xref: /llvm-project-15.0.7/libcxx/include/deque (revision 052d95a6)
1// -*- C++ -*-
2//===---------------------------- deque -----------------------------------===//
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_DEQUE
12#define _LIBCPP_DEQUE
13
14/*
15    deque synopsis
16
17namespace std
18{
19
20template <class T, class Allocator = allocator<T> >
21class deque
22{
23public:
24    // types:
25    typedef T value_type;
26    typedef Allocator allocator_type;
27
28    typedef typename allocator_type::reference       reference;
29    typedef typename allocator_type::const_reference const_reference;
30    typedef implementation-defined                   iterator;
31    typedef implementation-defined                   const_iterator;
32    typedef typename allocator_type::size_type       size_type;
33    typedef typename allocator_type::difference_type difference_type;
34
35    typedef typename allocator_type::pointer         pointer;
36    typedef typename allocator_type::const_pointer   const_pointer;
37    typedef std::reverse_iterator<iterator>          reverse_iterator;
38    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
39
40    // construct/copy/destroy:
41    deque() noexcept(is_nothrow_default_constructible<allocator_type>::value);
42    explicit deque(const allocator_type& a);
43    explicit deque(size_type n);
44    explicit deque(size_type n, const allocator_type& a); // C++14
45    deque(size_type n, const value_type& v);
46    deque(size_type n, const value_type& v, const allocator_type& a);
47    template <class InputIterator>
48        deque(InputIterator f, InputIterator l);
49    template <class InputIterator>
50        deque(InputIterator f, InputIterator l, const allocator_type& a);
51    deque(const deque& c);
52    deque(deque&& c)
53        noexcept(is_nothrow_move_constructible<allocator_type>::value);
54    deque(initializer_list<value_type> il, const Allocator& a = allocator_type());
55    deque(const deque& c, const allocator_type& a);
56    deque(deque&& c, const allocator_type& a);
57    ~deque();
58
59    deque& operator=(const deque& c);
60    deque& operator=(deque&& c)
61        noexcept(
62             allocator_type::propagate_on_container_move_assignment::value &&
63             is_nothrow_move_assignable<allocator_type>::value);
64    deque& operator=(initializer_list<value_type> il);
65
66    template <class InputIterator>
67        void assign(InputIterator f, InputIterator l);
68    void assign(size_type n, const value_type& v);
69    void assign(initializer_list<value_type> il);
70
71    allocator_type get_allocator() const noexcept;
72
73    // iterators:
74
75    iterator       begin() noexcept;
76    const_iterator begin() const noexcept;
77    iterator       end() noexcept;
78    const_iterator end() const noexcept;
79
80    reverse_iterator       rbegin() noexcept;
81    const_reverse_iterator rbegin() const noexcept;
82    reverse_iterator       rend() noexcept;
83    const_reverse_iterator rend() const noexcept;
84
85    const_iterator         cbegin() const noexcept;
86    const_iterator         cend() const noexcept;
87    const_reverse_iterator crbegin() const noexcept;
88    const_reverse_iterator crend() const noexcept;
89
90    // capacity:
91    size_type size() const noexcept;
92    size_type max_size() const noexcept;
93    void resize(size_type n);
94    void resize(size_type n, const value_type& v);
95    void shrink_to_fit();
96    bool empty() const noexcept;
97
98    // element access:
99    reference operator[](size_type i);
100    const_reference operator[](size_type i) const;
101    reference at(size_type i);
102    const_reference at(size_type i) const;
103    reference front();
104    const_reference front() const;
105    reference back();
106    const_reference back() const;
107
108    // modifiers:
109    void push_front(const value_type& v);
110    void push_front(value_type&& v);
111    void push_back(const value_type& v);
112    void push_back(value_type&& v);
113    template <class... Args> reference emplace_front(Args&&... args);
114    template <class... Args> reference emplace_back(Args&&... args);
115    template <class... Args> iterator emplace(const_iterator p, Args&&... args);
116    iterator insert(const_iterator p, const value_type& v);
117    iterator insert(const_iterator p, value_type&& v);
118    iterator insert(const_iterator p, size_type n, const value_type& v);
119    template <class InputIterator>
120        iterator insert(const_iterator p, InputIterator f, InputIterator l);
121    iterator insert(const_iterator p, initializer_list<value_type> il);
122    void pop_front();
123    void pop_back();
124    iterator erase(const_iterator p);
125    iterator erase(const_iterator f, const_iterator l);
126    void swap(deque& c)
127        noexcept(allocator_traits<allocator_type>::is_always_equal::value);  // C++17
128    void clear() noexcept;
129};
130
131template <class T, class Allocator>
132    bool operator==(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
133template <class T, class Allocator>
134    bool operator< (const deque<T,Allocator>& x, const deque<T,Allocator>& y);
135template <class T, class Allocator>
136    bool operator!=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
137template <class T, class Allocator>
138    bool operator> (const deque<T,Allocator>& x, const deque<T,Allocator>& y);
139template <class T, class Allocator>
140    bool operator>=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
