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
11#define _LIBCPP_ITERATOR
12
13/*
14 iterator synopsis
15
16#include <compare>
17#include <concepts>
18#include <initializer_list>
19
20namespace std
21{
22template<class> struct incrementable_traits; // since C++20
23template<class T>
24 using iter_difference_t = see below; // since C++20
25
26template<class> struct indirectly_readable_traits; // since C++20
27template<class T>
28 using iter_value_t = see below; // since C++20
29
30template<class Iterator>
31struct iterator_traits;
32
33template<class T>
34 requires is_object_v<T> // since C++20
35struct iterator_traits<T*>;
36
37template<dereferenceable T>
38 using iter_reference_t = decltype(*declval<T&>());
39
40namespace ranges::inline unspecified {
41 inline constexpr unspecified iter_move = unspecified; // since C++20, nodiscard as an extension
42}}
43
44template<dereferenceable T>
45 requires ...
46using iter_rvalue_reference_t = decltype(ranges::iter_move(declval<T&>())); // since C++20
47
48// [iterator.concepts], iterator concepts
49// [iterator.concept.readable], concept indirectly_readable
50template<class In>
51 concept indirectly_readable = see below; // since C++20
52
53template<indirectly_readable T>
54 using iter_common_reference_t =
55 common_reference_t<iter_reference_t<T>, iter_value_t<T>&>; // since C++20
56
57// [iterator.concept.writable], concept indirectly_writable
58template<class Out, class T>
59 concept indirectly_writable = see below; // since C++20
60
61// [iterator.concept.winc], concept weakly_incrementable
62template<class I>
63 concept weakly_incrementable = see below; // since C++20
64
65// [iterator.concept.inc], concept incrementable
66template<class I>
67 concept incrementable = see below; // since C++20
68
69// [iterator.concept.iterator], concept input_or_output_iterator
70 template<class I>
71 concept input_or_output_iterator = see below; // since C++20
72
73// [iterator.concept.sentinel], concept sentinel_for
74template<class S, class I>
75 concept sentinel_for = see below; // since C++20
76
77// [iterator.concept.sizedsentinel], concept sized_sentinel_for
78template<class S, class I>
79 inline constexpr bool disable_sized_sentinel_for = false;
80
81template<class S, class I>
82 concept sized_sentinel_for = see below;
83
84// [iterator.concept.input], concept input_iterator
85template<class I>
86 concept input_iterator = see below; // since C++20
87
88// [iterator.concept.output], concept output_iterator
89template<class I, class T>
90 concept output_iterator = see below; // since C++20
91
92// [iterator.concept.forward], concept forward_iterator
93template<class I>
94 concept forward_iterator = see below; // since C++20
95
96// [iterator.concept.bidir], concept bidirectional_iterator
97template<class I>
98 concept bidirectional_iterator = see below; // since C++20
99
100// [iterator.concept.random.access], concept random_access_iterator
101template<class I>
102 concept random_access_iterator = see below; // since C++20
103
104// [indirectcallable]
105// [indirectcallable.indirectinvocable]
106template<class F, class I>
107 concept indirectly_unary_invocable = see below; // since C++20
108
109template<class F, class I>
110 concept indirectly_regular_unary_invocable = see below; // since C++20
111
112template<class F, class I>
113 concept indirect_unary_predicate = see below; // since C++20
114
115template<class F, class I1, class I2>
116 concept indirect_binary_predicate = see below; // since C++20
117
118template<class F, class I1, class I2 = I1>
119 concept indirect_equivalence_relation = see below; // since C++20
120
121template<class F, class I1, class I2 = I1>
122 concept indirect_strict_weak_order = see below; // since C++20
123
124template<class F, class... Is>
125 using indirect_result_t = see below; // since C++20
126
