1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9
10 #ifndef _LIBCPP___ALGORITHM_EQUAL_H
11 #define _LIBCPP___ALGORITHM_EQUAL_H
12
13 #include <__algorithm/comp.h>
14 #include <__algorithm/unwrap_iter.h>
15 #include <__config>
16 #include <__functional/identity.h>
17 #include <__functional/invoke.h>
18 #include <__iterator/distance.h>
19 #include <__iterator/iterator_traits.h>
20 #include <__string/constexpr_c_functions.h>
21 #include <__type_traits/desugars_to.h>
22 #include <__type_traits/enable_if.h>
23 #include <__type_traits/is_constant_evaluated.h>
24 #include <__type_traits/is_equality_comparable.h>
25 #include <__type_traits/is_volatile.h>
26 #include <__utility/move.h>
27
28 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
29 # pragma GCC system_header
30 #endif
31
32 _LIBCPP_PUSH_MACROS
33 #include <__undef_macros>
34
35 _LIBCPP_BEGIN_NAMESPACE_STD
36
37 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
__equal_iter_impl(_InputIterator1 __first1,_InputIterator1 __last1,_InputIterator2 __first2,_BinaryPredicate & __pred)38 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_iter_impl(
39 _InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate& __pred) {
40 for (; __first1 != __last1; ++__first1, (void)++__first2)
41 if (!__pred(*__first1, *__first2))
42 return false;
43 return true;
44 }
45
46 template <class _Tp,
47 class _Up,
48 class _BinaryPredicate,
49 __enable_if_t<__desugars_to_v<__equal_tag, _BinaryPredicate, _Tp, _Up> && !is_volatile<_Tp>::value &&
50 !is_volatile<_Up>::value && __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value,
51 int> = 0>
52 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
__equal_iter_impl(_Tp * __first1,_Tp * __last1,_Up * __first2,_BinaryPredicate &)53 __equal_iter_impl(_Tp* __first1, _Tp* __last1, _Up* __first2, _BinaryPredicate&) {
54 return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
55 }
56
57 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
58 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
equal(_InputIterator1 __first1,_InputIterator1 __last1,_InputIterator2 __first2,_BinaryPredicate __pred)59 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
60 return std::__equal_iter_impl(
61 std::__unwrap_iter(__first1), std::__unwrap_iter(__last1), std::__unwrap_iter(__first2), __pred);
62 }
63
64 template <class _InputIterator1, class _InputIterator2>
65 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
equal(_InputIterator1 __first1,_InputIterator1 __last1,_InputIterator2 __first2)66 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
67 return std::equal(__first1, __last1, __first2, __equal_to());
68 }
69
70 #if _LIBCPP_STD_VER >= 14
71
72 template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _Proj2>
__equal_impl(_Iter1 __first1,_Sent1 __last1,_Iter2 __first2,_Sent2 __last2,_Pred & __comp,_Proj1 & __proj1,_Proj2 & __proj2)73 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_impl(
74 _Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2, _Pred& __comp, _Proj1& __proj1, _Proj2& __proj2) {
75 while (__first1 != __last1 && __first2 != __last2) {
76 if (!std::__invoke(__comp, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2)))
77 return false;
78 ++__first1;
79 ++__first2;
80 }
81 return __first1 == __last1 && __first2 == __last2;
82 }
83
84 template <class _Tp,
85 class _Up,
86 class _Pred,
87 class _Proj1,
88 class _Proj2,
89 __enable_if_t<__desugars_to_v<__equal_tag, _Pred, _Tp, _Up> && __is_identity<_Proj1>::value &&
90 __is_identity<_Proj2>::value && !is_volatile<_Tp>::value && !is_volatile<_Up>::value &&
91 __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value,
92 int> = 0>
93 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
__equal_impl(_Tp * __first1,_Tp * __last1,_Up * __first2,_Up *,_Pred &,_Proj1 &,_Proj2 &)94 __equal_impl(_Tp* __first1, _Tp* __last1, _Up* __first2, _Up*, _Pred&, _Proj1&, _Proj2&) {
95 return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
96 }
97
98 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
99 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
equal(_InputIterator1 __first1,_InputIterator1 __last1,_InputIterator2 __first2,_InputIterator2 __last2,_BinaryPredicate __pred)100 equal(_InputIterator1 __first1,
101 _InputIterator1 __last1,
102 _InputIterator2 __first2,
103 _InputIterator2 __last2,
104 _BinaryPredicate __pred) {
105 if constexpr (__has_random_access_iterator_category<_InputIterator1>::value &&
106 __has_random_access_iterator_category<_InputIterator2>::value) {
107 if (std::distance(__first1, __last1) != std::distance(__first2, __last2))
108 return false;
109 }
110 __identity __proj;
111 return std::__equal_impl(
112 std::__unwrap_iter(__first1),
113 std::__unwrap_iter(__last1),
114 std::__unwrap_iter(__first2),
115 std::__unwrap_iter(__last2),
116 __pred,
117 __proj,
118 __proj);
119 }
120
121 template <class _InputIterator1, class _InputIterator2>
122 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
equal(_InputIterator1 __first1,_InputIterator1 __last1,_InputIterator2 __first2,_InputIterator2 __last2)123 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
124 return std::equal(__first1, __last1, __first2, __last2, __equal_to());
125 }
126
127 #endif // _LIBCPP_STD_VER >= 14
128
129 _LIBCPP_END_NAMESPACE_STD
130
131 _LIBCPP_POP_MACROS
132
133 #endif // _LIBCPP___ALGORITHM_EQUAL_H
134