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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___ITERATOR_CPP17_ITERATOR_CONCEPTS_H
10#define _LIBCPP___ITERATOR_CPP17_ITERATOR_CONCEPTS_H
11
12#include <__concepts/boolean_testable.h>
13#include <__concepts/convertible_to.h>
14#include <__concepts/same_as.h>
15#include <__config>
16#include <__iterator/iterator_traits.h>
17#include <__type_traits/is_constructible.h>
18#include <__type_traits/is_convertible.h>
19#include <__type_traits/is_signed.h>
20#include <__type_traits/is_void.h>
21#include <__utility/as_const.h>
22#include <__utility/forward.h>
23#include <__utility/move.h>
24#include <__utility/swap.h>
25
26#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
27# pragma GCC system_header
28#endif
29
30_LIBCPP_PUSH_MACROS
31#include <__undef_macros>
32
33#if _LIBCPP_STD_VER >= 20
34
35_LIBCPP_BEGIN_NAMESPACE_STD
36
37template <class _Tp>
38concept __cpp17_move_constructible = is_move_constructible_v<_Tp>;
39
40template <class _Tp>
41concept __cpp17_copy_constructible = __cpp17_move_constructible<_Tp> && is_copy_constructible_v<_Tp>;
42
43template <class _Tp>
44concept __cpp17_move_assignable = requires(_Tp __lhs, _Tp __rhs) {
45 { __lhs = std::move(__rhs) } -> same_as<_Tp&>;
46};
47
48template <class _Tp>
49concept __cpp17_copy_assignable = __cpp17_move_assignable<_Tp> && requires(_Tp __lhs, _Tp __rhs) {
50 { __lhs = __rhs } -> same_as<_Tp&>;
51 { __lhs = std::as_const(__rhs) } -> same_as<_Tp&>;
52};
53
54template <class _Tp>
55concept __cpp17_destructible = requires(_Tp __v) { __v.~_Tp(); };
56
57template <class _Tp>
58concept __cpp17_equality_comparable = requires(_Tp __lhs, _Tp __rhs) {
59 { __lhs == __rhs } -> __boolean_testable;
60 { std::as_const(__lhs) == __rhs } -> __boolean_testable;
61 { __lhs == std::as_const(__rhs) } -> __boolean_testable;
62 { std::as_const(__lhs) == std::as_const(__rhs) } -> __boolean_testable;
63};
64
65template <class _Tp>
66concept __cpp17_default_constructible = is_default_constructible_v<_Tp>;
67
68template <class _Iter>
69concept __cpp17_iterator =
70 __cpp17_copy_constructible<_Iter> && __cpp17_copy_assignable<_Iter> && __cpp17_destructible<_Iter> &&
71 (is_signed_v<__iter_diff_t<_Iter>> || is_void_v<__iter_diff_t<_Iter>>) && requires(_Iter __iter) {
72 { *__iter };
73 { ++__iter } -> same_as<_Iter&>;
74 };
75
76template <class _Iter>
77concept __cpp17_input_iterator =
78 __cpp17_iterator<_Iter> && __cpp17_equality_comparable<_Iter> && requires(_Iter __lhs, _Iter __rhs) {
79 { __lhs != __rhs } -> __boolean_testable;
80 { std::as_const(__lhs) != __rhs } -> __boolean_testable;
81 { __lhs != std::as_const(__rhs) } -> __boolean_testable;
82 { std::as_const(__lhs) != std::as_const(__rhs) } -> __boolean_testable;
83
84 { *__lhs } -> same_as<__iter_reference<_Iter>>;
85 { *std::as_const(__lhs) } -> same_as<__iter_reference<_Iter>>;
86
87 { ++__lhs } -> same_as<_Iter&>;
88 { (void)__lhs++ };
89 { *__lhs++ };
90 };
91
92template <class _Iter, class _WriteTo>
93concept __cpp17_output_iterator = __cpp17_iterator<_Iter> && requires(_Iter __iter, _WriteTo __write) {
94 { *__iter = std::forward<_WriteTo>(__write) };
95 { ++__iter } -> same_as<_Iter&>;
96 { __iter++ } -> convertible_to<const _Iter&>;
97 { *__iter++ = std::forward<_WriteTo>(__write) };
98};
99
100template <class _Iter>
101concept __cpp17_forward_iterator =
102 __cpp17_input_iterator<_Iter> && __cpp17_default_constructible<_Iter> && requires(_Iter __iter) {
103 { __iter++ } -> convertible_to<const _Iter&>;
104 { *__iter++ } -> same_as<__iter_reference<_Iter>>;
105 };
106
107template <class _Iter>
108concept __cpp17_bidirectional_iterator = __cpp17_forward_iterator<_Iter> && requires(_Iter __iter) {
109 { --__iter } -> same_as<_Iter&>;
110 { __iter-- } -> convertible_to<const _Iter&>;
111 { *__iter-- } -> same_as<__iter_reference<_Iter>>;
112};
113
114template <class _Iter>
115concept __cpp17_random_access_iterator =