127// [projected], projected
128template<indirectly_readable I, indirectly_regular_unary_invocable<I> Proj>
129 struct projected; // since C++20
130
131template<weakly_incrementable I, indirectly_regular_unary_invocable<I> Proj>
132 struct incrementable_traits<projected<I, Proj>>; // since C++20
133
134// [alg.req.ind.move], concept indirectly_movable
135template<class In, class Out>
136 concept indirectly_movable = see below; // since C++20
137
138template<class In, class Out>
139 concept indirectly_movable_storable = see below; // since C++20
140
141// [alg.req.ind.copy], concept indirectly_copyable
142template<class In, class Out>
143 concept indirectly_copyable = see below; // since C++20
144
145template<class In, class Out>
146 concept indirectly_copyable_storable = see below; // since C++20
147
148// [alg.req.ind.swap], concept indirectly_swappable
149template<class I1, class I2 = I1>
150 concept indirectly_swappable = see below; // since C++20
151
152template<class I1, class I2, class R, class P1 = identity,
153 class P2 = identity>
154 concept indirectly_comparable =
155 indirect_binary_predicate<R, projected<I1, P1>, projected<I2, P2>>; // since C++20
156
157// [alg.req.permutable], concept permutable
158template<class I>
159 concept permutable = see below; // since C++20
160
161 // [alg.req.mergeable], concept mergeable
162template<class I1, class I2, class Out,
163 class R = ranges::less, class P1 = identity, class P2 = identity>
164 concept mergeable = see below; // since C++20
165
166// [alg.req.sortable], concept sortable
167template<class I, class R = ranges::less, class P = identity>
168 concept sortable = see below; // since C++20
169
170template<input_or_output_iterator I, sentinel_for<I> S>
171 requires (!same_as<I, S> && copyable<I>)
172class common_iterator; // since C++20
173
174template<class Category, class T, class Distance = ptrdiff_t,
175 class Pointer = T*, class Reference = T&>
176struct iterator // deprecated in C++17
177{
178 typedef T value_type;
179 typedef Distance difference_type;
180 typedef Pointer pointer;
181 typedef Reference reference;
182 typedef Category iterator_category;
183};
184
185struct input_iterator_tag {};
186struct output_iterator_tag {};
187struct forward_iterator_tag : public input_iterator_tag {};
188struct bidirectional_iterator_tag : public forward_iterator_tag {};
189struct random_access_iterator_tag : public bidirectional_iterator_tag {};
190struct contiguous_iterator_tag : public random_access_iterator_tag {};
191
192// 27.4.3, iterator operations
193template <class InputIterator, class Distance> // constexpr in C++17
194 constexpr void advance(InputIterator& i, Distance n);
195
196template <class InputIterator> // constexpr in C++17
197 constexpr typename iterator_traits<InputIterator>::difference_type
198 distance(InputIterator first, InputIterator last);
199
200template <class InputIterator> // constexpr in C++17
201 constexpr InputIterator next(InputIterator x,
202typename iterator_traits<InputIterator>::difference_type n = 1);
203
204template <class BidirectionalIterator> // constexpr in C++17
205 constexpr BidirectionalIterator prev(BidirectionalIterator x,
206 typename iterator_traits<BidirectionalIterator>::difference_type n = 1);
207
208// [range.iter.ops], range iterator operations
209namespace ranges {
210 // [range.iter.op.advance], ranges::advance
211 template<input_or_output_iterator I>
212 constexpr void advance(I& i, iter_difference_t<I> n); // since C++20
213 template<input_or_output_iterator I, sentinel_for<I> S>
214 constexpr void advance(I& i, S bound); // since C++20
215 template<input_or_output_iterator I, sentinel_for<I> S>
216 constexpr iter_difference_t<I> advance(I& i, iter_difference_t<I> n, S bound); // since C++20
217}
218
219template <class Iterator>
220class reverse_iterator
