1// -*- C++ -*-
2//===-------------------------- iterator ----------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_ITERATOR
12#define _LIBCPP_ITERATOR
13
14/*
15    iterator synopsis
16
17namespace std
18{
19
20template<class Iterator>
21struct iterator_traits
22{
23    typedef typename Iterator::difference_type difference_type;
24    typedef typename Iterator::value_type value_type;
25    typedef typename Iterator::pointer pointer;
26    typedef typename Iterator::reference reference;
27    typedef typename Iterator::iterator_category iterator_category;
28};
29
30template<class T>
31struct iterator_traits<T*>
32{
33    typedef ptrdiff_t difference_type;
34    typedef T value_type;
35    typedef T* pointer;
36    typedef T& reference;
37    typedef random_access_iterator_tag iterator_category;
38};
39
40template<class Category, class T, class Distance = ptrdiff_t,
41         class Pointer = T*, class Reference = T&>
42struct iterator
43{
44    typedef T         value_type;
45    typedef Distance  difference_type;
46    typedef Pointer   pointer;
47    typedef Reference reference;
48    typedef Category  iterator_category;
49};
50
51struct input_iterator_tag  {};
52struct output_iterator_tag {};
53struct forward_iterator_tag       : public input_iterator_tag         {};
54struct bidirectional_iterator_tag : public forward_iterator_tag       {};
55struct random_access_iterator_tag : public bidirectional_iterator_tag {};
56
57// 27.4.3, iterator operations
58// extension: second argument not conforming to C++03
59template <class InputIterator>  // constexpr in C++17
60  constexpr void advance(InputIterator& i,
61             typename iterator_traits<InputIterator>::difference_type n);
62
63template <class InputIterator>  // constexpr in C++17
64  constexpr typename iterator_traits<InputIterator>::difference_type
65    distance(InputIterator first, InputIterator last);
66
67template <class InputIterator>  // constexpr in C++17
68  constexpr InputIterator next(InputIterator x,
69typename iterator_traits<InputIterator>::difference_type n = 1);
70
71template <class BidirectionalIterator>  // constexpr in C++17
72  constexpr BidirectionalIterator prev(BidirectionalIterator x,
73    typename iterator_traits<BidirectionalIterator>::difference_type n = 1);
74
75template <class Iterator>
76class reverse_iterator
77    : public iterator<typename iterator_traits<Iterator>::iterator_category,
78                      typename iterator_traits<Iterator>::value_type,
79                      typename iterator_traits<Iterator>::difference_type,
80                      typename iterator_traits<Iterator>::pointer,
81                      typename iterator_traits<Iterator>::reference>
82{
83protected:
84    Iterator current;
85public:
86    typedef Iterator                                            iterator_type;
87    typedef typename iterator_traits<Iterator>::difference_type difference_type;
88    typedef typename iterator_traits<Iterator>::reference       reference;
89    typedef typename iterator_traits<Iterator>::pointer         pointer;
90
91    constexpr reverse_iterator();
92    constexpr explicit reverse_iterator(Iterator x);
93    template <class U> constexpr reverse_iterator(const reverse_iterator<U>& u);
94    template <class U> constexpr reverse_iterator& operator=(const reverse_iterator<U>& u);
95    constexpr Iterator base() const;
96    constexpr reference operator*() const;
97    constexpr pointer   operator->() const;
98    constexpr reverse_iterator& operator++();
99    constexpr reverse_iterator  operator++(int);
100    constexpr reverse_iterator& operator--();
101    constexpr reverse_iterator  operator--(int);
102    constexpr reverse_iterator  operator+ (difference_type n) const;
103    constexpr reverse_iterator& operator+=(difference_type n);
104    constexpr reverse_iterator  operator- (difference_type n) const;
105    constexpr reverse_iterator& operator-=(difference_type n);
106    constexpr reference         operator[](difference_type n) const;
107};
108
109template <class Iterator1, class Iterator2>
110constexpr bool                          // constexpr in C++17
111operator==(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
112
113template <class Iterator1, class Iterator2>
114constexpr bool                          // constexpr in C++17
115operator<(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
116
117template <class Iterator1, class Iterator2>
118constexpr bool                          // constexpr in C++17
119operator!=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
120
121template <class Iterator1, class Iterator2>
122constexpr bool                          // constexpr in C++17
123operator>(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
124
125template <class Iterator1, class Iterator2>
126constexpr bool                          // constexpr in C++17
127operator>=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
128
129template <class Iterator1, class Iterator2>
130constexpr bool                          // constexpr in C++17
131operator<=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
132
133template <class Iterator1, class Iterator2>
134constexpr auto
135operator-(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y)
136-> decltype(__y.base() - __x.base());   // constexpr in C++17
137
138template <class Iterator>
139constexpr reverse_iterator<Iterator>
140operator+(typename reverse_iterator<Iterator>::difference_type n,
141          const reverse_iterator<Iterator>& x);   // constexpr in C++17
142
143template <class Iterator>
144constexpr reverse_iterator<Iterator> make_reverse_iterator(Iterator i); // C++14, constexpr in C++17
145
146template <class Container>
147class back_insert_iterator
148{
149protected:
150    Container* container;
151public:
152    typedef Container                   container_type;
153    typedef void                        value_type;
154    typedef void                        difference_type;
155    typedef void                        reference;
156    typedef void                        pointer;
157
158    explicit back_insert_iterator(Container& x);
159    back_insert_iterator& operator=(const typename Container::value_type& value);
160    back_insert_iterator& operator*();
161    back_insert_iterator& operator++();
162    back_insert_iterator  operator++(int);
163};
164
165template <class Container> back_insert_iterator<Container> back_inserter(Container& x);
166
167template <class Container>
168class front_insert_iterator
169{
170protected:
171    Container* container;
172public:
173    typedef Container                    container_type;
174    typedef void                         value_type;
175    typedef void                         difference_type;
176    typedef void                         reference;
177    typedef void                         pointer;
178
179    explicit front_insert_iterator(Container& x);
180    front_insert_iterator& operator=(const typename Container::value_type& value);
181    front_insert_iterator& operator*();
182    front_insert_iterator& operator++();
183    front_insert_iterator  operator++(int);
184};
185
186template <class Container> front_insert_iterator<Container> front_inserter(Container& x);
187
188template <class Container>
189class insert_iterator
190{
191protected:
192    Container* container;
193    typename Container::iterator iter;
194public:
195    typedef Container              container_type;
196    typedef void                   value_type;
197    typedef void                   difference_type;
198    typedef void                   reference;
199    typedef void                   pointer;
200
201    insert_iterator(Container& x, typename Container::iterator i);
202    insert_iterator& operator=(const typename Container::value_type& value);
203    insert_iterator& operator*();
204    insert_iterator& operator++();
205    insert_iterator& operator++(int);
206};
207
208template <class Container, class Iterator>
209insert_iterator<Container> inserter(Container& x, Iterator i);
210
211template <class Iterator>
212class move_iterator {
213public:
214    typedef Iterator                                              iterator_type;
215    typedef typename iterator_traits<Iterator>::difference_type   difference_type;
216    typedef Iterator                                              pointer;
217    typedef typename iterator_traits<Iterator>::value_type        value_type;
218    typedef typename iterator_traits<Iterator>::iterator_category iterator_category;
219    typedef value_type&&                                          reference;
220
221    constexpr move_iterator();  // all the constexprs are in C++17
222    constexpr explicit move_iterator(Iterator i);
223    template <class U>
224      constexpr move_iterator(const move_iterator<U>& u);
