xref: /openbsd-src/gnu/llvm/libcxx/include/__iterator/move_iterator.h (revision 4bdff4bed0e3d54e55670334c7d0077db4170f86)
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___ITERATOR_MOVE_ITERATOR_H
11 #define _LIBCPP___ITERATOR_MOVE_ITERATOR_H
12 
13 #include <__compare/compare_three_way_result.h>
14 #include <__compare/three_way_comparable.h>
15 #include <__concepts/assignable.h>
16 #include <__concepts/convertible_to.h>
17 #include <__concepts/derived_from.h>
18 #include <__concepts/same_as.h>
19 #include <__config>
20 #include <__iterator/concepts.h>
21 #include <__iterator/incrementable_traits.h>
22 #include <__iterator/iter_move.h>
23 #include <__iterator/iter_swap.h>
24 #include <__iterator/iterator_traits.h>
25 #include <__iterator/move_sentinel.h>
26 #include <__iterator/readable_traits.h>
27 #include <__type_traits/conditional.h>
28 #include <__type_traits/enable_if.h>
29 #include <__type_traits/is_assignable.h>
30 #include <__type_traits/is_constructible.h>
31 #include <__type_traits/is_convertible.h>
32 #include <__type_traits/is_reference.h>
33 #include <__type_traits/is_same.h>
34 #include <__type_traits/remove_reference.h>
35 #include <__utility/declval.h>
36 #include <__utility/move.h>
37 
38 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
39 #  pragma GCC system_header
40 #endif
41 
42 _LIBCPP_BEGIN_NAMESPACE_STD
43 
44 #if _LIBCPP_STD_VER > 17
45 template<class _Iter, class = void>
46 struct __move_iter_category_base {};
47 
48 template<class _Iter>
49   requires requires { typename iterator_traits<_Iter>::iterator_category; }
50 struct __move_iter_category_base<_Iter> {
51     using iterator_category = _If<
52         derived_from<typename iterator_traits<_Iter>::iterator_category, random_access_iterator_tag>,
53         random_access_iterator_tag,
54         typename iterator_traits<_Iter>::iterator_category
55     >;
56 };
57 
58 template<class _Iter, class _Sent>
59 concept __move_iter_comparable = requires {
60     { std::declval<const _Iter&>() == std::declval<_Sent>() } -> convertible_to<bool>;
61 };
62 #endif // _LIBCPP_STD_VER > 17
63 
64 template <class _Iter>
65 class _LIBCPP_TEMPLATE_VIS move_iterator
66 #if _LIBCPP_STD_VER > 17
67     : public __move_iter_category_base<_Iter>
68 #endif
69 {
70 public:
71 #if _LIBCPP_STD_VER > 17
72     using iterator_type = _Iter;
73     using iterator_concept = input_iterator_tag;
74     // iterator_category is inherited and not always present
75     using value_type = iter_value_t<_Iter>;
76     using difference_type = iter_difference_t<_Iter>;
77     using pointer = _Iter;
78     using reference = iter_rvalue_reference_t<_Iter>;
79 #else
80     typedef _Iter iterator_type;
81     typedef _If<
82         __is_cpp17_random_access_iterator<_Iter>::value,
83         random_access_iterator_tag,
84         typename iterator_traits<_Iter>::iterator_category
85     > iterator_category;
86     typedef typename iterator_traits<iterator_type>::value_type value_type;
87     typedef typename iterator_traits<iterator_type>::difference_type difference_type;
88     typedef iterator_type pointer;
89 
90     typedef typename iterator_traits<iterator_type>::reference __reference;
91     typedef typename conditional<
92             is_reference<__reference>::value,
93             __libcpp_remove_reference_t<__reference>&&,
94             __reference
95         >::type reference;
96 #endif // _LIBCPP_STD_VER > 17
97 
98     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
99     explicit move_iterator(_Iter __i) : __current_(std::move(__i)) {}
100 
101     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
102     move_iterator& operator++() { ++__current_; return *this; }
103 
104     _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
105     pointer operator->() const { return __current_; }
106 
107 #if _LIBCPP_STD_VER > 17
108     _LIBCPP_HIDE_FROM_ABI constexpr
109     move_iterator() requires is_constructible_v<_Iter> : __current_() {}
110 
111     template <class _Up>
112         requires (!_IsSame<_Up, _Iter>::value) && convertible_to<const _Up&, _Iter>
113     _LIBCPP_HIDE_FROM_ABI constexpr
114     move_iterator(const move_iterator<_Up>& __u) : __current_(__u.base()) {}
115 
116     template <class _Up>