141template <class T, class Allocator>
142    bool operator<=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
143
144// specialized algorithms:
145template <class T, class Allocator>
146    void swap(deque<T,Allocator>& x, deque<T,Allocator>& y)
147         noexcept(noexcept(x.swap(y)));
148
149}  // std
150
151*/
152
153#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
154#pragma GCC system_header
155#endif
156
157#include <__config>
158#include <__split_buffer>
159#include <type_traits>
160#include <initializer_list>
161#include <iterator>
162#include <algorithm>
163#include <stdexcept>
164
165#include <__undef_min_max>
166
167_LIBCPP_BEGIN_NAMESPACE_STD
168
169template <class _Tp, class _Allocator> class __deque_base;
170template <class _Tp, class _Allocator = allocator<_Tp> > class _LIBCPP_TEMPLATE_VIS deque;
171
172template <class _ValueType, class _Pointer, class _Reference, class _MapPointer,
173          class _DiffType, _DiffType _BlockSize>
174class _LIBCPP_TEMPLATE_VIS __deque_iterator;
175
176template <class _RAIter,
177          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
178__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
179copy(_RAIter __f,
180     _RAIter __l,
181     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
182     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
183
184template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
185          class _OutputIterator>
186_OutputIterator
187copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
188     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
189     _OutputIterator __r);
190
191template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
192          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
193__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
194copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
195     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
196     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
197
198template <class _RAIter,
199          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
200__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
201copy_backward(_RAIter __f,
202              _RAIter __l,
203              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
204              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
205
206template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
207          class _OutputIterator>
208_OutputIterator
209copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
210              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
211              _OutputIterator __r);
212
213template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
214          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
215__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
216copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
217              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
218              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
219
220template <class _RAIter,
221          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
222__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
223move(_RAIter __f,
224     _RAIter __l,
225     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
226     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
227
228template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
229          class _OutputIterator>
230_OutputIterator
231move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
232     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
233     _OutputIterator __r);
234
235template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
236          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
237__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
238move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
239     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
240     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
241
242template <class _RAIter,
243          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
244__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
245move_backward(_RAIter __f,
246              _RAIter __l,
247              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
248              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
249
250template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
251          class _OutputIterator>
252_OutputIterator
253move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
254              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
255              _OutputIterator __r);
256
257template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
258          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
259__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
260move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
261              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
262              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
263
264template <class _ValueType, class _DiffType>
265struct __deque_block_size {
266  static const _DiffType value = sizeof(_ValueType) < 256 ? 4096 / sizeof(_ValueType) : 16;
267};
268
269template <class _ValueType, class _Pointer, class _Reference, class _MapPointer,
270          class _DiffType, _DiffType _BS =
271#ifdef _LIBCPP_ABI_INCOMPLETE_TYPES_IN_DEQUE
272// Keep template parameter to avoid changing all template declarations thoughout
273// this file.
