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