1// -*- C++ -*-
2//===-------------------------- iterator ----------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_ITERATOR
11#define _LIBCPP_ITERATOR
12
13/*
14    iterator synopsis
15
16namespace std
17{
18
19template<class Iterator>
20struct iterator_traits
21{
22    typedef typename Iterator::difference_type difference_type;
23    typedef typename Iterator::value_type value_type;
24    typedef typename Iterator::pointer pointer;
25    typedef typename Iterator::reference reference;
26    typedef typename Iterator::iterator_category iterator_category;
27};
28
29template<class T>
30struct iterator_traits<T*>
31{
32    typedef ptrdiff_t difference_type;
33    typedef T value_type;
34    typedef T* pointer;
35    typedef T& reference;
36    typedef random_access_iterator_tag iterator_category;
37};
38
39template<class Category, class T, class Distance = ptrdiff_t,
40         class Pointer = T*, class Reference = T&>
41struct iterator
42{
43    typedef T         value_type;
44    typedef Distance  difference_type;
45    typedef Pointer   pointer;
46    typedef Reference reference;
47    typedef Category  iterator_category;
48};
49
50struct input_iterator_tag  {};
51struct output_iterator_tag {};
52struct forward_iterator_tag       : public input_iterator_tag         {};
53struct bidirectional_iterator_tag : public forward_iterator_tag       {};
54struct random_access_iterator_tag : public bidirectional_iterator_tag {};
55
56// 27.4.3, iterator operations
57// extension: second argument not conforming to C++03
58template <class InputIterator>  // constexpr in C++17
59  constexpr void advance(InputIterator& i,
60             typename iterator_traits<InputIterator>::difference_type n);
61
62template <class InputIterator>  // constexpr in C++17
63  constexpr typename iterator_traits<InputIterator>::difference_type
64    distance(InputIterator first, InputIterator last);
65
66template <class InputIterator>  // constexpr in C++17
67  constexpr InputIterator next(InputIterator x,
68typename iterator_traits<InputIterator>::difference_type n = 1);
69
70template <class BidirectionalIterator>  // constexpr in C++17
71  constexpr BidirectionalIterator prev(BidirectionalIterator x,
72    typename iterator_traits<BidirectionalIterator>::difference_type n = 1);
73
74template <class Iterator>
75class reverse_iterator
76    : public iterator<typename iterator_traits<Iterator>::iterator_category,
77                      typename iterator_traits<Iterator>::value_type,
78                      typename iterator_traits<Iterator>::difference_type,
79                      typename iterator_traits<Iterator>::pointer,
80                      typename iterator_traits<Iterator>::reference>
81{
82protected:
83    Iterator current;
84public:
85    typedef Iterator                                            iterator_type;
86    typedef typename iterator_traits<Iterator>::difference_type difference_type;
87    typedef typename iterator_traits<Iterator>::reference       reference;
88    typedef typename iterator_traits<Iterator>::pointer         pointer;
89
90    constexpr reverse_iterator();
91    constexpr explicit reverse_iterator(Iterator x);
92    template <class U> constexpr reverse_iterator(const reverse_iterator<U>& u);
93    template <class U> constexpr reverse_iterator& operator=(const reverse_iterator<U>& u);
94    constexpr Iterator base() const;
95    constexpr reference operator*() const;
96    constexpr pointer   operator->() const;
97    constexpr reverse_iterator& operator++();
98    constexpr reverse_iterator  operator++(int);
99    constexpr reverse_iterator& operator--();
100    constexpr reverse_iterator  operator--(int);
101    constexpr reverse_iterator  operator+ (difference_type n) const;
102    constexpr reverse_iterator& operator+=(difference_type n);
103    constexpr reverse_iterator  operator- (difference_type n) const;
104    constexpr reverse_iterator& operator-=(difference_type n);
105    constexpr reference         operator[](difference_type n) const;
106};
107
108template <class Iterator1, class Iterator2>
109constexpr bool                          // constexpr in C++17
110operator==(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
111
112template <class Iterator1, class Iterator2>
113constexpr bool                          // constexpr in C++17
114operator<(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
115
116template <class Iterator1, class Iterator2>
117constexpr bool                          // constexpr in C++17
118operator!=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
119
120template <class Iterator1, class Iterator2>
121constexpr bool                          // constexpr in C++17
122operator>(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
123
124template <class Iterator1, class Iterator2>
125constexpr bool                          // constexpr in C++17
126operator>=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
127
128template <class Iterator1, class Iterator2>
129constexpr bool                          // constexpr in C++17
130operator<=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
131
132template <class Iterator1, class Iterator2>
133constexpr auto
134operator-(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y)
135-> decltype(__y.base() - __x.base());   // constexpr in C++17
136
137template <class Iterator>
138constexpr reverse_iterator<Iterator>
139operator+(typename reverse_iterator<Iterator>::difference_type n,
140          const reverse_iterator<Iterator>& x);   // constexpr in C++17
141
142template <class Iterator>
143constexpr reverse_iterator<Iterator> make_reverse_iterator(Iterator i); // C++14, constexpr in C++17
144
145template <class Container>
146class back_insert_iterator
147{
148protected:
149    Container* container;
150public:
151    typedef Container                   container_type;
152    typedef void                        value_type;
153    typedef void                        difference_type;
154    typedef void                        reference;
155    typedef void                        pointer;
156
157    explicit back_insert_iterator(Container& x);
158    back_insert_iterator& operator=(const typename Container::value_type& value);
159    back_insert_iterator& operator*();
160    back_insert_iterator& operator++();
161    back_insert_iterator  operator++(int);
162};
163
164template <class Container> back_insert_iterator<Container> back_inserter(Container& x);
165
166template <class Container>
167class front_insert_iterator
168{
169protected:
170    Container* container;
171public:
172    typedef Container                    container_type;
173    typedef void                         value_type;
174    typedef void                         difference_type;
175    typedef void                         reference;
176    typedef void                         pointer;
177
178    explicit front_insert_iterator(Container& x);
179    front_insert_iterator& operator=(const typename Container::value_type& value);
180    front_insert_iterator& operator*();
181    front_insert_iterator& operator++();
182    front_insert_iterator  operator++(int);
183};
184
185template <class Container> front_insert_iterator<Container> front_inserter(Container& x);
186
187template <class Container>
188class insert_iterator
189{
190protected:
191    Container* container;
192    typename Container::iterator iter;
193public:
194    typedef Container              container_type;
195    typedef void                   value_type;
196    typedef void                   difference_type;
197    typedef void                   reference;
198    typedef void                   pointer;
199
200    insert_iterator(Container& x, typename Container::iterator i);
201    insert_iterator& operator=(const typename Container::value_type& value);
202    insert_iterator& operator*();
203    insert_iterator& operator++();
204    insert_iterator& operator++(int);
205};
206
207template <class Container, class Iterator>
208insert_iterator<Container> inserter(Container& x, Iterator i);
209
210template <class Iterator>
211class move_iterator {
212public:
213    typedef Iterator                                              iterator_type;
214    typedef typename iterator_traits<Iterator>::difference_type   difference_type;
215    typedef Iterator                                              pointer;
216    typedef typename iterator_traits<Iterator>::value_type        value_type;
217    typedef typename iterator_traits<Iterator>::iterator_category iterator_category;
218    typedef value_type&&                                          reference;
219
220    constexpr move_iterator();  // all the constexprs are in C++17
221    constexpr explicit move_iterator(Iterator i);
222    template <class U>
223      constexpr move_iterator(const move_iterator<U>& u);
224    template <class U>
225      constexpr move_iterator& operator=(const move_iterator<U>& u);
226    constexpr iterator_type base() const;