274                               0
275#else
276                               __deque_block_size<_ValueType, _DiffType>::value
277#endif
278          >
279class _LIBCPP_TEMPLATE_VIS __deque_iterator
280{
281    typedef _MapPointer __map_iterator;
282public:
283    typedef _Pointer  pointer;
284    typedef _DiffType difference_type;
285private:
286    __map_iterator __m_iter_;
287    pointer        __ptr_;
288
289    static const difference_type __block_size;
290public:
291    typedef _ValueType                  value_type;
292    typedef random_access_iterator_tag  iterator_category;
293    typedef _Reference                  reference;
294
295    _LIBCPP_INLINE_VISIBILITY __deque_iterator() _NOEXCEPT
296#if _LIBCPP_STD_VER > 11
297     : __m_iter_(nullptr), __ptr_(nullptr)
298#endif
299     {}
300
301    template <class _Pp, class _Rp, class _MP>
302    _LIBCPP_INLINE_VISIBILITY
303    __deque_iterator(const __deque_iterator<value_type, _Pp, _Rp, _MP, difference_type, _BS>& __it,
304                typename enable_if<is_convertible<_Pp, pointer>::value>::type* = 0) _NOEXCEPT
305        : __m_iter_(__it.__m_iter_), __ptr_(__it.__ptr_) {}
306
307    _LIBCPP_INLINE_VISIBILITY reference operator*() const {return *__ptr_;}
308    _LIBCPP_INLINE_VISIBILITY pointer operator->() const {return __ptr_;}
309
310    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator++()
311    {
312        if (++__ptr_ - *__m_iter_ == __block_size)
313        {
314            ++__m_iter_;
315            __ptr_ = *__m_iter_;
316        }
317        return *this;
318    }
319
320    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator++(int)
321    {
322        __deque_iterator __tmp = *this;
323        ++(*this);
324        return __tmp;
325    }
326
327    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator--()
328    {
329        if (__ptr_ == *__m_iter_)
330        {
331            --__m_iter_;
332            __ptr_ = *__m_iter_ + __block_size;
333        }
334        --__ptr_;
335        return *this;
336    }
337
338    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator--(int)
339    {
340        __deque_iterator __tmp = *this;
341        --(*this);
342        return __tmp;
343    }
344
345    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator+=(difference_type __n)
346    {
347        if (__n != 0)
348        {
349            __n += __ptr_ - *__m_iter_;
350            if (__n > 0)
351            {
352                __m_iter_ += __n / __block_size;
353                __ptr_ = *__m_iter_ + __n % __block_size;
354            }
355            else // (__n < 0)
356            {
357                difference_type __z = __block_size - 1 - __n;
358                __m_iter_ -= __z / __block_size;
359                __ptr_ = *__m_iter_ + (__block_size - 1 - __z % __block_size);
360            }
361        }
362        return *this;
363    }
364
365    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator-=(difference_type __n)
366    {
367        return *this += -__n;
368    }
369
370    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator+(difference_type __n) const
371    {
372        __deque_iterator __t(*this);
373        __t += __n;
374        return __t;
375    }
376
377    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator-(difference_type __n) const
378    {
379        __deque_iterator __t(*this);
380        __t -= __n;
381        return __t;
382    }
383
384    _LIBCPP_INLINE_VISIBILITY
385    friend __deque_iterator operator+(difference_type __n, const __deque_iterator& __it)
386        {return __it + __n;}
387
388    _LIBCPP_INLINE_VISIBILITY
389    friend difference_type operator-(const __deque_iterator& __x, const __deque_iterator& __y)
390    {
391        if (__x != __y)
392            return (__x.__m_iter_ - __y.__m_iter_) * __block_size
393                 + (__x.__ptr_ - *__x.__m_iter_)
394                 - (__y.__ptr_ - *__y.__m_iter_);
395        return 0;
396    }
397
398    _LIBCPP_INLINE_VISIBILITY reference operator[](difference_type __n) const
399        {return *(*this + __n);}
400
401    _LIBCPP_INLINE_VISIBILITY friend
402        bool operator==(const __deque_iterator& __x, const __deque_iterator& __y)
403        {return __x.__ptr_ == __y.__ptr_;}
404
405    _LIBCPP_INLINE_VISIBILITY friend
406        bool operator!=(const __deque_iterator& __x, const __deque_iterator& __y)
407        {return !(__x == __y);}
408
409    _LIBCPP_INLINE_VISIBILITY friend
410        bool operator<(const __deque_iterator& __x, const __deque_iterator& __y)
411        {return __x.__m_iter_ < __y.__m_iter_ ||
412               (__x.__m_iter_ == __y.__m_iter_ && __x.__ptr_ < __y.__ptr_);}
413
414    _LIBCPP_INLINE_VISIBILITY friend
415        bool operator>(const __deque_iterator& __x, const __deque_iterator& __y)
416        {return __y < __x;}
417
418    _LIBCPP_INLINE_VISIBILITY friend
419        bool operator<=(const __deque_iterator& __x, const __deque_iterator& __y)
420        {return !(__y < __x);}
421
422    _LIBCPP_INLINE_VISIBILITY friend
423        bool operator>=(const __deque_iterator& __x, const __deque_iterator& __y)
424        {return !(__x < __y);}
425
426private:
427    _LIBCPP_INLINE_VISIBILITY __deque_iterator(__map_iterator __m, pointer __p) _NOEXCEPT
428        : __m_iter_(__m), __ptr_(__p) {}
429