117         requires (!_IsSame<_Up, _Iter>::value) &&
118                  convertible_to<const _Up&, _Iter> &&
119                  assignable_from<_Iter&, const _Up&>
120     _LIBCPP_HIDE_FROM_ABI constexpr
121     move_iterator& operator=(const move_iterator<_Up>& __u) {
122         __current_ = __u.base();
123         return *this;
124     }
125 
126     _LIBCPP_HIDE_FROM_ABI constexpr const _Iter& base() const & noexcept { return __current_; }
127     _LIBCPP_HIDE_FROM_ABI constexpr _Iter base() && { return std::move(__current_); }
128 
129     _LIBCPP_HIDE_FROM_ABI constexpr
130     reference operator*() const { return ranges::iter_move(__current_); }
131     _LIBCPP_HIDE_FROM_ABI constexpr
132     reference operator[](difference_type __n) const { return ranges::iter_move(__current_ + __n); }
133 
134     _LIBCPP_HIDE_FROM_ABI constexpr
135     auto operator++(int)
136         requires forward_iterator<_Iter>
137     {
138         move_iterator __tmp(*this); ++__current_; return __tmp;
139     }
140 
141     _LIBCPP_HIDE_FROM_ABI constexpr
142     void operator++(int) { ++__current_; }
143 #else
144     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
145     move_iterator() : __current_() {}
146 
147     template <class _Up, class = __enable_if_t<
148         !is_same<_Up, _Iter>::value && is_convertible<const _Up&, _Iter>::value
149     > >
150     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
151     move_iterator(const move_iterator<_Up>& __u) : __current_(__u.base()) {}
152 
153     template <class _Up, class = __enable_if_t<
154         !is_same<_Up, _Iter>::value &&
155         is_convertible<const _Up&, _Iter>::value &&
156         is_assignable<_Iter&, const _Up&>::value
157     > >
158     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
159     move_iterator& operator=(const move_iterator<_Up>& __u) {
160         __current_ = __u.base();
161         return *this;
162     }
163 
164     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
165     _Iter base() const { return __current_; }
166 
167     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
168     reference operator*() const { return static_cast<reference>(*__current_); }
169     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
170     reference operator[](difference_type __n) const { return static_cast<reference>(__current_[__n]); }
171 
172     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
173     move_iterator operator++(int) { move_iterator __tmp(*this); ++__current_; return __tmp; }
174 #endif // _LIBCPP_STD_VER > 17
175 
176     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
177     move_iterator& operator--() { --__current_; return *this; }
178     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
179     move_iterator operator--(int) { move_iterator __tmp(*this); --__current_; return __tmp; }
180     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
181     move_iterator operator+(difference_type __n) const { return move_iterator(__current_ + __n); }
182     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
183     move_iterator& operator+=(difference_type __n) { __current_ += __n; return *this; }
184     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
185     move_iterator operator-(difference_type __n) const { return move_iterator(__current_ - __n); }
186     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
187     move_iterator& operator-=(difference_type __n) { __current_ -= __n; return *this; }
188 
189 #if _LIBCPP_STD_VER > 17
190     template<sentinel_for<_Iter> _Sent>
191     friend _LIBCPP_HIDE_FROM_ABI constexpr
192     bool operator==(const move_iterator& __x, const move_sentinel<_Sent>& __y)
193         requires __move_iter_comparable<_Iter, _Sent>
194     {
195         return __x.base() == __y.base();
196     }
197 
198     template<sized_sentinel_for<_Iter> _Sent>
199     friend _LIBCPP_HIDE_FROM_ABI constexpr
200     iter_difference_t<_Iter> operator-(const move_sentinel<_Sent>& __x, const move_iterator& __y)
201     {
202         return __x.base() - __y.base();
203     }
204 
205     template<sized_sentinel_for<_Iter> _Sent>
206     friend _LIBCPP_HIDE_FROM_ABI constexpr
207     iter_difference_t<_Iter> operator-(const move_iterator& __x, const move_sentinel<_Sent>& __y)