225    template <class U>
226      constexpr move_iterator& operator=(const move_iterator<U>& u);
227    constexpr iterator_type base() const;
228    constexpr reference operator*() const;
229    constexpr pointer operator->() const;
230    constexpr move_iterator& operator++();
231    constexpr move_iterator operator++(int);
232    constexpr move_iterator& operator--();
233    constexpr move_iterator operator--(int);
234    constexpr move_iterator operator+(difference_type n) const;
235    constexpr move_iterator& operator+=(difference_type n);
236    constexpr move_iterator operator-(difference_type n) const;
237    constexpr move_iterator& operator-=(difference_type n);
238    constexpr unspecified operator[](difference_type n) const;
239private:
240    Iterator current; // exposition only
241};
242
243template <class Iterator1, class Iterator2>
244constexpr bool   // constexpr in C++17
245operator==(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
246
247template <class Iterator1, class Iterator2>
248constexpr bool   // constexpr in C++17
249operator!=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
250
251template <class Iterator1, class Iterator2>
252constexpr bool   // constexpr in C++17
253operator<(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
254
255template <class Iterator1, class Iterator2>
256constexpr bool   // constexpr in C++17
257operator<=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
258
259template <class Iterator1, class Iterator2>
260constexpr bool   // constexpr in C++17
261operator>(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
262
263template <class Iterator1, class Iterator2>
264constexpr bool   // constexpr in C++17
265operator>=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
266
267template <class Iterator1, class Iterator2>
268constexpr auto   // constexpr in C++17
269operator-(const move_iterator<Iterator1>& x,
270          const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
271
272template <class Iterator>
273constexpr move_iterator<Iterator> operator+(   // constexpr in C++17
274            typename move_iterator<Iterator>::difference_type n,
275            const move_iterator<Iterator>& x);
276
277template <class Iterator>   // constexpr in C++17
278constexpr  move_iterator<Iterator> make_move_iterator(const Iterator& i);
279
280
281template <class T, class charT = char, class traits = char_traits<charT>, class Distance = ptrdiff_t>
282class istream_iterator
283    : public iterator<input_iterator_tag, T, Distance, const T*, const T&>
284{
285public:
286    typedef charT char_type;
287    typedef traits traits_type;
288    typedef basic_istream<charT,traits> istream_type;
289
290    constexpr istream_iterator();
291    istream_iterator(istream_type& s);
292    istream_iterator(const istream_iterator& x);
293    ~istream_iterator();
294
295    const T& operator*() const;
296    const T* operator->() const;
297    istream_iterator& operator++();
298    istream_iterator  operator++(int);
299};
300
301template <class T, class charT, class traits, class Distance>
302bool operator==(const istream_iterator<T,charT,traits,Distance>& x,
303                const istream_iterator<T,charT,traits,Distance>& y);
304template <class T, class charT, class traits, class Distance>
305bool operator!=(const istream_iterator<T,charT,traits,Distance>& x,
306                const istream_iterator<T,charT,traits,Distance>& y);
307
308template <class T, class charT = char, class traits = char_traits<charT> >
309class ostream_iterator
310    : public iterator<output_iterator_tag, void, void, void ,void>
311{
312public:
313    typedef charT char_type;
314    typedef traits traits_type;
315    typedef basic_ostream<charT,traits> ostream_type;
316
317    ostream_iterator(ostream_type& s);
318    ostream_iterator(ostream_type& s, const charT* delimiter);
319    ostream_iterator(const ostream_iterator& x);
320    ~ostream_iterator();
321    ostream_iterator& operator=(const T& value);
322
323    ostream_iterator& operator*();
324    ostream_iterator& operator++();
325    ostream_iterator& operator++(int);
326};
327
328template<class charT, class traits = char_traits<charT> >
329class istreambuf_iterator
330    : public iterator<input_iterator_tag, charT,
331                      typename traits::off_type, unspecified,
332                      charT>
333{
334public:
335    typedef charT                         char_type;
336    typedef traits                        traits_type;
337    typedef typename traits::int_type     int_type;
338    typedef basic_streambuf<charT,traits> streambuf_type;
339    typedef basic_istream<charT,traits>   istream_type;
340
341    istreambuf_iterator() noexcept;
342    istreambuf_iterator(istream_type& s) noexcept;
343    istreambuf_iterator(streambuf_type* s) noexcept;
344    istreambuf_iterator(a-private-type) noexcept;
345
346    charT                operator*() const;
347    pointer operator->() const;
348    istreambuf_iterator& operator++();
349    a-private-type       operator++(int);
350
351    bool equal(const istreambuf_iterator& b) const;
352};
353
354template <class charT, class traits>
355bool operator==(const istreambuf_iterator<charT,traits>& a,
356                const istreambuf_iterator<charT,traits>& b);
357template <class charT, class traits>
358bool operator!=(const istreambuf_iterator<charT,traits>& a,
359                const istreambuf_iterator<charT,traits>& b);
360
361template <class charT, class traits = char_traits<charT> >
362class ostreambuf_iterator
363    : public iterator<output_iterator_tag, void, void, void, void>
364{
365public:
366    typedef charT                         char_type;
367    typedef traits                        traits_type;
368    typedef basic_streambuf<charT,traits> streambuf_type;
369    typedef basic_ostream<charT,traits>   ostream_type;
370
371    ostreambuf_iterator(ostream_type& s) noexcept;
372    ostreambuf_iterator(streambuf_type* s) noexcept;
373    ostreambuf_iterator& operator=(charT c);
374    ostreambuf_iterator& operator*();
375    ostreambuf_iterator& operator++();
376    ostreambuf_iterator& operator++(int);
377    bool failed() const noexcept;
378};
379
380template <class C> constexpr auto begin(C& c) -> decltype(c.begin());
381template <class C> constexpr auto begin(const C& c) -> decltype(c.begin());
382template <class C> constexpr auto end(C& c) -> decltype(c.end());
383template <class C> constexpr auto end(const C& c) -> decltype(c.end());
384template <class T, size_t N> constexpr T* begin(T (&array)[N]);
385template <class T, size_t N> constexpr T* end(T (&array)[N]);
386
387template <class C> auto constexpr cbegin(const C& c) -> decltype(std::begin(c));        // C++14
388template <class C> auto constexpr cend(const C& c) -> decltype(std::end(c));            // C++14
389template <class C> auto constexpr rbegin(C& c) -> decltype(c.rbegin());                 // C++14
390template <class C> auto constexpr rbegin(const C& c) -> decltype(c.rbegin());           // C++14
391template <class C> auto constexpr rend(C& c) -> decltype(c.rend());                     // C++14
392template <class C> constexpr auto rend(const C& c) -> decltype(c.rend());               // C++14
393template <class E> reverse_iterator<const E*> constexpr rbegin(initializer_list<E> il); // C++14
394template <class E> reverse_iterator<const E*> constexpr rend(initializer_list<E> il);   // C++14
395template <class T, size_t N> reverse_iterator<T*> constexpr rbegin(T (&array)[N]);      // C++14
396template <class T, size_t N> reverse_iterator<T*> constexpr rend(T (&array)[N]);        // C++14
397template <class C> constexpr auto crbegin(const C& c) -> decltype(std::rbegin(c));      // C++14
398template <class C> constexpr auto crend(const C& c) -> decltype(std::rend(c));          // C++14
399
400// 24.8, container access:
401template <class C> constexpr auto size(const C& c) -> decltype(c.size());         // C++17
402template <class T, size_t N> constexpr size_t size(const T (&array)[N]) noexcept; // C++17
403template <class C> constexpr auto empty(const C& c) -> decltype(c.empty());       // C++17
404template <class T, size_t N> constexpr bool empty(const T (&array)[N]) noexcept;  // C++17
405template <class E> constexpr bool empty(initializer_list<E> il) noexcept;         // C++17
406template <class C> constexpr auto data(C& c) -> decltype(c.data());               // C++17
407template <class C> constexpr auto data(const C& c) -> decltype(c.data());         // C++17
408template <class T, size_t N> constexpr T* data(T (&array)[N]) noexcept;           // C++17
409template <class E> constexpr const E* data(initializer_list<E> il) noexcept;      // C++17
410
411}  // std
412
413*/
414
415#include <__config>
416#include <iosfwd> // for forward declarations of vector and string.
