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_MISMATCH_H
10 #define _LIBCPP___ALGORITHM_RANGES_MISMATCH_H
11 
12 #include <__algorithm/in_in_result.h>
13 #include <__config>
14 #include <__functional/identity.h>
15 #include <__functional/invoke.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 <__ranges/dangling.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_BEGIN_NAMESPACE_STD
29 
30 #if _LIBCPP_STD_VER >= 20
31 
32 namespace ranges {
33 
34 template <class _I1, class _I2>
35 using mismatch_result = in_in_result<_I1, _I2>;
36 
37 namespace __mismatch {
38 struct __fn {
39   template <class _I1, class _S1, class _I2, class _S2, class _Pred, class _Proj1, class _Proj2>
40   static _LIBCPP_HIDE_FROM_ABI constexpr mismatch_result<_I1, _I2>
41   __go(_I1 __first1, _S1 __last1, _I2 __first2, _S2 __last2, _Pred& __pred, _Proj1& __proj1, _Proj2& __proj2) {
42     while (__first1 != __last1 && __first2 != __last2) {
43       if (!std::invoke(__pred, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__first2)))
44         break;
45       ++__first1;
46       ++__first2;
47     }
48     return {std::move(__first1), std::move(__first2)};
49   }
50 
51   template <input_iterator _I1,
52             sentinel_for<_I1> _S1,
53             input_iterator _I2,
54             sentinel_for<_I2> _S2,
55             class _Pred  = ranges::equal_to,
56             class _Proj1 = identity,
57             class _Proj2 = identity>
58     requires indirectly_comparable<_I1, _I2, _Pred, _Proj1, _Proj2>
59   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr mismatch_result<_I1, _I2> operator()(
60       _I1 __first1, _S1 __last1, _I2 __first2, _S2 __last2, _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {})
61       const {
62     return __go(std::move(__first1), __last1, std::move(__first2), __last2, __pred, __proj1, __proj2);
63   }
64 
65   template <input_range _R1,
66             input_range _R2,
67             class _Pred  = ranges::equal_to,
68             class _Proj1 = identity,
69             class _Proj2 = identity>
70     requires indirectly_comparable<iterator_t<_R1>, iterator_t<_R2>, _Pred, _Proj1, _Proj2>
71   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr mismatch_result<borrowed_iterator_t<_R1>,
72                                                                         borrowed_iterator_t<_R2>>
73   operator()(_R1&& __r1, _R2&& __r2, _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
74     return __go(
75         ranges::begin(__r1), ranges::end(__r1), ranges::begin(__r2), ranges::end(__r2), __pred, __proj1, __proj2);
76   }
77 };
78 } // namespace __mismatch
79 
80 inline namespace __cpo {
81 constexpr inline auto mismatch = __mismatch::__fn{};
82 } // namespace __cpo
83 } // namespace ranges
84 
85 #endif // _LIBCPP_STD_VER >= 20
86 
87 _LIBCPP_END_NAMESPACE_STD
88 
89 #endif // _LIBCPP___ALGORITHM_RANGES_MISMATCH_H
90