430    template <class _Tp, class _Ap> friend class __deque_base;
431    template <class _Tp, class _Ap> friend class _LIBCPP_TEMPLATE_VIS deque;
432    template <class _Vp, class _Pp, class _Rp, class _MP, class _Dp, _Dp>
433        friend class _LIBCPP_TEMPLATE_VIS __deque_iterator;
434
435    template <class _RAIter,
436              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
437    friend
438    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
439    copy(_RAIter __f,
440         _RAIter __l,
441         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
442         typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
443
444    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
445              class _OutputIterator>
446    friend
447    _OutputIterator
448    copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
449         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
450         _OutputIterator __r);
451
452    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
453              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
454    friend
455    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
456    copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
457         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
458         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
459
460    template <class _RAIter,
461              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
462    friend
463    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
464    copy_backward(_RAIter __f,
465                  _RAIter __l,
466                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
467                  typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
468
469    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
470              class _OutputIterator>
471    friend
472    _OutputIterator
473    copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
474                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
475                  _OutputIterator __r);
476
477    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
478              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
479    friend
480    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
481    copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
482                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
483                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
484
485    template <class _RAIter,
486              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
487    friend
488    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
489    move(_RAIter __f,
490         _RAIter __l,
491         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
492         typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
493
494    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
495              class _OutputIterator>
496    friend
497    _OutputIterator
498    move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
499         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
500         _OutputIterator __r);
501
502    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
503              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
504    friend
505    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
506    move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
507         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
508         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
509
510    template <class _RAIter,
511              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
512    friend
513    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
514    move_backward(_RAIter __f,
515                  _RAIter __l,
516                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
517                  typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
518
519    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
520              class _OutputIterator>
521    friend
522    _OutputIterator
523    move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
524                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
525                  _OutputIterator __r);
526
527    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
528              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
529    friend
530    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
531    move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
532                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
533                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
534};
535
536template <class _ValueType, class _Pointer, class _Reference, class _MapPointer,
537          class _DiffType, _DiffType _BlockSize>
538const _DiffType __deque_iterator<_ValueType, _Pointer, _Reference, _MapPointer,
539                                 _DiffType, _BlockSize>::__block_size =
540    __deque_block_size<_ValueType, _DiffType>::value;
541
542// copy
543
544template <class _RAIter,
545          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
546__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
547copy(_RAIter __f,
548     _RAIter __l,
549     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
