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#include <version>
422#ifdef __APPLE__
423#include <Availability.h>
424#endif
425
426#include <__debug>
427
428#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
429#pragma GCC system_header
430#endif
431
432_LIBCPP_BEGIN_NAMESPACE_STD
433
434struct _LIBCPP_TEMPLATE_VIS input_iterator_tag {};
435struct _LIBCPP_TEMPLATE_VIS output_iterator_tag {};
436struct _LIBCPP_TEMPLATE_VIS forward_iterator_tag       : public input_iterator_tag {};
437struct _LIBCPP_TEMPLATE_VIS bidirectional_iterator_tag : public forward_iterator_tag {};
438struct _LIBCPP_TEMPLATE_VIS random_access_iterator_tag : public bidirectional_iterator_tag {};
439
440template <class _Tp>
441struct __has_iterator_category
442{
443private:
444    struct __two {char __lx; char __lxx;};
445    template <class _Up> static __two __test(...);
446    template <class _Up> static char __test(typename _Up::iterator_category* = 0);
447public:
448    static const bool value = sizeof(__test<_Tp>(0)) == 1;
449};
450
451template <class _Iter, bool> struct __iterator_traits_impl {};
452
453template <class _Iter>
454struct __iterator_traits_impl<_Iter, true>
455{
456    typedef typename _Iter::difference_type   difference_type;
457    typedef typename _Iter::value_type        value_type;
458    typedef typename _Iter::pointer           pointer;
459    typedef typename _Iter::reference         reference;
460    typedef typename _Iter::iterator_category iterator_category;
461};
462
463template <class _Iter, bool> struct __iterator_traits {};
464
465template <class _Iter>
466struct __iterator_traits<_Iter, true>
467    :  __iterator_traits_impl
468      <
469        _Iter,
470        is_convertible<typename _Iter::iterator_category, input_iterator_tag>::value ||
471        is_convertible<typename _Iter::iterator_category, output_iterator_tag>::value
472      >
473{};
474
475// iterator_traits<Iterator> will only have the nested types if Iterator::iterator_category
476//    exists.  Else iterator_traits<Iterator> will be an empty class.  This is a
477//    conforming extension which allows some programs to compile and behave as
478//    the client expects instead of failing at compile time.
479
480template <class _Iter>
481struct _LIBCPP_TEMPLATE_VIS iterator_traits
482    : __iterator_traits<_Iter, __has_iterator_category<_Iter>::value> {};
483
484template<class _Tp>
485struct _LIBCPP_TEMPLATE_VIS iterator_traits<_Tp*>
486{
487    typedef ptrdiff_t difference_type;
488    typedef typename remove_cv<_Tp>::type value_type;
489    typedef _Tp* pointer;
490    typedef _Tp& reference;
491    typedef random_access_iterator_tag iterator_category;
492};
493
494template <class _Tp, class _Up, bool = __has_iterator_category<iterator_traits<_Tp> >::value>
495struct __has_iterator_category_convertible_to
496    : public integral_constant<bool, is_convertible<typename iterator_traits<_Tp>::iterator_category, _Up>::value>
497{};
498
499template <class _Tp, class _Up>
500struct __has_iterator_category_convertible_to<_Tp, _Up, false> : public false_type {};
501
502template <class _Tp>
503struct __is_input_iterator : public __has_iterator_category_convertible_to<_Tp, input_iterator_tag> {};
504
505template <class _Tp>
506struct __is_forward_iterator : public __has_iterator_category_convertible_to<_Tp, forward_iterator_tag> {};
507
508template <class _Tp>
509struct __is_bidirectional_iterator : public __has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag> {};
510
511template <class _Tp>
512struct __is_random_access_iterator : public __has_iterator_category_convertible_to<_Tp, random_access_iterator_tag> {};
513
514template <class _Tp>
515struct __is_exactly_input_iterator
516    : public integral_constant<bool,
517         __has_iterator_category_convertible_to<_Tp, input_iterator_tag>::value &&
518        !__has_iterator_category_convertible_to<_Tp, forward_iterator_tag>::value> {};
519
520template<class _Category, class _Tp, class _Distance = ptrdiff_t,
521         class _Pointer = _Tp*, class _Reference = _Tp&>
522struct _LIBCPP_TEMPLATE_VIS iterator
523{
524    typedef _Tp        value_type;
525    typedef _Distance  difference_type;
526    typedef _Pointer   pointer;
527    typedef _Reference reference;
528    typedef _Category  iterator_category;
529};
530
531template <class _InputIter>
532inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
533void __advance(_InputIter& __i,
534             typename iterator_traits<_InputIter>::difference_type __n, input_iterator_tag)
535{
536    for (; __n > 0; --__n)
537        ++__i;
538}
539
540template <class _BiDirIter>
541inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
542void __advance(_BiDirIter& __i,
543             typename iterator_traits<_BiDirIter>::difference_type __n, bidirectional_iterator_tag)
544{
545    if (__n >= 0)
546        for (; __n > 0; --__n)
547            ++__i;
548    else
549        for (; __n < 0; ++__n)
550            --__i;
551}
552
553template <class _RandIter>
554inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
555void __advance(_RandIter& __i,
556             typename iterator_traits<_RandIter>::difference_type __n, random_access_iterator_tag)
557{
558   __i += __n;
559}
560
561template <class _InputIter>
562inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
563void advance(_InputIter& __i,
564             typename iterator_traits<_InputIter>::difference_type __n)
565{
566    __advance(__i, __n, typename iterator_traits<_InputIter>::iterator_category());
567}
568
569template <class _InputIter>
570inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
571typename iterator_traits<_InputIter>::difference_type
572__distance(_InputIter __first, _InputIter __last, input_iterator_tag)
573{
574    typename iterator_traits<_InputIter>::difference_type __r(0);
575    for (; __first != __last; ++__first)
576        ++__r;
577    return __r;
578}
579
580template <class _RandIter>
581inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
582typename iterator_traits<_RandIter>::difference_type
583__distance(_RandIter __first, _RandIter __last, random_access_iterator_tag)
584{
585    return __last - __first;
586}
587
588template <class _InputIter>
589inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
590typename iterator_traits<_InputIter>::difference_type
591distance(_InputIter __first, _InputIter __last)
592{
593    return __distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category());
594}
595
596template <class _InputIter>
597inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
598typename enable_if
599<
600    __is_input_iterator<_InputIter>::value,
601    _InputIter
