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_convertible.h>
18#include <__type_traits/is_copy_constructible.h>
19#include <__type_traits/is_default_constructible.h>
20#include <__type_traits/is_move_constructible.h>
21#include <__type_traits/is_signed.h>
22#include <__type_traits/is_void.h>
23#include <__utility/as_const.h>
24#include <__utility/forward.h>
25#include <__utility/move.h>
26#include <__utility/swap.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#if _LIBCPP_STD_VER >= 20
36
37_LIBCPP_BEGIN_NAMESPACE_STD
38
39template <class _Tp>
40concept __cpp17_move_constructible = is_move_constructible_v<_Tp>;
41
42template <class _Tp>
43concept __cpp17_copy_constructible = __cpp17_move_constructible<_Tp> && is_copy_constructible_v<_Tp>;
44
45template <class _Tp>
46concept __cpp17_move_assignable = requires(_Tp __lhs, _Tp __rhs) {
47  { __lhs = std::move(__rhs) } -> same_as<_Tp&>;
48};
49
50template <class _Tp>
51concept __cpp17_copy_assignable = __cpp17_move_assignable<_Tp> && requires(_Tp __lhs, _Tp __rhs) {
52  { __lhs = __rhs } -> same_as<_Tp&>;
53  { __lhs = std::as_const(__rhs) } -> same_as<_Tp&>;
54};
55
56template <class _Tp>
57concept __cpp17_destructible = requires(_Tp __v) { __v.~_Tp(); };
58
59template <class _Tp>
60concept __cpp17_equality_comparable = requires(_Tp __lhs, _Tp __rhs) {
61  { __lhs == __rhs } -> __boolean_testable;
62  { std::as_const(__lhs) == __rhs } -> __boolean_testable;
63  { __lhs == std::as_const(__rhs) } -> __boolean_testable;
64  { std::as_const(__lhs) == std::as_const(__rhs) } -> __boolean_testable;
65};
66
67template <class _Tp>
68concept __cpp17_default_constructible = is_default_constructible_v<_Tp>;
69
70template <class _Iter>
71concept __cpp17_iterator =
72    __cpp17_copy_constructible<_Iter> && __cpp17_copy_assignable<_Iter> && __cpp17_destructible<_Iter> &&
73    (is_signed_v<__iter_diff_t<_Iter>> || is_void_v<__iter_diff_t<_Iter>>)&&requires(_Iter __iter) {
74      { *__iter };
75      { ++__iter } -> same_as<_Iter&>;
76    };
77
78template <class _Iter>
79concept __cpp17_input_iterator =
80    __cpp17_iterator<_Iter> && __cpp17_equality_comparable<_Iter> && requires(_Iter __lhs, _Iter __rhs) {
81      { __lhs != __rhs } -> __boolean_testable;
82      { std::as_const(__lhs) != __rhs } -> __boolean_testable;
83      { __lhs != std::as_const(__rhs) } -> __boolean_testable;
84      { std::as_const(__lhs) != std::as_const(__rhs) } -> __boolean_testable;
85
86      { *__lhs } -> same_as<__iter_reference<_Iter>>;
87      { *std::as_const(__lhs) } -> same_as<__iter_reference<_Iter>>;
88
89      { ++__lhs } -> same_as<_Iter&>;
90      { (void)__lhs++ };
91      { *__lhs++ };
92    };
93
94template <class _Iter, class _WriteTo>
95concept __cpp17_output_iterator = __cpp17_iterator<_Iter> && requires(_Iter __iter, _WriteTo __write) {
96  { *__iter = std::forward<_WriteTo>(__write) };
97  { ++__iter } -> same_as<_Iter&>;
98  { __iter++ } -> convertible_to<const _Iter&>;
99  { *__iter++ = std::forward<_WriteTo>(__write) };
100};
101
102template <class _Iter>
103concept __cpp17_forward_iterator =
104    __cpp17_input_iterator<_Iter> && __cpp17_default_constructible<_Iter> && requires(_Iter __iter) {
105      { __iter++ } -> convertible_to<const _Iter&>;
106      { *__iter++ } -> same_as<__iter_reference<_Iter>>;
107    };
108
109template <class _Iter>
110concept __cpp17_bidirectional_iterator = __cpp17_forward_iterator<_Iter> && requires(_Iter __iter) {
111  { --__iter } -> same_as<_Iter&>;
112  { __iter-- } -> convertible_to<const _Iter&>;
113  { *__iter-- } -> same_as<__iter_reference<_Iter>>;
114};
115
116template <class _Iter>
117concept __cpp17_random_access_iterator =
118    __cpp17_bidirectional_iterator<_Iter> && requires(_Iter __iter, __iter_diff_t<_Iter> __n) {