417#include <__functional_base>
418#include <type_traits>
419#include <cstddef>
420#include <initializer_list>
421#ifdef __APPLE__
422#include <Availability.h>
423#endif
424
425#include <__debug>
426
427#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
428#pragma GCC system_header
429#endif
430
431_LIBCPP_BEGIN_NAMESPACE_STD
432
433struct _LIBCPP_TEMPLATE_VIS input_iterator_tag {};
434struct _LIBCPP_TEMPLATE_VIS output_iterator_tag {};
435struct _LIBCPP_TEMPLATE_VIS forward_iterator_tag       : public input_iterator_tag {};
436struct _LIBCPP_TEMPLATE_VIS bidirectional_iterator_tag : public forward_iterator_tag {};
437struct _LIBCPP_TEMPLATE_VIS random_access_iterator_tag : public bidirectional_iterator_tag {};
438
439template <class _Tp>
440struct __has_iterator_category
441{
442private:
443    struct __two {char __lx; char __lxx;};
444    template <class _Up> static __two __test(...);
445    template <class _Up> static char __test(typename _Up::iterator_category* = 0);
446public:
447    static const bool value = sizeof(__test<_Tp>(0)) == 1;
448};
449
450template <class _Iter, bool> struct __iterator_traits_impl {};
451
452template <class _Iter>
453struct __iterator_traits_impl<_Iter, true>
454{
455    typedef typename _Iter::difference_type   difference_type;
456    typedef typename _Iter::value_type        value_type;
457    typedef typename _Iter::pointer           pointer;
458    typedef typename _Iter::reference         reference;
459    typedef typename _Iter::iterator_category iterator_category;
460};
461
462template <class _Iter, bool> struct __iterator_traits {};
463
464template <class _Iter>
465struct __iterator_traits<_Iter, true>
466    :  __iterator_traits_impl
467      <
468        _Iter,
469        is_convertible<typename _Iter::iterator_category, input_iterator_tag>::value ||
470        is_convertible<typename _Iter::iterator_category, output_iterator_tag>::value
471      >
472{};
473
474// iterator_traits<Iterator> will only have the nested types if Iterator::iterator_category
475//    exists.  Else iterator_traits<Iterator> will be an empty class.  This is a
476//    conforming extension which allows some programs to compile and behave as
477//    the client expects instead of failing at compile time.
478
479template <class _Iter>
480struct _LIBCPP_TEMPLATE_VIS iterator_traits
481    : __iterator_traits<_Iter, __has_iterator_category<_Iter>::value> {};
482
483template<class _Tp>
484struct _LIBCPP_TEMPLATE_VIS iterator_traits<_Tp*>
485{
486    typedef ptrdiff_t difference_type;
487    typedef typename remove_cv<_Tp>::type value_type;
488    typedef _Tp* pointer;
489    typedef _Tp& reference;
490    typedef random_access_iterator_tag iterator_category;
491};
492
493template <class _Tp, class _Up, bool = __has_iterator_category<iterator_traits<_Tp> >::value>
494struct __has_iterator_category_convertible_to
495    : public integral_constant<bool, is_convertible<typename iterator_traits<_Tp>::iterator_category, _Up>::value>
496{};
497
498template <class _Tp, class _Up>
499struct __has_iterator_category_convertible_to<_Tp, _Up, false> : public false_type {};
500
501template <class _Tp>
502struct __is_input_iterator : public __has_iterator_category_convertible_to<_Tp, input_iterator_tag> {};
503
504template <class _Tp>
505struct __is_forward_iterator : public __has_iterator_category_convertible_to<_Tp, forward_iterator_tag> {};
506
507template <class _Tp>
508struct __is_bidirectional_iterator : public __has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag> {};
509
510template <class _Tp>
511struct __is_random_access_iterator : public __has_iterator_category_convertible_to<_Tp, random_access_iterator_tag> {};
512
513template <class _Tp>
514struct __is_exactly_input_iterator
515    : public integral_constant<bool,
516         __has_iterator_category_convertible_to<_Tp, input_iterator_tag>::value &&
517        !__has_iterator_category_convertible_to<_Tp, forward_iterator_tag>::value> {};
518
519template<class _Category, class _Tp, class _Distance = ptrdiff_t,
520         class _Pointer = _Tp*, class _Reference = _Tp&>
521struct _LIBCPP_TEMPLATE_VIS iterator
522{
523    typedef _Tp        value_type;
524    typedef _Distance  difference_type;
525    typedef _Pointer   pointer;
526    typedef _Reference reference;
527    typedef _Category  iterator_category;
528};
529
530template <class _InputIter>
531inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
532void __advance(_InputIter& __i,
533             typename iterator_traits<_InputIter>::difference_type __n, input_iterator_tag)
534{
535    for (; __n > 0; --__n)
536        ++__i;
537}
538
539template <class _BiDirIter>
540inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
541void __advance(_BiDirIter& __i,
542             typename iterator_traits<_BiDirIter>::difference_type __n, bidirectional_iterator_tag)
543{
544    if (__n >= 0)
545        for (; __n > 0; --__n)
546            ++__i;
547    else
548        for (; __n < 0; ++__n)
549            --__i;
550}
551
552template <class _RandIter>
553inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
554void __advance(_RandIter& __i,
555             typename iterator_traits<_RandIter>::difference_type __n, random_access_iterator_tag)
556{
557   __i += __n;
558}
559
560template <class _InputIter>
561inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
562void advance(_InputIter& __i,
563             typename iterator_traits<_InputIter>::difference_type __n)
564{
565    __advance(__i, __n, typename iterator_traits<_InputIter>::iterator_category());
566}
567
568template <class _InputIter>
569inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
570typename iterator_traits<_InputIter>::difference_type
571__distance(_InputIter __first, _InputIter __last, input_iterator_tag)
572{
573    typename iterator_traits<_InputIter>::difference_type __r(0);
574    for (; __first != __last; ++__first)
575        ++__r;
576    return __r;
577}
578
579template <class _RandIter>
580inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
581typename iterator_traits<_RandIter>::difference_type
582__distance(_RandIter __first, _RandIter __last, random_access_iterator_tag)
583{
584    return __last - __first;
585}
586
587template <class _InputIter>
588inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
589typename iterator_traits<_InputIter>::difference_type
590distance(_InputIter __first, _InputIter __last)
591{
592    return __distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category());
593}
594
595template <class _InputIter>
596inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
597typename enable_if
598<
599    __is_input_iterator<_InputIter>::value,
600    _InputIter
601>::type
602next(_InputIter __x,
603     typename iterator_traits<_InputIter>::difference_type __n = 1)
604{
605    _VSTD::advance(__x, __n);
606    return __x;
607}
608
609template <class _BidirectionalIter>
610inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
611typename enable_if
612<
613    __is_bidirectional_iterator<_BidirectionalIter>::value,
614    _BidirectionalIter
615>::type
616prev(_BidirectionalIter __x,
617     typename iterator_traits<_BidirectionalIter>::difference_type __n = 1)
618{
619    _VSTD::advance(__x, -__n);
620    return __x;
621}
622
623
624template <class _Tp, class = void>
625struct __is_stashing_iterator : false_type {};
626
627template <class _Tp>
628struct __is_stashing_iterator<_Tp, typename __void_t<typename _Tp::__stashing_iterator_tag>::type>
629  : true_type {};
630
631template <class _Iter>
632class _LIBCPP_TEMPLATE_VIS reverse_iterator
633    : public iterator<typename iterator_traits<_Iter>::iterator_category,
634                      typename iterator_traits<_Iter>::value_type,
635                      typename iterator_traits<_Iter>::difference_type,
636                      typename iterator_traits<_Iter>::pointer,
637                      typename iterator_traits<_Iter>::reference>
638{
639private:
640    /*mutable*/ _Iter __t;  // no longer used as of LWG #2360, not removed due to ABI break
641
642    static_assert(!__is_stashing_iterator<_Iter>::value,
643      "The specified iterator type cannot be used with reverse_iterator; "
644      "Using stashing iterators with reverse_iterator causes undefined behavior");
645
646protected:
647    _Iter current;
648public:
649    typedef _Iter                                            iterator_type;
650    typedef typename iterator_traits<_Iter>::difference_type difference_type;
651    typedef typename iterator_traits<_Iter>::reference       reference;
652    typedef typename iterator_traits<_Iter>::pointer         pointer;
653
654    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
655    reverse_iterator() : __t(), current() {}
656    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