602>::type
603next(_InputIter __x,
604     typename iterator_traits<_InputIter>::difference_type __n = 1)
605{
606    _VSTD::advance(__x, __n);
607    return __x;
608}
609
610template <class _BidirectionalIter>
611inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
612typename enable_if
613<
614    __is_bidirectional_iterator<_BidirectionalIter>::value,
615    _BidirectionalIter
616>::type
617prev(_BidirectionalIter __x,
618     typename iterator_traits<_BidirectionalIter>::difference_type __n = 1)
619{
620    _VSTD::advance(__x, -__n);
621    return __x;
622}
623
624
625template <class _Tp, class = void>
626struct __is_stashing_iterator : false_type {};
627
628template <class _Tp>
629struct __is_stashing_iterator<_Tp, typename __void_t<typename _Tp::__stashing_iterator_tag>::type>
630  : true_type {};
631
632template <class _Iter>
633class _LIBCPP_TEMPLATE_VIS reverse_iterator
634    : public iterator<typename iterator_traits<_Iter>::iterator_category,
635                      typename iterator_traits<_Iter>::value_type,
636                      typename iterator_traits<_Iter>::difference_type,
637                      typename iterator_traits<_Iter>::pointer,
638                      typename iterator_traits<_Iter>::reference>
639{
640private:
641    /*mutable*/ _Iter __t;  // no longer used as of LWG #2360, not removed due to ABI break
642
643    static_assert(!__is_stashing_iterator<_Iter>::value,
644      "The specified iterator type cannot be used with reverse_iterator; "
645      "Using stashing iterators with reverse_iterator causes undefined behavior");
646
647protected:
648    _Iter current;
649public:
650    typedef _Iter                                            iterator_type;
651    typedef typename iterator_traits<_Iter>::difference_type difference_type;
652    typedef typename iterator_traits<_Iter>::reference       reference;
653    typedef typename iterator_traits<_Iter>::pointer         pointer;
654
655    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
656    reverse_iterator() : __t(), current() {}
657    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
658    explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}
659    template <class _Up>
660        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
661        reverse_iterator(const reverse_iterator<_Up>& __u) : __t(__u.base()), current(__u.base()) {}
662    template <class _Up>
663        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
664        reverse_iterator& operator=(const reverse_iterator<_Up>& __u)
665            { __t = current = __u.base(); return *this; }
666    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
667    _Iter base() const {return current;}
668    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
669    reference operator*() const {_Iter __tmp = current; return *--__tmp;}
670    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
671    pointer  operator->() const {return _VSTD::addressof(operator*());}
672    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
673    reverse_iterator& operator++() {--current; return *this;}
674    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
675    reverse_iterator  operator++(int) {reverse_iterator __tmp(*this); --current; return __tmp;}
676    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
677    reverse_iterator& operator--() {++current; return *this;}
678    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
679    reverse_iterator  operator--(int) {reverse_iterator __tmp(*this); ++current; return __tmp;}
680    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
681    reverse_iterator  operator+ (difference_type __n) const {return reverse_iterator(current - __n);}
682    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
683    reverse_iterator& operator+=(difference_type __n) {current -= __n; return *this;}
684    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
685    reverse_iterator  operator- (difference_type __n) const {return reverse_iterator(current + __n);}
686    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
687    reverse_iterator& operator-=(difference_type __n) {current += __n; return *this;}
688    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
689    reference         operator[](difference_type __n) const {return *(*this + __n);}
690};
691
692template <class _Iter1, class _Iter2>
693inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
694bool
695operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
696{
697    return __x.base() == __y.base();
698}
699
700template <class _Iter1, class _Iter2>
701inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
702bool
703operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
704{
705    return __x.base() > __y.base();
706}
707
708template <class _Iter1, class _Iter2>
709inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
710bool
711operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
712{
713    return __x.base() != __y.base();
714}
715
716template <class _Iter1, class _Iter2>
717inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
718bool
719operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
720{
721    return __x.base() < __y.base();
722}
723
724template <class _Iter1, class _Iter2>
725inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
726bool
727operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
728{
729    return __x.base() <= __y.base();
730}
731
732template <class _Iter1, class _Iter2>
733inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
734bool
735operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
736{
737    return __x.base() >= __y.base();
738}
739
740#ifndef _LIBCPP_CXX03_LANG
741template <class _Iter1, class _Iter2>
742inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
743auto
744operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
745-> decltype(__y.base() - __x.base())
746{
747    return __y.base() - __x.base();
748}
749#else
750template <class _Iter1, class _Iter2>
751inline _LIBCPP_INLINE_VISIBILITY
752typename reverse_iterator<_Iter1>::difference_type
753operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
754{
755    return __y.base() - __x.base();
756}
757#endif
758
759template <class _Iter>
760inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
761reverse_iterator<_Iter>
762operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x)
763{
764    return reverse_iterator<_Iter>(__x.base() - __n);
765}
766
767#if _LIBCPP_STD_VER > 11
768template <class _Iter>
769inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
770reverse_iterator<_Iter> make_reverse_iterator(_Iter __i)
771{