221 : public iterator<typename iterator_traits<Iterator>::iterator_category, // until C++17
222 typename iterator_traits<Iterator>::value_type,
223 typename iterator_traits<Iterator>::difference_type,
224 typename iterator_traits<Iterator>::pointer,
225 typename iterator_traits<Iterator>::reference>
226{
227protected:
228 Iterator current;
229public:
230 using iterator_type = Iterator;
231 using iterator_concept = see below; // since C++20
232 using iterator_category = typename iterator_traits<Iterator>::iterator_category; // since C++17, until C++20
233 using iterator_category = see below; // since C++20
234 using value_type = typename iterator_traits<Iterator>::value_type; // since C++17, until C++20
235 using value_type = iter_value_t<Iterator>; // since C++20
236 using difference_type = typename iterator_traits<Iterator>::difference_type; // until C++20
237 using difference_type = iter_difference_t<Iterator>; // since C++20
238 using pointer = typename iterator_traits<Iterator>::pointer;
239 using reference = typename iterator_traits<Iterator>::reference; // until C++20
240 using reference = iter_reference_t<Iterator>; // since C++20
241
242 constexpr reverse_iterator();
243 constexpr explicit reverse_iterator(Iterator x);
244 template <class U> constexpr reverse_iterator(const reverse_iterator<U>& u);
245 template <class U> constexpr reverse_iterator& operator=(const reverse_iterator<U>& u);
246 constexpr Iterator base() const;
247 constexpr reference operator*() const;
248 constexpr pointer operator->() const; // until C++20
249 constexpr pointer operator->() const requires see below; // since C++20
250 constexpr reverse_iterator& operator++();
251 constexpr reverse_iterator operator++(int);
252 constexpr reverse_iterator& operator--();
253 constexpr reverse_iterator operator--(int);
254 constexpr reverse_iterator operator+ (difference_type n) const;
255 constexpr reverse_iterator& operator+=(difference_type n);
256 constexpr reverse_iterator operator- (difference_type n) const;
257 constexpr reverse_iterator& operator-=(difference_type n);
258 constexpr unspecified operator[](difference_type n) const;
259
260 friend constexpr iter_rvalue_reference_t<Iterator>
261 iter_move(const reverse_iterator& i) noexcept(see below);
262 template<indirectly_swappable<Iterator> Iterator2>
263 friend constexpr void
264 iter_swap(const reverse_iterator& x,
265 const reverse_iterator<Iterator2>& y) noexcept(see below);
266};
267
268template <class Iterator1, class Iterator2>
269constexpr bool // constexpr in C++17
270operator==(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
271
272template <class Iterator1, class Iterator2>
273constexpr bool // constexpr in C++17
274operator!=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
275
276template <class Iterator1, class Iterator2>
277constexpr bool // constexpr in C++17
278operator<(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
279
280template <class Iterator1, class Iterator2>
281constexpr bool // constexpr in C++17
282operator>(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
283
284template <class Iterator1, class Iterator2>
285constexpr bool // constexpr in C++17
286operator<=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
287
288template <class Iterator1, class Iterator2>
289constexpr bool // constexpr in C++17
290operator>=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
291
292template<class Iterator1, three_way_comparable_with<Iterator1> Iterator2>
293 constexpr compare_three_way_result_t<Iterator1, Iterator2>
294 operator<=>(const reverse_iterator<Iterator1>& x,
295 const reverse_iterator<Iterator2>& y);
296
297template <class Iterator1, class Iterator2>
298constexpr auto
299operator-(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y)
300-> decltype(__y.base() - __x.base()); // constexpr in C++17
301
302template <class Iterator>
