepts.h>
17 #include <__iterator/projected.h>
18 #include <__ranges/access.h>
19 #include <__ranges/concepts.h>
20 #include <__utility/move.h>
21 
22 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23 #  pragma GCC system_header
24 #endif
25 
26 _LIBCPP_PUSH_MACROS
27 #include <__undef_macros>
28 
29 #if _LIBCPP_STD_VER >= 20
30 
31 _LIBCPP_BEGIN_NAMESPACE_STD
32 
33 namespace ranges {
34 namespace __lexicographical_compare {
35 struct __fn {
36   template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Proj1, class _Proj2, class _Comp>
__lexicographical_compare_impl__fn37   _LIBCPP_HIDE_FROM_ABI constexpr static bool __lexicographical_compare_impl(
38       _Iter1 __first1,
39       _Sent1 __last1,
40       _Iter2 __first2,
41       _Sent2 __last2,
42       _Comp& __comp,
43       _Proj1& __proj1,
44       _Proj2& __proj2) {
45     while (__first2 != __last2) {
46       if (__first1 == __last1 || std::invoke(__comp, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__first2)))
47         return true;
48       if (std::invoke(__comp, std::invoke(__proj2, *__first2), std::invoke(__proj1, *__first1)))
49         return false;
50       ++__first1;
51       ++__first2;
52     }
53     return false;
54   }
55 
56   template <input_iterator _Iter1,
57             sentinel_for<_Iter1> _Sent1,
58             input_iterator _Iter2,
59             sentinel_for<_Iter2> _Sent2,
60             class _Proj1                                                                           = identity,
61             class _Proj2                                                                           = identity,
62             indirect_strict_weak_order<projected<_Iter1, _Proj1>, projected<_Iter2, _Proj2>> _Comp = ranges::less>
operator__fn63   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(
64       _Iter1 __first1,
65       _Sent1 __last1,
66       _Iter2 __first2,
67       _Sent2 __last2,
68       _Comp __comp   = {},
69       _Proj1 __proj1 = {},
70       _Proj2 __proj2 = {}) const {
71     return __lexicographical_compare_impl(
72         std::move(__first1), std::move(__last1), std::move(__first2), std::move(__last2), __comp, __proj1, __proj2);
73   }
74 
75   template <input_range _Range1,
76             input_range _Range2,
77             class _Proj1 = identity,
78             class _Proj2 = identity,
79             indirect_strict_weak_order<projected<iterator_t<_Range1>, _Proj1>, projected<iterator_t<_Range2>, _Proj2>>
80                 _Comp = ranges::less>
operator__fn81   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(
82       _Range1&& __range1, _Range2&& __range2, _Comp __comp = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
83     return __lexicographical_compare_impl(
84         ranges::begin(__range1),
85         ranges::end(__range1),
86         ranges::begin(__range2),
87         ranges::end(__range2),
88         __comp,
89         __proj1,
90         __proj2);
91   }
92 };
93 } // namespace __lexicographical_compare
94 
95 inline namespace __cpo {
96 inline constexpr auto lexicographical_compare = __lexicographical_compare::__fn{};
97 } // namespace __cpo
98 } // namespace ranges
99 
100 _LIBCPP_END_NAMESPACE_STD
101 
102 #endif // _LIBCPP_STD_VER >= 20
103 
104 _LIBCPP_POP_MACROS
105 
106 #endif // _LIBCPP___ALGORITHM_RANGES_LEXICOGRAPHICAL_COMPARE_H
107