772    return reverse_iterator<_Iter>(__i);
773}
774#endif
775
776template <class _Container>
777class _LIBCPP_TEMPLATE_VIS back_insert_iterator
778    : public iterator<output_iterator_tag,
779                      void,
780                      void,
781                      void,
782                      void>
783{
784protected:
785    _Container* container;
786public:
787    typedef _Container container_type;
788
789    _LIBCPP_INLINE_VISIBILITY explicit back_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
790    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(const typename _Container::value_type& __value_)
791        {container->push_back(__value_); return *this;}
792#ifndef _LIBCPP_CXX03_LANG
793    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(typename _Container::value_type&& __value_)
794        {container->push_back(_VSTD::move(__value_)); return *this;}
795#endif  // _LIBCPP_CXX03_LANG
796    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator*()     {return *this;}
797    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator++()    {return *this;}
798    _LIBCPP_INLINE_VISIBILITY back_insert_iterator  operator++(int) {return *this;}
799};
800
801template <class _Container>
802inline _LIBCPP_INLINE_VISIBILITY
803back_insert_iterator<_Container>
804back_inserter(_Container& __x)
805{
806    return back_insert_iterator<_Container>(__x);
807}
808
809template <class _Container>
810class _LIBCPP_TEMPLATE_VIS front_insert_iterator
811    : public iterator<output_iterator_tag,
812                      void,
813                      void,
814                      void,
815                      void>
816{
817protected:
818    _Container* container;
819public:
820    typedef _Container container_type;
821
822    _LIBCPP_INLINE_VISIBILITY explicit front_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
823    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(const typename _Container::value_type& __value_)
824        {container->push_front(__value_); return *this;}
825#ifndef _LIBCPP_CXX03_LANG
826    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(typename _Container::value_type&& __value_)
827        {container->push_front(_VSTD::move(__value_)); return *this;}
828#endif  // _LIBCPP_CXX03_LANG
829    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator*()     {return *this;}
830    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator++()    {return *this;}
831    _LIBCPP_INLINE_VISIBILITY front_insert_iterator  operator++(int) {return *this;}
832};
833
834template <class _Container>
835inline _LIBCPP_INLINE_VISIBILITY
836front_insert_iterator<_Container>
837front_inserter(_Container& __x)
838{
839    return front_insert_iterator<_Container>(__x);
840}
841
842template <class _Container>
843class _LIBCPP_TEMPLATE_VIS insert_iterator
844    : public iterator<output_iterator_tag,
845                      void,
846                      void,
847                      void,
848                      void>
849{
850protected:
851    _Container* container;
852    typename _Container::iterator iter;
853public:
854    typedef _Container container_type;
855
856    _LIBCPP_INLINE_VISIBILITY insert_iterator(_Container& __x, typename _Container::iterator __i)
857        : container(_VSTD::addressof(__x)), iter(__i) {}
858    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(const typename _Container::value_type& __value_)
859        {iter = container->insert(iter, __value_); ++iter; return *this;}
860#ifndef _LIBCPP_CXX03_LANG
861    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(typename _Container::value_type&& __value_)
862        {iter = container->insert(iter, _VSTD::move(__value_)); ++iter; return *this;}
863#endif  // _LIBCPP_CXX03_LANG
864    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator*()        {return *this;}
865    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++()       {return *this;}
866    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++(int)    {return *this;}
867};
868
869template <class _Container>
870inline _LIBCPP_INLINE_VISIBILITY
871insert_iterator<_Container>
872inserter(_Container& __x, typename _Container::iterator __i)
873{
874    return insert_iterator<_Container>(__x, __i);
875}
876
877template <class _Tp, class _CharT = char,
878          class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
879class _LIBCPP_TEMPLATE_VIS istream_iterator
880    : public iterator<input_iterator_tag, _Tp, _Distance, const _Tp*, const _Tp&>
881{
882public:
883    typedef _CharT char_type;
884    typedef _Traits traits_type;
885    typedef basic_istream<_CharT,_Traits> istream_type;
886private:
887    istream_type* __in_stream_;
888    _Tp __value_;
889public:
890    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istream_iterator() : __in_stream_(0), __value_() {}
891    _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s) : __in_stream_(_VSTD::addressof(__s))
892        {
893            if (!(*__in_stream_ >> __value_))
894                __in_stream_ = 0;
895        }
896
897    _LIBCPP_INLINE_VISIBILITY const _Tp& operator*() const {return __value_;}
898    _LIBCPP_INLINE_VISIBILITY const _Tp* operator->() const {return _VSTD::addressof((operator*()));}
899    _LIBCPP_INLINE_VISIBILITY istream_iterator& operator++()
900        {
901            if (!(*__in_stream_ >> __value_))
902                __in_stream_ = 0;
903            return *this;
904        }
905    _LIBCPP_INLINE_VISIBILITY istream_iterator  operator++(int)
906        {istream_iterator __t(*this); ++(*this); return __t;}
907
908    template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
909    friend _LIBCPP_INLINE_VISIBILITY
910    bool
911    operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
912               const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
913
914    template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
915    friend _LIBCPP_INLINE_VISIBILITY
916    bool
917    operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
918               const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
919};
920
921template <class _Tp, class _CharT, class _Traits, class _Distance>
922inline _LIBCPP_INLINE_VISIBILITY
923bool
924operator==(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
925           const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
926{
927    return __x.__in_stream_ == __y.__in_stream_;
928}
929
930template <class _Tp, class _CharT, class _Traits, class _Distance>
931inline _LIBCPP_INLINE_VISIBILITY
932bool
933operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
934           const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