303constexpr reverse_iterator<Iterator>
304operator+(typename reverse_iterator<Iterator>::difference_type n,
305 const reverse_iterator<Iterator>& x); // constexpr in C++17
306
307template <class Iterator>
308constexpr reverse_iterator<Iterator> make_reverse_iterator(Iterator i); // C++14, constexpr in C++17
309
310template<class Iterator1, class Iterator2>
311 requires (!sized_sentinel_for<Iterator1, Iterator2>)
312 inline constexpr bool disable_sized_sentinel_for<reverse_iterator<Iterator1>,
313 reverse_iterator<Iterator2>> = true;
314
315template <class Container>
316class back_insert_iterator
317 : public iterator<output_iterator_tag, void, void, void, void> // until C++17
318{
319protected:
320 Container* container;
321public:
322 typedef Container container_type;
323 typedef void value_type;
324 typedef void difference_type; // until C++20
325 typedef ptrdiff_t difference_type; // since C++20
326 typedef void reference;
327 typedef void pointer;
328
329 explicit back_insert_iterator(Container& x); // constexpr in C++20
330 back_insert_iterator& operator=(const typename Container::value_type& value); // constexpr in C++20
331 back_insert_iterator& operator*(); // constexpr in C++20
332 back_insert_iterator& operator++(); // constexpr in C++20
333 back_insert_iterator operator++(int); // constexpr in C++20
334};
335
336template <class Container> back_insert_iterator<Container> back_inserter(Container& x); // constexpr in C++20
337
338template <class Container>
339class front_insert_iterator
340 : public iterator<output_iterator_tag, void, void, void, void> // until C++17
341{
342protected:
343 Container* container;
344public:
345 typedef Container container_type;
346 typedef void value_type;
347 typedef void difference_type; // until C++20
348 typedef ptrdiff_t difference_type; // since C++20
349 typedef void reference;
350 typedef void pointer;
351
352 explicit front_insert_iterator(Container& x); // constexpr in C++20
353 front_insert_iterator& operator=(const typename Container::value_type& value); // constexpr in C++20
354 front_insert_iterator& operator*(); // constexpr in C++20
355 front_insert_iterator& operator++(); // constexpr in C++20
356 front_insert_iterator operator++(int); // constexpr in C++20
357};
358
359template <class Container> front_insert_iterator<Container> front_inserter(Container& x); // constexpr in C++20
360
361template <class Container>
362class insert_iterator
363 : public iterator<output_iterator_tag, void, void, void, void> // until C++17
364{
365protected:
366 Container* container;
367 typename Container::iterator iter;
368public:
369 typedef Container container_type;
370 typedef void value_type;
371 typedef void difference_type; // until C++20
372 typedef ptrdiff_t difference_type; // since C++20
373 typedef void reference;
374 typedef void pointer;
375
376 insert_iterator(Container& x, typename Container::iterator i); // constexpr in C++20
377 insert_iterator& operator=(const typename Container::value_type& value); // constexpr in C++20
378 insert_iterator& operator*(); // constexpr in C++20
379 insert_iterator& operator++(); // constexpr in C++20
380 insert_iterator& operator++(int); // constexpr in C++20
381};
382
383template <class Container>
384insert_iterator<Container> inserter(Container& x, typename Container::iterator i); // until C++20
385template <class Container>
386constexpr insert_iterator<Container> inserter(Container& x, ranges::iterator_t<Container> i); // since C++20
387
388template <class Iterator>
389class move_iterator {
390public:
391 using iterator_type = Iterator;
392 using iterator_concept = see below; // From C++20
393 using iterator_category = see below; // not always present starting from C++20
394 using value_type = iter_value_t<Iterator>; // Until C++20, iterator_traits<Iterator>::value_type