657    explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}
658    template <class _Up>
659        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
660        reverse_iterator(const reverse_iterator<_Up>& __u) : __t(__u.base()), current(__u.base()) {}
661    template <class _Up>
662        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
663        reverse_iterator& operator=(const reverse_iterator<_Up>& __u)
664            { __t = current = __u.base(); return *this; }
665    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
666    _Iter base() const {return current;}
667    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
668    reference operator*() const {_Iter __tmp = current; return *--__tmp;}
669    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
670    pointer  operator->() const {return _VSTD::addressof(operator*());}
671    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
672    reverse_iterator& operator++() {--current; return *this;}
673    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
674    reverse_iterator  operator++(int) {reverse_iterator __tmp(*this); --current; return __tmp;}
675    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
676    reverse_iterator& operator--() {++current; return *this;}
677    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
678    reverse_iterator  operator--(int) {reverse_iterator __tmp(*this); ++current; return __tmp;}
679    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
680    reverse_iterator  operator+ (difference_type __n) const {return reverse_iterator(current - __n);}
681    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
682    reverse_iterator& operator+=(difference_type __n) {current -= __n; return *this;}
683    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
684    reverse_iterator  operator- (difference_type __n) const {return reverse_iterator(current + __n);}
685    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
686    reverse_iterator& operator-=(difference_type __n) {current += __n; return *this;}
687    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
688    reference         operator[](difference_type __n) const {return *(*this + __n);}
689};
690
691template <class _Iter1, class _Iter2>
692inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
693bool
694operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
695{
696    return __x.base() == __y.base();
697}
698
699template <class _Iter1, class _Iter2>
700inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
701bool
702operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
703{
704    return __x.base() > __y.base();
705}
706
707template <class _Iter1, class _Iter2>
708inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
709bool
710operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
711{
712    return __x.base() != __y.base();
713}
714
715template <class _Iter1, class _Iter2>
716inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
717bool
718operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
719{
720    return __x.base() < __y.base();
721}
722
723template <class _Iter1, class _Iter2>
724inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
725bool
726operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
727{
728    return __x.base() <= __y.base();
729}
730
731template <class _Iter1, class _Iter2>
732inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
733bool
734operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
735{
736    return __x.base() >= __y.base();
737}
738
739#ifndef _LIBCPP_CXX03_LANG
740template <class _Iter1, class _Iter2>
741inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
742auto
743operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
744-> decltype(__y.base() - __x.base())
745{
746    return __y.base() - __x.base();
747}
748#else
749template <class _Iter1, class _Iter2>
750inline _LIBCPP_INLINE_VISIBILITY
751typename reverse_iterator<_Iter1>::difference_type
752operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
753{
754    return __y.base() - __x.base();
755}
756#endif
757
758template <class _Iter>
759inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
760reverse_iterator<_Iter>
761operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x)
762{
763    return reverse_iterator<_Iter>(__x.base() - __n);
764}
765
766#if _LIBCPP_STD_VER > 11
767template <class _Iter>
768inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
769reverse_iterator<_Iter> make_reverse_iterator(_Iter __i)
770{
771    return reverse_iterator<_Iter>(__i);
772}
773#endif
774
775template <class _Container>
776class _LIBCPP_TEMPLATE_VIS back_insert_iterator
777    : public iterator<output_iterator_tag,
778                      void,
779                      void,
780                      void,
781                      void>
782{
783protected:
784    _Container* container;
785public:
786    typedef _Container container_type;
787
788    _LIBCPP_INLINE_VISIBILITY explicit back_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
789    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(const typename _Container::value_type& __value_)
790        {container->push_back(__value_); return *this;}
791#ifndef _LIBCPP_CXX03_LANG
792    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(typename _Container::value_type&& __value_)
793        {container->push_back(_VSTD::move(__value_)); return *this;}
794#endif  // _LIBCPP_CXX03_LANG
795    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator*()     {return *this;}
796    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator++()    {return *this;}
797    _LIBCPP_INLINE_VISIBILITY back_insert_iterator  operator++(int) {return *this;}
798};
799
800template <class _Container>
801inline _LIBCPP_INLINE_VISIBILITY
802back_insert_iterator<_Container>
803back_inserter(_Container& __x)
804{
805    return back_insert_iterator<_Container>(__x);
806}
807
808template <class _Container>
809class _LIBCPP_TEMPLATE_VIS front_insert_iterator
810    : public iterator<output_iterator_tag,
811                      void,
812                      void,
813                      void,
814                      void>
815{
816protected:
817    _Container* container;
818public:
819    typedef _Container container_type;
820
821    _LIBCPP_INLINE_VISIBILITY explicit front_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
822    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(const typename _Container::value_type& __value_)
823        {container->push_front(__value_); return *this;}
824#ifndef _LIBCPP_CXX03_LANG
825    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(typename _Container::value_type&& __value_)
826        {container->push_front(_VSTD::move(__value_)); return *this;}
827#endif  // _LIBCPP_CXX03_LANG
828    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator*()     {return *this;}
829    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator++()    {return *this;}
830    _LIBCPP_INLINE_VISIBILITY front_insert_iterator  operator++(int) {return *this;}
831};
832
833template <class _Container>
834inline _LIBCPP_INLINE_VISIBILITY
835front_insert_iterator<_Container>
836front_inserter(_Container& __x)
837{
838    return front_insert_iterator<_Container>(__x);
839}
840
841template <class _Container>
842class _LIBCPP_TEMPLATE_VIS insert_iterator
843    : public iterator<output_iterator_tag,
844                      void,
845                      void,
846                      void,
847                      void>
848{
849protected:
850    _Container* container;
851    typename _Container::iterator iter;
852public:
853    typedef _Container container_type;
854
855    _LIBCPP_INLINE_VISIBILITY insert_iterator(_Container& __x, typename _Container::iterator __i)
856        : container(_VSTD::addressof(__x)), iter(__i) {}
857    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(const typename _Container::value_type& __value_)
858        {iter = container->insert(iter, __value_); ++iter; return *this;}
859#ifndef _LIBCPP_CXX03_LANG
860    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(typename _Container::value_type&& __value_)
861        {iter = container->insert(iter, _VSTD::move(__value_)); ++iter; return *this;}
862#endif  // _LIBCPP_CXX03_LANG
863    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator*()        {return *this;}
864    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++()       {return *this;}
865    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++(int)    {return *this;}
866};
867
868template <class _Container>
869inline _LIBCPP_INLINE_VISIBILITY
870insert_iterator<_Container>
871inserter(_Container& __x, typename _Container::iterator __i)
872{
873    return insert_iterator<_Container>(__x, __i);
