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<__iterator_difference_type<_Iter>> || is_void_v<__iterator_difference_type<_Iter>>) &&
72 requires(_Iter __iter) {
73 { *__iter };
74 { ++__iter } -> same_as<_Iter&>;
75 };
76
77template <class _Iter>
78concept __cpp17_input_iterator =
79 __cpp17_iterator<_Iter> && __cpp17_equality_comparable<_Iter> && requires(_Iter __lhs, _Iter __rhs) {
80 { __lhs != __rhs } -> __boolean_testable;
81 { std::as_const(__lhs) != __rhs } -> __boolean_testable;
82 { __lhs != std::as_const(__rhs) } -> __boolean_testable;
83 { std::as_const(__lhs) != std::as_const(__rhs) } -> __boolean_testable;
84
85 { *__lhs } -> same_as<__iterator_reference<_Iter>>;
86 { *std::as_const(__lhs) } -> same_as<__iterator_reference<_Iter>>;
87
88 { ++__lhs } -> same_as<_Iter&>;
89 { (void)__lhs++ };
90 { *__lhs++ };
91 };
92
93template <class _Iter, class _WriteTo>
94concept __cpp17_output_iterator = __cpp17_iterator<_Iter> && requires(_Iter __iter, _WriteTo __write) {
95 { *__iter = std::forward<_WriteTo>(__write) };
96 { ++__iter } -> same_as<_Iter&>;
97 { __iter++ } -> convertible_to<const _Iter&>;
98 { *__iter++ = std::forward<_WriteTo>(__write) };
99};
100
101template <class _Iter>
102concept __cpp17_forward_iterator =
103 __cpp17_input_iterator<_Iter> && __cpp17_default_constructible<_Iter> && requires(_Iter __iter) {
104 { __iter++ } -> convertible_to<const _Iter&>;
105 { *__iter++ } -> same_as<__iterator_reference<_Iter>>;
106 };
107
108template <class _Iter>
109concept __cpp17_bidirectional_iterator = __cpp17_forward_iterator<_Iter> && requires(_Iter __iter) {
110 { --__iter } -> same_as<_Iter&>;
111 { __iter-- } -> convertible_to<const _Iter&>;
112 { *__iter-- } -> same_as<__iterator_reference<_Iter>>;
113};
114
115template <class _Iter>
116concept __cpp17_random_access_iterator =
117 __cpp17_bidirectional_iterator<_Iter> && requires(_Iter __iter, __iterator_difference_type<_Iter> __n) {
118 { __iter += __n } -> same_as<_Iter&>;
119
120 { __iter + __n } -> same_as<_Iter>;
121 { __n + __iter } -> same_as<_Iter>;
122 { std::as_const(__iter) + __n } -> same_as<_Iter>;
123 { __n + std::as_const(__iter) } -> same_as<_Iter>;
124
125 { __iter -= __n } -> same_as<_Iter&>;
126 { __iter - __n } -> same_as<_Iter>;
127 { std::as_const(__iter) - __n } -> same_as<_Iter>;
128
129 { __iter - __iter } -> same_as<__iterator_difference_type<_Iter>>;
130 { std::as_const(__iter) - __iter } -> same_as<__iterator_difference_type<_Iter>>;
131 { __iter - std::as_const(__iter) } -> same_as<__iterator_difference_type<_Iter>>;
132 { std::as_const(__iter) - std::as_const(__iter) } -> same_as<__iterator_difference_type<_Iter>>;
133
134 { __iter[__n] } -> convertible_to<__iterator_reference<_Iter>>;
135 { std::as_const(__iter)[__n] } -> convertible_to<__iterator_reference<_Iter>>;
136
137 { __iter < __iter } -> __boolean_testable;
138 { std::as_const(__iter) < __iter } -> __boolean_testable;
139 { __iter < std::as_const(__iter) } -> __boolean_testable;
140 { std::as_const(__iter) < std::as_const(__iter) } -> __boolean_testable;
141
142 { __iter > __iter } -> __boolean_testable;
143 { std::as_const(__iter) > __iter } -> __boolean_testable;
144 { __iter > std::as_const(__iter) } -> __boolean_testable;
145 { std::as_const(__iter) > std::as_const(__iter) } -> __boolean_testable;
146
147 { __iter >= __iter } -> __boolean_testable;
148 { std::as_const(__iter) >= __iter } -> __boolean_testable;
149 { __iter >= std::as_const(__iter) } -> __boolean_testable;
150 { std::as_const(__iter) >= std::as_const(__iter) } -> __boolean_testable;
151
152 { __iter <= __iter } -> __boolean_testable;
153 { std::as_const(__iter) <= __iter } -> __boolean_testable;
154 { __iter <= std::as_const(__iter) } -> __boolean_testable;
155 { std::as_const(__iter) <= std::as_const(__iter) } -> __boolean_testable;
156 };
157
158_LIBCPP_END_NAMESPACE_STD
159
160# ifndef _LIBCPP_DISABLE_ITERATOR_CHECKS
161# define _LIBCPP_REQUIRE_CPP17_INPUT_ITERATOR(iter_t, message) \
162 static_assert(::std::__cpp17_input_iterator<iter_t>, message)
163# define _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(iter_t, write_t, message) \
164 static_assert(::std::__cpp17_output_iterator<iter_t, write_t>, message)
165# define _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(iter_t, message) \
166 static_assert(::std::__cpp17_forward_iterator<iter_t>, message)
167# define _LIBCPP_REQUIRE_CPP17_BIDIRECTIONAL_ITERATOR(iter_t, message) \
168 static_assert(::std::__cpp17_bidirectional_iterator<iter_t>, message)
169# define _LIBCPP_REQUIRE_CPP17_RANDOM_ACCESS_ITERATOR(iter_t, message) \
170 static_assert(::std::__cpp17_random_access_iterator<iter_t>, message)
171# else
172# define _LIBCPP_REQUIRE_CPP17_INPUT_ITERATOR(iter_t, message) static_assert(true)
173# define _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(iter_t, write_t, message) static_assert(true)
174# define _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(iter_t, message) static_assert(true)
175# define _LIBCPP_REQUIRE_CPP17_BIDIRECTIONAL_ITERATOR(iter_t, message) static_assert(true)
176# define _LIBCPP_REQUIRE_CPP17_RANDOM_ACCESS_ITERATOR(iter_t, message) static_assert(true)
177# endif
178
179#else // _LIBCPP_STD_VER >= 20
180
181# define _LIBCPP_REQUIRE_CPP17_INPUT_ITERATOR(iter_t, message) static_assert(true)
182# define _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(iter_t, write_t, message) static_assert(true)
183# define _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(iter_t, message) static_assert(true)
184# define _LIBCPP_REQUIRE_CPP17_BIDIRECTIONAL_ITERATOR(iter_t, message) static_assert(true)
185# define _LIBCPP_REQUIRE_CPP17_RANDOM_ACCESS_ITERATOR(iter_t, message) static_assert(true)
186
187#endif // _LIBCPP_STD_VER >= 20
188
189_LIBCPP_POP_MACROS
190
191#endif // _LIBCPP___ITERATOR_CPP17_ITERATOR_CONCEPTS_H