395 using difference_type = iter_difference_t<Iterator>; // Until C++20, iterator_traits<Iterator>::difference_type;
396 using pointer = Iterator;
397 using reference = iter_rvalue_reference_t<Iterator>; // Until C++20, value_type&&
398
399 constexpr move_iterator(); // all the constexprs are in C++17
400 constexpr explicit move_iterator(Iterator i);
401 template <class U>
402 constexpr move_iterator(const move_iterator<U>& u);
403 template <class U>
404 constexpr move_iterator& operator=(const move_iterator<U>& u);
405
406 constexpr iterator_type base() const; // Until C++20
407 constexpr const Iterator& base() const & noexcept; // From C++20
408 constexpr Iterator base() &&; // From C++20
409
410 constexpr reference operator*() const;
411 constexpr pointer operator->() const; // Deprecated in C++20
412 constexpr move_iterator& operator++();
413 constexpr auto operator++(int); // Return type was move_iterator until C++20
414 constexpr move_iterator& operator--();
415 constexpr move_iterator operator--(int);
416 constexpr move_iterator operator+(difference_type n) const;
417 constexpr move_iterator& operator+=(difference_type n);
418 constexpr move_iterator operator-(difference_type n) const;
419 constexpr move_iterator& operator-=(difference_type n);
420 constexpr reference operator[](difference_type n) const; // Return type unspecified until C++20
421
422 template<sentinel_for<Iterator> S>
423 friend constexpr bool
424 operator==(const move_iterator& x, const move_sentinel<S>& y); // Since C++20
425 template<sized_sentinel_for<Iterator> S>
426 friend constexpr iter_difference_t<Iterator>
427 operator-(const move_sentinel<S>& x, const move_iterator& y); // Since C++20
428 template<sized_sentinel_for<Iterator> S>
429 friend constexpr iter_difference_t<Iterator>
430 operator-(const move_iterator& x, const move_sentinel<S>& y); // Since C++20
431 friend constexpr iter_rvalue_reference_t<Iterator>
432 iter_move(const move_iterator& i)
433 noexcept(noexcept(ranges::iter_move(i.current))); // Since C++20
434 template<indirectly_swappable<Iterator> Iterator2>
435 friend constexpr void
436 iter_swap(const move_iterator& x, const move_iterator<Iterator2>& y)
437 noexcept(noexcept(ranges::iter_swap(x.current, y.current))); // Since C++20
438
439private:
440 Iterator current; // exposition only
441};
442
443template <class Iterator1, class Iterator2>
444constexpr bool // constexpr in C++17
445operator==(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
446
447template <class Iterator1, class Iterator2>
448constexpr bool // constexpr in C++17
449operator!=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
450
451template <class Iterator1, class Iterator2>
452constexpr bool // constexpr in C++17
453operator<(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
454
455template <class Iterator1, class Iterator2>
456constexpr bool // constexpr in C++17
457operator<=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
458
459template <class Iterator1, class Iterator2>
460constexpr bool // constexpr in C++17
461operator>(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
462
463template <class Iterator1, class Iterator2>
464constexpr bool // constexpr in C++17
465operator>=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
466
467template <class Iterator1, class Iterator2>
468constexpr auto // constexpr in C++17
469operator-(const move_iterator<Iterator1>& x,
470 const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
471
472template <class Iterator>
473constexpr move_iterator<Iterator> operator+( // constexpr in C++17
474 typename move_iterator<Iterator>::difference_type n,
475 const move_iterator<Iterator>& x);
476
477template <class Iterator> // constexpr in C++17
478constexpr move_iterator<Iterator> make_move_iterator(const Iterator& i);
479
480template<class Iterator1, class Iterator2>