935{
936    return !(__x == __y);
937}
938
939template <class _Tp, class _CharT = char, class _Traits = char_traits<_CharT> >
940class _LIBCPP_TEMPLATE_VIS ostream_iterator
941    : public iterator<output_iterator_tag, void, void, void, void>
942{
943public:
944    typedef _CharT char_type;
945    typedef _Traits traits_type;
946    typedef basic_ostream<_CharT,_Traits> ostream_type;
947private:
948    ostream_type* __out_stream_;
949    const char_type* __delim_;
950public:
951    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s) _NOEXCEPT
952        : __out_stream_(_VSTD::addressof(__s)), __delim_(0) {}
953    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s, const _CharT* __delimiter) _NOEXCEPT
954        : __out_stream_(_VSTD::addressof(__s)), __delim_(__delimiter) {}
955    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator=(const _Tp& __value_)
956        {
957            *__out_stream_ << __value_;
958            if (__delim_)
959                *__out_stream_ << __delim_;
960            return *this;
961        }
962
963    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator*()     {return *this;}
964    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++()    {return *this;}
965    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++(int) {return *this;}
966};
967
968template<class _CharT, class _Traits>
969class _LIBCPP_TEMPLATE_VIS istreambuf_iterator
970    : public iterator<input_iterator_tag, _CharT,
971                      typename _Traits::off_type, _CharT*,
972                      _CharT>
973{
974public:
975    typedef _CharT                          char_type;
976    typedef _Traits                         traits_type;
977    typedef typename _Traits::int_type      int_type;
978    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
979    typedef basic_istream<_CharT,_Traits>   istream_type;
980private:
981    mutable streambuf_type* __sbuf_;
982
983    class __proxy
984    {
985        char_type __keep_;
986        streambuf_type* __sbuf_;
987        _LIBCPP_INLINE_VISIBILITY __proxy(char_type __c, streambuf_type* __s)
988            : __keep_(__c), __sbuf_(__s) {}
989        friend class istreambuf_iterator;
990    public:
991        _LIBCPP_INLINE_VISIBILITY char_type operator*() const {return __keep_;}
992    };
993
994    _LIBCPP_INLINE_VISIBILITY
995    bool __test_for_eof() const
996    {
997        if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
998            __sbuf_ = 0;
999        return __sbuf_ == 0;
1000    }
1001public:
1002    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(0) {}
1003    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(istream_type& __s) _NOEXCEPT
1004        : __sbuf_(__s.rdbuf()) {}
1005    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(streambuf_type* __s) _NOEXCEPT
1006        : __sbuf_(__s) {}
1007    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(const __proxy& __p) _NOEXCEPT
1008        : __sbuf_(__p.__sbuf_) {}
1009
1010    _LIBCPP_INLINE_VISIBILITY char_type  operator*() const
1011        {return static_cast<char_type>(__sbuf_->sgetc());}
1012    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator& operator++()
1013        {
1014            __sbuf_->sbumpc();
1015            return *this;
1016        }
1017    _LIBCPP_INLINE_VISIBILITY __proxy              operator++(int)
1018        {
1019            return __proxy(__sbuf_->sbumpc(), __sbuf_);
1020        }
1021
1022    _LIBCPP_INLINE_VISIBILITY bool equal(const istreambuf_iterator& __b) const
1023        {return __test_for_eof() == __b.__test_for_eof();}
1024};
1025
1026template <class _CharT, class _Traits>
1027inline _LIBCPP_INLINE_VISIBILITY
1028bool operator==(const istreambuf_iterator<_CharT,_Traits>& __a,
1029                const istreambuf_iterator<_CharT,_Traits>& __b)
1030                {return __a.equal(__b);}
1031
1032template <class _CharT, class _Traits>
1033inline _LIBCPP_INLINE_VISIBILITY
1034bool operator!=(const istreambuf_iterator<_CharT,_Traits>& __a,
1035                const istreambuf_iterator<_CharT,_Traits>& __b)
1036                {return !__a.equal(__b);}
1037
1038template <class _CharT, class _Traits>
1039class _LIBCPP_TEMPLATE_VIS ostreambuf_iterator
1040    : public iterator<output_iterator_tag, void, void, void, void>
1041{
1042public:
1043    typedef _CharT                          char_type;
1044    typedef _Traits                         traits_type;
1045    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
1046    typedef basic_ostream<_CharT,_Traits>   ostream_type;
1047private:
1048    streambuf_type* __sbuf_;
1049public:
1050    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(ostream_type& __s) _NOEXCEPT
1051        : __sbuf_(__s.rdbuf()) {}
1052    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(streambuf_type* __s) _NOEXCEPT
1053        : __sbuf_(__s) {}
1054    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator=(_CharT __c)
1055        {
1056            if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sputc(__c), traits_type::eof()))
1057                __sbuf_ = 0;
1058            return *this;
1059        }
1060    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator*()     {return *this;}
1061    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++()    {return *this;}
1062    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++(int) {return *this;}
1063    _LIBCPP_INLINE_VISIBILITY bool failed() const _NOEXCEPT {return __sbuf_ == 0;}
1064
1065#if !defined(__APPLE__) || \
1066    (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED > __MAC_10_8) || \
1067    (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && __IPHONE_OS_VERSION_MIN_REQUIRED > __IPHONE_6_0)
1068
1069    template <class _Ch, class _Tr>
1070    friend
1071    _LIBCPP_HIDDEN
1072    ostreambuf_iterator<_Ch, _Tr>
1073    __pad_and_output(ostreambuf_iterator<_Ch, _Tr> __s,
1074                     const _Ch* __ob, const _Ch* __op, const _Ch* __oe,
1075                     ios_base& __iob, _Ch __fl);
1076#endif
1077};
1078
1079template <class _Iter>
1080class _LIBCPP_TEMPLATE_VIS move_iterator
1081{
1082private:
1083    _Iter __i;
1084public:
1085    typedef _Iter                                            iterator_type;
1086    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
1087    typedef typename iterator_traits<iterator_type>::value_type value_type;
1088    typedef typename iterator_traits<iterator_type>::difference_type difference_type;
1089    typedef iterator_type pointer;
1090#ifndef _LIBCPP_CXX03_LANG
1091    typedef typename iterator_traits<iterator_type>::reference __reference;