227    constexpr reference operator*() const;
228    constexpr pointer operator->() const;
229    constexpr move_iterator& operator++();
230    constexpr move_iterator operator++(int);
231    constexpr move_iterator& operator--();
232    constexpr move_iterator operator--(int);
233    constexpr move_iterator operator+(difference_type n) const;
234    constexpr move_iterator& operator+=(difference_type n);
235    constexpr move_iterator operator-(difference_type n) const;
236    constexpr move_iterator& operator-=(difference_type n);
237    constexpr unspecified operator[](difference_type n) const;
238private:
239    Iterator current; // exposition only
240};
241
242template <class Iterator1, class Iterator2>
243constexpr bool   // constexpr in C++17
244operator==(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
245
246template <class Iterator1, class Iterator2>
247constexpr bool   // constexpr in C++17
248operator!=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
249
250template <class Iterator1, class Iterator2>
251constexpr bool   // constexpr in C++17
252operator<(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
253
254template <class Iterator1, class Iterator2>
255constexpr bool   // constexpr in C++17
256operator<=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
257
258template <class Iterator1, class Iterator2>
259constexpr bool   // constexpr in C++17
260operator>(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
261
262template <class Iterator1, class Iterator2>
263constexpr bool   // constexpr in C++17
264operator>=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
265
266template <class Iterator1, class Iterator2>
267constexpr auto   // constexpr in C++17
268operator-(const move_iterator<Iterator1>& x,
269          const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
270
271template <class Iterator>
272constexpr move_iterator<Iterator> operator+(   // constexpr in C++17
273            typename move_iterator<Iterator>::difference_type n,
274            const move_iterator<Iterator>& x);
275
276template <class Iterator>   // constexpr in C++17
277constexpr  move_iterator<Iterator> make_move_iterator(const Iterator& i);
278
279
280template <class T, class charT = char, class traits = char_traits<charT>, class Distance = ptrdiff_t>
281class istream_iterator
282    : public iterator<input_iterator_tag, T, Distance, const T*, const T&>
283{
284public:
285    typedef charT char_type;
286    typedef traits traits_type;
287    typedef basic_istream<charT,traits> istream_type;
288
289    constexpr istream_iterator();
290    istream_iterator(istream_type& s);
291    istream_iterator(const istream_iterator& x);
292    ~istream_iterator();
293
294    const T& operator*() const;
295    const T* operator->() const;
296    istream_iterator& operator++();
297    istream_iterator  operator++(int);
298};
299
300template <class T, class charT, class traits, class Distance>
301bool operator==(const istream_iterator<T,charT,traits,Distance>& x,
302                const istream_iterator<T,charT,traits,Distance>& y);
303template <class T, class charT, class traits, class Distance>
304bool operator!=(const istream_iterator<T,charT,traits,Distance>& x,
305                const istream_iterator<T,charT,traits,Distance>& y);
306
307template <class T, class charT = char, class traits = char_traits<charT> >
308class ostream_iterator
309    : public iterator<output_iterator_tag, void, void, void ,void>
310{
311public:
312    typedef charT char_type;
313    typedef traits traits_type;
314    typedef basic_ostream<charT,traits> ostream_type;
315
316    ostream_iterator(ostream_type& s);
317    ostream_iterator(ostream_type& s, const charT* delimiter);
318    ostream_iterator(const ostream_iterator& x);
319    ~ostream_iterator();
320    ostream_iterator& operator=(const T& value);
321
322    ostream_iterator& operator*();
323    ostream_iterator& operator++();
324    ostream_iterator& operator++(int);
325};
326
327template<class charT, class traits = char_traits<charT> >
328class istreambuf_iterator
329    : public iterator<input_iterator_tag, charT,
330                      typename traits::off_type, unspecified,
331                      charT>
332{
333public:
334    typedef charT                         char_type;
335    typedef traits                        traits_type;
336    typedef typename traits::int_type     int_type;
337    typedef basic_streambuf<charT,traits> streambuf_type;
338    typedef basic_istream<charT,traits>   istream_type;
339
340    istreambuf_iterator() noexcept;
341    istreambuf_iterator(istream_type& s) noexcept;
342    istreambuf_iterator(streambuf_type* s) noexcept;
343    istreambuf_iterator(a-private-type) noexcept;
344
345    charT                operator*() const;
346    pointer operator->() const;
347    istreambuf_iterator& operator++();
348    a-private-type       operator++(int);
349
350    bool equal(const istreambuf_iterator& b) const;
351};
352
353template <class charT, class traits>
354bool operator==(const istreambuf_iterator<charT,traits>& a,
355                const istreambuf_iterator<charT,traits>& b);
356template <class charT, class traits>
357bool operator!=(const istreambuf_iterator<charT,traits>& a,
358                const istreambuf_iterator<charT,traits>& b);
359
360template <class charT, class traits = char_traits<charT> >
361class ostreambuf_iterator
362    : public iterator<output_iterator_tag, void, void, void, void>
363{
364public:
365    typedef charT                         char_type;
366    typedef traits                        traits_type;
367    typedef basic_streambuf<charT,traits> streambuf_type;
368    typedef basic_ostream<charT,traits>   ostream_type;
369
370    ostreambuf_iterator(ostream_type& s) noexcept;
371    ostreambuf_iterator(streambuf_type* s) noexcept;
372    ostreambuf_iterator& operator=(charT c);
373    ostreambuf_iterator& operator*();
374    ostreambuf_iterator& operator++();
375    ostreambuf_iterator& operator++(int);
376    bool failed() const noexcept;
377};
378
379template <class C> constexpr auto begin(C& c) -> decltype(c.begin());
380template <class C> constexpr auto begin(const C& c) -> decltype(c.begin());
381template <class C> constexpr auto end(C& c) -> decltype(c.end());
382template <class C> constexpr auto end(const C& c) -> decltype(c.end());
383template <class T, size_t N> constexpr T* begin(T (&array)[N]);
384template <class T, size_t N> constexpr T* end(T (&array)[N]);
385
386template <class C> auto constexpr cbegin(const C& c) -> decltype(std::begin(c));        // C++14
387template <class C> auto constexpr cend(const C& c) -> decltype(std::end(c));            // C++14
388template <class C> auto constexpr rbegin(C& c) -> decltype(c.rbegin());                 // C++14
389template <class C> auto constexpr rbegin(const C& c) -> decltype(c.rbegin());           // C++14
390template <class C> auto constexpr rend(C& c) -> decltype(c.rend());                     // C++14
391template <class C> constexpr auto rend(const C& c) -> decltype(c.rend());               // C++14
392template <class E> reverse_iterator<const E*> constexpr rbegin(initializer_list<E> il); // C++14
393template <class E> reverse_iterator<const E*> constexpr rend(initializer_list<E> il);   // C++14
394template <class T, size_t N> reverse_iterator<T*> constexpr rbegin(T (&array)[N]);      // C++14
395template <class T, size_t N> reverse_iterator<T*> constexpr rend(T (&array)[N]);        // C++14
396template <class C> constexpr auto crbegin(const C& c) -> decltype(std::rbegin(c));      // C++14
397template <class C> constexpr auto crend(const C& c) -> decltype(std::rend(c));          // C++14
398
399// 24.8, container access:
400template <class C> constexpr auto size(const C& c) -> decltype(c.size());         // C++17
401template <class T, size_t N> constexpr size_t size(const T (&array)[N]) noexcept; // C++17
402
403template <class C> constexpr auto ssize(const C& c)
404    -> common_type_t<ptrdiff_t, make_signed_t<decltype(c.size())>>;				       // C++20
405template <class T, ptrdiff_t> constexpr ptrdiff_t ssize(const T (&array)[N]) noexcept; // C++20
406
407template <class C> constexpr auto empty(const C& c) -> decltype(c.empty());       // C++17
408template <class T, size_t N> constexpr bool empty(const T (&array)[N]) noexcept;  // C++17
409template <class E> constexpr bool empty(initializer_list<E> il) noexcept;         // C++17
410template <class C> constexpr auto data(C& c) -> decltype(c.data());               // C++17
411template <class C> constexpr auto data(const C& c) -> decltype(c.data());         // C++17
412template <class T, size_t N> constexpr T* data(T (&array)[N]) noexcept;           // C++17
413template <class E> constexpr const E* data(initializer_list<E> il) noexcept;      // C++17
414
415}  // std
416
417*/
418
419#include <__config>
420#include <iosfwd> // for forward declarations of vector and string.