208     {
209         return __x.base() - __y.base();
210     }
211 
212     friend _LIBCPP_HIDE_FROM_ABI constexpr
213     iter_rvalue_reference_t<_Iter> iter_move(const move_iterator& __i)
214         noexcept(noexcept(ranges::iter_move(__i.__current_)))
215     {
216         return ranges::iter_move(__i.__current_);
217     }
218 
219     template<indirectly_swappable<_Iter> _It2>
220     friend _LIBCPP_HIDE_FROM_ABI constexpr
221     void iter_swap(const move_iterator& __x, const move_iterator<_It2>& __y)
222         noexcept(noexcept(ranges::iter_swap(__x.__current_, __y.__current_)))
223     {
224         return ranges::iter_swap(__x.__current_, __y.__current_);
225     }
226 #endif // _LIBCPP_STD_VER > 17
227 
228 private:
229     template<class _It2> friend class move_iterator;
230 
231     _Iter __current_;
232 };
233 _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(move_iterator);
234 
235 template <class _Iter1, class _Iter2>
236 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
237 bool operator==(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
238 {
239     return __x.base() == __y.base();
240 }
241 
242 #if _LIBCPP_STD_VER <= 17
243 template <class _Iter1, class _Iter2>
244 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
245 bool operator!=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
246 {
247     return __x.base() != __y.base();
248 }
249 #endif // _LIBCPP_STD_VER <= 17
250 
251 template <class _Iter1, class _Iter2>
252 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
253 bool operator<(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
254 {
255     return __x.base() < __y.base();
256 }
257 
258 template <class _Iter1, class _Iter2>
259 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
260 bool operator>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
261 {
262     return __x.base() > __y.base();
263 }
264 
265 template <class _Iter1, class _Iter2>
266 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
267 bool operator<=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
268 {
269     return __x.base() <= __y.base();
270 }
271 
272 template <class _Iter1, class _Iter2>
273 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
274 bool operator>=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
275 {
276     return __x.base() >= __y.base();
277 }
278 
279 #if _LIBCPP_STD_VER > 17
280 template <class _Iter1, three_way_comparable_with<_Iter1> _Iter2>
281 inline _LIBCPP_HIDE_FROM_ABI constexpr
282 auto operator<=>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
283     -> compare_three_way_result_t<_Iter1, _Iter2>
284 {
285     return __x.base() <=> __y.base();
286 }
287 #endif // _LIBCPP_STD_VER > 17
288 
289 #ifndef _LIBCPP_CXX03_LANG
290 template <class _Iter1, class _Iter2>
291 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
292 auto operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
293     -> decltype(__x.base() - __y.base())
294 {
295     return __x.base() - __y.base();
296 }
297 #else
298 template <class _Iter1, class _Iter2>
299 inline _LIBCPP_HIDE_FROM_ABI
300 typename move_iterator<_Iter1>::difference_type
301 operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
302 {
303     return __x.base() - __y.base();
304 }
305 #endif // !_LIBCPP_CXX03_LANG
306 
307 #if _LIBCPP_STD_VER > 17
308 template <class _Iter>
309 inline _LIBCPP_HIDE_FROM_ABI constexpr
310 move_iterator<_Iter> operator+(iter_difference_t<_Iter> __n, const move_iterator<_Iter>& __x)
311     requires requires { { __x.base() + __n } -> same_as<_Iter>; }
312 {
313     return __x + __n;
314 }
315 #else
316 template <class _Iter>
317 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
318 move_iterator<_Iter>
319 operator+(typename move_iterator<_Iter>::difference_type __n, const move_iterator<_Iter>& __x)
320 {
321     return move_iterator<_Iter>(__x.base() + __n);
322 }
323 #endif // _LIBCPP_STD_VER > 17
324 
325 template <class _Iter>
326 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17
327 move_iterator<_Iter>
328 make_move_iterator(_Iter __i)
329 {
330     return move_iterator<_Iter>(std::move(__i));
331 }
332 
333 _LIBCPP_END_NAMESPACE_STD
334 
335 #endif // _LIBCPP___ITERATOR_MOVE_ITERATOR_H
336