1092    typedef typename conditional<
1093            is_reference<__reference>::value,
1094            typename remove_reference<__reference>::type&&,
1095            __reference
1096        >::type reference;
1097#else
1098    typedef typename iterator_traits<iterator_type>::reference reference;
1099#endif
1100
1101    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1102    move_iterator() : __i() {}
1103    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1104    explicit move_iterator(_Iter __x) : __i(__x) {}
1105    template <class _Up>
1106      _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1107      move_iterator(const move_iterator<_Up>& __u) : __i(__u.base()) {}
1108    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 _Iter base() const {return __i;}
1109    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1110    reference operator*() const { return static_cast<reference>(*__i); }
1111    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1112    pointer  operator->() const { return __i;}
1113    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1114    move_iterator& operator++() {++__i; return *this;}
1115    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1116    move_iterator  operator++(int) {move_iterator __tmp(*this); ++__i; return __tmp;}
1117    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1118    move_iterator& operator--() {--__i; return *this;}
1119    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1120    move_iterator  operator--(int) {move_iterator __tmp(*this); --__i; return __tmp;}
1121    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1122    move_iterator  operator+ (difference_type __n) const {return move_iterator(__i + __n);}
1123    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1124    move_iterator& operator+=(difference_type __n) {__i += __n; return *this;}
1125    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1126    move_iterator  operator- (difference_type __n) const {return move_iterator(__i - __n);}
1127    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1128    move_iterator& operator-=(difference_type __n) {__i -= __n; return *this;}
1129    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1130    reference operator[](difference_type __n) const { return static_cast<reference>(__i[__n]); }
1131};
1132
1133template <class _Iter1, class _Iter2>
1134inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1135bool
1136operator==(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1137{
1138    return __x.base() == __y.base();
1139}
1140
1141template <class _Iter1, class _Iter2>
1142inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1143bool
1144operator<(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1145{
1146    return __x.base() < __y.base();
1147}
1148
1149template <class _Iter1, class _Iter2>
1150inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1151bool
1152operator!=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1153{
1154    return __x.base() != __y.base();
1155}
1156
1157template <class _Iter1, class _Iter2>
1158inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1159bool
1160operator>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1161{
1162    return __x.base() > __y.base();
1163}
1164
1165template <class _Iter1, class _Iter2>
1166inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1167bool
1168operator>=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1169{
1170    return __x.base() >= __y.base();
1171}
1172
1173template <class _Iter1, class _Iter2>
1174inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1175bool
1176operator<=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1177{
1178    return __x.base() <= __y.base();
1179}
1180
1181#ifndef _LIBCPP_CXX03_LANG
1182template <class _Iter1, class _Iter2>
1183inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1184auto
1185operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1186-> decltype(__x.base() - __y.base())
1187{
1188    return __x.base() - __y.base();
1189}
1190#else
1191template <class _Iter1, class _Iter2>
1192inline _LIBCPP_INLINE_VISIBILITY
1193typename move_iterator<_Iter1>::difference_type
1194operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1195{
1196    return __x.base() - __y.base();
1197}
1198#endif
1199
1200template <class _Iter>
1201inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1202move_iterator<_Iter>
1203operator+(typename move_iterator<_Iter>::difference_type __n, const move_iterator<_Iter>& __x)
1204{
1205    return move_iterator<_Iter>(__x.base() + __n);
1206}
1207
1208template <class _Iter>
1209inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1210move_iterator<_Iter>
1211make_move_iterator(_Iter __i)
1212{
1213    return move_iterator<_Iter>(__i);
1214}
1215
1216// __wrap_iter
1217
1218template <class _Iter> class __wrap_iter;
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_DEBUG;
1224
1225template <class _Iter1, class _Iter2>
1226_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1227bool
1228operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1229
1230template <class _Iter1, class _Iter2>
1231_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1232bool
1233operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1234
1235template <class _Iter1, class _Iter2>
1236_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1237bool
1238operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1239
1240template <class _Iter1, class _Iter2>
1241_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1242bool
1243operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1244
1245template <class _Iter1, class _Iter2>
1246_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1247bool
1248operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1249
1250#ifndef _LIBCPP_CXX03_LANG
1251template <class _Iter1, class _Iter2>
1252_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1253auto
1254operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1255-> decltype(__x.base() - __y.base());
1256#else
1257template <class _Iter1, class _Iter2>
1258_LIBCPP_INLINE_VISIBILITY
1259typename __wrap_iter<_Iter1>::difference_type
1260operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1261#endif
1262
1263template <class _Iter>
1264_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1265__wrap_iter<_Iter>
1266operator+(typename __wrap_iter<_Iter>::difference_type, __wrap_iter<_Iter>) _NOEXCEPT_DEBUG;
1267
1268template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY copy(_Ip, _Ip, _Op);
1269template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY copy_backward(_B1, _B1, _B2);
