1// -*- C++ -*-
2//===-------------------------- iterator ----------------------------------===//
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 <concepts>
17
18namespace std
19{
20template<class> struct incrementable_traits;       // since C++20
21template<class T>
22  using iter_difference_t = see below;             // since C++20
23
24template<class> struct indirectly_readable_traits; // since C++20
25template<class T>
26  using iter_value_t = see below;                  // since C++20
27
28template<class Iterator>
29struct iterator_traits;
30
31template<class T>
32  requires is_object_v<T>                    // since C++20
33struct iterator_traits<T*>;
34
35template<dereferenceable T>
36  using iter_reference_t = decltype(*declval<T&>());
37
38namespace ranges::inline unspecified {
39    inline constexpr unspecified iter_move = unspecified; // since C++20, nodiscard as an extension
40}}
41
42template<dereferenceable T>
43  requires ...
44using iter_rvalue_reference_t = decltype(ranges::iter_move(declval<T&>())); // since C++20
45
46// [iterator.concepts], iterator concepts
47// [iterator.concept.readable], concept indirectly_readable
48template<class In>
49  concept indirectly_readable = see below;                // since C++20
50
51// [iterator.concept.writable], concept indirectly_writable
52template<class Out, class T>
53  concept indirectly_writable = see below;                // since C++20
54
55template<class Category, class T, class Distance = ptrdiff_t,
56         class Pointer = T*, class Reference = T&>
57struct iterator
58{
59    typedef T         value_type;
60    typedef Distance  difference_type;
61    typedef Pointer   pointer;
62    typedef Reference reference;
63    typedef Category  iterator_category;
64};
65
66struct input_iterator_tag  {};
67struct output_iterator_tag {};
68struct forward_iterator_tag       : public input_iterator_tag         {};
69struct bidirectional_iterator_tag : public forward_iterator_tag       {};
70struct random_access_iterator_tag : public bidirectional_iterator_tag {};
71
72// 27.4.3, iterator operations
73template <class InputIterator, class Distance>  // constexpr in C++17
74  constexpr void advance(InputIterator& i, Distance n);
75
76template <class InputIterator>  // constexpr in C++17
77  constexpr typename iterator_traits<InputIterator>::difference_type
78    distance(InputIterator first, InputIterator last);
79
80template <class InputIterator>  // constexpr in C++17
81  constexpr InputIterator next(InputIterator x,
82typename iterator_traits<InputIterator>::difference_type n = 1);
83
84template <class BidirectionalIterator>  // constexpr in C++17
85  constexpr BidirectionalIterator prev(BidirectionalIterator x,
86    typename iterator_traits<BidirectionalIterator>::difference_type n = 1);
87
88template <class Iterator>
89class reverse_iterator
90    : public iterator<typename iterator_traits<Iterator>::iterator_category,
91                      typename iterator_traits<Iterator>::value_type,
92                      typename iterator_traits<Iterator>::difference_type,
93                      typename iterator_traits<Iterator>::pointer,
94                      typename iterator_traits<Iterator>::reference>
95{
96protected:
97    Iterator current;
98public:
99    typedef Iterator                                            iterator_type;
100    typedef typename iterator_traits<Iterator>::difference_type difference_type;
101    typedef typename iterator_traits<Iterator>::reference       reference;
102    typedef typename iterator_traits<Iterator>::pointer         pointer;
103
104    constexpr reverse_iterator();
105    constexpr explicit reverse_iterator(Iterator x);
106    template <class U> constexpr reverse_iterator(const reverse_iterator<U>& u);
107    template <class U> constexpr reverse_iterator& operator=(const reverse_iterator<U>& u);
108    constexpr Iterator base() const;
109    constexpr reference operator*() const;
110    constexpr pointer   operator->() const;
111    constexpr reverse_iterator& operator++();
112    constexpr reverse_iterator  operator++(int);
113    constexpr reverse_iterator& operator--();
114    constexpr reverse_iterator  operator--(int);
115    constexpr reverse_iterator  operator+ (difference_type n) const;
116    constexpr reverse_iterator& operator+=(difference_type n);
117    constexpr reverse_iterator  operator- (difference_type n) const;
118    constexpr reverse_iterator& operator-=(difference_type n);
119    constexpr reference         operator[](difference_type n) const;
120};
121
122template <class Iterator1, class Iterator2>
123constexpr bool                          // constexpr in C++17
124operator==(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
125
126template <class Iterator1, class Iterator2>
127constexpr bool                          // constexpr in C++17
128operator<(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
129
130template <class Iterator1, class Iterator2>
131constexpr bool                          // constexpr in C++17
132operator!=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
133
134template <class Iterator1, class Iterator2>
135constexpr bool                          // constexpr in C++17
136operator>(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
137
138template <class Iterator1, class Iterator2>
139constexpr bool                          // constexpr in C++17
140operator>=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
141
142template <class Iterator1, class Iterator2>
143constexpr bool                          // constexpr in C++17
144operator<=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
145
146template <class Iterator1, class Iterator2>
147constexpr auto
148operator-(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y)
149-> decltype(__y.base() - __x.base());   // constexpr in C++17
150
151template <class Iterator>
152constexpr reverse_iterator<Iterator>
153operator+(typename reverse_iterator<Iterator>::difference_type n,
154          const reverse_iterator<Iterator>& x);   // constexpr in C++17
155
156template <class Iterator>
157constexpr reverse_iterator<Iterator> make_reverse_iterator(Iterator i); // C++14, constexpr in C++17
158
159template <class Container>
160class back_insert_iterator
161{
162protected:
163    Container* container;
164public:
165    typedef Container                   container_type;
166    typedef void                        value_type;
167    typedef void                        difference_type;
168    typedef void                        reference;
169    typedef void                        pointer;
170
171    explicit back_insert_iterator(Container& x);  // constexpr in C++20
172    back_insert_iterator& operator=(const typename Container::value_type& value);  // constexpr in C++20
173    back_insert_iterator& operator*();  // constexpr in C++20
174    back_insert_iterator& operator++();  // constexpr in C++20
175    back_insert_iterator  operator++(int);  // constexpr in C++20
176};
177
178template <class Container> back_insert_iterator<Container> back_inserter(Container& x);  // constexpr in C++20
179
180template <class Container>
181class front_insert_iterator
182{
183protected:
184    Container* container;
185public:
186    typedef Container                    container_type;
187    typedef void                         value_type;
188    typedef void                         difference_type;
189    typedef void                         reference;
190    typedef void                         pointer;
191
192    explicit front_insert_iterator(Container& x);  // constexpr in C++20
193    front_insert_iterator& operator=(const typename Container::value_type& value);  // constexpr in C++20
194    front_insert_iterator& operator*();  // constexpr in C++20
195    front_insert_iterator& operator++();  // constexpr in C++20
196    front_insert_iterator  operator++(int);  // constexpr in C++20
197};
198
199template <class Container> front_insert_iterator<Container> front_inserter(Container& x);  // constexpr in C++20
200
201template <class Container>
202class insert_iterator
203{
204protected:
205    Container* container;
206    typename Container::iterator iter;
207public:
208    typedef Container              container_type;
209    typedef void                   value_type;
210    typedef void                   difference_type;
211    typedef void                   reference;
212    typedef void                   pointer;
213
214    insert_iterator(Container& x, typename Container::iterator i);  // constexpr in C++20
215    insert_iterator& operator=(const typename Container::value_type& value);  // constexpr in C++20
216    insert_iterator& operator*();  // constexpr in C++20
217    insert_iterator& operator++();  // constexpr in C++20
218    insert_iterator& operator++(int);  // constexpr in C++20
219};
220
221template <class Container, class Iterator>
222insert_iterator<Container> inserter(Container& x, Iterator i);  // constexpr in C++20
223
224template <class Iterator>
225class move_iterator {
226public:
227    typedef Iterator                                              iterator_type;
228    typedef typename iterator_traits<Iterator>::difference_type   difference_type;
229    typedef Iterator                                              pointer;
230    typedef typename iterator_traits<Iterator>::value_type        value_type;
231    typedef typename iterator_traits<Iterator>::iterator_category iterator_category;