421#include <__functional_base>
422#include <type_traits>
423#include <cstddef>
424#include <initializer_list>
425#include <version>
426#ifdef __APPLE__
427#include <Availability.h>
428#endif
429
430#include <__debug>
431
432#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
433#pragma GCC system_header
434#endif
435
436_LIBCPP_BEGIN_NAMESPACE_STD
437
438struct _LIBCPP_TEMPLATE_VIS input_iterator_tag {};
439struct _LIBCPP_TEMPLATE_VIS output_iterator_tag {};
440struct _LIBCPP_TEMPLATE_VIS forward_iterator_tag       : public input_iterator_tag {};
441struct _LIBCPP_TEMPLATE_VIS bidirectional_iterator_tag : public forward_iterator_tag {};
442struct _LIBCPP_TEMPLATE_VIS random_access_iterator_tag : public bidirectional_iterator_tag {};
443
444template <class _Tp>
445struct __has_iterator_typedefs
446{
447private:
448    struct __two {char __lx; char __lxx;};
449    template <class _Up> static __two __test(...);
450    template <class _Up> static char __test(typename std::__void_t<typename _Up::iterator_category>::type* = 0,
451    										typename std::__void_t<typename _Up::difference_type>::type* = 0,
452    										typename std::__void_t<typename _Up::value_type>::type* = 0,
453    										typename std::__void_t<typename _Up::reference>::type* = 0,
454    										typename std::__void_t<typename _Up::pointer>::type* = 0
455    										);
456public:
457    static const bool value = sizeof(__test<_Tp>(0,0,0,0,0)) == 1;
458};
459
460
461template <class _Tp>
462struct __has_iterator_category
463{
464private:
465    struct __two {char __lx; char __lxx;};
466    template <class _Up> static __two __test(...);
467    template <class _Up> static char __test(typename _Up::iterator_category* = 0);
468public:
469    static const bool value = sizeof(__test<_Tp>(0)) == 1;
470};
471
472template <class _Iter, bool> struct __iterator_traits_impl {};
473
474template <class _Iter>
475struct __iterator_traits_impl<_Iter, true>
476{
477    typedef typename _Iter::difference_type   difference_type;
478    typedef typename _Iter::value_type        value_type;
479    typedef typename _Iter::pointer           pointer;
480    typedef typename _Iter::reference         reference;
481    typedef typename _Iter::iterator_category iterator_category;
482};
483
484template <class _Iter, bool> struct __iterator_traits {};
485
486template <class _Iter>
487struct __iterator_traits<_Iter, true>
488    :  __iterator_traits_impl
489      <
490        _Iter,
491        is_convertible<typename _Iter::iterator_category, input_iterator_tag>::value ||
492        is_convertible<typename _Iter::iterator_category, output_iterator_tag>::value
493      >
494{};
495
496// iterator_traits<Iterator> will only have the nested types if Iterator::iterator_category
497//    exists.  Else iterator_traits<Iterator> will be an empty class.  This is a
498//    conforming extension which allows some programs to compile and behave as
499//    the client expects instead of failing at compile time.
500
501template <class _Iter>
502struct _LIBCPP_TEMPLATE_VIS iterator_traits
503    : __iterator_traits<_Iter, __has_iterator_typedefs<_Iter>::value> {};
504
505template<class _Tp>
506struct _LIBCPP_TEMPLATE_VIS iterator_traits<_Tp*>
507{
508    typedef ptrdiff_t difference_type;
509    typedef typename remove_cv<_Tp>::type value_type;
510    typedef _Tp* pointer;
511    typedef _Tp& reference;
512    typedef random_access_iterator_tag iterator_category;
513};
514
515template <class _Tp, class _Up, bool = __has_iterator_category<iterator_traits<_Tp> >::value>
516struct __has_iterator_category_convertible_to
517    : public integral_constant<bool, is_convertible<typename iterator_traits<_Tp>::iterator_category, _Up>::value>
518{};
519
520template <class _Tp, class _Up>
521struct __has_iterator_category_convertible_to<_Tp, _Up, false> : public false_type {};
522
523template <class _Tp>
524struct __is_input_iterator : public __has_iterator_category_convertible_to<_Tp, input_iterator_tag> {};
525
526template <class _Tp>
527struct __is_forward_iterator : public __has_iterator_category_convertible_to<_Tp, forward_iterator_tag> {};
528
529template <class _Tp>
530struct __is_bidirectional_iterator : public __has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag> {};
531
532template <class _Tp>
533struct __is_random_access_iterator : public __has_iterator_category_convertible_to<_Tp, random_access_iterator_tag> {};
534
535template <class _Tp>
536struct __is_exactly_input_iterator
537    : public integral_constant<bool,
538         __has_iterator_category_convertible_to<_Tp, input_iterator_tag>::value &&
539        !__has_iterator_category_convertible_to<_Tp, forward_iterator_tag>::value> {};
540
541template<class _Category, class _Tp, class _Distance = ptrdiff_t,
542         class _Pointer = _Tp*, class _Reference = _Tp&>
543struct _LIBCPP_TEMPLATE_VIS iterator
544{
545    typedef _Tp        value_type;
546    typedef _Distance  difference_type;
547    typedef _Pointer   pointer;
548    typedef _Reference reference;
549    typedef _Category  iterator_category;
550};
551
552template <class _InputIter>
553inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
554void __advance(_InputIter& __i,
555             typename iterator_traits<_InputIter>::difference_type __n, input_iterator_tag)
556{
557    for (; __n > 0; --__n)
558        ++__i;
559}
560
561template <class _BiDirIter>
562inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
563void __advance(_BiDirIter& __i,
564             typename iterator_traits<_BiDirIter>::difference_type __n, bidirectional_iterator_tag)
565{
566    if (__n >= 0)
567        for (; __n > 0; --__n)
568            ++__i;
569    else
570        for (; __n < 0; ++__n)
571            --__i;
572}
573
574template <class _RandIter>
575inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
576void __advance(_RandIter& __i,
577             typename iterator_traits<_RandIter>::difference_type __n, random_access_iterator_tag)
578{
579   __i += __n;
580}
581
582template <class _InputIter>
583inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
584void advance(_InputIter& __i,
585             typename iterator_traits<_InputIter>::difference_type __n)
586{
587    __advance(__i, __n, typename iterator_traits<_InputIter>::iterator_category());
588}
589
590template <class _InputIter>
591inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
592typename iterator_traits<_InputIter>::difference_type
593__distance(_InputIter __first, _InputIter __last, input_iterator_tag)
594{
595    typename iterator_traits<_InputIter>::difference_type __r(0);
596    for (; __first != __last; ++__first)
597        ++__r;
598    return __r;
599}
600
601template <class _RandIter>
602inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
603typename iterator_traits<_RandIter>::difference_type
604__distance(_RandIter __first, _RandIter __last, random_access_iterator_tag)
605{
606    return __last - __first;
607}
608
609template <class _InputIter>
610inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
611typename iterator_traits<_InputIter>::difference_type
612distance(_InputIter __first, _InputIter __last)
613{
614    return __distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category());
615}
616
617template <class _InputIter>
618inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
619typename enable_if
620<
621    __is_input_iterator<_InputIter>::value,
622    _InputIter
623>::type
624next(_InputIter __x,
625     typename iterator_traits<_InputIter>::difference_type __n = 1)
626{
627    _VSTD::advance(__x, __n);
628    return __x;
629}
630
631template <class _BidirectionalIter>
632inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
633typename enable_if
634<
635    __is_bidirectional_iterator<_BidirectionalIter>::value,
636    _BidirectionalIter
637>::type
638prev(_BidirectionalIter __x,
639     typename iterator_traits<_BidirectionalIter>::difference_type __n = 1)
640{
641    _VSTD::advance(__x, -__n);
642    return __x;
643}
644
645
646template <class _Tp, class = void>
647struct __is_stashing_iterator : false_type {};
648
649template <class _Tp>
650struct __is_stashing_iterator<_Tp, typename __void_t<typename _Tp::__stashing_iterator_tag>::type>
651  : true_type {};
652
653template <class _Iter>
654class _LIBCPP_TEMPLATE_VIS reverse_iterator
655    : public iterator<typename iterator_traits<_Iter>::iterator_category,
656                      typename iterator_traits<_Iter>::value_type,
657                      typename iterator_traits<_Iter>::difference_type,
658                      typename iterator_traits<_Iter>::pointer,
659                      typename iterator_traits<_Iter>::reference>
660{
661private:
662    /*mutable*/ _Iter __t;  // no longer used as of LWG #2360, not removed due to ABI break
663
664    static_assert(!__is_stashing_iterator<_Iter>::value,
665      "The specified iterator type cannot be used with reverse_iterator; "
666      "Using stashing iterators with reverse_iterator causes undefined behavior");
667
668protected:
669    _Iter current;
670public:
671    typedef _Iter                                            iterator_type;
672    typedef typename iterator_traits<_Iter>::difference_type difference_type;
673    typedef typename iterator_traits<_Iter>::reference       reference;
674    typedef typename iterator_traits<_Iter>::pointer         pointer;
675
676    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
677    reverse_iterator() : __t(), current() {}
678    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
679    explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}
680    template <class _Up>
681        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
682        reverse_iterator(const reverse_iterator<_Up>& __u) : __t(__u.base()), current(__u.base()) {}
683    template <class _Up>
684        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
685        reverse_iterator& operator=(const reverse_iterator<_Up>& __u)
686            { __t = current = __u.base(); return *this; }
687    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
688    _Iter base() const {return current;}
689    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
690    reference operator*() const {_Iter __tmp = current; return *--__tmp;}
691    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
692    pointer  operator->() const {return _VSTD::addressof(operator*());}
693    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
694    reverse_iterator& operator++() {--current; return *this;}
695    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
696    reverse_iterator  operator++(int) {reverse_iterator __tmp(*this); --current; return __tmp;}
697    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
698    reverse_iterator& operator--() {++current; return *this;}
699    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
700    reverse_iterator  operator--(int) {reverse_iterator __tmp(*this); ++current; return __tmp;}
701    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
702    reverse_iterator  operator+ (difference_type __n) const {return reverse_iterator(current - __n);}
703    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
704    reverse_iterator& operator+=(difference_type __n) {current -= __n; return *this;}
705    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
706    reverse_iterator  operator- (difference_type __n) const {return reverse_iterator(current + __n);}
707    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
708    reverse_iterator& operator-=(difference_type __n) {current += __n; return *this;}
709    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
710    reference         operator[](difference_type __n) const {return *(*this + __n);}
711};
712
713template <class _Iter1, class _Iter2>
714inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
715bool
716operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
717{
718    return __x.base() == __y.base();
719}
720
721template <class _Iter1, class _Iter2>
722inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
723bool
724operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
725{
726    return __x.base() > __y.base();
727}
728
729template <class _Iter1, class _Iter2>
730inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
731bool
732operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
733{
734    return __x.base() != __y.base();
735}
736
737template <class _Iter1, class _Iter2>
738inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
739bool
740operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
741{
742    return __x.base() < __y.base();
743}
744
745template <class _Iter1, class _Iter2>
746inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
747bool
748operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
749{
750    return __x.base() <= __y.base();
751}
752
753template <class _Iter1, class _Iter2>
754inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
755bool
756operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
757{
758    return __x.base() >= __y.base();
759}
760
761#ifndef _LIBCPP_CXX03_LANG
762template <class _Iter1, class _Iter2>
763inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
764auto
765operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
766-> decltype(__y.base() - __x.base())
767{
768    return __y.base() - __x.base();
769}
770#else
771template <class _Iter1, class _Iter2>
772inline _LIBCPP_INLINE_VISIBILITY
773typename reverse_iterator<_Iter1>::difference_type
774operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
775{
776    return __y.base() - __x.base();
777}
778#endif
779
780template <class _Iter>
781inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
782reverse_iterator<_Iter>
783operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x)
784{
785    return reverse_iterator<_Iter>(__x.base() - __n);
786}
787
788#if _LIBCPP_STD_VER > 11
789template <class _Iter>
790inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
791reverse_iterator<_Iter> make_reverse_iterator(_Iter __i)
792{
793    return reverse_iterator<_Iter>(__i);
794}
795#endif
796
797template <class _Container>
798class _LIBCPP_TEMPLATE_VIS back_insert_iterator
799    : public iterator<output_iterator_tag,
800                      void,
801                      void,
802                      void,
803                      void>
804{
805protected:
806    _Container* container;
807public:
808    typedef _Container container_type;
809
810    _LIBCPP_INLINE_VISIBILITY explicit back_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
811    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(const typename _Container::value_type& __value_)
812        {container->push_back(__value_); return *this;}
813#ifndef _LIBCPP_CXX03_LANG
814    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(typename _Container::value_type&& __value_)
815        {container->push_back(_VSTD::move(__value_)); return *this;}
816#endif  // _LIBCPP_CXX03_LANG
817    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator*()     {return *this;}
818    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator++()    {return *this;}
819    _LIBCPP_INLINE_VISIBILITY back_insert_iterator  operator++(int) {return *this;}
820};
821
822template <class _Container>
823inline _LIBCPP_INLINE_VISIBILITY
824back_insert_iterator<_Container>
825back_inserter(_Container& __x)
826{
827    return back_insert_iterator<_Container>(__x);
828}
829
830template <class _Container>
831class _LIBCPP_TEMPLATE_VIS front_insert_iterator
832    : public iterator<output_iterator_tag,
833                      void,
834                      void,
835                      void,
836                      void>
837{
838protected:
839    _Container* container;
840public:
841    typedef _Container container_type;
842
843    _LIBCPP_INLINE_VISIBILITY explicit front_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
844    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(const typename _Container::value_type& __value_)
845        {container->push_front(__value_); return *this;}
846#ifndef _LIBCPP_CXX03_LANG
847    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(typename _Container::value_type&& __value_)
848        {container->push_front(_VSTD::move(__value_)); return *this;}
849#endif  // _LIBCPP_CXX03_LANG
850    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator*()     {return *this;}
851    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator++()    {return *this;}
852    _LIBCPP_INLINE_VISIBILITY front_insert_iterator  operator++(int) {return *this;}
853};
854
855template <class _Container>
856inline _LIBCPP_INLINE_VISIBILITY
857front_insert_iterator<_Container>
858front_inserter(_Container& __x)
859{
860    return front_insert_iterator<_Container>(__x);
861}
862
863template <class _Container>
864class _LIBCPP_TEMPLATE_VIS insert_iterator
865    : public iterator<output_iterator_tag,
866                      void,
867                      void,
868                      void,
869                      void>
870{
871protected:
872    _Container* container;
873    typename _Container::iterator iter;
874public:
875    typedef _Container container_type;
876
877    _LIBCPP_INLINE_VISIBILITY insert_iterator(_Container& __x, typename _Container::iterator __i)
878        : container(_VSTD::addressof(__x)), iter(__i) {}
879    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(const typename _Container::value_type& __value_)
880        {iter = container->insert(iter, __value_); ++iter; return *this;}
881#ifndef _LIBCPP_CXX03_LANG
882    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(typename _Container::value_type&& __value_)
883        {iter = container->insert(iter, _VSTD::move(__value_)); ++iter; return *this;}
884#endif  // _LIBCPP_CXX03_LANG
885    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator*()        {return *this;}
886    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++()       {return *this;}
887    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++(int)    {return *this;}
888};
889
890template <class _Container>
891inline _LIBCPP_INLINE_VISIBILITY