550     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
551{
552    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
553    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
554    const difference_type __block_size = __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::__block_size;
555    while (__f != __l)
556    {
557        pointer __rb = __r.__ptr_;
558        pointer __re = *__r.__m_iter_ + __block_size;
559        difference_type __bs = __re - __rb;
560        difference_type __n = __l - __f;
561        _RAIter __m = __l;
562        if (__n > __bs)
563        {
564            __n = __bs;
565            __m = __f + __n;
566        }
567        _VSTD::copy(__f, __m, __rb);
568        __f = __m;
569        __r += __n;
570    }
571    return __r;
572}
573
574template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
575          class _OutputIterator>
576_OutputIterator
577copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
578     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
579     _OutputIterator __r)
580{
581    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
582    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
583    const difference_type __block_size = __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::__block_size;
584    difference_type __n = __l - __f;
585    while (__n > 0)
586    {
587        pointer __fb = __f.__ptr_;
588        pointer __fe = *__f.__m_iter_ + __block_size;
589        difference_type __bs = __fe - __fb;
590        if (__bs > __n)
591        {
592            __bs = __n;
593            __fe = __fb + __bs;
594        }
595        __r = _VSTD::copy(__fb, __fe, __r);
596        __n -= __bs;
597        __f += __bs;
598    }
599    return __r;
600}
601
602template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
603          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
604__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
605copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
606     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
607     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
608{
609    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
610    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
611    const difference_type __block_size = __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::__block_size;
612    difference_type __n = __l - __f;
613    while (__n > 0)
614    {
615        pointer __fb = __f.__ptr_;
616        pointer __fe = *__f.__m_iter_ + __block_size;
617        difference_type __bs = __fe - __fb;
618        if (__bs > __n)
619        {
620            __bs = __n;
621            __fe = __fb + __bs;
622        }
623        __r = _VSTD::copy(__fb, __fe, __r);
624        __n -= __bs;
625        __f += __bs;
626    }
627    return __r;
628}
629
630// copy_backward
631
632template <class _RAIter,
633          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
634__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
635copy_backward(_RAIter __f,
636              _RAIter __l,
637              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
638              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
639{
640    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
641    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
642    while (__f != __l)
643    {
644        __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __rp = _VSTD::prev(__r);
645        pointer __rb = *__rp.__m_iter_;
646        pointer __re = __rp.__ptr_ + 1;
647        difference_type __bs = __re - __rb;
648        difference_type __n = __l - __f;
649        _RAIter __m = __f;
650        if (__n > __bs)
651        {
652            __n = __bs;
653            __m = __l - __n;
654        }
655        _VSTD::copy_backward(__m, __l, __re);
656        __l = __m;
657        __r -= __n;
658    }
659    return __r;
660}
661
662template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
663          class _OutputIterator>
664_OutputIterator
665copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
666              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
667              _OutputIterator __r)
668{
669    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
670    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
671    difference_type __n = __l - __f;
672    while (__n > 0)
673    {
674        --__l;
675        pointer __lb = *__l.__m_iter_;
676        pointer __le = __l.__ptr_ + 1;
677        difference_type __bs = __le - __lb;
678        if (__bs > __n)
679        {
680            __bs = __n;
681            __lb = __le - __bs;
682        }
683        __r = _VSTD::copy_backward(__lb, __le, __r);
684        __n -= __bs;
685        __l -= __bs - 1;
686    }
687    return __r;
688}
689
690template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
691          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
692__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
693copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
694              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
695              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
696{
697    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
698    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