116 __cpp17_bidirectional_iterator<_Iter> && requires(_Iter __iter, __iter_diff_t<_Iter> __n) {
117 { __iter += __n } -> same_as<_Iter&>;
118
119 { __iter + __n } -> same_as<_Iter>;
120 { __n + __iter } -> same_as<_Iter>;
121 { std::as_const(__iter) + __n } -> same_as<_Iter>;
122 { __n + std::as_const(__iter) } -> same_as<_Iter>;
123
124 { __iter -= __n } -> same_as<_Iter&>;
125 { __iter - __n } -> same_as<_Iter>;
126 { std::as_const(__iter) - __n } -> same_as<_Iter>;
127
128 { __iter - __iter } -> same_as<__iter_diff_t<_Iter>>;
129 { std::as_const(__iter) - __iter } -> same_as<__iter_diff_t<_Iter>>;
130 { __iter - std::as_const(__iter) } -> same_as<__iter_diff_t<_Iter>>;
131 { std::as_const(__iter) - std::as_const(__iter) } -> same_as<__iter_diff_t<_Iter>>;
132
133 { __iter[__n] } -> convertible_to<__iter_reference<_Iter>>;
134 { std::as_const(__iter)[__n] } -> convertible_to<__iter_reference<_Iter>>;
135
136 { __iter < __iter } -> __boolean_testable;
137 { std::as_const(__iter) < __iter } -> __boolean_testable;
138 { __iter < std::as_const(__iter) } -> __boolean_testable;
139 { std::as_const(__iter) < std::as_const(__iter) } -> __boolean_testable;
140
141 { __iter > __iter } -> __boolean_testable;
142 { std::as_const(__iter) > __iter } -> __boolean_testable;
143 { __iter > std::as_const(__iter) } -> __boolean_testable;
144 { std::as_const(__iter) > std::as_const(__iter) } -> __boolean_testable;
145
146 { __iter >= __iter } -> __boolean_testable;
147 { std::as_const(__iter) >= __iter } -> __boolean_testable;
148 { __iter >= std::as_const(__iter) } -> __boolean_testable;
149 { std::as_const(__iter) >= std::as_const(__iter) } -> __boolean_testable;
150
151 { __iter <= __iter } -> __boolean_testable;
152 { std::as_const(__iter) <= __iter } -> __boolean_testable;
153 { __iter <= std::as_const(__iter) } -> __boolean_testable;
154 { std::as_const(__iter) <= std::as_const(__iter) } -> __boolean_testable;
155 };
156
157_LIBCPP_END_NAMESPACE_STD
158
159# ifndef _LIBCPP_DISABLE_ITERATOR_CHECKS
160# define _LIBCPP_REQUIRE_CPP17_INPUT_ITERATOR(iter_t, message) \
161 static_assert(::std::__cpp17_input_iterator<iter_t>, message)
162# define _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(iter_t, write_t, message) \
163 static_assert(::std::__cpp17_output_iterator<iter_t, write_t>, message)
164# define _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(iter_t, message) \
165 static_assert(::std::__cpp17_forward_iterator<iter_t>, message)
166# define _LIBCPP_REQUIRE_CPP17_BIDIRECTIONAL_ITERATOR(iter_t, message) \
167 static_assert(::std::__cpp17_bidirectional_iterator<iter_t>, message)
168# define _LIBCPP_REQUIRE_CPP17_RANDOM_ACCESS_ITERATOR(iter_t, message) \
169 static_assert(::std::__cpp17_random_access_iterator<iter_t>, message)
170# else
171# define _LIBCPP_REQUIRE_CPP17_INPUT_ITERATOR(iter_t, message) static_assert(true)
172# define _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(iter_t, write_t, message) static_assert(true)
173# define _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(iter_t, message) static_assert(true)
174# define _LIBCPP_REQUIRE_CPP17_BIDIRECTIONAL_ITERATOR(iter_t, message) static_assert(true)
175# define _LIBCPP_REQUIRE_CPP17_RANDOM_ACCESS_ITERATOR(iter_t, message) static_assert(true)
176# endif
177
178#else // _LIBCPP_STD_VER >= 20
179
180# define _LIBCPP_REQUIRE_CPP17_INPUT_ITERATOR(iter_t, message) static_assert(true)
181# define _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(iter_t, write_t, message) static_assert(true)
182# define _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(iter_t, message) static_assert(true)
183# define _LIBCPP_REQUIRE_CPP17_BIDIRECTIONAL_ITERATOR(iter_t, message) static_assert(true)
184# define _LIBCPP_REQUIRE_CPP17_RANDOM_ACCESS_ITERATOR(iter_t, message) static_assert(true)
185
186#endif // _LIBCPP_STD_VER >= 20
187
188_LIBCPP_POP_MACROS
189
190#endif // _LIBCPP___ITERATOR_CPP17_ITERATOR_CONCEPTS_H