874}
875
876template <class _Tp, class _CharT = char,
877          class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
878class _LIBCPP_TEMPLATE_VIS istream_iterator
879    : public iterator<input_iterator_tag, _Tp, _Distance, const _Tp*, const _Tp&>
880{
881public:
882    typedef _CharT char_type;
883    typedef _Traits traits_type;
884    typedef basic_istream<_CharT,_Traits> istream_type;
885private:
886    istream_type* __in_stream_;
887    _Tp __value_;
888public:
889    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istream_iterator() : __in_stream_(0), __value_() {}
890    _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s) : __in_stream_(_VSTD::addressof(__s))
891        {
892            if (!(*__in_stream_ >> __value_))
893                __in_stream_ = 0;
894        }
895
896    _LIBCPP_INLINE_VISIBILITY const _Tp& operator*() const {return __value_;}
897    _LIBCPP_INLINE_VISIBILITY const _Tp* operator->() const {return _VSTD::addressof((operator*()));}
898    _LIBCPP_INLINE_VISIBILITY istream_iterator& operator++()
899        {
900            if (!(*__in_stream_ >> __value_))
901                __in_stream_ = 0;
902            return *this;
903        }
904    _LIBCPP_INLINE_VISIBILITY istream_iterator  operator++(int)
905        {istream_iterator __t(*this); ++(*this); return __t;}
906
907    template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
908    friend _LIBCPP_INLINE_VISIBILITY
909    bool
910    operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
911               const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
912
913    template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
914    friend _LIBCPP_INLINE_VISIBILITY
915    bool
916    operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
917               const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
918};
919
920template <class _Tp, class _CharT, class _Traits, class _Distance>
921inline _LIBCPP_INLINE_VISIBILITY
922bool
923operator==(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
924           const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
925{
926    return __x.__in_stream_ == __y.__in_stream_;
927}
928
929template <class _Tp, class _CharT, class _Traits, class _Distance>
930inline _LIBCPP_INLINE_VISIBILITY
931bool
932operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
933           const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
934{
935    return !(__x == __y);
936}
937
938template <class _Tp, class _CharT = char, class _Traits = char_traits<_CharT> >
939class _LIBCPP_TEMPLATE_VIS ostream_iterator
940    : public iterator<output_iterator_tag, void, void, void, void>
941{
942public:
943    typedef _CharT char_type;
944    typedef _Traits traits_type;
945    typedef basic_ostream<_CharT,_Traits> ostream_type;
946private:
947    ostream_type* __out_stream_;
948    const char_type* __delim_;
949public:
950    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s) _NOEXCEPT
951        : __out_stream_(_VSTD::addressof(__s)), __delim_(0) {}
952    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s, const _CharT* __delimiter) _NOEXCEPT
953        : __out_stream_(_VSTD::addressof(__s)), __delim_(__delimiter) {}
954    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator=(const _Tp& __value_)
955        {
956            *__out_stream_ << __value_;
957            if (__delim_)
958                *__out_stream_ << __delim_;
959            return *this;
960        }
961
962    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator*()     {return *this;}
963    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++()    {return *this;}
964    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++(int) {return *this;}
965};
966
967template<class _CharT, class _Traits>
968class _LIBCPP_TEMPLATE_VIS istreambuf_iterator
969    : public iterator<input_iterator_tag, _CharT,
970                      typename _Traits::off_type, _CharT*,
971                      _CharT>
972{
973public:
974    typedef _CharT                          char_type;
975    typedef _Traits                         traits_type;
976    typedef typename _Traits::int_type      int_type;
977    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
978    typedef basic_istream<_CharT,_Traits>   istream_type;
979private:
980    mutable streambuf_type* __sbuf_;
981
982    class __proxy
983    {
984        char_type __keep_;
985        streambuf_type* __sbuf_;
986        _LIBCPP_INLINE_VISIBILITY __proxy(char_type __c, streambuf_type* __s)
987            : __keep_(__c), __sbuf_(__s) {}
988        friend class istreambuf_iterator;
989    public:
990        _LIBCPP_INLINE_VISIBILITY char_type operator*() const {return __keep_;}
991    };
992
993    _LIBCPP_INLINE_VISIBILITY
994    bool __test_for_eof() const
995    {
996        if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
997            __sbuf_ = 0;
998        return __sbuf_ == 0;
999    }
1000public:
1001    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(0) {}
1002    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(istream_type& __s) _NOEXCEPT
1003        : __sbuf_(__s.rdbuf()) {}
1004    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(streambuf_type* __s) _NOEXCEPT
1005        : __sbuf_(__s) {}
1006    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(const __proxy& __p) _NOEXCEPT
1007        : __sbuf_(__p.__sbuf_) {}
1008
1009    _LIBCPP_INLINE_VISIBILITY char_type  operator*() const
1010        {return static_cast<char_type>(__sbuf_->sgetc());}
1011    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator& operator++()
1012        {
1013            __sbuf_->sbumpc();
1014            return *this;
1015        }
1016    _LIBCPP_INLINE_VISIBILITY __proxy              operator++(int)
1017        {
1018            return __proxy(__sbuf_->sbumpc(), __sbuf_);
1019        }
1020
1021    _LIBCPP_INLINE_VISIBILITY bool equal(const istreambuf_iterator& __b) const
1022        {return __test_for_eof() == __b.__test_for_eof();}
1023};
1024
1025template <class _CharT, class _Traits>
1026inline _LIBCPP_INLINE_VISIBILITY
1027bool operator==(const istreambuf_iterator<_CharT,_Traits>& __a,
1028                const istreambuf_iterator<_CharT,_Traits>& __b)
1029                {return __a.equal(__b);}
1030
1031template <class _CharT, class _Traits>
1032inline _LIBCPP_INLINE_VISIBILITY
1033bool operator!=(const istreambuf_iterator<_CharT,_Traits>& __a,
1034                const istreambuf_iterator<_CharT,_Traits>& __b)
1035                {return !__a.equal(__b);}
1036
1037template <class _CharT, class _Traits>
1038class _LIBCPP_TEMPLATE_VIS ostreambuf_iterator
1039    : public iterator<output_iterator_tag, void, void, void, void>
1040{
1041public:
1042    typedef _CharT                          char_type;
1043    typedef _Traits                         traits_type;
1044    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
1045    typedef basic_ostream<_CharT,_Traits>   ostream_type;
1046private:
1047    streambuf_type* __sbuf_;
1048public:
1049    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(ostream_type& __s) _NOEXCEPT
1050        : __sbuf_(__s.rdbuf()) {}
1051    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(streambuf_type* __s) _NOEXCEPT
1052        : __sbuf_(__s) {}
1053    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator=(_CharT __c)
1054        {
1055            if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sputc(__c), traits_type::eof()))
1056                __sbuf_ = 0;
1057            return *this;
1058        }
1059    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator*()     {return *this;}
1060    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++()    {return *this;}
1061    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++(int) {return *this;}
1062    _LIBCPP_INLINE_VISIBILITY bool failed() const _NOEXCEPT {return __sbuf_ == 0;}
1063
1064#if !defined(__APPLE__) || \
1065    (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED > __MAC_10_8) || \
1066    (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && __IPHONE_OS_VERSION_MIN_REQUIRED > __IPHONE_6_0)
1067
1068    template <class _Ch, class _Tr>
1069    friend
1070    _LIBCPP_HIDDEN
1071    ostreambuf_iterator<_Ch, _Tr>
1072    __pad_and_output(ostreambuf_iterator<_Ch, _Tr> __s,
1073                     const _Ch* __ob, const _Ch* __op, const _Ch* __oe,
1074                     ios_base& __iob, _Ch __fl);
1075#endif
1076};
1077
1078template <class _Iter>
1079class _LIBCPP_TEMPLATE_VIS move_iterator
1080{
1081private:
1082    _Iter __i;
1083public:
1084    typedef _Iter                                            iterator_type;
1085    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