232    typedef value_type&&                                          reference;
233
234    constexpr move_iterator();  // all the constexprs are in C++17
235    constexpr explicit move_iterator(Iterator i);
236    template <class U>
237      constexpr move_iterator(const move_iterator<U>& u);
238    template <class U>
239      constexpr move_iterator& operator=(const move_iterator<U>& u);
240    constexpr iterator_type base() const;
241    constexpr reference operator*() const;
242    constexpr pointer operator->() const;
243    constexpr move_iterator& operator++();
244    constexpr move_iterator operator++(int);
245    constexpr move_iterator& operator--();
246    constexpr move_iterator operator--(int);
247    constexpr move_iterator operator+(difference_type n) const;
248    constexpr move_iterator& operator+=(difference_type n);
249    constexpr move_iterator operator-(difference_type n) const;
250    constexpr move_iterator& operator-=(difference_type n);
251    constexpr unspecified operator[](difference_type n) const;
252private:
253    Iterator current; // exposition only
254};
255
256template <class Iterator1, class Iterator2>
257constexpr bool   // constexpr in C++17
258operator==(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
259
260template <class Iterator1, class Iterator2>
261constexpr bool   // constexpr in C++17
262operator!=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
263
264template <class Iterator1, class Iterator2>
265constexpr bool   // constexpr in C++17
266operator<(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
267
268template <class Iterator1, class Iterator2>
269constexpr bool   // constexpr in C++17
270operator<=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
271
272template <class Iterator1, class Iterator2>
273constexpr bool   // constexpr in C++17
274operator>(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
275
276template <class Iterator1, class Iterator2>
277constexpr bool   // constexpr in C++17
278operator>=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
279
280template <class Iterator1, class Iterator2>
281constexpr auto   // constexpr in C++17
282operator-(const move_iterator<Iterator1>& x,
283          const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
284
285template <class Iterator>
286constexpr move_iterator<Iterator> operator+(   // constexpr in C++17
287            typename move_iterator<Iterator>::difference_type n,
288            const move_iterator<Iterator>& x);
289
290template <class Iterator>   // constexpr in C++17
291constexpr  move_iterator<Iterator> make_move_iterator(const Iterator& i);
292
293
294template <class T, class charT = char, class traits = char_traits<charT>, class Distance = ptrdiff_t>
295class istream_iterator
296    : public iterator<input_iterator_tag, T, Distance, const T*, const T&>
297{
298public:
299    typedef charT char_type;
300    typedef traits traits_type;
301    typedef basic_istream<charT,traits> istream_type;
302
303    constexpr istream_iterator();
304    istream_iterator(istream_type& s);
305    istream_iterator(const istream_iterator& x);
306    ~istream_iterator();
307
308    const T& operator*() const;
309    const T* operator->() const;
310    istream_iterator& operator++();
311    istream_iterator  operator++(int);
312};
313
314template <class T, class charT, class traits, class Distance>
315bool operator==(const istream_iterator<T,charT,traits,Distance>& x,
316                const istream_iterator<T,charT,traits,Distance>& y);
317template <class T, class charT, class traits, class Distance>
318bool operator!=(const istream_iterator<T,charT,traits,Distance>& x,
319                const istream_iterator<T,charT,traits,Distance>& y);
320
321template <class T, class charT = char, class traits = char_traits<charT> >
322class ostream_iterator
323    : public iterator<output_iterator_tag, void, void, void ,void>
324{
325public:
326    typedef charT char_type;
327    typedef traits traits_type;
328    typedef basic_ostream<charT,traits> ostream_type;
329
330    ostream_iterator(ostream_type& s);
331    ostream_iterator(ostream_type& s, const charT* delimiter);
332    ostream_iterator(const ostream_iterator& x);
333    ~ostream_iterator();
334    ostream_iterator& operator=(const T& value);
335
336    ostream_iterator& operator*();
337    ostream_iterator& operator++();
338    ostream_iterator& operator++(int);
339};
340
341template<class charT, class traits = char_traits<charT> >
342class istreambuf_iterator
343    : public iterator<input_iterator_tag, charT,
344                      typename traits::off_type, unspecified,
345                      charT>
346{
347public:
348    typedef charT                         char_type;
349    typedef traits                        traits_type;
350    typedef typename traits::int_type     int_type;
351    typedef basic_streambuf<charT,traits> streambuf_type;
352    typedef basic_istream<charT,traits>   istream_type;
353
354    istreambuf_iterator() noexcept;
355    istreambuf_iterator(istream_type& s) noexcept;
356    istreambuf_iterator(streambuf_type* s) noexcept;
357    istreambuf_iterator(a-private-type) noexcept;
358
359    charT                operator*() const;
360    pointer operator->() const;
361    istreambuf_iterator& operator++();
362    a-private-type       operator++(int);
363
364    bool equal(const istreambuf_iterator& b) const;
365};
366
367template <class charT, class traits>
368bool operator==(const istreambuf_iterator<charT,traits>& a,
369                const istreambuf_iterator<charT,traits>& b);
370template <class charT, class traits>
371bool operator!=(const istreambuf_iterator<charT,traits>& a,
372                const istreambuf_iterator<charT,traits>& b);
373
374template <class charT, class traits = char_traits<charT> >
375class ostreambuf_iterator
376    : public iterator<output_iterator_tag, void, void, void, void>
377{
378public:
379    typedef charT                         char_type;
380    typedef traits                        traits_type;
381    typedef basic_streambuf<charT,traits> streambuf_type;
382    typedef basic_ostream<charT,traits>   ostream_type;
383
384    ostreambuf_iterator(ostream_type& s) noexcept;
385    ostreambuf_iterator(streambuf_type* s) noexcept;
386    ostreambuf_iterator& operator=(charT c);
387    ostreambuf_iterator& operator*();
388    ostreambuf_iterator& operator++();
389    ostreambuf_iterator& operator++(int);
390    bool failed() const noexcept;
391};
392
393template <class C> constexpr auto begin(C& c) -> decltype(c.begin());
394template <class C> constexpr auto begin(const C& c) -> decltype(c.begin());
395template <class C> constexpr auto end(C& c) -> decltype(c.end());
396template <class C> constexpr auto end(const C& c) -> decltype(c.end());
397template <class T, size_t N> constexpr T* begin(T (&array)[N]);
398template <class T, size_t N> constexpr T* end(T (&array)[N]);
399
400template <class C> auto constexpr cbegin(const C& c) -> decltype(std::begin(c));        // C++14
401template <class C> auto constexpr cend(const C& c) -> decltype(std::end(c));            // C++14
402template <class C> auto constexpr rbegin(C& c) -> decltype(c.rbegin());                 // C++14
403template <class C> auto constexpr rbegin(const C& c) -> decltype(c.rbegin());           // C++14
404template <class C> auto constexpr rend(C& c) -> decltype(c.rend());                     // C++14
405template <class C> constexpr auto rend(const C& c) -> decltype(c.rend());               // C++14
406template <class E> reverse_iterator<const E*> constexpr rbegin(initializer_list<E> il); // C++14
407template <class E> reverse_iterator<const E*> constexpr rend(initializer_list<E> il);   // C++14
408template <class T, size_t N> reverse_iterator<T*> constexpr rbegin(T (&array)[N]);      // C++14
409template <class T, size_t N> reverse_iterator<T*> constexpr rend(T (&array)[N]);        // C++14
410template <class C> constexpr auto crbegin(const C& c) -> decltype(std::rbegin(c));      // C++14
411template <class C> constexpr auto crend(const C& c) -> decltype(std::rend(c));          // C++14
412
413// 24.8, container access:
414template <class C> constexpr auto size(const C& c) -> decltype(c.size());         // C++17
415template <class T, size_t N> constexpr size_t size(const T (&array)[N]) noexcept; // C++17
416
417template <class C> constexpr auto ssize(const C& c)
418    -> common_type_t<ptrdiff_t, make_signed_t<decltype(c.size())>>;                    // C++20
419template <class T, ptrdiff_t> constexpr ptrdiff_t ssize(const T (&array)[N]) noexcept; // C++20
420
421template <class C> constexpr auto empty(const C& c) -> decltype(c.empty());       // C++17
422template <class T, size_t N> constexpr bool empty(const T (&array)[N]) noexcept;  // C++17
423template <class E> constexpr bool empty(initializer_list<E> il) noexcept;         // C++17
424template <class C> constexpr auto data(C& c) -> decltype(c.data());               // C++17
425template <class C> constexpr auto data(const C& c) -> decltype(c.data());         // C++17
426template <class T, size_t N> constexpr T* data(T (&array)[N]) noexcept;           // C++17
427template <class E> constexpr const E* data(initializer_list<E> il) noexcept;      // C++17
428
429}  // std
430
431*/
432
433#include <__config>
434#include <iosfwd> // for forward declarations of vector and string.
