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/enable_if.h>
22 #include <__type_traits/integral_constant.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 <__type_traits/predicate_traits.h>
27 #include <__utility/move.h>
28 
29 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
30 #  pragma GCC system_header
31 #endif
32 
33 _LIBCPP_BEGIN_NAMESPACE_STD
34 
35 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
36 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_iter_impl(
37     _InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate& __pred) {
38   for (; __first1 != __last1; ++__first1, (void)++__first2)
39     if (!__pred(*__first1, *__first2))
40       return false;
41   return true;
42 }
43 
44 template <
45     class _Tp,
46     class _Up,
47     class _BinaryPredicate,
48     __enable_if_t<__is_trivial_equality_predicate<_BinaryPredicate, _Tp, _Up>::value && !is_volatile<_Tp>::value &&
49                       !is_volatile<_Up>::value && __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value,
50                   int> = 0>
51 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
52 __equal_iter_impl(_Tp* __first1, _Tp* __last1, _Up* __first2, _BinaryPredicate&) {
53   return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
54 }
55 
56 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
57 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
58 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
59   return std::__equal_iter_impl(
60       std::__unwrap_iter(__first1), std::__unwrap_iter(__last1), std::__unwrap_iter(__first2), __pred);
61 }
62 
63 template <class _InputIterator1, class _InputIterator2>
64 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
65 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
66   return std::equal(__first1, __last1, __first2, __equal_to());
67 }
68 
69 #if _LIBCPP_STD_VER >= 14
70 template <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
71 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
72 __equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
73         _BinaryPredicate __pred, input_iterator_tag, input_iterator_tag) {
74   for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void)++__first2)
75     if (!__pred(*__first1, *__first2))
76       return false;
77   return __first1 == __last1 && __first2 == __last2;
78 }
79 
80 template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _Proj2>
81 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_impl(
82     _Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2, _Pred& __comp, _Proj1& __proj1, _Proj2& __proj2) {
83   while (__first1 != __last1 && __first2 != __last2) {
84     if (!std::__invoke(__comp, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2)))
85       return false;
86     ++__first1;
87     ++__first2;
88   }
89   return __first1 == __last1 && __first2 == __last2;
90 }
91 
92 template <class _Tp,
93           class _Up,
94           class _Pred,
95           class _Proj1,
96           class _Proj2,
97           __enable_if_t<__is_trivial_equality_predicate<_Pred, _Tp, _Up>::value && __is_identity<_Proj1>::value &&
98                             __is_identity<_Proj2>::value && !is_volatile<_Tp>::value && !is_volatile<_Up>::value &&
99                             __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value,
100                         int> = 0>
101 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_impl(
102     _Tp* __first1, _Tp* __last1, _Up* __first2, _Up*, _Pred&, _Proj1&, _Proj2&) {
103   return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
104 }
105 
106 template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
107 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
108 __equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1, _RandomAccessIterator2 __first2,
109         _RandomAccessIterator2 __last2, _BinaryPredicate __pred, random_access_iterator_tag,
110         random_access_iterator_tag) {
111   if (_VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
112     return false;
113   __identity __proj;
114   return std::__equal_impl(
115       std::__unwrap_iter(__first1),
116       std::__unwrap_iter(__last1),
117       std::__unwrap_iter(__first2),
118       std::__unwrap_iter(__last2),
119       __pred,
120       __proj,
121       __proj);
122 }
123 
124 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
125 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
126 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
127       _BinaryPredicate __pred) {
128   return _VSTD::__equal<_BinaryPredicate&>(
129       __first1, __last1, __first2, __last2, __pred, typename iterator_traits<_InputIterator1>::iterator_category(),
130       typename iterator_traits<_InputIterator2>::iterator_category());
131 }
132 
133 template <class _InputIterator1, class _InputIterator2>
134 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
135 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
136   return std::__equal(
137       __first1,
138       __last1,
139       __first2,
140       __last2,
141       __equal_to(),
142       typename iterator_traits<_InputIterator1>::iterator_category(),
143       typename iterator_traits<_InputIterator2>::iterator_category());
144 }
145 #endif
146 
147 _LIBCPP_END_NAMESPACE_STD
148 
149 #endif // _LIBCPP___ALGORITHM_EQUAL_H
150