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