1086    typedef typename iterator_traits<iterator_type>::value_type value_type;
1087    typedef typename iterator_traits<iterator_type>::difference_type difference_type;
1088    typedef iterator_type pointer;
1089#ifndef _LIBCPP_CXX03_LANG
1090    typedef typename iterator_traits<iterator_type>::reference __reference;
1091    typedef typename conditional<
1092            is_reference<__reference>::value,
1093            typename remove_reference<__reference>::type&&,
1094            __reference
1095        >::type reference;
1096#else
1097    typedef typename iterator_traits<iterator_type>::reference reference;
1098#endif
1099
1100    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1101    move_iterator() : __i() {}
1102    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1103    explicit move_iterator(_Iter __x) : __i(__x) {}
1104    template <class _Up>
1105      _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1106      move_iterator(const move_iterator<_Up>& __u) : __i(__u.base()) {}
1107    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 _Iter base() const {return __i;}
1108    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1109    reference operator*() const { return static_cast<reference>(*__i); }
1110    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1111    pointer  operator->() const { return __i;}
1112    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1113    move_iterator& operator++() {++__i; return *this;}
1114    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1115    move_iterator  operator++(int) {move_iterator __tmp(*this); ++__i; return __tmp;}
1116    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1117    move_iterator& operator--() {--__i; return *this;}
1118    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1119    move_iterator  operator--(int) {move_iterator __tmp(*this); --__i; return __tmp;}
1120    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1121    move_iterator  operator+ (difference_type __n) const {return move_iterator(__i + __n);}
1122    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1123    move_iterator& operator+=(difference_type __n) {__i += __n; return *this;}
1124    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1125    move_iterator  operator- (difference_type __n) const {return move_iterator(__i - __n);}
1126    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1127    move_iterator& operator-=(difference_type __n) {__i -= __n; return *this;}
1128    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1129    reference operator[](difference_type __n) const { return static_cast<reference>(__i[__n]); }
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
1156template <class _Iter1, class _Iter2>
1157inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1158bool
1159operator>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1160{
1161    return __x.base() > __y.base();
1162}
1163
1164template <class _Iter1, class _Iter2>
1165inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1166bool
1167operator>=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1168{
1169    return __x.base() >= __y.base();
1170}
1171
1172template <class _Iter1, class _Iter2>
1173inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1174bool
1175operator<=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1176{
1177    return __x.base() <= __y.base();
1178}
1179
1180#ifndef _LIBCPP_CXX03_LANG
1181template <class _Iter1, class _Iter2>
1182inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1183auto
1184operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1185-> decltype(__x.base() - __y.base())
1186{
1187    return __x.base() - __y.base();
1188}
1189#else
1190template <class _Iter1, class _Iter2>
1191inline _LIBCPP_INLINE_VISIBILITY
1192typename move_iterator<_Iter1>::difference_type
1193operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1194{
1195    return __x.base() - __y.base();
1196}
1197#endif
1198
1199template <class _Iter>
1200inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1201move_iterator<_Iter>
1202operator+(typename move_iterator<_Iter>::difference_type __n, const move_iterator<_Iter>& __x)
1203{
1204    return move_iterator<_Iter>(__x.base() + __n);
1205}
1206
1207template <class _Iter>
1208inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1209move_iterator<_Iter>
1210make_move_iterator(_Iter __i)
1211{
1212    return move_iterator<_Iter>(__i);
1213}
1214
1215// __wrap_iter
1216
1217template <class _Iter> class __wrap_iter;
1218
1219template <class _Iter1, class _Iter2>
1220_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1221bool
1222operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1223
1224template <class _Iter1, class _Iter2>
1225_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1226bool
1227operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1228
1229template <class _Iter1, class _Iter2>
1230_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1231bool
1232operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1233
1234template <class _Iter1, class _Iter2>
1235_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1236bool
1237operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1238
1239template <class _Iter1, class _Iter2>
1240_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1241bool
1242operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1243
1244template <class _Iter1, class _Iter2>
1245_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1246bool
1247operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1248
1249#ifndef _LIBCPP_CXX03_LANG
1250template <class _Iter1, class _Iter2>
1251_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1252auto
1253operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1254-> decltype(__x.base() - __y.base());
1255#else
1256template <class _Iter1, class _Iter2>
1257_LIBCPP_INLINE_VISIBILITY
1258typename __wrap_iter<_Iter1>::difference_type
1259operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1260#endif
1261
1262template <class _Iter>
1263_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1264__wrap_iter<_Iter>
1265operator+(typename __wrap_iter<_Iter>::difference_type, __wrap_iter<_Iter>) _NOEXCEPT_DEBUG;
1266
1267template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY copy(_Ip, _Ip, _Op);
1268template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY copy_backward(_B1, _B1, _B2);
1269template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY move(_Ip, _Ip, _Op);
1270template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY move_backward(_B1, _B1, _B2);
1271
1272#if _LIBCPP_DEBUG_LEVEL < 2
1273
1274template <class _Tp>
1275_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1276typename enable_if
1277<
1278    is_trivially_copy_assignable<_Tp>::value,
1279    _Tp*
1280>::type
1281__unwrap_iter(__wrap_iter<_Tp*>);
1282
1283#else
1284
1285template <class _Tp>
1286inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1287typename enable_if
1288<
1289    is_trivially_copy_assignable<_Tp>::value,
1290    __wrap_iter<_Tp*>
1291>::type
1292__unwrap_iter(__wrap_iter<_Tp*> __i);
1293
1294#endif
1295
1296template <class _Iter>
1297class __wrap_iter
1298{
1299public:
1300    typedef _Iter                                                      iterator_type;
1301    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
1302    typedef typename iterator_traits<iterator_type>::value_type        value_type;
1303    typedef typename iterator_traits<iterator_type>::difference_type   difference_type;
1304    typedef typename iterator_traits<iterator_type>::pointer           pointer;
1305    typedef typename iterator_traits<iterator_type>::reference         reference;
1306private:
1307    iterator_type __i;
1308public:
1309    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter() _NOEXCEPT_DEBUG
1310#if _LIBCPP_STD_VER > 11
1311                : __i{}
1312#endif
1313    {
1314#if _LIBCPP_DEBUG_LEVEL >= 2
1315        __get_db()->__insert_i(this);
1316#endif
1317    }
1318    template <class _Up> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1319        __wrap_iter(const __wrap_iter<_Up>& __u,
1320            typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = 0) _NOEXCEPT_DEBUG
1321            : __i(__u.base())
1322    {
1323#if _LIBCPP_DEBUG_LEVEL >= 2
1324        __get_db()->__iterator_copy(this, &__u);
1325#endif
1326    }
1327#if _LIBCPP_DEBUG_LEVEL >= 2
1328    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1329    __wrap_iter(const __wrap_iter& __x)
1330        : __i(__x.base())
1331    {
1332        __get_db()->__iterator_copy(this, &__x);
1333    }
1334    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1335    __wrap_iter& operator=(const __wrap_iter& __x)
1336    {
1337        if (this != &__x)
1338        {
