xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/equal.h (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
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/operation_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_PUSH_MACROS
34 #include <__undef_macros>
35 
36 _LIBCPP_BEGIN_NAMESPACE_STD
37 
38 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
39 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_iter_impl(
40     _InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate& __pred) {
41   for (; __first1 != __last1; ++__first1, (void)++__first2)
42     if (!__pred(*__first1, *__first2))
43       return false;
44   return true;
45 }
46 
47 template <class _Tp,
48           class _Up,
49           class _BinaryPredicate,
50           __enable_if_t<__desugars_to<__equal_tag, _BinaryPredicate, _Tp, _Up>::value && !is_volatile<_Tp>::value &&
51                             !is_volatile<_Up>::value && __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value,
52                         int> = 0>
53 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
54 __equal_iter_impl(_Tp* __first1, _Tp* __last1, _Up* __first2, _BinaryPredicate&) {
55   return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
56 }
57 
58 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
59 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
60 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred) {
61   return std::__equal_iter_impl(
62       std::__unwrap_iter(__first1), std::__unwrap_iter(__last1), std::__unwrap_iter(__first2), __pred);
63 }
64 
65 template <class _InputIterator1, class _InputIterator2>
66 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
67 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
68   return std::equal(__first1, __last1, __first2, __equal_to());
69 }
70 
71 #if _LIBCPP_STD_VER >= 14
72 template <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
73 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
74 __equal(_InputIterator1 __first1,
75         _InputIterator1 __last1,
76         _InputIterator2 __first2,
77         _InputIterator2 __last2,
78         _BinaryPredicate __pred,
79         input_iterator_tag,
80         input_iterator_tag) {
81   for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void)++__first2)
82     if (!__pred(*__first1, *__first2))
83       return false;
84   return __first1 == __last1 && __first2 == __last2;
85 }
86 
87 template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _Proj2>
88 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __equal_impl(
89     _Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2, _Pred& __comp, _Proj1& __proj1, _Proj2& __proj2) {
90   while (__first1 != __last1 && __first2 != __last2) {
91     if (!std::__invoke(__comp, std::__invoke(__proj1, *__first1), std::__invoke(__proj2, *__first2)))
92       return false;
93     ++__first1;
94     ++__first2;
95   }
96   return __first1 == __last1 && __first2 == __last2;
97 }
98 
99 template <class _Tp,
100           class _Up,
101           class _Pred,
102           class _Proj1,
103           class _Proj2,
104           __enable_if_t<__desugars_to<__equal_tag, _Pred, _Tp, _Up>::value && __is_identity<_Proj1>::value &&
105                             __is_identity<_Proj2>::value && !is_volatile<_Tp>::value && !is_volatile<_Up>::value &&
106                             __libcpp_is_trivially_equality_comparable<_Tp, _Up>::value,
107                         int> = 0>
108 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
109 __equal_impl(_Tp* __first1, _Tp* __last1, _Up* __first2, _Up*, _Pred&, _Proj1&, _Proj2&) {
110   return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
111 }
112 
113 template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
114 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
115 __equal(_RandomAccessIterator1 __first1,
116         _RandomAccessIterator1 __last1,
117         _RandomAccessIterator2 __first2,
118         _RandomAccessIterator2 __last2,
119         _BinaryPredicate __pred,
120         random_access_iterator_tag,
121         random_access_iterator_tag) {
122   if (std::distance(__first1, __last1) != std::distance(__first2, __last2))
123     return false;
124   __identity __proj;
125   return std::__equal_impl(
126       std::__unwrap_iter(__first1),
127       std::__unwrap_iter(__last1),
128       std::__unwrap_iter(__first2),
129       std::__unwrap_iter(__last2),
130       __pred,
131       __proj,
132       __proj);
133 }
134 
135 template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
136 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
137 equal(_InputIterator1 __first1,
138       _InputIterator1 __last1,
139       _InputIterator2 __first2,
140       _InputIterator2 __last2,
141       _BinaryPredicate __pred) {
142   return std::__equal<_BinaryPredicate&>(
143       __first1,
144       __last1,
145       __first2,
146       __last2,
147       __pred,
148       typename iterator_traits<_InputIterator1>::iterator_category(),
149       typename iterator_traits<_InputIterator2>::iterator_category());
150 }
151 
152 template <class _InputIterator1, class _InputIterator2>
153 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
154 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
155   return std::__equal(
156       __first1,
157       __last1,
158       __first2,
159       __last2,
160       __equal_to(),
161       typename iterator_traits<_InputIterator1>::iterator_category(),
162       typename iterator_traits<_InputIterator2>::iterator_category());
163 }
164 #endif
165 
166 _LIBCPP_END_NAMESPACE_STD
167 
168 _LIBCPP_POP_MACROS
169 
170 #endif // _LIBCPP___ALGORITHM_EQUAL_H
171