435#include <__functional_base>
436#include <type_traits>
437#include <compare>
438#include <concepts> // Mandated by the Standard.
439#include <cstddef>
440#include <initializer_list>
441#include <__iterator/concepts.h>
442#include <__iterator/incrementable_traits.h>
443#include <__iterator/iter_move.h>
444#include <__iterator/iterator_traits.h>
445#include <__iterator/readable_traits.h>
446#include <__memory/addressof.h>
447#include <__memory/pointer_traits.h>
448#include <version>
449
450#include <__debug>
451
452#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
453#pragma GCC system_header
454#endif
455
456_LIBCPP_BEGIN_NAMESPACE_STD
457
458template<class _Category, class _Tp, class _Distance = ptrdiff_t,
459         class _Pointer = _Tp*, class _Reference = _Tp&>
460struct _LIBCPP_TEMPLATE_VIS iterator
461{
462    typedef _Tp        value_type;
463    typedef _Distance  difference_type;
464    typedef _Pointer   pointer;
465    typedef _Reference reference;
466    typedef _Category  iterator_category;
467};
468
469template <class _InputIter>
470inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
471void __advance(_InputIter& __i,
472             typename iterator_traits<_InputIter>::difference_type __n, input_iterator_tag)
473{
474    for (; __n > 0; --__n)
475        ++__i;
476}
477
478template <class _BiDirIter>
479inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
480void __advance(_BiDirIter& __i,
481             typename iterator_traits<_BiDirIter>::difference_type __n, bidirectional_iterator_tag)
482{
483    if (__n >= 0)
484        for (; __n > 0; --__n)
485            ++__i;
486    else
487        for (; __n < 0; ++__n)
488            --__i;
489}
490
491template <class _RandIter>
492inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
493void __advance(_RandIter& __i,
494             typename iterator_traits<_RandIter>::difference_type __n, random_access_iterator_tag)
495{
496   __i += __n;
497}
498
499template <class _InputIter, class _Distance>
500inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
501void advance(_InputIter& __i, _Distance __orig_n)
502{
503    _LIBCPP_ASSERT(__orig_n >= 0 || __is_cpp17_bidirectional_iterator<_InputIter>::value,
504                   "Attempt to advance(it, n) with negative n on a non-bidirectional iterator");
505    typedef decltype(_VSTD::__convert_to_integral(__orig_n)) _IntegralSize;
506    _IntegralSize __n = __orig_n;
507    _VSTD::__advance(__i, __n, typename iterator_traits<_InputIter>::iterator_category());
508}
509
510template <class _InputIter>
511inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
512typename iterator_traits<_InputIter>::difference_type
513__distance(_InputIter __first, _InputIter __last, input_iterator_tag)
514{
515    typename iterator_traits<_InputIter>::difference_type __r(0);
516    for (; __first != __last; ++__first)
517        ++__r;
518    return __r;
519}
520
521template <class _RandIter>
522inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
523typename iterator_traits<_RandIter>::difference_type
524__distance(_RandIter __first, _RandIter __last, random_access_iterator_tag)
525{
526    return __last - __first;
527}
528
529template <class _InputIter>
530inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
531typename iterator_traits<_InputIter>::difference_type
532distance(_InputIter __first, _InputIter __last)
533{
534    return _VSTD::__distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category());
535}
536
537template <class _InputIter>
538inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
539typename enable_if
540<
541    __is_cpp17_input_iterator<_InputIter>::value,
542    _InputIter
543>::type
544next(_InputIter __x,
545     typename iterator_traits<_InputIter>::difference_type __n = 1)
546{
547    _LIBCPP_ASSERT(__n >= 0 || __is_cpp17_bidirectional_iterator<_InputIter>::value,
548                       "Attempt to next(it, n) with negative n on a non-bidirectional iterator");
549
550    _VSTD::advance(__x, __n);
551    return __x;
552}
553
554template <class _InputIter>
555inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
556typename enable_if
557<
558    __is_cpp17_input_iterator<_InputIter>::value,
559    _InputIter
560>::type
561prev(_InputIter __x,
562     typename iterator_traits<_InputIter>::difference_type __n = 1)
563{
564    _LIBCPP_ASSERT(__n <= 0 || __is_cpp17_bidirectional_iterator<_InputIter>::value,
565                       "Attempt to prev(it, n) with a positive n on a non-bidirectional iterator");
566    _VSTD::advance(__x, -__n);
567    return __x;
568}
569
570
571template <class _Tp, class = void>
572struct __is_stashing_iterator : false_type {};
573
574template <class _Tp>
575struct __is_stashing_iterator<_Tp, typename __void_t<typename _Tp::__stashing_iterator_tag>::type>
576  : true_type {};
577
578template <class _Iter>
579class _LIBCPP_TEMPLATE_VIS reverse_iterator
580    : public iterator<typename iterator_traits<_Iter>::iterator_category,
581                      typename iterator_traits<_Iter>::value_type,
582                      typename iterator_traits<_Iter>::difference_type,
583                      typename iterator_traits<_Iter>::pointer,
584                      typename iterator_traits<_Iter>::reference>
585{
586private:
587    /*mutable*/ _Iter __t;  // no longer used as of LWG #2360, not removed due to ABI break
588
589    static_assert(!__is_stashing_iterator<_Iter>::value,
590      "The specified iterator type cannot be used with reverse_iterator; "
591      "Using stashing iterators with reverse_iterator causes undefined behavior");
592
593protected:
594    _Iter current;
595public:
596    typedef _Iter                                            iterator_type;
597    typedef typename iterator_traits<_Iter>::difference_type difference_type;
598    typedef typename iterator_traits<_Iter>::reference       reference;
599    typedef typename iterator_traits<_Iter>::pointer         pointer;
600    typedef _If<__is_cpp17_random_access_iterator<_Iter>::value,
601        random_access_iterator_tag,
602        typename iterator_traits<_Iter>::iterator_category>  iterator_category;
603#if _LIBCPP_STD_VER > 17
604    typedef _If<__is_cpp17_random_access_iterator<_Iter>::value,
605        random_access_iterator_tag,
606        bidirectional_iterator_tag>                          iterator_concept;
607#endif
608
609    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
610    reverse_iterator() : __t(), current() {}
611    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
612    explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}
613    template <class _Up>
614        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
615        reverse_iterator(const reverse_iterator<_Up>& __u) : __t(__u.base()), current(__u.base()) {}
616    template <class _Up>
617        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
618        reverse_iterator& operator=(const reverse_iterator<_Up>& __u)
619            { __t = current = __u.base(); return *this; }
620    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
621    _Iter base() const {return current;}
622    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
623    reference operator*() const {_Iter __tmp = current; return *--__tmp;}
624    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
625    pointer  operator->() const {return _VSTD::addressof(operator*());}
626    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
627    reverse_iterator& operator++() {--current; return *this;}
628    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
629    reverse_iterator  operator++(int) {reverse_iterator __tmp(*this); --current; return __tmp;}
630    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
631    reverse_iterator& operator--() {++current; return *this;}
632    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
633    reverse_iterator  operator--(int) {reverse_iterator __tmp(*this); ++current; return __tmp;}
634    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
635    reverse_iterator  operator+ (difference_type __n) const {return reverse_iterator(current - __n);}
636    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
637    reverse_iterator& operator+=(difference_type __n) {current -= __n; return *this;}
638    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
639    reverse_iterator  operator- (difference_type __n) const {return reverse_iterator(current + __n);}
640    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
641    reverse_iterator& operator-=(difference_type __n) {current += __n; return *this;}
642    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
643    reference         operator[](difference_type __n) const {return *(*this + __n);}
644};
645
646template <class _Iter1, class _Iter2>
647inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
648bool
649operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
650{
651    return __x.base() == __y.base();
652}
653
654template <class _Iter1, class _Iter2>
655inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
656bool
657operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
658{
659    return __x.base() > __y.base();
660}
661
662template <class _Iter1, class _Iter2>
663inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
664bool
665operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
666{
667    return __x.base() != __y.base();
668}
669
670template <class _Iter1, class _Iter2>
671inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
672bool
673operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
674{
675    return __x.base() < __y.base();
676}
677
678template <class _Iter1, class _Iter2>
679inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
680bool
681operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
682{
683    return __x.base() <= __y.base();
684}
685
686template <class _Iter1, class _Iter2>
687inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
688bool
689operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
690{
691    return __x.base() >= __y.base();
692}
693
694#ifndef _LIBCPP_CXX03_LANG
695template <class _Iter1, class _Iter2>
696inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
697auto
698operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
699-> decltype(__y.base() - __x.base())
700{
701    return __y.base() - __x.base();
702}
703#else
704template <class _Iter1, class _Iter2>
705inline _LIBCPP_INLINE_VISIBILITY
706typename reverse_iterator<_Iter1>::difference_type
707operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
708{
709    return __y.base() - __x.base();
710}
711#endif
712
713template <class _Iter>
714inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
715reverse_iterator<_Iter>
716operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x)
717{
718    return reverse_iterator<_Iter>(__x.base() - __n);
719}
720
721#if _LIBCPP_STD_VER > 11
722template <class _Iter>
723inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
724reverse_iterator<_Iter> make_reverse_iterator(_Iter __i)
725{
726    return reverse_iterator<_Iter>(__i);
727}
728#endif
729
730template <class _Container>
731class _LIBCPP_TEMPLATE_VIS back_insert_iterator
732    : public iterator<output_iterator_tag,
733                      void,
734                      void,
735                      void,
736                      void>
737{
738protected:
739    _Container* container;
740public:
741    typedef _Container container_type;
742
743    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit back_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
744    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 back_insert_iterator& operator=(const typename _Container::value_type& __value_)
745        {container->push_back(__value_); return *this;}
746#ifndef _LIBCPP_CXX03_LANG
747    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 back_insert_iterator& operator=(typename _Container::value_type&& __value_)
748        {container->push_back(_VSTD::move(__value_)); return *this;}
749#endif // _LIBCPP_CXX03_LANG
750    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 back_insert_iterator& operator*()     {return *this;}
751    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 back_insert_iterator& operator++()    {return *this;}
752    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 back_insert_iterator  operator++(int) {return *this;}
753};
754
755template <class _Container>
756inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
757back_insert_iterator<_Container>
758back_inserter(_Container& __x)
759{
760    return back_insert_iterator<_Container>(__x);
761}
762
763template <class _Container>
764class _LIBCPP_TEMPLATE_VIS front_insert_iterator
765    : public iterator<output_iterator_tag,
766                      void,
767                      void,
768                      void,
769                      void>
770{
771protected:
772    _Container* container;
773public:
774    typedef _Container container_type;
775
776    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit front_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
777    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator=(const typename _Container::value_type& __value_)
778        {container->push_front(__value_); return *this;}
779#ifndef _LIBCPP_CXX03_LANG
780    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator=(typename _Container::value_type&& __value_)
781        {container->push_front(_VSTD::move(__value_)); return *this;}
782#endif // _LIBCPP_CXX03_LANG
783    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator*()     {return *this;}
784    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator++()    {return *this;}
785    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator  operator++(int) {return *this;}
786};
787
788template <class _Container>
789inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
790front_insert_iterator<_Container>
791front_inserter(_Container& __x)
792{
793    return front_insert_iterator<_Container>(__x);
794}
795
796template <class _Container>
797class _LIBCPP_TEMPLATE_VIS insert_iterator
798    : public iterator<output_iterator_tag,
799                      void,
800                      void,
801                      void,
802                      void>
803{
804protected:
805    _Container* container;
806    typename _Container::iterator iter;
807public:
808    typedef _Container container_type;
809
810    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator(_Container& __x, typename _Container::iterator __i)
811        : container(_VSTD::addressof(__x)), iter(__i) {}
812    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator=(const typename _Container::value_type& __value_)
813        {iter = container->insert(iter, __value_); ++iter; return *this;}
814#ifndef _LIBCPP_CXX03_LANG
815    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator=(typename _Container::value_type&& __value_)
816        {iter = container->insert(iter, _VSTD::move(__value_)); ++iter; return *this;}
817#endif // _LIBCPP_CXX03_LANG
818    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator*()        {return *this;}
819    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator++()       {return *this;}
820    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator++(int)    {return *this;}
821};
822
823template <class _Container>
824inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
825insert_iterator<_Container>
826inserter(_Container& __x, typename _Container::iterator __i)
827{
828    return insert_iterator<_Container>(__x, __i);
829}
830
831template <class _Tp, class _CharT = char,
832          class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
833class _LIBCPP_TEMPLATE_VIS istream_iterator
834    : public iterator<input_iterator_tag, _Tp, _Distance, const _Tp*, const _Tp&>
835{
836public:
837    typedef _CharT char_type;
838    typedef _Traits traits_type;
839    typedef basic_istream<_CharT,_Traits> istream_type;
840private:
841    istream_type* __in_stream_;
842    _Tp __value_;
843public:
844    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istream_iterator() : __in_stream_(nullptr), __value_() {}
845    _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s) : __in_stream_(_VSTD::addressof(__s))
846        {
847            if (!(*__in_stream_ >> __value_))
848                __in_stream_ = nullptr;
849        }
850
851    _LIBCPP_INLINE_VISIBILITY const _Tp& operator*() const {return __value_;}
852    _LIBCPP_INLINE_VISIBILITY const _Tp* operator->() const {return _VSTD::addressof((operator*()));}
853    _LIBCPP_INLINE_VISIBILITY istream_iterator& operator++()
854        {
855            if (!(*__in_stream_ >> __value_))
856                __in_stream_ = nullptr;
857            return *this;
858        }
859    _LIBCPP_INLINE_VISIBILITY istream_iterator  operator++(int)
860        {istream_iterator __t(*this); ++(*this); return __t;}
861
862    template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
863    friend _LIBCPP_INLINE_VISIBILITY
864    bool
865    operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
866               const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
867
868    template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
869    friend _LIBCPP_INLINE_VISIBILITY
870    bool
871    operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
872               const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
873};
874
875template <class _Tp, class _CharT, class _Traits, class _Distance>
876inline _LIBCPP_INLINE_VISIBILITY
877bool
