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 
39 template <class _Tp>
40 concept __cpp17_move_constructible = is_move_constructible_v<_Tp>;
41 
42 template <class _Tp>
43 concept __cpp17_copy_constructible = __cpp17_move_constructible<_Tp> && is_copy_constructible_v<_Tp>;
44 
45 template <class _Tp>
requires(_Tp __lhs,_Tp __rhs)46 concept __cpp17_move_assignable = requires(_Tp __lhs, _Tp __rhs) {
47   { __lhs = std::move(__rhs) } -> same_as<_Tp&>;
48 };
49 
50 template <class _Tp>
requires(_Tp __lhs,_Tp __rhs)51 concept __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 
56 template <class _Tp>
requires(_Tp __v)57 concept __cpp17_destructible = requires(_Tp __v) { __v.~_Tp(); };
58 
59 template <class _Tp>
requires(_Tp __lhs,_Tp __rhs)60 concept __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 
67 template <class _Tp>
68 concept __cpp17_default_constructible = is_default_constructible_v<_Tp>;
69 
70 template <class _Iter>
71 concept __cpp17_iterator =
72     __cpp17_copy_constructible<_Iter> && __cpp17_copy_assignable<_Iter> && __cpp17_destructible<_Iter> &&
requires(_Iter __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 
78 template <class _Iter>
79 concept __cpp17_input_iterator =
requires(_Iter __lhs,_Iter __rhs)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 
94 template <class _Iter, class _WriteTo>
requires(_Iter __iter,_WriteTo __write)95 concept __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 
102 template <class _Iter>
103 concept __cpp17_forward_iterator =
requires(_Iter __iter)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 
109 template <class _Iter>
requires(_Iter __iter)110 concept __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 
116 template <class _Iter>
117 concept __cpp17_random_access_iterator =
requires(_Iter __iter,__iter_diff_t<_Iter> __n)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