892insert_iterator<_Container>
893inserter(_Container& __x, typename _Container::iterator __i)
894{
895    return insert_iterator<_Container>(__x, __i);
896}
897
898template <class _Tp, class _CharT = char,
899          class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
900class _LIBCPP_TEMPLATE_VIS istream_iterator
901    : public iterator<input_iterator_tag, _Tp, _Distance, const _Tp*, const _Tp&>
902{
903public:
904    typedef _CharT char_type;
905    typedef _Traits traits_type;
906    typedef basic_istream<_CharT,_Traits> istream_type;
907private:
908    istream_type* __in_stream_;
909    _Tp __value_;
910public:
911    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istream_iterator() : __in_stream_(0), __value_() {}
912    _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s) : __in_stream_(_VSTD::addressof(__s))
913        {
914            if (!(*__in_stream_ >> __value_))
915                __in_stream_ = 0;
916        }
917
918    _LIBCPP_INLINE_VISIBILITY const _Tp& operator*() const {return __value_;}
919    _LIBCPP_INLINE_VISIBILITY const _Tp* operator->() const {return _VSTD::addressof((operator*()));}
920    _LIBCPP_INLINE_VISIBILITY istream_iterator& operator++()
921        {
922            if (!(*__in_stream_ >> __value_))
923                __in_stream_ = 0;
924            return *this;
925        }
926    _LIBCPP_INLINE_VISIBILITY istream_iterator  operator++(int)
927        {istream_iterator __t(*this); ++(*this); return __t;}
928
929    template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
930    friend _LIBCPP_INLINE_VISIBILITY
931    bool
932    operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
933               const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
934
935    template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
936    friend _LIBCPP_INLINE_VISIBILITY
937    bool
938    operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
939               const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
940};
941
942template <class _Tp, class _CharT, class _Traits, class _Distance>
943inline _LIBCPP_INLINE_VISIBILITY
944bool
945operator==(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
946           const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
947{
948    return __x.__in_stream_ == __y.__in_stream_;
949}
950
951template <class _Tp, class _CharT, class _Traits, class _Distance>
952inline _LIBCPP_INLINE_VISIBILITY
953bool
954operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
955           const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
956{
957    return !(__x == __y);
958}
959
960template <class _Tp, class _CharT = char, class _Traits = char_traits<_CharT> >
961class _LIBCPP_TEMPLATE_VIS ostream_iterator
962    : public iterator<output_iterator_tag, void, void, void, void>
963{
964public:
965    typedef _CharT char_type;
966    typedef _Traits traits_type;
967    typedef basic_ostream<_CharT,_Traits> ostream_type;
968private:
969    ostream_type* __out_stream_;
970    const char_type* __delim_;
971public:
972    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s) _NOEXCEPT
973        : __out_stream_(_VSTD::addressof(__s)), __delim_(0) {}
974    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s, const _CharT* __delimiter) _NOEXCEPT
975        : __out_stream_(_VSTD::addressof(__s)), __delim_(__delimiter) {}
976    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator=(const _Tp& __value_)
977        {
978            *__out_stream_ << __value_;
979            if (__delim_)
980                *__out_stream_ << __delim_;
981            return *this;
982        }
983
984    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator*()     {return *this;}
985    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++()    {return *this;}
986    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++(int) {return *this;}
987};
988
989template<class _CharT, class _Traits>
990class _LIBCPP_TEMPLATE_VIS istreambuf_iterator
991    : public iterator<input_iterator_tag, _CharT,
992                      typename _Traits::off_type, _CharT*,
993                      _CharT>
994{
995public:
996    typedef _CharT                          char_type;
997    typedef _Traits                         traits_type;
998    typedef typename _Traits::int_type      int_type;
999    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
1000    typedef basic_istream<_CharT,_Traits>   istream_type;
1001private:
1002    mutable streambuf_type* __sbuf_;
1003
1004    class __proxy
1005    {
1006        char_type __keep_;
1007        streambuf_type* __sbuf_;
1008        _LIBCPP_INLINE_VISIBILITY __proxy(char_type __c, streambuf_type* __s)
1009            : __keep_(__c), __sbuf_(__s) {}
1010        friend class istreambuf_iterator;
1011    public:
1012        _LIBCPP_INLINE_VISIBILITY char_type operator*() const {return __keep_;}
1013    };
1014
1015    _LIBCPP_INLINE_VISIBILITY
1016    bool __test_for_eof() const
1017    {
1018        if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
1019            __sbuf_ = 0;
1020        return __sbuf_ == 0;
1021    }
1022public:
1023    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(0) {}
1024    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(istream_type& __s) _NOEXCEPT
1025        : __sbuf_(__s.rdbuf()) {}
1026    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(streambuf_type* __s) _NOEXCEPT
1027        : __sbuf_(__s) {}
1028    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(const __proxy& __p) _NOEXCEPT
1029        : __sbuf_(__p.__sbuf_) {}
1030
1031    _LIBCPP_INLINE_VISIBILITY char_type  operator*() const
1032        {return static_cast<char_type>(__sbuf_->sgetc());}
1033    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator& operator++()
1034        {
1035            __sbuf_->sbumpc();
1036            return *this;
1037        }
1038    _LIBCPP_INLINE_VISIBILITY __proxy              operator++(int)
1039        {
1040            return __proxy(__sbuf_->sbumpc(), __sbuf_);
1041        }
1042
1043    _LIBCPP_INLINE_VISIBILITY bool equal(const istreambuf_iterator& __b) const
1044        {return __test_for_eof() == __b.__test_for_eof();}
1045};
1046
1047template <class _CharT, class _Traits>
1048inline _LIBCPP_INLINE_VISIBILITY
1049bool operator==(const istreambuf_iterator<_CharT,_Traits>& __a,
1050                const istreambuf_iterator<_CharT,_Traits>& __b)
1051                {return __a.equal(__b);}
1052
1053template <class _CharT, class _Traits>
1054inline _LIBCPP_INLINE_VISIBILITY
1055bool operator!=(const istreambuf_iterator<_CharT,_Traits>& __a,
1056                const istreambuf_iterator<_CharT,_Traits>& __b)
1057                {return !__a.equal(__b);}
1058
1059template <class _CharT, class _Traits>
1060class _LIBCPP_TEMPLATE_VIS ostreambuf_iterator
1061    : public iterator<output_iterator_tag, void, void, void, void>
1062{
1063public:
1064    typedef _CharT                          char_type;
1065    typedef _Traits                         traits_type;
1066    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
1067    typedef basic_ostream<_CharT,_Traits>   ostream_type;
1068private:
1069    streambuf_type* __sbuf_;
1070public:
1071    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(ostream_type& __s) _NOEXCEPT
1072        : __sbuf_(__s.rdbuf()) {}
1073    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(streambuf_type* __s) _NOEXCEPT
1074        : __sbuf_(__s) {}
1075    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator=(_CharT __c)
1076        {
1077            if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sputc(__c), traits_type::eof()))
1078                __sbuf_ = 0;
1079            return *this;
1080        }
1081    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator*()     {return *this;}
1082    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++()    {return *this;}
1083    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++(int) {return *this;}
1084    _LIBCPP_INLINE_VISIBILITY bool failed() const _NOEXCEPT {return __sbuf_ == 0;}
1085
1086#if !defined(__APPLE__) || \
1087    (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED > __MAC_10_8) || \
1088    (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && __IPHONE_OS_VERSION_MIN_REQUIRED > __IPHONE_6_0)
1089
1090    template <class _Ch, class _Tr>
1091    friend
1092    _LIBCPP_HIDDEN
1093    ostreambuf_iterator<_Ch, _Tr>
1094    __pad_and_output(ostreambuf_iterator<_Ch, _Tr> __s,
1095                     const _Ch* __ob, const _Ch* __op, const _Ch* __oe,
1096                     ios_base& __iob, _Ch __fl);
1097#endif
1098};
1099
1100template <class _Iter>
1101class _LIBCPP_TEMPLATE_VIS move_iterator
1102{
1103private:
1104    _Iter __i;
1105public:
1106    typedef _Iter                                            iterator_type;
1107    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
1108    typedef typename iterator_traits<iterator_type>::value_type value_type;
1109    typedef typename iterator_traits<iterator_type>::difference_type difference_type;