481 requires (!sized_sentinel_for<Iterator1, Iterator2>)
482 inline constexpr bool disable_sized_sentinel_for<move_iterator<Iterator1>, // since C++20
483 move_iterator<Iterator2>> = true;
484
485template<semiregular S>
486class move_sentinel {
487public:
488 constexpr move_sentinel();
489 constexpr explicit move_sentinel(S s);
490 template<class S2>
491 requires convertible_to<const S2&, S>
492 constexpr move_sentinel(const move_sentinel<S2>& s);
493 template<class S2>
494 requires assignable_from<S&, const S2&>
495 constexpr move_sentinel& operator=(const move_sentinel<S2>& s);
496
497 constexpr S base() const;
498private:
499 S last; // exposition only
500};
501
502// [default.sentinel], default sentinel
503struct default_sentinel_t;
504inline constexpr default_sentinel_t default_sentinel{};
505
506// [iterators.counted], counted iterators
507template<input_or_output_iterator I> class counted_iterator;
508
509template<input_iterator I>
510 requires see below
511 struct iterator_traits<counted_iterator<I>>;
512
513// [unreachable.sentinel], unreachable sentinel
514struct unreachable_sentinel_t;
515inline constexpr unreachable_sentinel_t unreachable_sentinel{};
516
517template <class T, class charT = char, class traits = char_traits<charT>, class Distance = ptrdiff_t>
518class istream_iterator
519 : public iterator<input_iterator_tag, T, Distance, const T*, const T&> // until C++17
520{
521public:
522 typedef input_iterator_tag iterator_category;
523 typedef T value_type;
524 typedef Distance difference_type;
525 typedef const T* pointer;
526 typedef const T& reference;
527
528 typedef charT char_type;
529 typedef traits traits_type;
530 typedef basic_istream<charT, traits> istream_type;
531
532 istream_iterator(); // constexpr since C++11
533 constexpr istream_iterator(default_sentinel_t); // since C++20
534 istream_iterator(istream_type& s);
535 constexpr istream_iterator(const istream_iterator& x) noexcept(see below);
536 ~istream_iterator();
537
538 const T& operator*() const;
539 const T* operator->() const;
540 istream_iterator& operator++();
541 istream_iterator operator++(int);
542 friend bool operator==(const istream_iterator& i, default_sentinel_t); // since C++20
543};
544
545template <class T, class charT, class traits, class Distance>
546bool operator==(const istream_iterator<T,charT,traits,Distance>& x,
547 const istream_iterator<T,charT,traits,Distance>& y);
548template <class T, class charT, class traits, class Distance>
549bool operator!=(const istream_iterator<T,charT,traits,Distance>& x,
550 const istream_iterator<T,charT,traits,Distance>& y); // until C++20
551
552template <class T, class charT = char, class traits = char_traits<charT> >
553class ostream_iterator
554 : public iterator<output_iterator_tag, void, void, void, void> // until C++17
555{
556public:
557 typedef output_iterator_tag iterator_category;
558 typedef void value_type;
559 typedef void difference_type; // until C++20
560 typedef ptrdiff_t difference_type; // since C++20
561 typedef void pointer;
562 typedef void reference;
563
564 typedef charT char_type;
565 typedef traits traits_type;
566 typedef basic_ostream<charT,traits> ostream_type;
567
568 ostream_iterator(ostream_type& s);
569 ostream_iterator(ostream_type& s, const charT* delimiter);
570 ostream_iterator(const ostream_iterator& x);
571 ~ostream_iterator();
572 ostream_iterator& operator=(const T& value);
573
574 ostream_iterator& operator*();
575 ostream_iterator& operator++();
576 ostream_iterator& operator++(int);
577};
578
579template<class charT, class traits = char_traits<charT> >
580class istreambuf_iterator
581 : public iterator<input_iterator_tag, charT, traits::off_type, unspecified, charT> // until C++17
582{
583public:
584 typedef input_iterator_tag iterator_category;
585 typedef charT value_type;
586 typedef traits::off_type difference_type;