878operator==(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
879           const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
880{
881    return __x.__in_stream_ == __y.__in_stream_;
882}
883
884template <class _Tp, class _CharT, class _Traits, class _Distance>
885inline _LIBCPP_INLINE_VISIBILITY
886bool
887operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
888           const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
889{
890    return !(__x == __y);
891}
892
893template <class _Tp, class _CharT = char, class _Traits = char_traits<_CharT> >
894class _LIBCPP_TEMPLATE_VIS ostream_iterator
895    : public iterator<output_iterator_tag, void, void, void, void>
896{
897public:
898    typedef output_iterator_tag             iterator_category;
899    typedef void                            value_type;
900#if _LIBCPP_STD_VER > 17
901    typedef std::ptrdiff_t                  difference_type;
902#else
903    typedef void                            difference_type;
904#endif
905    typedef void                            pointer;
906    typedef void                            reference;
907    typedef _CharT                          char_type;
908    typedef _Traits                         traits_type;
909    typedef basic_ostream<_CharT, _Traits>  ostream_type;
910
911private:
912    ostream_type* __out_stream_;
913    const char_type* __delim_;
914public:
915    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s) _NOEXCEPT
916        : __out_stream_(_VSTD::addressof(__s)), __delim_(nullptr) {}
917    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s, const _CharT* __delimiter) _NOEXCEPT
918        : __out_stream_(_VSTD::addressof(__s)), __delim_(__delimiter) {}
919    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator=(const _Tp& __value_)
920        {
921            *__out_stream_ << __value_;
922            if (__delim_)
923                *__out_stream_ << __delim_;
924            return *this;
925        }
926
927    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator*()     {return *this;}
928    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++()    {return *this;}
929    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++(int) {return *this;}
930};
931
932template<class _CharT, class _Traits>
933class _LIBCPP_TEMPLATE_VIS istreambuf_iterator
934    : public iterator<input_iterator_tag, _CharT,
935                      typename _Traits::off_type, _CharT*,
936                      _CharT>
937{
938public:
939    typedef _CharT                          char_type;
940    typedef _Traits                         traits_type;
941    typedef typename _Traits::int_type      int_type;
942    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
943    typedef basic_istream<_CharT,_Traits>   istream_type;
944private:
945    mutable streambuf_type* __sbuf_;
946
947    class __proxy
948    {
949        char_type __keep_;
950        streambuf_type* __sbuf_;
951        _LIBCPP_INLINE_VISIBILITY __proxy(char_type __c, streambuf_type* __s)
952            : __keep_(__c), __sbuf_(__s) {}
953        friend class istreambuf_iterator;
954    public:
955        _LIBCPP_INLINE_VISIBILITY char_type operator*() const {return __keep_;}
956    };
957
958    _LIBCPP_INLINE_VISIBILITY
959    bool __test_for_eof() const
960    {
961        if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
962            __sbuf_ = nullptr;
963        return __sbuf_ == nullptr;
964    }
965public:
966    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(nullptr) {}
967    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(istream_type& __s) _NOEXCEPT
968        : __sbuf_(__s.rdbuf()) {}
969    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(streambuf_type* __s) _NOEXCEPT
970        : __sbuf_(__s) {}
971    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(const __proxy& __p) _NOEXCEPT
972        : __sbuf_(__p.__sbuf_) {}
973
974    _LIBCPP_INLINE_VISIBILITY char_type  operator*() const
975        {return static_cast<char_type>(__sbuf_->sgetc());}
976    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator& operator++()
977        {
978            __sbuf_->sbumpc();
979            return *this;
980        }
981    _LIBCPP_INLINE_VISIBILITY __proxy              operator++(int)
982        {
983            return __proxy(__sbuf_->sbumpc(), __sbuf_);
984        }
985
986    _LIBCPP_INLINE_VISIBILITY bool equal(const istreambuf_iterator& __b) const
987        {return __test_for_eof() == __b.__test_for_eof();}
988};
989
990template <class _CharT, class _Traits>
991inline _LIBCPP_INLINE_VISIBILITY
992bool operator==(const istreambuf_iterator<_CharT,_Traits>& __a,
993                const istreambuf_iterator<_CharT,_Traits>& __b)
994                {return __a.equal(__b);}
995
996template <class _CharT, class _Traits>
997inline _LIBCPP_INLINE_VISIBILITY
998bool operator!=(const istreambuf_iterator<_CharT,_Traits>& __a,
999                const istreambuf_iterator<_CharT,_Traits>& __b)
1000                {return !__a.equal(__b);}
1001
1002template <class _CharT, class _Traits>
1003class _LIBCPP_TEMPLATE_VIS ostreambuf_iterator
1004    : public iterator<output_iterator_tag, void, void, void, void>
1005{
1006public:
1007    typedef output_iterator_tag                 iterator_category;
1008    typedef void                                value_type;
1009#if _LIBCPP_STD_VER > 17
1010    typedef std::ptrdiff_t                      difference_type;
1011#else
1012    typedef void                                difference_type;
1013#endif
1014    typedef void                                pointer;
1015    typedef void                                reference;
1016    typedef _CharT                              char_type;
1017    typedef _Traits                             traits_type;
1018    typedef basic_streambuf<_CharT, _Traits>    streambuf_type;
1019    typedef basic_ostream<_CharT, _Traits>      ostream_type;
1020
1021private:
1022    streambuf_type* __sbuf_;
1023public:
1024    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(ostream_type& __s) _NOEXCEPT
1025        : __sbuf_(__s.rdbuf()) {}
1026    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(streambuf_type* __s) _NOEXCEPT
1027        : __sbuf_(__s) {}
1028    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator=(_CharT __c)
1029        {
1030            if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sputc(__c), traits_type::eof()))
1031                __sbuf_ = nullptr;
1032            return *this;
1033        }
1034    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator*()     {return *this;}
1035    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++()    {return *this;}
1036    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++(int) {return *this;}
1037    _LIBCPP_INLINE_VISIBILITY bool failed() const _NOEXCEPT {return __sbuf_ == nullptr;}
1038
1039    template <class _Ch, class _Tr>
1040    friend
1041    _LIBCPP_HIDDEN
1042    ostreambuf_iterator<_Ch, _Tr>
1043    __pad_and_output(ostreambuf_iterator<_Ch, _Tr> __s,
1044                     const _Ch* __ob, const _Ch* __op, const _Ch* __oe,
1045                     ios_base& __iob, _Ch __fl);
1046};
1047
1048template <class _Iter>
1049class _LIBCPP_TEMPLATE_VIS move_iterator
1050{
1051private:
1052    _Iter __i;
1053public:
1054    typedef _Iter                                            iterator_type;
1055    typedef typename iterator_traits<iterator_type>::value_type value_type;
1056    typedef typename iterator_traits<iterator_type>::difference_type difference_type;
1057    typedef iterator_type pointer;
1058    typedef _If<__is_cpp17_random_access_iterator<_Iter>::value,
1059        random_access_iterator_tag,
1060        typename iterator_traits<_Iter>::iterator_category>  iterator_category;
1061#if _LIBCPP_STD_VER > 17
1062    typedef input_iterator_tag                               iterator_concept;
1063#endif
1064
1065#ifndef _LIBCPP_CXX03_LANG
1066    typedef typename iterator_traits<iterator_type>::reference __reference;
1067    typedef typename conditional<
1068            is_reference<__reference>::value,
1069            typename remove_reference<__reference>::type&&,
1070            __reference
1071        >::type reference;
1072#else
1073    typedef typename iterator_traits<iterator_type>::reference reference;
1074#endif
1075
1076    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1077    move_iterator() : __i() {}
1078    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1079    explicit move_iterator(_Iter __x) : __i(__x) {}
1080    template <class _Up>
1081      _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1082      move_iterator(const move_iterator<_Up>& __u) : __i(__u.base()) {}
1083    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 _Iter base() const {return __i;}
