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_PUSH_MACROS
43#include <__undef_macros>
44
45_LIBCPP_BEGIN_NAMESPACE_STD
46
47#if _LIBCPP_STD_VER >= 20
48template <class _Iter, class = void>
49struct __move_iter_category_base {};
50
51template <class _Iter>
52  requires requires { typename iterator_traits<_Iter>::iterator_category; }
53struct __move_iter_category_base<_Iter> {
54  using iterator_category =
55      _If< derived_from<typename iterator_traits<_Iter>::iterator_category, random_access_iterator_tag>,
56           random_access_iterator_tag,
57           typename iterator_traits<_Iter>::iterator_category >;
58};
59
60template <class _Iter, class _Sent>
61concept __move_iter_comparable = requires {
62  { std::declval<const _Iter&>() == std::declval<_Sent>() } -> convertible_to<bool>;
63};
64#endif // _LIBCPP_STD_VER >= 20
65
66template <class _Iter>
67class _LIBCPP_TEMPLATE_VIS move_iterator
68#if _LIBCPP_STD_VER >= 20
69    : public __move_iter_category_base<_Iter>
70#endif
71{
72#if _LIBCPP_STD_VER >= 20
73
74private:
75  _LIBCPP_HIDE_FROM_ABI static constexpr auto __get_iter_concept() {
76    if constexpr (random_access_iterator<_Iter>) {
77      return random_access_iterator_tag{};
78    } else if constexpr (bidirectional_iterator<_Iter>) {
79      return bidirectional_iterator_tag{};
80    } else if constexpr (forward_iterator<_Iter>) {
81      return forward_iterator_tag{};
82    } else {
83      return input_iterator_tag{};
84    }
85  }
86#endif // _LIBCPP_STD_VER >= 20
87
88public:
89#if _LIBCPP_STD_VER >= 20
90  using iterator_type    = _Iter;
91  using iterator_concept = decltype(__get_iter_concept());
92  // iterator_category is inherited and not always present
93  using value_type      = iter_value_t<_Iter>;
94  using difference_type = iter_difference_t<_Iter>;
95  using pointer         = _Iter;
96  using reference       = iter_rvalue_reference_t<_Iter>;
97#else
98  typedef _Iter iterator_type;
99  typedef _If< __has_random_access_iterator_category<_Iter>::value,
100               random_access_iterator_tag,
101               typename iterator_traits<_Iter>::iterator_category >
102      iterator_category;
103  typedef typename iterator_traits<iterator_type>::value_type value_type;
104  typedef typename iterator_traits<iterator_type>::difference_type difference_type;
105  typedef iterator_type pointer;
106
107  typedef typename iterator_traits<iterator_type>::reference __reference;
108  typedef typename conditional< is_reference<__reference>::value,
109                                __libcpp_remove_reference_t<__reference>&&,
110                                __reference >::type reference;
111#endif // _LIBCPP_STD_VER >= 20
112
113  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 explicit move_iterator(_Iter __i) : __current_(std::move(__i)) {}
114
115  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator& operator++() {
116    ++__current_;
117    return *this;
118  }
119
120  _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 pointer operator->() const {
121    return __current_;
122  }
123
124#if _LIBCPP_STD_VER >= 20
125  _LIBCPP_HIDE_FROM_ABI constexpr move_iterator()
126    requires is_constructible_v<_Iter>
127      : __current_() {}
128
129  template <class _Up>
130    requires(!_IsSame<_Up, _Iter>::value) && convertible_to<const _Up&, _Iter>
131  _LIBCPP_HIDE_FROM_ABI constexpr move_iterator(const move_iterator<_Up>& __u) : __current_(__u.base()) {}
132
133  template <class _Up>
134    requires(!_IsSame<_Up, _Iter>::value) && convertible_to<const _Up&, _Iter> && assignable_from<_Iter&, const _Up&>
135  _LIBCPP_HIDE_FROM_ABI constexpr move_iterator& operator=(const move_iterator<_Up>& __u) {
136    __current_ = __u.base();
137    return *this;
138  }
139
140  _LIBCPP_HIDE_FROM_ABI constexpr const _Iter& base() const& noexcept { return __current_; }
141  _LIBCPP_HIDE_FROM_ABI constexpr _Iter base() && { return std::move(__current_); }
142
143  _LIBCPP_HIDE_FROM_ABI constexpr reference operator*() const { return ranges::iter_move(__current_); }
144  _LIBCPP_HIDE_FROM_ABI constexpr reference operator[](difference_type __n) const {
145    return ranges::iter_move(__current_ + __n);
146  }
147
148  _LIBCPP_HIDE_FROM_ABI constexpr auto operator++(int)
149    requires forward_iterator<_Iter>
150  {
151    move_iterator __tmp(*this);
152    ++__current_;
153    return __tmp;
154  }
155
156  _LIBCPP_HIDE_FROM_ABI constexpr void operator++(int) { ++__current_; }
157#else
158  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator() : __current_() {}
159
160  template <class _Up,
161            class = __enable_if_t< !is_same<_Up, _Iter>::value && is_convertible<const _Up&, _Iter>::value > >
162  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator(const move_iterator<_Up>& __u)
163      : __current_(__u.base()) {}
164
165  template <class _Up,
166            class = __enable_if_t< !is_same<_Up, _Iter>::value && is_convertible<const _Up&, _Iter>::value &&
167                                   is_assignable<_Iter&, const _Up&>::value > >
168  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator& operator=(const move_iterator<_Up>& __u) {
169    __current_ = __u.base();
170    return *this;
171  }
172
173  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 _Iter base() const { return __current_; }
174
175  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference operator*() const {
176    return static_cast<reference>(*__current_);
177  }
178  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference operator[](difference_type __n) const {
179    return static_cast<reference>(__current_[__n]);
180  }
181
182  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator operator++(int) {
183    move_iterator __tmp(*this);