587 typedef unspecified pointer;
588 typedef charT reference;
589
590 typedef charT char_type;
591 typedef traits traits_type;
592 typedef traits::int_type int_type;
593 typedef basic_streambuf<charT, traits> streambuf_type;
594 typedef basic_istream<charT, traits> istream_type;
595
596 istreambuf_iterator() noexcept; // constexpr since C++11
597 constexpr istreambuf_iterator(default_sentinel_t) noexcept; // since C++20
598 istreambuf_iterator(istream_type& s) noexcept;
599 istreambuf_iterator(streambuf_type* s) noexcept;
600 istreambuf_iterator(a-private-type) noexcept;
601
602 charT operator*() const;
603 pointer operator->() const;
604 istreambuf_iterator& operator++();
605 a-private-type operator++(int);
606
607 bool equal(const istreambuf_iterator& b) const;
608 friend bool operator==(const istreambuf_iterator& i, default_sentinel_t s); // since C++20
609};
610
611template <class charT, class traits>
612bool operator==(const istreambuf_iterator<charT,traits>& a,
613 const istreambuf_iterator<charT,traits>& b);
614template <class charT, class traits>
615bool operator!=(const istreambuf_iterator<charT,traits>& a,
616 const istreambuf_iterator<charT,traits>& b); // until C++20
617
618template <class charT, class traits = char_traits<charT> >
619class ostreambuf_iterator
620 : public iterator<output_iterator_tag, void, void, void, void> // until C++17
621{
622public:
623 typedef output_iterator_tag iterator_category;
624 typedef void value_type;
625 typedef void difference_type; // until C++20
626 typedef ptrdiff_t difference_type; // since C++20
627 typedef void pointer;
628 typedef void reference;
629
630 typedef charT char_type;
631 typedef traits traits_type;
632 typedef basic_streambuf<charT, traits> streambuf_type;
633 typedef basic_ostream<charT, traits> ostream_type;
634
635 ostreambuf_iterator(ostream_type& s) noexcept;
636 ostreambuf_iterator(streambuf_type* s) noexcept;
637 ostreambuf_iterator& operator=(charT c);
638 ostreambuf_iterator& operator*();
639 ostreambuf_iterator& operator++();
640 ostreambuf_iterator& operator++(int);
641 bool failed() const noexcept;
642};
643
644template <class C> constexpr auto begin(C& c) noexcept(see-below) -> decltype(c.begin()); // constexpr since C++17
645template <class C> constexpr auto begin(const C& c) noexcept(see-below) -> decltype(c.begin()); // constexpr since C++17
646template <class C> constexpr auto end(C& c) noexcept(see-below) -> decltype(c.end()); // constexpr since C++17
647template <class C> constexpr auto end(const C& c) noexcept(see-below) -> decltype(c.end()); // constexpr since C++17
648template <class T, size_t N> constexpr T* begin(T (&array)[N]) noexcept;
649template <class T, size_t N> constexpr T* end(T (&array)[N]) noexcept;
650
651template <class C> constexpr auto cbegin(const C& c) noexcept(see-below) -> decltype(std::begin(c)); // C++14
652template <class C> constexpr auto cend(const C& c) noexcept(see-below) -> decltype(std::end(c)); // C++14
653template <class C>
654constexpr auto rbegin(C& c) noexcept(see-below) -> decltype(c.rbegin()); // C++14, constexpr since C++17
655template <class C>
656constexpr auto rbegin(const C& c) noexcept(see-below) -> decltype(c.rbegin()); // C++14, constexpr since C++17
657template <class C>
658constexpr auto rend(C& c) noexcept(see-below) -> decltype(c.rend()); // C++14, constexpr since C++17
659template <class C>
660constexpr auto rend(const C& c) noexcept(see-below) -> decltype(c.rend()); // C++14, constexpr since C++17
661template <class E>
662constexpr reverse_iterator<const E*> rbegin(initializer_list<E> il) noexcept; // C++14, constexpr since C++17
663template <class E>
664constexpr reverse_iterator<const E*> rend(initializer_list<E> il) noexcept; // C++14, constexpr since C++17
665template <class T, size_t N>