699    difference_type __n = __l - __f;
700    while (__n > 0)
701    {
702        --__l;
703        pointer __lb = *__l.__m_iter_;
704        pointer __le = __l.__ptr_ + 1;
705        difference_type __bs = __le - __lb;
706        if (__bs > __n)
707        {
708            __bs = __n;
709            __lb = __le - __bs;
710        }
711        __r = _VSTD::copy_backward(__lb, __le, __r);
712        __n -= __bs;
713        __l -= __bs - 1;
714    }
715    return __r;
716}
717
718// move
719
720template <class _RAIter,
721          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
722__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
723move(_RAIter __f,
724     _RAIter __l,
725     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
726     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
727{
728    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
729    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
730    const difference_type __block_size = __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::__block_size;
731    while (__f != __l)
732    {
733        pointer __rb = __r.__ptr_;
734        pointer __re = *__r.__m_iter_ + __block_size;
735        difference_type __bs = __re - __rb;
736        difference_type __n = __l - __f;
737        _RAIter __m = __l;
738        if (__n > __bs)
739        {
740            __n = __bs;
741            __m = __f + __n;
742        }
743        _VSTD::move(__f, __m, __rb);
744        __f = __m;
745        __r += __n;
746    }
747    return __r;
748}
749
750template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
751          class _OutputIterator>
752_OutputIterator
753move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
754     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
755     _OutputIterator __r)
756{
757    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
758    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
759    const difference_type __block_size = __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::__block_size;
760    difference_type __n = __l - __f;
761    while (__n > 0)
762    {
763        pointer __fb = __f.__ptr_;
764        pointer __fe = *__f.__m_iter_ + __block_size;
765        difference_type __bs = __fe - __fb;
766        if (__bs > __n)
767        {
768            __bs = __n;
769            __fe = __fb + __bs;
770        }
771        __r = _VSTD::move(__fb, __fe, __r);
772        __n -= __bs;
773        __f += __bs;
774    }
775    return __r;
776}
777
778template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
779          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
780__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
781move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
782     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
783     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
784{
785    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
786    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
787    const difference_type __block_size = __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::__block_size;
788    difference_type __n = __l - __f;
789    while (__n > 0)
790    {
791        pointer __fb = __f.__ptr_;
792        pointer __fe = *__f.__m_iter_ + __block_size;
793        difference_type __bs = __fe - __fb;
794        if (__bs > __n)
795        {
796            __bs = __n;
797            __fe = __fb + __bs;
798        }
799        __r = _VSTD::move(__fb, __fe, __r);
800        __n -= __bs;
801        __f += __bs;
802    }
803    return __r;
804}
805
806// move_backward
807
808template <class _RAIter,
809          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
810__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
811move_backward(_RAIter __f,
812              _RAIter __l,
813              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
814              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
815{
816    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
817    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
818    while (__f != __l)
819    {
820        __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __rp = _VSTD::prev(__r);
821        pointer __rb = *__rp.__m_iter_;
822        pointer __re = __rp.__ptr_ + 1;
823        difference_type __bs = __re - __rb;
824        difference_type __n = __l - __f;
825        _RAIter __m = __f;
826        if (__n > __bs)
827        {
828            __n = __bs;
829            __m = __l - __n;
830        }
831        _VSTD::move_backward(__m, __l, __re);
832        __l = __m;
833        __r -= __n;
834    }
835    return __r;
836}
837
838template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
839          class _OutputIterator>
840_OutputIterator
841move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
842              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
843              _OutputIterator __r)
844{
845    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
846    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
847    difference_type __n = __l - __f;
848    while (__n > 0)
849    {
850        --__l;
851        pointer __lb = *__l.__m_iter_;
852        pointer __le = __l.__ptr_ + 1;
853        difference_type __bs = __le - __lb;
854        if (__bs > __n)