1110    typedef iterator_type pointer;
1111#ifndef _LIBCPP_CXX03_LANG
1112    typedef typename iterator_traits<iterator_type>::reference __reference;
1113    typedef typename conditional<
1114            is_reference<__reference>::value,
1115            typename remove_reference<__reference>::type&&,
1116            __reference
1117        >::type reference;
1118#else
1119    typedef typename iterator_traits<iterator_type>::reference reference;
1120#endif
1121
1122    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1123    move_iterator() : __i() {}
1124    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1125    explicit move_iterator(_Iter __x) : __i(__x) {}
1126    template <class _Up>
1127      _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1128      move_iterator(const move_iterator<_Up>& __u) : __i(__u.base()) {}
1129    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 _Iter base() const {return __i;}
1130    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1131    reference operator*() const { return static_cast<reference>(*__i); }
1132    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1133    pointer  operator->() const { return __i;}
1134    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1135    move_iterator& operator++() {++__i; return *this;}
1136    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1137    move_iterator  operator++(int) {move_iterator __tmp(*this); ++__i; return __tmp;}
1138    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1139    move_iterator& operator--() {--__i; return *this;}
1140    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1141    move_iterator  operator--(int) {move_iterator __tmp(*this); --__i; return __tmp;}
1142    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1143    move_iterator  operator+ (difference_type __n) const {return move_iterator(__i + __n);}
1144    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1145    move_iterator& operator+=(difference_type __n) {__i += __n; return *this;}
1146    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1147    move_iterator  operator- (difference_type __n) const {return move_iterator(__i - __n);}
1148    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1149    move_iterator& operator-=(difference_type __n) {__i -= __n; return *this;}
1150    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1151    reference operator[](difference_type __n) const { return static_cast<reference>(__i[__n]); }
1152};
1153
1154template <class _Iter1, class _Iter2>
1155inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1156bool
1157operator==(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1158{
1159    return __x.base() == __y.base();
1160}
1161
1162template <class _Iter1, class _Iter2>
1163inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1164bool
1165operator<(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1166{
1167    return __x.base() < __y.base();
1168}
1169
1170template <class _Iter1, class _Iter2>
1171inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1172bool
1173operator!=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1174{
1175    return __x.base() != __y.base();
1176}
1177
1178template <class _Iter1, class _Iter2>
1179inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1180bool
1181operator>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1182{
1183    return __x.base() > __y.base();
1184}
1185
1186template <class _Iter1, class _Iter2>
1187inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1188bool
1189operator>=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1190{
1191    return __x.base() >= __y.base();
1192}
1193
1194template <class _Iter1, class _Iter2>
1195inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1196bool
1197operator<=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1198{
1199    return __x.base() <= __y.base();
1200}
1201
1202#ifndef _LIBCPP_CXX03_LANG
1203template <class _Iter1, class _Iter2>
1204inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1205auto
1206operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1207-> decltype(__x.base() - __y.base())
1208{
1209    return __x.base() - __y.base();
1210}
1211#else
1212template <class _Iter1, class _Iter2>
1213inline _LIBCPP_INLINE_VISIBILITY
1214typename move_iterator<_Iter1>::difference_type
1215operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
1216{
1217    return __x.base() - __y.base();
1218}
1219#endif
1220
1221template <class _Iter>
1222inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1223move_iterator<_Iter>
1224operator+(typename move_iterator<_Iter>::difference_type __n, const move_iterator<_Iter>& __x)
1225{
1226    return move_iterator<_Iter>(__x.base() + __n);
1227}
1228
1229template <class _Iter>
1230inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1231move_iterator<_Iter>
1232make_move_iterator(_Iter __i)
1233{
1234    return move_iterator<_Iter>(__i);
1235}
1236
1237// __wrap_iter
1238
1239template <class _Iter> class __wrap_iter;
1240
1241template <class _Iter1, class _Iter2>
1242_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1243bool
1244operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1245
1246template <class _Iter1, class _Iter2>
1247_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1248bool
1249operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1250
1251template <class _Iter1, class _Iter2>
1252_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1253bool
1254operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1255
1256template <class _Iter1, class _Iter2>
1257_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1258bool
1259operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1260
1261template <class _Iter1, class _Iter2>
1262_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1263bool
1264operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1265
1266template <class _Iter1, class _Iter2>
1267_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1268bool
1269operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1270
1271#ifndef _LIBCPP_CXX03_LANG
1272template <class _Iter1, class _Iter2>
1273_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1274auto
1275operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1276-> decltype(__x.base() - __y.base());
1277#else
1278template <class _Iter1, class _Iter2>
1279_LIBCPP_INLINE_VISIBILITY
1280typename __wrap_iter<_Iter1>::difference_type
1281operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1282#endif
1283
1284template <class _Iter>
1285_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1286__wrap_iter<_Iter>
1287operator+(typename __wrap_iter<_Iter>::difference_type, __wrap_iter<_Iter>) _NOEXCEPT;
1288
1289template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY copy(_Ip, _Ip, _Op);
1290template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY copy_backward(_B1, _B1, _B2);
1291template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY move(_Ip, _Ip, _Op);
1292template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY move_backward(_B1, _B1, _B2);
1293
1294#if _LIBCPP_DEBUG_LEVEL < 2
1295
1296template <class _Tp>
1297_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1298typename enable_if
1299<
1300    is_trivially_copy_assignable<_Tp>::value,
1301    _Tp*
1302>::type
1303__unwrap_iter(__wrap_iter<_Tp*>);
1304
1305#else
1306
1307template <class _Tp>
1308inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1309typename enable_if
1310<
1311    is_trivially_copy_assignable<_Tp>::value,
1312    __wrap_iter<_Tp*>
1313>::type
1314__unwrap_iter(__wrap_iter<_Tp*> __i);
1315
1316#endif
1317
1318template <class _Iter>
1319class __wrap_iter
1320{
1321public:
1322    typedef _Iter                                                      iterator_type;
1323    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
1324    typedef typename iterator_traits<iterator_type>::value_type        value_type;
1325    typedef typename iterator_traits<iterator_type>::difference_type   difference_type;
1326    typedef typename iterator_traits<iterator_type>::pointer           pointer;
1327    typedef typename iterator_traits<iterator_type>::reference         reference;
1328private:
1329    iterator_type __i;
1330public:
1331    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter() _NOEXCEPT
1332#if _LIBCPP_STD_VER > 11
1333                : __i{}
1334#endif
1335    {
1336#if _LIBCPP_DEBUG_LEVEL >= 2
1337        __get_db()->__insert_i(this);
1338#endif
1339    }
1340    template <class _Up> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1341        __wrap_iter(const __wrap_iter<_Up>& __u,
1342            typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = 0) _NOEXCEPT
1343            : __i(__u.base())
1344    {
1345#if _LIBCPP_DEBUG_LEVEL >= 2
1346        __get_db()->__iterator_copy(this, &__u);
1347#endif
1348    }
1349#if _LIBCPP_DEBUG_LEVEL >= 2
1350    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1351    __wrap_iter(const __wrap_iter& __x)
1352        : __i(__x.base())
1353    {
1354        __get_db()->__iterator_copy(this, &__x);