666constexpr reverse_iterator<T*> rbegin(T (&array)[N]) noexcept; // C++14, constexpr since C++17
667template <class T, size_t N>
668constexpr reverse_iterator<T*> rend(T (&array)[N]) noexcept; // C++14, constexpr since C++17
669template <class C>
670constexpr auto crbegin(const C& c) noexcept(see-below) -> decltype(std::rbegin(c)); // C++14, constexpr since C++17
671template <class C>
672constexpr auto crend(const C& c) noexcept(see-below) -> decltype(std::rend(c)); // C++14, constexpr since C++17
673
674// 24.8, container access:
675template <class C> constexpr auto size(const C& c) noexcept(see-below) -> decltype(c.size()); // C++17
676template <class T, size_t N> constexpr size_t size(const T (&array)[N]) noexcept; // C++17
677
678template <class C> constexpr auto ssize(const C& c) noexcept(see-below)
679 -> common_type_t<ptrdiff_t, make_signed_t<decltype(c.size())>>; // C++20
680template <class T, ptrdiff_t> constexpr ptrdiff_t ssize(const T (&array)[N]) noexcept; // C++20
681
682template <class C> constexpr auto empty(const C& c) noexcept(see-below) -> decltype(c.empty()); // C++17
683template <class T, size_t N> constexpr bool empty(const T (&array)[N]) noexcept; // C++17
684template <class C> constexpr auto data(C& c) noexcept(see-below) -> decltype(c.data()); // C++17
685template <class C> constexpr auto data(const C& c) noexcept(see-below) -> decltype(c.data()); // C++17
686template <class T, size_t N> constexpr T* data(T (&array)[N]) noexcept; // C++17
687
688} // std
689
690*/
691
692#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
693# include <__cxx03/iterator>
694#else
695# include <__config>
696# include <__iterator/access.h>
697# include <__iterator/advance.h>
698# include <__iterator/back_insert_iterator.h>
699# include <__iterator/distance.h>
700# include <__iterator/front_insert_iterator.h>
701# include <__iterator/insert_iterator.h>
702# include <__iterator/istream_iterator.h>
703# include <__iterator/istreambuf_iterator.h>
704# include <__iterator/iterator.h>
705# include <__iterator/iterator_traits.h>
706# include <__iterator/move_iterator.h>
707# include <__iterator/next.h>
708# include <__iterator/ostream_iterator.h>
709# include <__iterator/ostreambuf_iterator.h>
710# include <__iterator/prev.h>
711# include <__iterator/reverse_iterator.h>
712# include <__iterator/wrap_iter.h>
713
714# if _LIBCPP_STD_VER >= 14
715# include <__iterator/reverse_access.h>
716# endif
717
718# if _LIBCPP_STD_VER >= 17
719# include <__iterator/data.h>
720# include <__iterator/empty.h>
721# include <__iterator/size.h>
722# endif
723
724# if _LIBCPP_STD_VER >= 20
725# include <__iterator/common_iterator.h>
726# include <__iterator/concepts.h>
727# include <__iterator/counted_iterator.h>
728# include <__iterator/default_sentinel.h>
729# include <__iterator/incrementable_traits.h>
730# include <__iterator/indirectly_comparable.h>
731# include <__iterator/iter_move.h>
732# include <__iterator/iter_swap.h>
733# include <__iterator/mergeable.h>
734# include <__iterator/move_sentinel.h>
735# include <__iterator/permutable.h>
736# include <__iterator/projected.h>
737# include <__iterator/readable_traits.h>
738# include <__iterator/sortable.h>
739# include <__iterator/unreachable_sentinel.h>
740# endif
741
742# include <version>
743
744// standard-mandated includes
745
746// [iterator.synopsis]
747# include <compare>
748# include <concepts>
749# include <initializer_list>
750
751// [range.access.general]
752# if _LIBCPP_STD_VER >= 20
753# include <__ranges/access.h>
754# include <__ranges/data.h>
755# include <__ranges/empty.h>
756# include <__ranges/rbegin.h>
757# include <__ranges/rend.h>
758# include <__ranges/size.h>
759# endif
760
761# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
762# pragma GCC system_header
763# endif
764
765#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
766
767#endif // _LIBCPP_ITERATOR
768