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 > 17
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,
40             class _Pred, class _Proj1, class _Proj2>
41   static _LIBCPP_HIDE_FROM_ABI constexpr
42   mismatch_result<_I1, _I2>
43   __go(_I1 __first1, _S1 __last1, _I2 __first2, _S2 __last2,
44        _Pred& __pred, _Proj1& __proj1, _Proj2& __proj2) {
45     while (__first1 != __last1 && __first2 != __last2) {
46       if (!std::invoke(__pred, std::invoke(__proj1, *__first1), std::invoke(__proj2, *__first2)))
47         break;
48       ++__first1;
49       ++__first2;
50     }
51     return {std::move(__first1), std::move(__first2)};
52   }
53 
54   template <input_iterator _I1, sentinel_for<_I1> _S1,
55             input_iterator _I2, sentinel_for<_I2> _S2,
56             class _Pred = ranges::equal_to, class _Proj1 = identity, class _Proj2 = identity>
57     requires indirectly_comparable<_I1, _I2, _Pred, _Proj1, _Proj2>
58   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr
59   mismatch_result<_I1, _I2> operator()(_I1 __first1, _S1 __last1, _I2 __first2, _S2 __last2,
60                                        _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
61     return __go(std::move(__first1), __last1, std::move(__first2), __last2, __pred, __proj1, __proj2);
62   }
63 
64   template <input_range _R1, input_range _R2,
65             class _Pred = ranges::equal_to, class _Proj1 = identity, class _Proj2 = identity>
66     requires indirectly_comparable<iterator_t<_R1>, iterator_t<_R2>, _Pred, _Proj1, _Proj2>
67   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr
68   mismatch_result<borrowed_iterator_t<_R1>, borrowed_iterator_t<_R2>>
69   operator()(_R1&& __r1, _R2&& __r2, _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
70     return __go(ranges::begin(__r1), ranges::end(__r1), ranges::begin(__r2), ranges::end(__r2),
71                 __pred, __proj1, __proj2);
72   }
73 };
74 } // namespace __mismatch
75 
76 inline namespace __cpo {
77   constexpr inline auto mismatch = __mismatch::__fn{};
78 } // namespace __cpo
79 } // namespace ranges
80 
81 #endif // _LIBCPP_STD_VER > 17
82 
83 _LIBCPP_END_NAMESPACE_STD
84 
85 #endif // _LIBCPP___ALGORITHM_RANGES_MISMATCH_H
86