1355    }
1356    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1357    __wrap_iter& operator=(const __wrap_iter& __x)
1358    {
1359        if (this != &__x)
1360        {
1361            __get_db()->__iterator_copy(this, &__x);
1362            __i = __x.__i;
1363        }
1364        return *this;
1365    }
1366    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1367    ~__wrap_iter()
1368    {
1369        __get_db()->__erase_i(this);
1370    }
1371#endif
1372    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference operator*() const _NOEXCEPT
1373    {
1374#if _LIBCPP_DEBUG_LEVEL >= 2
1375        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1376                       "Attempted to dereference a non-dereferenceable iterator");
1377#endif
1378        return *__i;
1379    }
1380    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG pointer  operator->() const _NOEXCEPT
1381    {
1382#if _LIBCPP_DEBUG_LEVEL >= 2
1383        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1384                       "Attempted to dereference a non-dereferenceable iterator");
1385#endif
1386        return (pointer)_VSTD::addressof(*__i);
1387    }
1388    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator++() _NOEXCEPT
1389    {
1390#if _LIBCPP_DEBUG_LEVEL >= 2
1391        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
1392                       "Attempted to increment non-incrementable iterator");
1393#endif
1394        ++__i;
1395        return *this;
1396    }
1397    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator++(int) _NOEXCEPT
1398        {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
1399
1400    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator--() _NOEXCEPT
1401    {
1402#if _LIBCPP_DEBUG_LEVEL >= 2
1403        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
1404                       "Attempted to decrement non-decrementable iterator");
1405#endif
1406        --__i;
1407        return *this;
1408    }
1409    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator--(int) _NOEXCEPT
1410        {__wrap_iter __tmp(*this); --(*this); return __tmp;}
1411    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT
1412        {__wrap_iter __w(*this); __w += __n; return __w;}
1413    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator+=(difference_type __n) _NOEXCEPT
1414    {
1415#if _LIBCPP_DEBUG_LEVEL >= 2
1416        _LIBCPP_ASSERT(__get_const_db()->__addable(this, __n),
1417                   "Attempted to add/subtract iterator outside of valid range");
1418#endif
1419        __i += __n;
1420        return *this;
1421    }
1422    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator- (difference_type __n) const _NOEXCEPT
1423        {return *this + (-__n);}
1424    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator-=(difference_type __n) _NOEXCEPT
1425        {*this += -__n; return *this;}
1426    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference    operator[](difference_type __n) const _NOEXCEPT
1427    {
1428#if _LIBCPP_DEBUG_LEVEL >= 2
1429        _LIBCPP_ASSERT(__get_const_db()->__subscriptable(this, __n),
1430                   "Attempted to subscript iterator outside of valid range");
1431#endif
1432        return __i[__n];
1433    }
1434
1435    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG iterator_type base() const _NOEXCEPT {return __i;}
1436
1437private:
1438#if _LIBCPP_DEBUG_LEVEL >= 2
1439    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(const void* __p, iterator_type __x) : __i(__x)
1440    {
1441        __get_db()->__insert_ic(this, __p);
1442    }
1443#else
1444    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(iterator_type __x) _NOEXCEPT : __i(__x) {}
1445#endif
1446
1447    template <class _Up> friend class __wrap_iter;
1448    template <class _CharT, class _Traits, class _Alloc> friend class basic_string;
1449    template <class _Tp, class _Alloc> friend class _LIBCPP_TEMPLATE_VIS vector;
1450    template <class _Tp, size_t> friend class _LIBCPP_TEMPLATE_VIS span;
1451
1452    template <class _Iter1, class _Iter2>
1453    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1454    bool
1455    operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1456
1457    template <class _Iter1, class _Iter2>
1458    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1459    bool
1460    operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1461
1462    template <class _Iter1, class _Iter2>
1463    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1464    bool
1465    operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1466
1467    template <class _Iter1, class _Iter2>
1468    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1469    bool
1470    operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1471
1472    template <class _Iter1, class _Iter2>
1473    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1474    bool
1475    operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1476
1477    template <class _Iter1, class _Iter2>
1478    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1479    bool
1480    operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1481
1482#ifndef _LIBCPP_CXX03_LANG
1483    template <class _Iter1, class _Iter2>
1484    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1485    auto
1486    operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1487    -> decltype(__x.base() - __y.base());
1488#else
1489    template <class _Iter1, class _Iter2>
1490    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1491    typename __wrap_iter<_Iter1>::difference_type
1492    operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
1493#endif
1494
1495    template <class _Iter1>
1496    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1497    __wrap_iter<_Iter1>
1498    operator+(typename __wrap_iter<_Iter1>::difference_type, __wrap_iter<_Iter1>) _NOEXCEPT;
1499
1500    template <class _Ip, class _Op> friend _Op copy(_Ip, _Ip, _Op);
1501    template <class _B1, class _B2> friend _B2 copy_backward(_B1, _B1, _B2);
1502    template <class _Ip, class _Op> friend _Op move(_Ip, _Ip, _Op);
1503    template <class _B1, class _B2> friend _B2 move_backward(_B1, _B1, _B2);
1504
1505#if _LIBCPP_DEBUG_LEVEL < 2
1506    template <class _Tp>
1507    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
1508    typename enable_if
1509    <
1510        is_trivially_copy_assignable<_Tp>::value,
1511        _Tp*
1512    >::type
1513    __unwrap_iter(__wrap_iter<_Tp*>);
1514#else
1515  template <class _Tp>
1516  inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1517  typename enable_if
1518  <
1519      is_trivially_copy_assignable<_Tp>::value,
1520      __wrap_iter<_Tp*>
1521  >::type
1522  __unwrap_iter(__wrap_iter<_Tp*> __i);
1523#endif
1524};
1525
1526template <class _Iter1, class _Iter2>
1527inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1528bool
1529operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1530{
1531    return __x.base() == __y.base();
1532}
1533
1534template <class _Iter1, class _Iter2>
1535inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1536bool
1537operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1538{
1539#if _LIBCPP_DEBUG_LEVEL >= 2
1540    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1541                   "Attempted to compare incomparable iterators");
1542#endif
1543    return __x.base() < __y.base();
1544}
1545
1546template <class _Iter1, class _Iter2>
1547inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1548bool
1549operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1550{
1551    return !(__x == __y);
1552}
1553
1554template <class _Iter1, class _Iter2>
1555inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1556bool
1557operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1558{
1559    return __y < __x;
1560}
1561
1562template <class _Iter1, class _Iter2>
1563inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1564bool
1565operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1566{
1567    return !(__x < __y);
1568}
1569
1570template <class _Iter1, class _Iter2>
1571inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1572bool
1573operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1574{
1575    return !(__y < __x);
1576}
1577
1578template <class _Iter1>
1579inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1580bool
1581operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
1582{
1583    return !(__x == __y);
1584}
1585
1586template <class _Iter1>
1587inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1588bool
1589operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
1590{
1591    return __y < __x;
1592}
1593
1594template <class _Iter1>
1595inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1596bool
1597operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
1598{
1599    return !(__x < __y);
1600}
1601
1602template <class _Iter1>
1603inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1604bool
1605operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
