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
37template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
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
46template <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
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
57template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
58_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
59equal(_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
64template <class _InputIterator1, class _InputIterator2>
65_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
66equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
67 return std::equal(__first1, __last1, __first2, __equal_to());
68}
69
70#if _LIBCPP_STD_VER >= 14
71
72template <class _Iter1, class _Sent1, class _Iter2, class _Sent2, class _Pred, class _Proj1, class _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
84template <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
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
98template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
99_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
100equal(_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
121template <class _InputIterator1, class _InputIterator2>
122_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
123equal(_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