1084    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1085    reference operator*() const { return static_cast<reference>(*__i); }
1086    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1087    pointer  operator->() const { return __i;}
1088    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1089    move_iterator& operator++() {++__i; return *this;}
1090    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1091    move_iterator  operator++(int) {move_iterator __tmp(*this); ++__i; return __tmp;}
1092    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1093    move_iterator& operator--() {--__i; return *this;}
1094    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1095    move_iterator  operator--(int) {move_iterator __tmp(*this); --__i; return __tmp;}
1096    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1097    move_iterator  operator+ (difference_type __n) const {return move_iterator(__i + __n);}
1098    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1099    move_iterator& operator+=(difference_type __n) {__i += __n; return *this;}
1100    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1101    move_iterator  operator- (difference_type __n) const {return move_iterator(__i - __n);}
1102    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1103    move_iterator& operator-=(difference_type __n) {__i -= __n; return *this;}
1104    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1105    reference operator[](difference_type __n) const { return static_cast<reference>(__i[__n]); }
1106};
1107
1108template <class _Iter1, class _Iter2>
1109inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1110bool
1111operator==(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1112{
1113    return __x.base() == __y.base();
1114}
1115
1116template <class _Iter1, class _Iter2>
1117inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1118bool
1119operator<(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1120{
1121    return __x.base() < __y.base();
1122}
1123
1124template <class _Iter1, class _Iter2>
1125inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1126bool
1127operator!=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1128{
1129    return __x.base() != __y.base();
1130}
1131
1132template <class _Iter1, class _Iter2>
1133inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1134bool
1135operator>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1136{
1137    return __x.base() > __y.base();
1138}
1139
1140template <class _Iter1, class _Iter2>
1141inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1142bool
1143operator>=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1144{
1145    return __x.base() >= __y.base();
1146}
1147
1148template <class _Iter1, class _Iter2>
1149inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1150bool
1151operator<=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1152{
1153    return __x.base() <= __y.base();
1154}
1155
1156#ifndef _LIBCPP_CXX03_LANG
1157template <class _Iter1, class _Iter2>
1158inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1159auto
1160operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1161-> decltype(__x.base() - __y.base())
1162{
1163    return __x.base() - __y.base();
1164}
1165#else
1166template <class _Iter1, class _Iter2>
1167inline _LIBCPP_INLINE_VISIBILITY
1168typename move_iterator<_Iter1>::difference_type
1169operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1170{
1171    return __x.base() - __y.base();
1172}
1173#endif
1174
1175template <class _Iter>
1176inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1177move_iterator<_Iter>
1178operator+(typename move_iterator<_Iter>::difference_type __n, const move_iterator<_Iter>& __x)
1179{
1180    return move_iterator<_Iter>(__x.base() + __n);
1181}
1182
1183template <class _Iter>
1184inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1185move_iterator<_Iter>
1186make_move_iterator(_Iter __i)
1187{
1188    return move_iterator<_Iter>(__i);
1189}
1190
1191// __wrap_iter
1192
1193template <class _Iter> class __wrap_iter;
1194
1195template <class _Iter1, class _Iter2>
1196_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1197bool
1198operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1199
1200template <class _Iter1, class _Iter2>
1201_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1202bool
1203operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1204
1205template <class _Iter1, class _Iter2>
1206_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1207bool
1208operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1209
1210template <class _Iter1, class _Iter2>
1211_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1212bool
1213operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1214
1215template <class _Iter1, class _Iter2>
1216_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1217bool
1218operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1219
1220template <class _Iter1, class _Iter2>
1221_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1222bool
1223operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1224
1225#ifndef _LIBCPP_CXX03_LANG
1226template <class _Iter1, class _Iter2>
1227_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1228auto
1229operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1230-> decltype(__x.base() - __y.base());
1231#else
1232template <class _Iter1, class _Iter2>
1233_LIBCPP_INLINE_VISIBILITY
1234typename __wrap_iter<_Iter1>::difference_type
1235operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1236#endif
1237
1238template <class _Iter>
1239_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1240__wrap_iter<_Iter>
1241operator+(typename __wrap_iter<_Iter>::difference_type, __wrap_iter<_Iter>) _NOEXCEPT;
1242
1243template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 copy(_Ip, _Ip, _Op);
1244template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 copy_backward(_B1, _B1, _B2);
1245template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 move(_Ip, _Ip, _Op);
1246template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 move_backward(_B1, _B1, _B2);
1247
1248template <class _Iter>
1249class __wrap_iter
1250{
1251public:
1252    typedef _Iter                                                      iterator_type;
1253    typedef typename iterator_traits<iterator_type>::value_type        value_type;
1254    typedef typename iterator_traits<iterator_type>::difference_type   difference_type;
1255    typedef typename iterator_traits<iterator_type>::pointer           pointer;
1256    typedef typename iterator_traits<iterator_type>::reference         reference;
1257    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
1258#if _LIBCPP_STD_VER > 17
1259    typedef _If<__is_cpp17_contiguous_iterator<_Iter>::value,
1260                contiguous_iterator_tag, iterator_category>            iterator_concept;
1261#endif
1262
1263private:
1264    iterator_type __i;
1265public:
1266    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter() _NOEXCEPT
1267#if _LIBCPP_STD_VER > 11
1268                : __i{}
1269#endif
1270    {
1271#if _LIBCPP_DEBUG_LEVEL == 2
1272        __get_db()->__insert_i(this);
1273#endif
1274    }
1275    template <class _Up> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1276        __wrap_iter(const __wrap_iter<_Up>& __u,
1277            typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = nullptr) _NOEXCEPT
1278            : __i(__u.base())
1279    {
1280#if _LIBCPP_DEBUG_LEVEL == 2
1281        __get_db()->__iterator_copy(this, &__u);
1282#endif
1283    }
1284#if _LIBCPP_DEBUG_LEVEL == 2
1285    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1286    __wrap_iter(const __wrap_iter& __x)
1287        : __i(__x.base())
1288    {
1289        __get_db()->__iterator_copy(this, &__x);
1290    }
1291    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1292    __wrap_iter& operator=(const __wrap_iter& __x)
1293    {
1294        if (this != &__x)
1295        {
1296            __get_db()->__iterator_copy(this, &__x);
1297            __i = __x.__i;
1298        }
1299        return *this;
1300    }
1301    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1302    ~__wrap_iter()
1303    {
1304        __get_db()->__erase_i(this);
1305    }
1306#endif
1307    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference operator*() const _NOEXCEPT
1308    {
1309#if _LIBCPP_DEBUG_LEVEL == 2
1310        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1311                       "Attempted to dereference a non-dereferenceable iterator");
1312#endif
1313        return *__i;
1314    }
1315    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG pointer  operator->() const _NOEXCEPT
1316    {
1317#if _LIBCPP_DEBUG_LEVEL == 2
