xref: /llvm-project/libcxx/include/__algorithm/ranges_starts_with.h (revision d10dc5a06fac4dcabf2264c64c8672c6f6ae36fb)
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_STARTS_WITH_H
10 #define _LIBCPP___ALGORITHM_RANGES_STARTS_WITH_H
11 
12 #include <__algorithm/in_in_result.h>
13 #include <__algorithm/ranges_mismatch.h>
14 #include <__config>
15 #include <__functional/identity.h>
16 #include <__functional/ranges_operations.h>
17 #include <__iterator/concepts.h>
18 #include <__iterator/indirectly_comparable.h>
19 #include <__ranges/access.h>
20 #include <__ranges/concepts.h>
21 #include <__utility/move.h>
22 
23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24 #  pragma GCC system_header
25 #endif
26 
27 _LIBCPP_PUSH_MACROS
28 #include <__undef_macros>
29 
30 #if _LIBCPP_STD_VER >= 23
31 
32 _LIBCPP_BEGIN_NAMESPACE_STD
33 
34 namespace ranges {
35 struct __starts_with {
36   template <input_iterator _Iter1,
37             sentinel_for<_Iter1> _Sent1,
38             input_iterator _Iter2,
39             sentinel_for<_Iter2> _Sent2,
40             class _Pred  = ranges::equal_to,
41             class _Proj1 = identity,
42             class _Proj2 = identity>
43     requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2>
44   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static constexpr bool operator()(
45       _Iter1 __first1,
46       _Sent1 __last1,
47       _Iter2 __first2,
48       _Sent2 __last2,
49       _Pred __pred   = {},
50       _Proj1 __proj1 = {},
51       _Proj2 __proj2 = {}) {
52     return __mismatch::__go(
53                std::move(__first1),
54                std::move(__last1),
55                std::move(__first2),
56                std::move(__last2),
57                __pred,
58                __proj1,
59                __proj2)
60                .in2 == __last2;
61   }
62 
63   template <input_range _Range1,
64             input_range _Range2,
65             class _Pred  = ranges::equal_to,
66             class _Proj1 = identity,
67             class _Proj2 = identity>
68     requires indirectly_comparable<iterator_t<_Range1>, iterator_t<_Range2>, _Pred, _Proj1, _Proj2>
69   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static constexpr bool
70   operator()(_Range1&& __range1, _Range2&& __range2, _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) {
71     return __mismatch::__go(
72                ranges::begin(__range1),
73                ranges::end(__range1),
74                ranges::begin(__range2),
75                ranges::end(__range2),
76                __pred,
77                __proj1,
78                __proj2)
79                .in2 == ranges::end(__range2);
80   }
81 };
82 inline namespace __cpo {
83 inline constexpr auto starts_with = __starts_with{};
84 } // namespace __cpo
85 } // namespace ranges
86 
87 _LIBCPP_END_NAMESPACE_STD
88 
89 #endif // _LIBCPP_STD_VER >= 23
90 
91 _LIBCPP_POP_MACROS
92 
93 #endif // _LIBCPP___ALGORITHM_RANGES_STARTS_WITH_H
94