xref: /llvm-project/libcxx/include/__algorithm/ranges_find_first_of.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_FIND_FIRST_OF_H
10 #define _LIBCPP___ALGORITHM_RANGES_FIND_FIRST_OF_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/indirectly_comparable.h>
18 #include <__ranges/access.h>
19 #include <__ranges/concepts.h>
20 #include <__ranges/dangling.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 >= 20
31 
32 _LIBCPP_BEGIN_NAMESPACE_STD
33 
34 namespace ranges {
35 struct __find_first_of {
36   template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _Proj2>
37   _LIBCPP_HIDE_FROM_ABI constexpr static _Iter1 __find_first_of_impl(
38       _Iter1 __first1,
39       _Sent1 __last1,
40       _Iter2 __first2,
41       _Sent2 __last2,
42       _Pred& __pred,
43       _Proj1& __proj1,
44       _Proj2& __proj2) {
45     for (; __first1 != __last1; ++__first1) {
46       for (auto __j = __first2; __j != __last2; ++__j) {
47         if (std::invoke(__pred, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__j)))
48           return __first1;
49       }
50     }
51     return __first1;
52   }
53 
54   template <input_iterator _Iter1,
55             sentinel_for<_Iter1> _Sent1,
56             forward_iterator _Iter2,
57             sentinel_for<_Iter2> _Sent2,
58             class _Pred  = ranges::equal_to,
59             class _Proj1 = identity,
60             class _Proj2 = identity>
61     requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2>
62   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Iter1 operator()(
63       _Iter1 __first1,
64       _Sent1 __last1,
65       _Iter2 __first2,
66       _Sent2 __last2,
67       _Pred __pred   = {},
68       _Proj1 __proj1 = {},
69       _Proj2 __proj2 = {}) const {
70     return __find_first_of_impl(
71         std::move(__first1), std::move(__last1), std::move(__first2), std::move(__last2), __pred, __proj1, __proj2);
72   }
73 
74   template <input_range _Range1,
75             forward_range _Range2,
76             class _Pred  = ranges::equal_to,
77             class _Proj1 = identity,
78             class _Proj2 = identity>
79     requires indirectly_comparable<iterator_t<_Range1>, iterator_t<_Range2>, _Pred, _Proj1, _Proj2>
80   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Range1> operator()(
81       _Range1&& __range1, _Range2&& __range2, _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
82     return __find_first_of_impl(
83         ranges::begin(__range1),
84         ranges::end(__range1),
85         ranges::begin(__range2),
86         ranges::end(__range2),
87         __pred,
88         __proj1,
89         __proj2);
90   }
91 };
92 
93 inline namespace __cpo {
94 inline constexpr auto find_first_of = __find_first_of{};
95 } // namespace __cpo
96 } // namespace ranges
97 
98 _LIBCPP_END_NAMESPACE_STD
99 
100 #endif // _LIBCPP_STD_VER >= 20
101 
102 _LIBCPP_POP_MACROS
103 
104 #endif // _LIBCPP___ALGORITHM_RANGES_FIND_FIRST_OF_H
105