855        {
856            __bs = __n;
857            __lb = __le - __bs;
858        }
859        __r = _VSTD::move_backward(__lb, __le, __r);
860        __n -= __bs;
861        __l -= __bs - 1;
862    }
863    return __r;
864}
865
866template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
867          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
868__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
869move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
870              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
871              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
872{
873    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
874    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
875    difference_type __n = __l - __f;
876    while (__n > 0)
877    {
878        --__l;
879        pointer __lb = *__l.__m_iter_;
880        pointer __le = __l.__ptr_ + 1;
881        difference_type __bs = __le - __lb;
882        if (__bs > __n)
883        {
884            __bs = __n;
885            __lb = __le - __bs;
886        }
887        __r = _VSTD::move_backward(__lb, __le, __r);
888        __n -= __bs;
889        __l -= __bs - 1;
890    }
891    return __r;
892}
893
894template <bool>
895class __deque_base_common
896{
897protected:
898    _LIBCPP_NORETURN void __throw_length_error() const;
899    _LIBCPP_NORETURN void __throw_out_of_range() const;
900};
901
902template <bool __b>
903void
904__deque_base_common<__b>::__throw_length_error() const
905{
906    _VSTD::__throw_length_error("deque");
907}
908
909template <bool __b>
910void
911__deque_base_common<__b>::__throw_out_of_range() const
912{
913    _VSTD::__throw_out_of_range("deque");
914}
915
916template <class _Tp, class _Allocator>
917class __deque_base
918    : protected __deque_base_common<true>
919{
920    __deque_base(const __deque_base& __c);
921    __deque_base& operator=(const __deque_base& __c);
922protected:
923    typedef _Tp                                      value_type;
924    typedef _Allocator                               allocator_type;
925    typedef allocator_traits<allocator_type>         __alloc_traits;
926    typedef value_type&                              reference;
927    typedef const value_type&                        const_reference;
928    typedef typename __alloc_traits::size_type       size_type;
929    typedef typename __alloc_traits::difference_type difference_type;
930    typedef typename __alloc_traits::pointer         pointer;
931    typedef typename __alloc_traits::const_pointer   const_pointer;
932
933    static const difference_type __block_size;
934
935    typedef typename __rebind_alloc_helper<__alloc_traits, pointer>::type __pointer_allocator;
936    typedef allocator_traits<__pointer_allocator>        __map_traits;
937    typedef typename __map_traits::pointer               __map_pointer;
938    typedef typename __rebind_alloc_helper<__alloc_traits, const_pointer>::type __const_pointer_allocator;
939    typedef typename allocator_traits<__const_pointer_allocator>::const_pointer __map_const_pointer;
940    typedef __split_buffer<pointer, __pointer_allocator> __map;
941
942    typedef __deque_iterator<value_type, pointer, reference, __map_pointer,
943                             difference_type>    iterator;
944    typedef __deque_iterator<value_type, const_pointer, const_reference, __map_const_pointer,
945                             difference_type>    const_iterator;
946
947    __map __map_;
948    size_type __start_;
949    __compressed_pair<size_type, allocator_type> __size_;
950
951    iterator       begin() _NOEXCEPT;
952    const_iterator begin() const _NOEXCEPT;
953    iterator       end() _NOEXCEPT;
954    const_iterator end() const _NOEXCEPT;
955
956    _LIBCPP_INLINE_VISIBILITY size_type&            size()          {return __size_.first();}
957    _LIBCPP_INLINE_VISIBILITY
958    const size_type& size() const _NOEXCEPT {return __size_.first();}
959    _LIBCPP_INLINE_VISIBILITY allocator_type&       __alloc()       {return __size_.second();}
960    _LIBCPP_INLINE_VISIBILITY
961    const allocator_type& __alloc() const _NOEXCEPT {return __size_.second();}
962
963    _LIBCPP_INLINE_VISIBILITY
964    __deque_base()
965        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
966    _LIBCPP_INLINE_VISIBILITY
967    explicit __deque_base(const allocator_type& __a);
968public:
969    ~__deque_base();
970
971#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
972
973    __deque_base(__deque_base&& __c)
974        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
975    __deque_base(__deque_base&& __c, const allocator_type& __a);
976
977#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
978    void swap(__deque_base& __c)
979#if _LIBCPP_STD_VER >= 14
980        _NOEXCEPT;
981#else
982        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
983                    __is_nothrow_swappable<allocator_type>::value);
984#endif
985protected:
986    void clear() _NOEXCEPT;
987
988    bool __invariants() const;
989
990    _LIBCPP_INLINE_VISIBILITY
991    void __move_assign(__deque_base& __c)
992        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
993                   is_nothrow_move_assignable<allocator_type>::value)
994    {
995        __map_ = _VSTD::move(__c.__map_);