1270template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY move(_Ip, _Ip, _Op);
1271template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY move_backward(_B1, _B1, _B2);
1272
1273#if _LIBCPP_DEBUG_LEVEL < 2
1274
1275template <class _Tp>
1276_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1277typename enable_if
1278<
1279    is_trivially_copy_assignable<_Tp>::value,
1280    _Tp*
1281>::type
1282__unwrap_iter(__wrap_iter<_Tp*>);
1283
1284#else
1285
1286template <class _Tp>
1287inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1288typename enable_if
1289<
1290    is_trivially_copy_assignable<_Tp>::value,
1291    __wrap_iter<_Tp*>
1292>::type
1293__unwrap_iter(__wrap_iter<_Tp*> __i);
1294
1295#endif
1296
1297template <class _Iter>
1298class __wrap_iter
1299{
1300public:
1301    typedef _Iter                                                      iterator_type;
1302    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
1303    typedef typename iterator_traits<iterator_type>::value_type        value_type;
1304    typedef typename iterator_traits<iterator_type>::difference_type   difference_type;
1305    typedef typename iterator_traits<iterator_type>::pointer           pointer;
1306    typedef typename iterator_traits<iterator_type>::reference         reference;
1307private:
1308    iterator_type __i;
1309public:
1310    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter() _NOEXCEPT_DEBUG
1311#if _LIBCPP_STD_VER > 11
1312                : __i{}
1313#endif
1314    {
1315#if _LIBCPP_DEBUG_LEVEL >= 2
1316        __get_db()->__insert_i(this);
1317#endif
1318    }
1319    template <class _Up> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1320        __wrap_iter(const __wrap_iter<_Up>& __u,
1321            typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = 0) _NOEXCEPT_DEBUG
1322            : __i(__u.base())
1323    {
1324#if _LIBCPP_DEBUG_LEVEL >= 2
1325        __get_db()->__iterator_copy(this, &__u);
1326#endif
1327    }
1328#if _LIBCPP_DEBUG_LEVEL >= 2
1329    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1330    __wrap_iter(const __wrap_iter& __x)
1331        : __i(__x.base())
1332    {
1333        __get_db()->__iterator_copy(this, &__x);
1334    }
1335    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1336    __wrap_iter& operator=(const __wrap_iter& __x)
1337    {
1338        if (this != &__x)
1339        {
1340            __get_db()->__iterator_copy(this, &__x);
1341            __i = __x.__i;
1342        }
1343        return *this;
1344    }
1345    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1346    ~__wrap_iter()
1347    {
1348        __get_db()->__erase_i(this);
1349    }
1350#endif
1351    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference operator*() const _NOEXCEPT_DEBUG
1352    {
1353#if _LIBCPP_DEBUG_LEVEL >= 2
1354        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1355                       "Attempted to dereference a non-dereferenceable iterator");
1356#endif
1357        return *__i;
1358    }
1359    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG pointer  operator->() const _NOEXCEPT_DEBUG
1360    {
1361#if _LIBCPP_DEBUG_LEVEL >= 2
1362        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1363                       "Attempted to dereference a non-dereferenceable iterator");
1364#endif
1365        return (pointer)_VSTD::addressof(*__i);
1366    }
1367    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator++() _NOEXCEPT_DEBUG
1368    {
1369#if _LIBCPP_DEBUG_LEVEL >= 2
1370        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1371                       "Attempted to increment non-incrementable iterator");
1372#endif
1373        ++__i;
1374        return *this;
1375    }
1376    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator++(int) _NOEXCEPT_DEBUG
1377        {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
1378
1379    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator--() _NOEXCEPT_DEBUG
1380    {
1381#if _LIBCPP_DEBUG_LEVEL >= 2
1382        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
1383                       "Attempted to decrement non-decrementable iterator");
1384#endif
1385        --__i;
1386        return *this;
1387    }
1388    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator--(int) _NOEXCEPT_DEBUG
1389        {__wrap_iter __tmp(*this); --(*this); return __tmp;}
1390    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT_DEBUG
1391        {__wrap_iter __w(*this); __w += __n; return __w;}
1392    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator+=(difference_type __n) _NOEXCEPT_DEBUG
1393    {
1394#if _LIBCPP_DEBUG_LEVEL >= 2
1395        _LIBCPP_ASSERT(__get_const_db()->__addable(this, __n),
1396                   "Attempted to add/subtract iterator outside of valid range");
1397#endif
1398        __i += __n;
1399        return *this;
1400    }
1401    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator- (difference_type __n) const _NOEXCEPT_DEBUG
1402        {return *this + (-__n);}
1403    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator-=(difference_type __n) _NOEXCEPT_DEBUG
1404        {*this += -__n; return *this;}
1405    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference    operator[](difference_type __n) const _NOEXCEPT_DEBUG
1406    {
1407#if _LIBCPP_DEBUG_LEVEL >= 2
1408        _LIBCPP_ASSERT(__get_const_db()->__subscriptable(this, __n),
1409                   "Attempted to subscript iterator outside of valid range");
1410#endif
1411        return __i[__n];
1412    }
1413
1414    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG iterator_type base() const _NOEXCEPT_DEBUG {return __i;}
1415
1416private:
1417#if _LIBCPP_DEBUG_LEVEL >= 2
1418    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(const void* __p, iterator_type __x) : __i(__x)
1419    {
1420        __get_db()->__insert_ic(this, __p);
1421    }
1422#else
1423    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(iterator_type __x) _NOEXCEPT_DEBUG : __i(__x) {}
1424#endif
1425
1426    template <class _Up> friend class __wrap_iter;
1427    template <class _CharT, class _Traits, class _Alloc> friend class basic_string;
1428    template <class _Tp, class _Alloc> friend class _LIBCPP_TEMPLATE_VIS vector;
1429    template <class _Tp, ptrdiff_t> friend class _LIBCPP_TEMPLATE_VIS span;
1430
1431    template <class _Iter1, class _Iter2>
1432    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1433    bool
1434    operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1435
1436    template <class _Iter1, class _Iter2>
1437    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1438    bool