1318        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1319                       "Attempted to dereference a non-dereferenceable iterator");
1320#endif
1321        return (pointer)_VSTD::addressof(*__i);
1322    }
1323    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator++() _NOEXCEPT
1324    {
1325#if _LIBCPP_DEBUG_LEVEL == 2
1326        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1327                       "Attempted to increment non-incrementable iterator");
1328#endif
1329        ++__i;
1330        return *this;
1331    }
1332    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator++(int) _NOEXCEPT
1333        {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
1334
1335    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator--() _NOEXCEPT
1336    {
1337#if _LIBCPP_DEBUG_LEVEL == 2
1338        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
1339                       "Attempted to decrement non-decrementable iterator");
1340#endif
1341        --__i;
1342        return *this;
1343    }
1344    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator--(int) _NOEXCEPT
1345        {__wrap_iter __tmp(*this); --(*this); return __tmp;}
1346    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT
1347        {__wrap_iter __w(*this); __w += __n; return __w;}
1348    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator+=(difference_type __n) _NOEXCEPT
1349    {
1350#if _LIBCPP_DEBUG_LEVEL == 2
1351        _LIBCPP_ASSERT(__get_const_db()->__addable(this, __n),
1352                   "Attempted to add/subtract iterator outside of valid range");
1353#endif
1354        __i += __n;
1355        return *this;
1356    }
1357    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator- (difference_type __n) const _NOEXCEPT
1358        {return *this + (-__n);}
1359    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator-=(difference_type __n) _NOEXCEPT
1360        {*this += -__n; return *this;}
1361    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference    operator[](difference_type __n) const _NOEXCEPT
1362    {
1363#if _LIBCPP_DEBUG_LEVEL == 2
1364        _LIBCPP_ASSERT(__get_const_db()->__subscriptable(this, __n),
1365                   "Attempted to subscript iterator outside of valid range");
1366#endif
1367        return __i[__n];
1368    }
1369
1370    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG iterator_type base() const _NOEXCEPT {return __i;}
1371
1372private:
1373#if _LIBCPP_DEBUG_LEVEL == 2
1374    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(const void* __p, iterator_type __x) : __i(__x)
1375    {
1376        __get_db()->__insert_ic(this, __p);
1377    }
1378#else
1379    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(iterator_type __x) _NOEXCEPT : __i(__x) {}
1380#endif
1381
1382    template <class _Up> friend class __wrap_iter;
1383    template <class _CharT, class _Traits, class _Alloc> friend class basic_string;
1384    template <class _Tp, class _Alloc> friend class _LIBCPP_TEMPLATE_VIS vector;
1385    template <class _Tp, size_t> friend class _LIBCPP_TEMPLATE_VIS span;
1386
1387    template <class _Iter1, class _Iter2>
1388    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1389    bool
1390    operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1391
1392    template <class _Iter1, class _Iter2>
1393    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1394    bool
1395    operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1396
1397    template <class _Iter1, class _Iter2>
1398    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1399    bool
1400    operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1401
1402    template <class _Iter1, class _Iter2>
1403    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1404    bool
1405    operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1406
1407    template <class _Iter1, class _Iter2>
1408    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1409    bool
1410    operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1411
1412    template <class _Iter1, class _Iter2>
1413    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1414    bool
1415    operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1416
1417#ifndef _LIBCPP_CXX03_LANG
1418    template <class _Iter1, class _Iter2>
1419    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1420    auto
1421    operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1422    -> decltype(__x.base() - __y.base());
1423#else
1424    template <class _Iter1, class _Iter2>
1425    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1426    typename __wrap_iter<_Iter1>::difference_type
1427    operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1428#endif
1429
1430    template <class _Iter1>
1431    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1432    __wrap_iter<_Iter1>
1433    operator+(typename __wrap_iter<_Iter1>::difference_type, __wrap_iter<_Iter1>) _NOEXCEPT;
1434
1435    template <class _Ip, class _Op> friend _LIBCPP_CONSTEXPR_AFTER_CXX17 _Op copy(_Ip, _Ip, _Op);
1436    template <class _B1, class _B2> friend _LIBCPP_CONSTEXPR_AFTER_CXX17 _B2 copy_backward(_B1, _B1, _B2);
1437    template <class _Ip, class _Op> friend _LIBCPP_CONSTEXPR_AFTER_CXX17 _Op move(_Ip, _Ip, _Op);
1438    template <class _B1, class _B2> friend _LIBCPP_CONSTEXPR_AFTER_CXX17 _B2 move_backward(_B1, _B1, _B2);
1439};
1440
1441#if _LIBCPP_STD_VER <= 17
1442template <class _It>
1443struct __is_cpp17_contiguous_iterator<__wrap_iter<_It> > : __is_cpp17_contiguous_iterator<_It> {};
1444#endif
1445
1446template <class _Iter>
1447_LIBCPP_CONSTEXPR
1448_EnableIf<__is_cpp17_contiguous_iterator<_Iter>::value, decltype(_VSTD::__to_address(declval<_Iter>()))>
1449__to_address(__wrap_iter<_Iter> __w) _NOEXCEPT {
1450    return _VSTD::__to_address(__w.base());
1451}
1452
1453template <class _Iter1, class _Iter2>
1454inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1455bool
1456operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1457{
1458    return __x.base() == __y.base();
1459}
1460
1461template <class _Iter1, class _Iter2>
1462inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1463bool
1464operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1465{
1466#if _LIBCPP_DEBUG_LEVEL == 2
1467    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1468                   "Attempted to compare incomparable iterators");
1469#endif
1470    return __x.base() < __y.base();
1471}
1472
1473template <class _Iter1, class _Iter2>
1474inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1475bool
1476operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1477{
1478    return !(__x == __y);
1479}
1480
1481template <class _Iter1, class _Iter2>
1482inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1483bool
1484operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1485{
1486    return __y < __x;
1487}
1488
1489template <class _Iter1, class _Iter2>
1490inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1491bool
1492operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1493{
1494    return !(__x < __y);
1495}
1496
1497template <class _Iter1, class _Iter2>
1498inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1499bool
1500operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1501{
1502    return !(__y < __x);
1503}
1504
1505template <class _Iter1>
1506inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1507bool
1508operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
1509{
1510    return !(__x == __y);
1511}
1512
1513template <class _Iter1>
1514inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1515bool
1516operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
1517{
1518    return __y < __x;
1519}
1520
1521template <class _Iter1>
1522inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1523bool
1524operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
1525{
1526    return !(__x < __y);
1527}
1528
1529template <class _Iter1>
1530inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1531bool
1532operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
1533{
1534    return !(__y < __x);
1535}
1536
1537#ifndef _LIBCPP_CXX03_LANG
1538template <class _Iter1, class _Iter2>
1539inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1540auto
1541operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1542-> decltype(__x.base() - __y.base())
1543{
1544#if _LIBCPP_DEBUG_LEVEL == 2
1545    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1546                   "Attempted to subtract incompatible iterators");
1547#endif
1548    return __x.base() - __y.base();
1549}
1550#else
1551template <class _Iter1, class _Iter2>
1552inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1553typename __wrap_iter<_Iter1>::difference_type
1554operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1555{
1556#if _LIBCPP_DEBUG_LEVEL == 2