1606{
1607    return !(__y < __x);
1608}
1609
1610#ifndef _LIBCPP_CXX03_LANG
1611template <class _Iter1, class _Iter2>
1612inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1613auto
1614operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1615-> decltype(__x.base() - __y.base())
1616{
1617#if _LIBCPP_DEBUG_LEVEL >= 2
1618    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1619                   "Attempted to subtract incompatible iterators");
1620#endif
1621    return __x.base() - __y.base();
1622}
1623#else
1624template <class _Iter1, class _Iter2>
1625inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1626typename __wrap_iter<_Iter1>::difference_type
1627operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
1628{
1629#if _LIBCPP_DEBUG_LEVEL >= 2
1630    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
1631                   "Attempted to subtract incompatible iterators");
1632#endif
1633    return __x.base() - __y.base();
1634}
1635#endif
1636
1637template <class _Iter>
1638inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
1639__wrap_iter<_Iter>
1640operator+(typename __wrap_iter<_Iter>::difference_type __n,
1641          __wrap_iter<_Iter> __x) _NOEXCEPT
1642{
1643    __x += __n;
1644    return __x;
1645}
1646
1647template <class _Iter>
1648struct __libcpp_is_trivial_iterator
1649    : public _LIBCPP_BOOL_CONSTANT(is_pointer<_Iter>::value) {};
1650
1651template <class _Iter>
1652struct __libcpp_is_trivial_iterator<move_iterator<_Iter> >
1653    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1654
1655template <class _Iter>
1656struct __libcpp_is_trivial_iterator<reverse_iterator<_Iter> >
1657    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1658
1659template <class _Iter>
1660struct __libcpp_is_trivial_iterator<__wrap_iter<_Iter> >
1661    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
1662
1663
1664template <class _Tp, size_t _Np>
1665_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1666_Tp*
1667begin(_Tp (&__array)[_Np])
1668{
1669    return __array;
1670}
1671
1672template <class _Tp, size_t _Np>
1673_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1674_Tp*
1675end(_Tp (&__array)[_Np])
1676{
1677    return __array + _Np;
1678}
1679
1680#if !defined(_LIBCPP_CXX03_LANG)
1681
1682template <class _Cp>
1683_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1684auto
1685begin(_Cp& __c) -> decltype(__c.begin())
1686{
1687    return __c.begin();
1688}
1689
1690template <class _Cp>
1691_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1692auto
1693begin(const _Cp& __c) -> decltype(__c.begin())
1694{
1695    return __c.begin();
1696}
1697
1698template <class _Cp>
1699_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1700auto
1701end(_Cp& __c) -> decltype(__c.end())
1702{
1703    return __c.end();
1704}
1705
1706template <class _Cp>
1707_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1708auto
1709end(const _Cp& __c) -> decltype(__c.end())
1710{
1711    return __c.end();
1712}
1713
1714#if _LIBCPP_STD_VER > 11
1715
1716template <class _Tp, size_t _Np>
1717_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1718reverse_iterator<_Tp*> rbegin(_Tp (&__array)[_Np])
1719{
1720    return reverse_iterator<_Tp*>(__array + _Np);
1721}
1722
1723template <class _Tp, size_t _Np>
1724_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1725reverse_iterator<_Tp*> rend(_Tp (&__array)[_Np])
1726{
1727    return reverse_iterator<_Tp*>(__array);
1728}
1729
1730template <class _Ep>
1731_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1732reverse_iterator<const _Ep*> rbegin(initializer_list<_Ep> __il)
1733{
1734    return reverse_iterator<const _Ep*>(__il.end());
1735}
1736
1737template <class _Ep>
1738_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1739reverse_iterator<const _Ep*> rend(initializer_list<_Ep> __il)
1740{
1741    return reverse_iterator<const _Ep*>(__il.begin());
1742}
1743
1744template <class _Cp>
1745_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1746auto cbegin(const _Cp& __c) -> decltype(_VSTD::begin(__c))
1747{
1748    return _VSTD::begin(__c);
1749}
1750
1751template <class _Cp>
1752_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
1753auto cend(const _Cp& __c) -> decltype(_VSTD::end(__c))
1754{
1755    return _VSTD::end(__c);
1756}
1757
1758template <class _Cp>
1759_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1760auto rbegin(_Cp& __c) -> decltype(__c.rbegin())
1761{
1762    return __c.rbegin();
1763}
1764
1765template <class _Cp>
1766_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1767auto rbegin(const _Cp& __c) -> decltype(__c.rbegin())
1768{
1769    return __c.rbegin();
1770}
1771
1772template <class _Cp>
1773_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1774auto rend(_Cp& __c) -> decltype(__c.rend())
1775{
1776    return __c.rend();
1777}
1778
1779template <class _Cp>
1780_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1781auto rend(const _Cp& __c) -> decltype(__c.rend())
1782{
1783    return __c.rend();
1784}
1785
1786template <class _Cp>
1787_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1788auto crbegin(const _Cp& __c) -> decltype(_VSTD::rbegin(__c))
1789{
1790    return _VSTD::rbegin(__c);
1791}
1792
1793template <class _Cp>
1794_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1795auto crend(const _Cp& __c) -> decltype(_VSTD::rend(__c))
1796{
1797    return _VSTD::rend(__c);
1798}
1799
1800#endif
1801
1802
1803#else  // defined(_LIBCPP_CXX03_LANG)
1804
1805template <class _Cp>
1806_LIBCPP_INLINE_VISIBILITY
1807typename _Cp::iterator
1808begin(_Cp& __c)
1809{
1810    return __c.begin();
1811}
1812
1813template <class _Cp>
1814_LIBCPP_INLINE_VISIBILITY
1815typename _Cp::const_iterator
1816begin(const _Cp& __c)
1817{
1818    return __c.begin();
1819}
1820
1821template <class _Cp>
1822_LIBCPP_INLINE_VISIBILITY
1823typename _Cp::iterator
1824end(_Cp& __c)
1825{
1826    return __c.end();
1827}
1828
1829template <class _Cp>
1830_LIBCPP_INLINE_VISIBILITY
1831typename _Cp::const_iterator
1832end(const _Cp& __c)
1833{
1834    return __c.end();
1835}
1836
1837#endif  // !defined(_LIBCPP_CXX03_LANG)
1838
1839#if _LIBCPP_STD_VER > 14
1840
1841// #if _LIBCPP_STD_VER > 11
1842// template <>
1843// struct _LIBCPP_TEMPLATE_VIS plus<void>
1844// {
1845//     template <class _T1, class _T2>
1846//     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
1847//     auto operator()(_T1&& __t, _T2&& __u) const
1848//     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
1849//     -> decltype        (_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
1850//         { return        _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
1851//     typedef void is_transparent;
1852// };
1853// #endif
1854
1855template <class _Cont>
1856_LIBCPP_INLINE_VISIBILITY
1857constexpr auto size(const _Cont& __c)
1858_NOEXCEPT_(noexcept(__c.size()))
1859-> decltype        (__c.size())
1860{ return            __c.size(); }
1861
1862template <class _Tp, size_t _Sz>
1863_LIBCPP_INLINE_VISIBILITY
1864constexpr size_t size(const _Tp (&)[_Sz]) noexcept { return _Sz; }
1865
1866#if _LIBCPP_STD_VER > 17
1867template <class _Cont>
1868_LIBCPP_INLINE_VISIBILITY
1869constexpr auto ssize(const _Cont& __c)
1870_NOEXCEPT_(noexcept(static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size())))
1871->                              common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>
1872{ return            static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size()); }
1873
1874template <class _Tp, ptrdiff_t _Sz>
1875_LIBCPP_INLINE_VISIBILITY
1876constexpr ptrdiff_t ssize(const _Tp (&)[_Sz]) noexcept { return _Sz; }
1877#endif
1878
1879template <class _Cont>
1880_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1881constexpr auto empty(const _Cont& __c)
1882_NOEXCEPT_(noexcept(__c.empty()))
1883-> decltype        (__c.empty())
1884{ return            __c.empty(); }
1885
1886template <class _Tp, size_t _Sz>
1887_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1888constexpr bool empty(const _Tp (&)[_Sz]) noexcept { return false; }
1889
1890template <class _Ep>
1891_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1892constexpr bool empty(initializer_list<_Ep> __il) noexcept { return __il.size() == 0; }
1893
1894template <class _Cont> constexpr
1895_LIBCPP_INLINE_VISIBILITY
1896auto data(_Cont& __c)
1897_NOEXCEPT_(noexcept(__c.data()))
1898-> decltype        (__c.data())
1899{ return            __c.data(); }
1900
1901template <class _Cont> constexpr
1902_LIBCPP_INLINE_VISIBILITY
1903auto data(const _Cont& __c)
1904_NOEXCEPT_(noexcept(__c.data()))
1905-> decltype        (__c.data())
1906{ return            __c.data(); }
1907
1908template <class _Tp, size_t _Sz>
1909_LIBCPP_INLINE_VISIBILITY
1910constexpr _Tp* data(_Tp (&__array)[_Sz]) noexcept { return __array; }
1911
1912template <class _Ep>
1913_LIBCPP_INLINE_VISIBILITY
1914constexpr const _Ep* data(initializer_list<_Ep> __il) noexcept { return __il.begin(); }
1915#endif
1916
1917
1918_LIBCPP_END_NAMESPACE_STD
1919
1920#endif  // _LIBCPP_ITERATOR
1921