1439    operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1440
1441    template <class _Iter1, class _Iter2>
1442    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1443    bool
1444    operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1445
1446    template <class _Iter1, class _Iter2>
1447    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1448    bool
1449    operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1450
1451    template <class _Iter1, class _Iter2>
1452    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1453    bool
1454    operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1455
1456    template <class _Iter1, class _Iter2>
1457    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1458    bool
1459    operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1460
1461#ifndef _LIBCPP_CXX03_LANG
1462    template <class _Iter1, class _Iter2>
1463    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1464    auto
1465    operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1466    -> decltype(__x.base() - __y.base());
1467#else
1468    template <class _Iter1, class _Iter2>
1469    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1470    typename __wrap_iter<_Iter1>::difference_type
1471    operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
1472#endif
1473
1474    template <class _Iter1>
1475    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1476    __wrap_iter<_Iter1>
1477    operator+(typename __wrap_iter<_Iter1>::difference_type, __wrap_iter<_Iter1>) _NOEXCEPT_DEBUG;
1478
1479    template <class _Ip, class _Op> friend _Op copy(_Ip, _Ip, _Op);
1480    template <class _B1, class _B2> friend _B2 copy_backward(_B1, _B1, _B2);
1481    template <class _Ip, class _Op> friend _Op move(_Ip, _Ip, _Op);
1482    template <class _B1, class _B2> friend _B2 move_backward(_B1, _B1, _B2);
1483
1484#if _LIBCPP_DEBUG_LEVEL < 2
1485    template <class _Tp>
1486    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1487    typename enable_if
1488    <
1489        is_trivially_copy_assignable<_Tp>::value,
1490        _Tp*
1491    >::type
1492    __unwrap_iter(__wrap_iter<_Tp*>);
1493#else
1494  template <class _Tp>
1495  inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1496  typename enable_if
1497  <
1498      is_trivially_copy_assignable<_Tp>::value,
1499      __wrap_iter<_Tp*>
1500  >::type
1501  __unwrap_iter(__wrap_iter<_Tp*> __i);
1502#endif
1503};
1504
1505template <class _Iter1, class _Iter2>
1506inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1507bool
1508operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1509{
1510    return __x.base() == __y.base();
1511}
1512
1513template <class _Iter1, class _Iter2>
1514inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1515bool
1516operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1517{
1518#if _LIBCPP_DEBUG_LEVEL >= 2
1519    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1520                   "Attempted to compare incomparable iterators");
1521#endif
1522    return __x.base() < __y.base();
1523}
1524
1525template <class _Iter1, class _Iter2>
1526inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1527bool
1528operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1529{
1530    return !(__x == __y);
1531}
1532
1533template <class _Iter1, class _Iter2>
1534inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1535bool
1536operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1537{
1538    return __y < __x;
1539}
1540
1541template <class _Iter1, class _Iter2>
1542inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1543bool
1544operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1545{
1546    return !(__x < __y);
1547}
1548
1549template <class _Iter1, class _Iter2>
1550inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1551bool
1552operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1553{
1554    return !(__y < __x);
1555}
1556
1557template <class _Iter1>
1558inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1559bool
1560operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
1561{
1562    return !(__x == __y);
1563}
1564
1565template <class _Iter1>
1566inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1567bool
1568operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
1569{
1570    return __y < __x;
1571}
1572
1573template <class _Iter1>
1574inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1575bool
1576operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
1577{
1578    return !(__x < __y);
1579}
1580
1581template <class _Iter1>
1582inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1583bool
1584operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
1585{
1586    return !(__y < __x);
1587}
1588
1589#ifndef _LIBCPP_CXX03_LANG
1590template <class _Iter1, class _Iter2>
1591inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1592auto
1593operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1594-> decltype(__x.base() - __y.base())
1595{
1596#if _LIBCPP_DEBUG_LEVEL >= 2
1597    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1598                   "Attempted to subtract incompatible iterators");
1599#endif
1600    return __x.base() - __y.base();
1601}
1602#else
1603template <class _Iter1, class _Iter2>
1604inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1605typename __wrap_iter<_Iter1>::difference_type
1606operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
1607{
1608#if _LIBCPP_DEBUG_LEVEL >= 2
1609    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1610                   "Attempted to subtract incompatible iterators");
1611#endif
1612    return __x.base() - __y.base();
1613}
1614#endif
1615
1616template <class _Iter>
1617inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1618__wrap_iter<_Iter>
1619operator+(typename __wrap_iter<_Iter>::difference_type __n,
1620          __wrap_iter<_Iter> __x) _NOEXCEPT_DEBUG
1621{
1622    __x += __n;
1623    return __x;
1624}
1625
1626template <class _Iter>
1627struct __libcpp_is_trivial_iterator
1628    : public _LIBCPP_BOOL_CONSTANT(is_pointer<_Iter>::value) {};
1629
1630template <class _Iter>
1631struct __libcpp_is_trivial_iterator<move_iterator<_Iter> >
1632    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1633
1634template <class _Iter>
1635struct __libcpp_is_trivial_iterator<reverse_iterator<_Iter> >
1636    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1637
1638template <class _Iter>
1639struct __libcpp_is_trivial_iterator<__wrap_iter<_Iter> >
1640    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1641
1642
1643template <class _Tp, size_t _Np>