184    ++__current_;
185    return __tmp;
186  }
187#endif // _LIBCPP_STD_VER >= 20
188
189  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator& operator--() {
190    --__current_;
191    return *this;
192  }
193  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator operator--(int) {
194    move_iterator __tmp(*this);
195    --__current_;
196    return __tmp;
197  }
198  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator operator+(difference_type __n) const {
199    return move_iterator(__current_ + __n);
200  }
201  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator& operator+=(difference_type __n) {
202    __current_ += __n;
203    return *this;
204  }
205  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator operator-(difference_type __n) const {
206    return move_iterator(__current_ - __n);
207  }
208  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator& operator-=(difference_type __n) {
209    __current_ -= __n;
210    return *this;
211  }
212
213#if _LIBCPP_STD_VER >= 20
214  template <sentinel_for<_Iter> _Sent>
215  friend _LIBCPP_HIDE_FROM_ABI constexpr bool operator==(const move_iterator& __x, const move_sentinel<_Sent>& __y)
216    requires __move_iter_comparable<_Iter, _Sent>
217  {
218    return __x.base() == __y.base();
219  }
220
221  template <sized_sentinel_for<_Iter> _Sent>
222  friend _LIBCPP_HIDE_FROM_ABI constexpr iter_difference_t<_Iter>
223  operator-(const move_sentinel<_Sent>& __x, const move_iterator& __y) {
224    return __x.base() - __y.base();
225  }
226
227  template <sized_sentinel_for<_Iter> _Sent>
228  friend _LIBCPP_HIDE_FROM_ABI constexpr iter_difference_t<_Iter>
229  operator-(const move_iterator& __x, const move_sentinel<_Sent>& __y) {
230    return __x.base() - __y.base();
231  }
232
233  friend _LIBCPP_HIDE_FROM_ABI constexpr iter_rvalue_reference_t<_Iter>
234  iter_move(const move_iterator& __i) noexcept(noexcept(ranges::iter_move(__i.__current_))) {
235    return ranges::iter_move(__i.__current_);
236  }
237
238  template <indirectly_swappable<_Iter> _It2>
239  friend _LIBCPP_HIDE_FROM_ABI constexpr void
240  iter_swap(const move_iterator& __x,
241            const move_iterator<_It2>& __y) noexcept(noexcept(ranges::iter_swap(__x.__current_, __y.__current_))) {
242    return ranges::iter_swap(__x.__current_, __y.__current_);
243  }
244#endif // _LIBCPP_STD_VER >= 20
245
246private:
247  template <class _It2>
248  friend class move_iterator;
249
250  _Iter __current_;
251};
252_LIBCPP_CTAD_SUPPORTED_FOR_TYPE(move_iterator);
253
254template <class _Iter1, class _Iter2>
255inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 bool
256operator==(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y) {
257  return __x.base() == __y.base();
258}
259
260#if _LIBCPP_STD_VER <= 17
261template <class _Iter1, class _Iter2>
262inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 bool
263operator!=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y) {
264  return __x.base() != __y.base();
265}
266#endif // _LIBCPP_STD_VER <= 17
267
268template <class _Iter1, class _Iter2>
269inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 bool
270operator<(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y) {
271  return __x.base() < __y.base();
272}
273
274template <class _Iter1, class _Iter2>
275inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 bool
276operator>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y) {
277  return __x.base() > __y.base();
278}
279
280template <class _Iter1, class _Iter2>
281inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 bool
282operator<=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y) {
283  return __x.base() <= __y.base();
284}
285
286template <class _Iter1, class _Iter2>
287inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 bool
288operator>=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y) {
289  return __x.base() >= __y.base();
290}
291
292#if _LIBCPP_STD_VER >= 20
293template <class _Iter1, three_way_comparable_with<_Iter1> _Iter2>
294inline _LIBCPP_HIDE_FROM_ABI constexpr auto
295operator<=>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
296    -> compare_three_way_result_t<_Iter1, _Iter2> {
297  return __x.base() <=> __y.base();
298}
299#endif // _LIBCPP_STD_VER >= 20
300
301#ifndef _LIBCPP_CXX03_LANG
302template <class _Iter1, class _Iter2>
303inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 auto
304operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y) -> decltype(__x.base() - __y.base()) {
305  return __x.base() - __y.base();
306}
307#else
308template <class _Iter1, class _Iter2>
309inline _LIBCPP_HIDE_FROM_ABI typename move_iterator<_Iter1>::difference_type
310operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y) {
311  return __x.base() - __y.base();
312}
313#endif // !_LIBCPP_CXX03_LANG
314
315#if _LIBCPP_STD_VER >= 20
316template <class _Iter>
317inline _LIBCPP_HIDE_FROM_ABI constexpr move_iterator<_Iter>
318operator+(iter_difference_t<_Iter> __n, const move_iterator<_Iter>& __x)
319  requires requires {
320    { __x.base() + __n } -> same_as<_Iter>;
321  }
322{
323  return __x + __n;
324}
325#else
326template <class _Iter>
327inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator<_Iter>
328operator+(typename move_iterator<_Iter>::difference_type __n, const move_iterator<_Iter>& __x) {
329  return move_iterator<_Iter>(__x.base() + __n);
330}
331#endif // _LIBCPP_STD_VER >= 20
332
333template <class _Iter>
334inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 move_iterator<_Iter> make_move_iterator(_Iter __i) {
335  return move_iterator<_Iter>(std::move(__i));
336}
337
338_LIBCPP_END_NAMESPACE_STD
339
340_LIBCPP_POP_MACROS
341
342#endif // _LIBCPP___ITERATOR_MOVE_ITERATOR_H
343