1339            __get_db()->__iterator_copy(this, &__x);
1340            __i = __x.__i;
1341        }
1342        return *this;
1343    }
1344    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1345    ~__wrap_iter()
1346    {
1347        __get_db()->__erase_i(this);
1348    }
1349#endif
1350    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference operator*() const _NOEXCEPT_DEBUG
1351    {
1352#if _LIBCPP_DEBUG_LEVEL >= 2
1353        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1354                       "Attempted to dereference a non-dereferenceable iterator");
1355#endif
1356        return *__i;
1357    }
1358    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG pointer  operator->() const _NOEXCEPT_DEBUG
1359    {
1360#if _LIBCPP_DEBUG_LEVEL >= 2
1361        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1362                       "Attempted to dereference a non-dereferenceable iterator");
1363#endif
1364        return (pointer)_VSTD::addressof(*__i);
1365    }
1366    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator++() _NOEXCEPT_DEBUG
1367    {
1368#if _LIBCPP_DEBUG_LEVEL >= 2
1369        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1370                       "Attempted to increment non-incrementable iterator");
1371#endif
1372        ++__i;
1373        return *this;
1374    }
1375    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator++(int) _NOEXCEPT_DEBUG
1376        {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
1377
1378    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator--() _NOEXCEPT_DEBUG
1379    {
1380#if _LIBCPP_DEBUG_LEVEL >= 2
1381        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
1382                       "Attempted to decrement non-decrementable iterator");
1383#endif
1384        --__i;
1385        return *this;
1386    }
1387    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator--(int) _NOEXCEPT_DEBUG
1388        {__wrap_iter __tmp(*this); --(*this); return __tmp;}
1389    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT_DEBUG
1390        {__wrap_iter __w(*this); __w += __n; return __w;}
1391    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator+=(difference_type __n) _NOEXCEPT_DEBUG
1392    {
1393#if _LIBCPP_DEBUG_LEVEL >= 2
1394        _LIBCPP_ASSERT(__get_const_db()->__addable(this, __n),
1395                   "Attempted to add/subtract iterator outside of valid range");
1396#endif
1397        __i += __n;
1398        return *this;
1399    }
1400    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator- (difference_type __n) const _NOEXCEPT_DEBUG
1401        {return *this + (-__n);}
1402    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator-=(difference_type __n) _NOEXCEPT_DEBUG
1403        {*this += -__n; return *this;}
1404    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference    operator[](difference_type __n) const _NOEXCEPT_DEBUG
1405    {
1406#if _LIBCPP_DEBUG_LEVEL >= 2
1407        _LIBCPP_ASSERT(__get_const_db()->__subscriptable(this, __n),
1408                   "Attempted to subscript iterator outside of valid range");
1409#endif
1410        return __i[__n];
1411    }
1412
1413    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG iterator_type base() const _NOEXCEPT_DEBUG {return __i;}
1414
1415private:
1416#if _LIBCPP_DEBUG_LEVEL >= 2
1417    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(const void* __p, iterator_type __x) : __i(__x)
1418    {
1419        __get_db()->__insert_ic(this, __p);
1420    }
1421#else
1422    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(iterator_type __x) _NOEXCEPT_DEBUG : __i(__x) {}
1423#endif
1424
1425    template <class _Up> friend class __wrap_iter;
1426    template <class _CharT, class _Traits, class _Alloc> friend class basic_string;
1427    template <class _Tp, class _Alloc> friend class _LIBCPP_TEMPLATE_VIS vector;
1428    template <class _Tp, ptrdiff_t> friend class _LIBCPP_TEMPLATE_VIS span;
1429
1430    template <class _Iter1, class _Iter2>
1431    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1432    bool
1433    operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1434
1435    template <class _Iter1, class _Iter2>
1436    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1437    bool
1438    operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1439
1440    template <class _Iter1, class _Iter2>
1441    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1442    bool
1443    operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1444
1445    template <class _Iter1, class _Iter2>
1446    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1447    bool
1448    operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1449
1450    template <class _Iter1, class _Iter2>
1451    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1452    bool
1453    operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1454
1455    template <class _Iter1, class _Iter2>
1456    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1457    bool
1458    operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1459
1460#ifndef _LIBCPP_CXX03_LANG
1461    template <class _Iter1, class _Iter2>
1462    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1463    auto
1464    operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1465    -> decltype(__x.base() - __y.base());
1466#else
1467    template <class _Iter1, class _Iter2>
1468    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1469    typename __wrap_iter<_Iter1>::difference_type
1470    operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1471#endif
1472
1473    template <class _Iter1>
1474    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1475    __wrap_iter<_Iter1>
1476    operator+(typename __wrap_iter<_Iter1>::difference_type, __wrap_iter<_Iter1>) _NOEXCEPT_DEBUG;
1477
1478    template <class _Ip, class _Op> friend _Op copy(_Ip, _Ip, _Op);
1479    template <class _B1, class _B2> friend _B2 copy_backward(_B1, _B1, _B2);
1480    template <class _Ip, class _Op> friend _Op move(_Ip, _Ip, _Op);
1481    template <class _B1, class _B2> friend _B2 move_backward(_B1, _B1, _B2);
1482
1483#if _LIBCPP_DEBUG_LEVEL < 2
1484    template <class _Tp>
1485    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1486    typename enable_if
1487    <
1488        is_trivially_copy_assignable<_Tp>::value,
1489        _Tp*
1490    >::type
1491    __unwrap_iter(__wrap_iter<_Tp*>);
1492#else
1493  template <class _Tp>
1494  inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1495  typename enable_if
1496  <
1497      is_trivially_copy_assignable<_Tp>::value,
1498      __wrap_iter<_Tp*>
1499  >::type
1500  __unwrap_iter(__wrap_iter<_Tp*> __i);
1501#endif
1502};
1503
1504template <class _Iter1, class _Iter2>
1505inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1506bool
1507operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1508{
1509    return __x.base() == __y.base();
1510}
1511
1512template <class _Iter1, class _Iter2>
1513inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1514bool
1515operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1516{
1517#if _LIBCPP_DEBUG_LEVEL >= 2
1518    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1519                   "Attempted to compare incomparable iterators");
1520#endif
1521    return __x.base() < __y.base();
1522}
1523
1524template <class _Iter1, class _Iter2>
1525inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1526bool
1527operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1528{
1529    return !(__x == __y);
1530}
1531
1532template <class _Iter1, class _Iter2>
1533inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1534bool
1535operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1536{
1537    return __y < __x;
1538}
1539
1540template <class _Iter1, class _Iter2>
1541inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1542bool
1543operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1544{
1545    return !(__x < __y);
1546}
1547
1548template <class _Iter1, class _Iter2>
1549inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1550bool
1551operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1552{
1553    return !(__y < __x);
1554}
1555
1556template <class _Iter1>
1557inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1558bool
1559operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
1560{
1561    return !(__x == __y);
1562}
1563
1564template <class _Iter1>
1565inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1566bool
1567operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
1568{
1569    return __y < __x;
1570}
1571
1572template <class _Iter1>
1573inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1574bool
1575operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