1644inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1645_Tp*
1646begin(_Tp (&__array)[_Np])
1647{
1648    return __array;
1649}
1650
1651template <class _Tp, size_t _Np>
1652inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1653_Tp*
1654end(_Tp (&__array)[_Np])
1655{
1656    return __array + _Np;
1657}
1658
1659#if !defined(_LIBCPP_CXX03_LANG)
1660
1661template <class _Cp>
1662inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1663auto
1664begin(_Cp& __c) -> decltype(__c.begin())
1665{
1666    return __c.begin();
1667}
1668
1669template <class _Cp>
1670inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1671auto
1672begin(const _Cp& __c) -> decltype(__c.begin())
1673{
1674    return __c.begin();
1675}
1676
1677template <class _Cp>
1678inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1679auto
1680end(_Cp& __c) -> decltype(__c.end())
1681{
1682    return __c.end();
1683}
1684
1685template <class _Cp>
1686inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1687auto
1688end(const _Cp& __c) -> decltype(__c.end())
1689{
1690    return __c.end();
1691}
1692
1693#if _LIBCPP_STD_VER > 11
1694
1695template <class _Tp, size_t _Np>
1696inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1697reverse_iterator<_Tp*> rbegin(_Tp (&__array)[_Np])
1698{
1699    return reverse_iterator<_Tp*>(__array + _Np);
1700}
1701
1702template <class _Tp, size_t _Np>
1703inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1704reverse_iterator<_Tp*> rend(_Tp (&__array)[_Np])
1705{
1706    return reverse_iterator<_Tp*>(__array);
1707}
1708
1709template <class _Ep>
1710inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1711reverse_iterator<const _Ep*> rbegin(initializer_list<_Ep> __il)
1712{
1713    return reverse_iterator<const _Ep*>(__il.end());
1714}
1715
1716template <class _Ep>
1717inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1718reverse_iterator<const _Ep*> rend(initializer_list<_Ep> __il)
1719{
1720    return reverse_iterator<const _Ep*>(__il.begin());
1721}
1722
1723template <class _Cp>
1724inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1725auto cbegin(const _Cp& __c) -> decltype(_VSTD::begin(__c))
1726{
1727    return _VSTD::begin(__c);
1728}
1729
1730template <class _Cp>
1731inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1732auto cend(const _Cp& __c) -> decltype(_VSTD::end(__c))
1733{
1734    return _VSTD::end(__c);
1735}
1736
1737template <class _Cp>
1738inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1739auto rbegin(_Cp& __c) -> decltype(__c.rbegin())
1740{
1741    return __c.rbegin();
1742}
1743
1744template <class _Cp>
1745inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1746auto rbegin(const _Cp& __c) -> decltype(__c.rbegin())
1747{
1748    return __c.rbegin();
1749}
1750
1751template <class _Cp>
1752inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1753auto rend(_Cp& __c) -> decltype(__c.rend())
1754{
1755    return __c.rend();
1756}
1757
1758template <class _Cp>
1759inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1760auto rend(const _Cp& __c) -> decltype(__c.rend())
1761{
1762    return __c.rend();
1763}
1764
1765template <class _Cp>
1766inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1767auto crbegin(const _Cp& __c) -> decltype(_VSTD::rbegin(__c))
1768{
1769    return _VSTD::rbegin(__c);
1770}
1771
1772template <class _Cp>
1773inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1774auto crend(const _Cp& __c) -> decltype(_VSTD::rend(__c))
1775{
1776    return _VSTD::rend(__c);
1777}
1778
1779#endif
1780
1781
1782#else  // defined(_LIBCPP_CXX03_LANG)
1783
1784template <class _Cp>
1785inline _LIBCPP_INLINE_VISIBILITY
1786typename _Cp::iterator
1787begin(_Cp& __c)
1788{
1789    return __c.begin();
1790}
1791
1792template <class _Cp>
1793inline _LIBCPP_INLINE_VISIBILITY
1794typename _Cp::const_iterator
1795begin(const _Cp& __c)
1796{
1797    return __c.begin();
1798}
1799
1800template <class _Cp>
1801inline _LIBCPP_INLINE_VISIBILITY
1802typename _Cp::iterator
1803end(_Cp& __c)
1804{
1805    return __c.end();
1806}
1807
1808template <class _Cp>
1809inline _LIBCPP_INLINE_VISIBILITY
1810typename _Cp::const_iterator
1811end(const _Cp& __c)
1812{
1813    return __c.end();
1814}
1815
1816#endif  // !defined(_LIBCPP_CXX03_LANG)
1817
1818#if _LIBCPP_STD_VER > 14
1819
1820// #if _LIBCPP_STD_VER > 11
1821// template <>
1822// struct _LIBCPP_TEMPLATE_VIS plus<void>
1823// {
1824//     template <class _T1, class _T2>
1825//     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1826//     auto operator()(_T1&& __t, _T2&& __u) const
1827//     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
1828//     -> decltype        (_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
1829//         { return        _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
1830//     typedef void is_transparent;
1831// };
1832// #endif
1833
1834template <class _Cont>
1835inline _LIBCPP_INLINE_VISIBILITY
1836constexpr auto size(const _Cont& __c)
1837_NOEXCEPT_(noexcept(__c.size()))
1838-> decltype        (__c.size())
1839{ return            __c.size(); }
1840
1841template <class _Tp, size_t _Sz>
1842inline _LIBCPP_INLINE_VISIBILITY
1843constexpr size_t size(const _Tp (&)[_Sz]) noexcept { return _Sz; }
1844
1845template <class _Cont>
1846_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
1847constexpr auto empty(const _Cont& __c)
1848_NOEXCEPT_(noexcept(__c.empty()))
1849-> decltype        (__c.empty())
1850{ return            __c.empty(); }
1851
1852template <class _Tp, size_t _Sz>
1853_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
1854constexpr bool empty(const _Tp (&)[_Sz]) noexcept { return false; }
1855
1856template <class _Ep>
1857_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
1858constexpr bool empty(initializer_list<_Ep> __il) noexcept { return __il.size() == 0; }
1859
1860template <class _Cont> constexpr
1861inline _LIBCPP_INLINE_VISIBILITY
1862auto data(_Cont& __c)
1863_NOEXCEPT_(noexcept(__c.data()))
1864-> decltype        (__c.data())
1865{ return            __c.data(); }
1866
1867template <class _Cont> constexpr
1868inline _LIBCPP_INLINE_VISIBILITY
1869auto data(const _Cont& __c)
1870_NOEXCEPT_(noexcept(__c.data()))
1871-> decltype        (__c.data())
1872{ return            __c.data(); }
1873
1874template <class _Tp, size_t _Sz>
1875inline _LIBCPP_INLINE_VISIBILITY
1876constexpr _Tp* data(_Tp (&__array)[_Sz]) noexcept { return __array; }
1877
1878template <class _Ep>
1879inline _LIBCPP_INLINE_VISIBILITY
1880constexpr const _Ep* data(initializer_list<_Ep> __il) noexcept { return __il.begin(); }
1881#endif
1882
1883
1884_LIBCPP_END_NAMESPACE_STD
1885
1886#endif  // _LIBCPP_ITERATOR
1887