1557    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1558                   "Attempted to subtract incompatible iterators");
1559#endif
1560    return __x.base() - __y.base();
1561}
1562#endif
1563
1564template <class _Iter>
1565inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1566__wrap_iter<_Iter>
1567operator+(typename __wrap_iter<_Iter>::difference_type __n,
1568          __wrap_iter<_Iter> __x) _NOEXCEPT
1569{
1570    __x += __n;
1571    return __x;
1572}
1573
1574template <class _Iter>
1575struct __libcpp_is_trivial_iterator
1576    : public _LIBCPP_BOOL_CONSTANT(is_pointer<_Iter>::value) {};
1577
1578template <class _Iter>
1579struct __libcpp_is_trivial_iterator<move_iterator<_Iter> >
1580    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1581
1582template <class _Iter>
1583struct __libcpp_is_trivial_iterator<reverse_iterator<_Iter> >
1584    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1585
1586template <class _Iter>
1587struct __libcpp_is_trivial_iterator<__wrap_iter<_Iter> >
1588    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1589
1590
1591template <class _Tp, size_t _Np>
1592_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1593_Tp*
1594begin(_Tp (&__array)[_Np])
1595{
1596    return __array;
1597}
1598
1599template <class _Tp, size_t _Np>
1600_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1601_Tp*
1602end(_Tp (&__array)[_Np])
1603{
1604    return __array + _Np;
1605}
1606
1607#if !defined(_LIBCPP_CXX03_LANG)
1608
1609template <class _Cp>
1610_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1611auto
1612begin(_Cp& __c) -> decltype(__c.begin())
1613{
1614    return __c.begin();
1615}
1616
1617template <class _Cp>
1618_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1619auto
1620begin(const _Cp& __c) -> decltype(__c.begin())
1621{
1622    return __c.begin();
1623}
1624
1625template <class _Cp>
1626_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1627auto
1628end(_Cp& __c) -> decltype(__c.end())
1629{
1630    return __c.end();
1631}
1632
1633template <class _Cp>
1634_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1635auto
1636end(const _Cp& __c) -> decltype(__c.end())
1637{
1638    return __c.end();
1639}
1640
1641#if _LIBCPP_STD_VER > 11
1642
1643template <class _Tp, size_t _Np>
1644_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1645reverse_iterator<_Tp*> rbegin(_Tp (&__array)[_Np])
1646{
1647    return reverse_iterator<_Tp*>(__array + _Np);
1648}
1649
1650template <class _Tp, size_t _Np>
1651_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1652reverse_iterator<_Tp*> rend(_Tp (&__array)[_Np])
1653{
1654    return reverse_iterator<_Tp*>(__array);
1655}
1656
1657template <class _Ep>
1658_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1659reverse_iterator<const _Ep*> rbegin(initializer_list<_Ep> __il)
1660{
1661    return reverse_iterator<const _Ep*>(__il.end());
1662}
1663
1664template <class _Ep>
1665_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1666reverse_iterator<const _Ep*> rend(initializer_list<_Ep> __il)
1667{
1668    return reverse_iterator<const _Ep*>(__il.begin());
1669}
1670
1671template <class _Cp>
1672_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1673auto cbegin(const _Cp& __c) -> decltype(_VSTD::begin(__c))
1674{
1675    return _VSTD::begin(__c);
1676}
1677
1678template <class _Cp>
1679_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1680auto cend(const _Cp& __c) -> decltype(_VSTD::end(__c))
1681{
1682    return _VSTD::end(__c);
1683}
1684
1685template <class _Cp>
1686_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1687auto rbegin(_Cp& __c) -> decltype(__c.rbegin())
1688{
1689    return __c.rbegin();
1690}
1691
1692template <class _Cp>
1693_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1694auto rbegin(const _Cp& __c) -> decltype(__c.rbegin())
1695{
1696    return __c.rbegin();
1697}
1698
1699template <class _Cp>
1700_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1701auto rend(_Cp& __c) -> decltype(__c.rend())
1702{
1703    return __c.rend();
1704}
1705
1706template <class _Cp>
1707_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1708auto rend(const _Cp& __c) -> decltype(__c.rend())
1709{
1710    return __c.rend();
1711}
1712
1713template <class _Cp>
1714_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1715auto crbegin(const _Cp& __c) -> decltype(_VSTD::rbegin(__c))
1716{
1717    return _VSTD::rbegin(__c);
1718}
1719
1720template <class _Cp>
1721_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1722auto crend(const _Cp& __c) -> decltype(_VSTD::rend(__c))
1723{
1724    return _VSTD::rend(__c);
1725}
1726
1727#endif
1728
1729
1730#else  // defined(_LIBCPP_CXX03_LANG)
1731
1732template <class _Cp>
1733_LIBCPP_INLINE_VISIBILITY
1734typename _Cp::iterator
1735begin(_Cp& __c)
1736{
1737    return __c.begin();
1738}
1739
1740template <class _Cp>
1741_LIBCPP_INLINE_VISIBILITY
1742typename _Cp::const_iterator
1743begin(const _Cp& __c)
1744{
1745    return __c.begin();
1746}
1747
1748template <class _Cp>
1749_LIBCPP_INLINE_VISIBILITY
1750typename _Cp::iterator
1751end(_Cp& __c)
1752{
1753    return __c.end();
1754}
1755
1756template <class _Cp>
1757_LIBCPP_INLINE_VISIBILITY
1758typename _Cp::const_iterator
1759end(const _Cp& __c)
1760{
1761    return __c.end();
1762}
1763
1764#endif // !defined(_LIBCPP_CXX03_LANG)
1765
1766#if _LIBCPP_STD_VER > 14
1767
1768// #if _LIBCPP_STD_VER > 11
1769// template <>
1770// struct _LIBCPP_TEMPLATE_VIS plus<void>
1771// {
1772//     template <class _T1, class _T2>
1773//     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1774//     auto operator()(_T1&& __t, _T2&& __u) const
1775//     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
1776//     -> decltype        (_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
1777//         { return        _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
1778//     typedef void is_transparent;
1779// };
1780// #endif
1781
1782template <class _Cont>
1783_LIBCPP_INLINE_VISIBILITY
1784constexpr auto size(const _Cont& __c)
1785_NOEXCEPT_(noexcept(__c.size()))
1786-> decltype        (__c.size())
1787{ return            __c.size(); }
1788
1789template <class _Tp, size_t _Sz>
1790_LIBCPP_INLINE_VISIBILITY
1791constexpr size_t size(const _Tp (&)[_Sz]) noexcept { return _Sz; }
1792
1793#if _LIBCPP_STD_VER > 17
1794template <class _Cont>
1795_LIBCPP_INLINE_VISIBILITY
1796constexpr auto ssize(const _Cont& __c)
1797_NOEXCEPT_(noexcept(static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size())))
1798->                              common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>
1799{ return            static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size()); }
1800
1801template <class _Tp, ptrdiff_t _Sz>
1802_LIBCPP_INLINE_VISIBILITY
1803constexpr ptrdiff_t ssize(const _Tp (&)[_Sz]) noexcept { return _Sz; }
1804#endif
1805
1806template <class _Cont>
1807_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1808constexpr auto empty(const _Cont& __c)
1809_NOEXCEPT_(noexcept(__c.empty()))
1810-> decltype        (__c.empty())
1811{ return            __c.empty(); }
1812
1813template <class _Tp, size_t _Sz>
1814_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1815constexpr bool empty(const _Tp (&)[_Sz]) noexcept { return false; }
1816
1817template <class _Ep>
1818_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1819constexpr bool empty(initializer_list<_Ep> __il) noexcept { return __il.size() == 0; }
1820
1821template <class _Cont> constexpr
1822_LIBCPP_INLINE_VISIBILITY
1823auto data(_Cont& __c)
1824_NOEXCEPT_(noexcept(__c.data()))
1825-> decltype        (__c.data())
1826{ return            __c.data(); }
1827
1828template <class _Cont> constexpr
1829_LIBCPP_INLINE_VISIBILITY
1830auto data(const _Cont& __c)
1831_NOEXCEPT_(noexcept(__c.data()))
1832-> decltype        (__c.data())
1833{ return            __c.data(); }
1834
1835template <class _Tp, size_t _Sz>
1836_LIBCPP_INLINE_VISIBILITY
1837constexpr _Tp* data(_Tp (&__array)[_Sz]) noexcept { return __array; }
1838
1839template <class _Ep>
1840_LIBCPP_INLINE_VISIBILITY
1841constexpr const _Ep* data(initializer_list<_Ep> __il) noexcept { return __il.begin(); }
1842#endif
1843
1844template <class _Container, class _Predicate>
1845typename _Container::size_type
1846__libcpp_erase_if_container(_Container& __c, _Predicate& __pred) {
1847  typename _Container::size_type __old_size = __c.size();
1848
1849  const typename _Container::iterator __last = __c.end();
1850  for (typename _Container::iterator __iter = __c.begin(); __iter != __last;) {
1851    if (__pred(*__iter))
1852      __iter = __c.erase(__iter);
1853    else
1854      ++__iter;
1855  }
1856
1857  return __old_size - __c.size();
1858}
1859
1860_LIBCPP_END_NAMESPACE_STD
1861
1862#endif // _LIBCPP_ITERATOR
1863