119      { __iter += __n } -> same_as<_Iter&>;
120
121      { __iter + __n } -> same_as<_Iter>;
122      { __n + __iter } -> same_as<_Iter>;
123      { std::as_const(__iter) + __n } -> same_as<_Iter>;
124      { __n + std::as_const(__iter) } -> same_as<_Iter>;
125
126      { __iter -= __n } -> same_as<_Iter&>;
127      { __iter - __n } -> same_as<_Iter>;
128      { std::as_const(__iter) - __n } -> same_as<_Iter>;
129
130      { __iter - __iter } -> same_as<__iter_diff_t<_Iter>>;
131      { std::as_const(__iter) - __iter } -> same_as<__iter_diff_t<_Iter>>;
132      { __iter - std::as_const(__iter) } -> same_as<__iter_diff_t<_Iter>>;
133      { std::as_const(__iter) - std::as_const(__iter) } -> same_as<__iter_diff_t<_Iter>>;
134
135      { __iter[__n] } -> convertible_to<__iter_reference<_Iter>>;
136      { std::as_const(__iter)[__n] } -> convertible_to<__iter_reference<_Iter>>;
137
138      { __iter < __iter } -> __boolean_testable;
139      { std::as_const(__iter) < __iter } -> __boolean_testable;
140      { __iter < std::as_const(__iter) } -> __boolean_testable;
141      { std::as_const(__iter) < std::as_const(__iter) } -> __boolean_testable;
142
143      { __iter > __iter } -> __boolean_testable;
144      { std::as_const(__iter) > __iter } -> __boolean_testable;
145      { __iter > std::as_const(__iter) } -> __boolean_testable;
146      { std::as_const(__iter) > std::as_const(__iter) } -> __boolean_testable;
147
148      { __iter >= __iter } -> __boolean_testable;
149      { std::as_const(__iter) >= __iter } -> __boolean_testable;
150      { __iter >= std::as_const(__iter) } -> __boolean_testable;
151      { std::as_const(__iter) >= std::as_const(__iter) } -> __boolean_testable;
152
153      { __iter <= __iter } -> __boolean_testable;
154      { std::as_const(__iter) <= __iter } -> __boolean_testable;
155      { __iter <= std::as_const(__iter) } -> __boolean_testable;
156      { std::as_const(__iter) <= std::as_const(__iter) } -> __boolean_testable;
157    };
158
159_LIBCPP_END_NAMESPACE_STD
160
161#  ifndef _LIBCPP_DISABLE_ITERATOR_CHECKS
162#    define _LIBCPP_REQUIRE_CPP17_INPUT_ITERATOR(iter_t) static_assert(::std::__cpp17_input_iterator<iter_t>);
163#    define _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(iter_t, write_t)                                                     \
164      static_assert(::std::__cpp17_output_iterator<iter_t, write_t>);
165#    define _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(iter_t) static_assert(::std::__cpp17_forward_iterator<iter_t>);
166#    define _LIBCPP_REQUIRE_CPP17_BIDIRECTIONAL_ITERATOR(iter_t)                                                       \
167      static_assert(::std::__cpp17_bidirectional_iterator<iter_t>);
168#    define _LIBCPP_REQUIRE_CPP17_RANDOM_ACCESS_ITERATOR(iter_t)                                                       \
169      static_assert(::std::__cpp17_random_access_iterator<iter_t>);
170#  else
171#    define _LIBCPP_REQUIRE_CPP17_INPUT_ITERATOR(iter_t)
172#    define _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(iter_t, write_t)
173#    define _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(iter_t)
174#    define _LIBCPP_REQUIRE_CPP17_BIDIRECTIONAL_ITERATOR(iter_t)
175#    define _LIBCPP_REQUIRE_CPP17_RANDOM_ACCESS_ITERATOR(iter_t)
176#  endif
177
178#else // _LIBCPP_STD_VER >= 20
179
180#  define _LIBCPP_REQUIRE_CPP17_INPUT_ITERATOR(iter_t)
181#  define _LIBCPP_REQUIRE_CPP17_OUTPUT_ITERATOR(iter_t, write_t)
182#  define _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(iter_t)
183#  define _LIBCPP_REQUIRE_CPP17_BIDIRECTIONAL_ITERATOR(iter_t)
184#  define _LIBCPP_REQUIRE_CPP17_RANDOM_ACCESS_ITERATOR(iter_t)
185
186#endif // _LIBCPP_STD_VER >= 20
187
188_LIBCPP_POP_MACROS
189
190#endif // _LIBCPP___ITERATOR_CPP17_ITERATOR_CONCEPTS_H
191