1576{
1577    return !(__x < __y);
1578}
1579
1580template <class _Iter1>
1581inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1582bool
1583operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
1584{
1585    return !(__y < __x);
1586}
1587
1588#ifndef _LIBCPP_CXX03_LANG
1589template <class _Iter1, class _Iter2>
1590inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1591auto
1592operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1593-> decltype(__x.base() - __y.base())
1594{
1595#if _LIBCPP_DEBUG_LEVEL >= 2
1596    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1597                   "Attempted to subtract incompatible iterators");
1598#endif
1599    return __x.base() - __y.base();
1600}
1601#else
1602template <class _Iter1, class _Iter2>
1603inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1604typename __wrap_iter<_Iter1>::difference_type
1605operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1606{
1607#if _LIBCPP_DEBUG_LEVEL >= 2
1608    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1609                   "Attempted to subtract incompatible iterators");
1610#endif
1611    return __x.base() - __y.base();
1612}
1613#endif
1614
1615template <class _Iter>
1616inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1617__wrap_iter<_Iter>
1618operator+(typename __wrap_iter<_Iter>::difference_type __n,
1619          __wrap_iter<_Iter> __x) _NOEXCEPT_DEBUG
1620{
1621    __x += __n;
1622    return __x;
1623}
1624
1625template <class _Iter>
1626struct __libcpp_is_trivial_iterator
1627    : public _LIBCPP_BOOL_CONSTANT(is_pointer<_Iter>::value) {};
1628
1629template <class _Iter>
1630struct __libcpp_is_trivial_iterator<move_iterator<_Iter> >
1631    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1632
1633template <class _Iter>
1634struct __libcpp_is_trivial_iterator<reverse_iterator<_Iter> >
1635    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1636
1637template <class _Iter>
1638struct __libcpp_is_trivial_iterator<__wrap_iter<_Iter> >
1639    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1640
1641
1642template <class _Tp, size_t _Np>
1643inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1644_Tp*
1645begin(_Tp (&__array)[_Np])
1646{
1647    return __array;
1648}
1649
1650template <class _Tp, size_t _Np>
1651inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1652_Tp*
1653end(_Tp (&__array)[_Np])
1654{
1655    return __array + _Np;
1656}
1657
1658#if !defined(_LIBCPP_CXX03_LANG)
1659
1660template <class _Cp>
1661inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1662auto
1663begin(_Cp& __c) -> decltype(__c.begin())
1664{
1665    return __c.begin();
1666}
1667
1668template <class _Cp>
1669inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1670auto
1671begin(const _Cp& __c) -> decltype(__c.begin())
1672{
1673    return __c.begin();
1674}
1675
1676template <class _Cp>
1677inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1678auto
1679end(_Cp& __c) -> decltype(__c.end())
1680{
1681    return __c.end();
1682}
1683
1684template <class _Cp>
1685inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1686auto
1687end(const _Cp& __c) -> decltype(__c.end())
1688{
1689    return __c.end();
1690}
1691
1692#if _LIBCPP_STD_VER > 11
1693
1694template <class _Tp, size_t _Np>
1695inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1696reverse_iterator<_Tp*> rbegin(_Tp (&__array)[_Np])
1697{
1698    return reverse_iterator<_Tp*>(__array + _Np);
1699}
1700
1701template <class _Tp, size_t _Np>
1702inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1703reverse_iterator<_Tp*> rend(_Tp (&__array)[_Np])
1704{
1705    return reverse_iterator<_Tp*>(__array);
1706}
1707
1708template <class _Ep>
1709inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1710reverse_iterator<const _Ep*> rbegin(initializer_list<_Ep> __il)
1711{
1712    return reverse_iterator<const _Ep*>(__il.end());
1713}
1714
1715template <class _Ep>
1716inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1717reverse_iterator<const _Ep*> rend(initializer_list<_Ep> __il)
1718{
1719    return reverse_iterator<const _Ep*>(__il.begin());
1720}
1721
1722template <class _Cp>
1723inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1724auto cbegin(const _Cp& __c) -> decltype(_VSTD::begin(__c))
1725{
1726    return _VSTD::begin(__c);
1727}
1728
1729template <class _Cp>
1730inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1731auto cend(const _Cp& __c) -> decltype(_VSTD::end(__c))
1732{
1733    return _VSTD::end(__c);
1734}
1735
1736template <class _Cp>
1737inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1738auto rbegin(_Cp& __c) -> decltype(__c.rbegin())
1739{
1740    return __c.rbegin();
1741}
1742
1743template <class _Cp>
1744inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1745auto rbegin(const _Cp& __c) -> decltype(__c.rbegin())
1746{
1747    return __c.rbegin();
1748}
1749
1750template <class _Cp>
1751inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1752auto rend(_Cp& __c) -> decltype(__c.rend())
1753{
1754    return __c.rend();
1755}
1756
1757template <class _Cp>
1758inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1759auto rend(const _Cp& __c) -> decltype(__c.rend())
1760{
1761    return __c.rend();
1762}
1763
1764template <class _Cp>
1765inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1766auto crbegin(const _Cp& __c) -> decltype(_VSTD::rbegin(__c))
1767{
1768    return _VSTD::rbegin(__c);
1769}
1770
1771template <class _Cp>
1772inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1773auto crend(const _Cp& __c) -> decltype(_VSTD::rend(__c))
1774{
1775    return _VSTD::rend(__c);
1776}
1777
1778#endif
1779
1780
1781#else  // defined(_LIBCPP_CXX03_LANG)
1782
1783template <class _Cp>
1784inline _LIBCPP_INLINE_VISIBILITY
1785typename _Cp::iterator
1786begin(_Cp& __c)
1787{
1788    return __c.begin();
1789}
1790
1791template <class _Cp>
1792inline _LIBCPP_INLINE_VISIBILITY
1793typename _Cp::const_iterator
1794begin(const _Cp& __c)
1795{
1796    return __c.begin();
1797}
1798
1799template <class _Cp>
1800inline _LIBCPP_INLINE_VISIBILITY
1801typename _Cp::iterator
1802end(_Cp& __c)
1803{
1804    return __c.end();
1805}
1806
1807template <class _Cp>
1808inline _LIBCPP_INLINE_VISIBILITY
1809typename _Cp::const_iterator
1810end(const _Cp& __c)
1811{
1812    return __c.end();
1813}
1814
1815#endif  // !defined(_LIBCPP_CXX03_LANG)
1816
1817#if _LIBCPP_STD_VER > 14
1818
1819// #if _LIBCPP_STD_VER > 11
1820// template <>
1821// struct _LIBCPP_TEMPLATE_VIS plus<void>
1822// {
1823//     template <class _T1, class _T2>
1824//     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1825//     auto operator()(_T1&& __t, _T2&& __u) const
1826//     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
1827//     -> decltype        (_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
1828//         { return        _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
1829//     typedef void is_transparent;
1830// };
1831// #endif
1832
1833template <class _Cont>
1834inline _LIBCPP_INLINE_VISIBILITY
1835constexpr auto size(const _Cont& __c)
1836_NOEXCEPT_(noexcept(__c.size()))
1837-> decltype        (__c.size())
1838{ return            __c.size(); }
1839
1840template <class _Tp, size_t _Sz>
1841inline _LIBCPP_INLINE_VISIBILITY
1842constexpr size_t size(const _Tp (&)[_Sz]) noexcept { return _Sz; }
1843
1844template <class _Cont>
1845_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
1846constexpr auto empty(const _Cont& __c)
1847_NOEXCEPT_(noexcept(__c.empty()))
1848-> decltype        (__c.empty())
1849{ return            __c.empty(); }
1850
1851template <class _Tp, size_t _Sz>
1852_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
1853constexpr bool empty(const _Tp (&)[_Sz]) noexcept { return false; }
1854
1855template <class _Ep>
1856_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
1857constexpr bool empty(initializer_list<_Ep> __il) noexcept { return __il.size() == 0; }
1858
1859template <class _Cont> constexpr
1860inline _LIBCPP_INLINE_VISIBILITY
1861auto data(_Cont& __c)
1862_NOEXCEPT_(noexcept(__c.data()))
1863-> decltype        (__c.data())
1864{ return            __c.data(); }
1865
1866template <class _Cont> constexpr
1867inline _LIBCPP_INLINE_VISIBILITY
1868auto data(const _Cont& __c)
1869_NOEXCEPT_(noexcept(__c.data()))
1870-> decltype        (__c.data())
1871{ return            __c.data(); }
1872
1873template <class _Tp, size_t _Sz>
1874inline _LIBCPP_INLINE_VISIBILITY
1875constexpr _Tp* data(_Tp (&__array)[_Sz]) noexcept { return __array; }
1876
1877template <class _Ep>
1878inline _LIBCPP_INLINE_VISIBILITY
1879constexpr const _Ep* data(initializer_list<_Ep> __il) noexcept { return __il.begin(); }
1880#endif
1881
1882
1883_LIBCPP_END_NAMESPACE_STD
1884
1885#endif  // _LIBCPP_ITERATOR
1886