996        __start_ = __c.__start_;
997        size() = __c.size();
998        __move_assign_alloc(__c);
999        __c.__start_ = __c.size() = 0;
1000    }
1001
1002    _LIBCPP_INLINE_VISIBILITY
1003    void __move_assign_alloc(__deque_base& __c)
1004        _NOEXCEPT_(!__alloc_traits::propagate_on_container_move_assignment::value ||
1005                   is_nothrow_move_assignable<allocator_type>::value)
1006        {__move_assign_alloc(__c, integral_constant<bool,
1007                      __alloc_traits::propagate_on_container_move_assignment::value>());}
1008
1009private:
1010    _LIBCPP_INLINE_VISIBILITY
1011    void __move_assign_alloc(__deque_base& __c, true_type)
1012        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
1013        {
1014            __alloc() = _VSTD::move(__c.__alloc());
1015        }
1016
1017    _LIBCPP_INLINE_VISIBILITY
1018    void __move_assign_alloc(__deque_base&, false_type) _NOEXCEPT
1019        {}
1020};
1021
1022template <class _Tp, class _Allocator>
1023const typename __deque_base<_Tp, _Allocator>::difference_type
1024    __deque_base<_Tp, _Allocator>::__block_size =
1025        __deque_block_size<value_type, difference_type>::value;
1026
1027template <class _Tp, class _Allocator>
1028bool
1029__deque_base<_Tp, _Allocator>::__invariants() const
1030{
1031    if (!__map_.__invariants())
1032        return false;
1033    if (__map_.size() >= size_type(-1) / __block_size)
1034        return false;
1035    for (typename __map::const_iterator __i = __map_.begin(), __e = __map_.end();
1036         __i != __e; ++__i)
1037        if (*__i == nullptr)
1038            return false;
1039    if (__map_.size() != 0)
1040    {
1041        if (size() >= __map_.size() * __block_size)
1042            return false;
1043        if (__start_ >= __map_.size() * __block_size - size())
1044            return false;
1045    }
1046    else
1047    {
1048        if (size() != 0)
1049            return false;
1050        if (__start_ != 0)
1051            return false;
1052    }
1053    return true;
1054}
1055
1056template <class _Tp, class _Allocator>
1057typename __deque_base<_Tp, _Allocator>::iterator
1058__deque_base<_Tp, _Allocator>::begin() _NOEXCEPT
1059{
1060    __map_pointer __mp = __map_.begin() + __start_ / __block_size;
1061    return iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
1062}
1063
1064template <class _Tp, class _Allocator>
1065typename __deque_base<_Tp, _Allocator>::const_iterator
1066__deque_base<_Tp, _Allocator>::begin() const _NOEXCEPT
1067{
1068    __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __start_ / __block_size);
1069    return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
1070}
1071
1072template <class _Tp, class _Allocator>
1073typename __deque_base<_Tp, _Allocator>::iterator
1074__deque_base<_Tp, _Allocator>::end() _NOEXCEPT
1075{
1076    size_type __p = size() + __start_;
1077    __map_pointer __mp = __map_.begin() + __p / __block_size;
1078    return iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
1079}
1080
1081template <class _Tp, class _Allocator>
1082typename __deque_base<_Tp, _Allocator>::const_iterator
1083__deque_base<_Tp, _Allocator>::end() const _NOEXCEPT
1084{
1085    size_type __p = size() + __start_;
1086    __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __p / __block_size);
1087    return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
1088}
1089
1090template <class _Tp, class _Allocator>
1091inline
1092__deque_base<_Tp, _Allocator>::__deque_base()
1093    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
1094    : __start_(0), __size_(0) {}
1095
1096template <class _Tp, class _Allocator>
1097inline
1098__deque_base<_Tp, _Allocator>::__deque_base(const allocator_type& __a)
1099    : __map_(__pointer_allocator(__a)), __start_(0), __size_(0, __a) {}
1100
1101template <class _Tp, class _Allocator>
1102__deque_base<_Tp, _Allocator>::~__deque_base()
1103{
1104    clear();
1105    typename __map::iterator __i = __map_.begin();
1106    typename __map::iterator __e = __map_.end();
1107    for (; __i != __e; ++__i)
1108        __alloc_traits::deallocate(__alloc(), *__i, __block_size);
1109}
1110
1111#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1112
1113template <class _Tp, class _Allocator>
1114__deque_base<_Tp, _Allocator>::__deque_base(__deque_base&& __c)
1115    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
1116    : __map_(_VSTD::move(__c.__map_)),
1117      __start_(_VSTD::move(__c.__start_)),
1118      __size_(_VSTD::move(__c.__size_))
1119{
1120    __c.__start_ = 0;
1121    __c.size() = 0;
1122}
1123
1124template <class _Tp, class _Allocator>
1125__deque_base<_Tp, _Allocator>::__deque_base(__deque_base&& __c, const allocator_type& __a)
1126    : __map_(_VSTD::move(__c.__map_), __pointer_allocator(__a)),
1127      __start_(_VSTD::move(__c.__start_)),
1128      __size_(_VSTD::move(__c.size()), __a)
1129{
1130    if (__a == __c.__alloc())
1131    {
1132        __c.__start_ = 0;
1133        __c.size() = 0;
1134    }
1135    else
1136    {
1137        __map_.clear();
1138        __start_ = 0;
1139        size() = 0;
1140    }
1141}
1142
1143#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1144
1145template <class _Tp, class _Allocator>
1146void
1147__deque_base<_Tp, _Allocator>::swap(__deque_base& __c)
1148#if _LIBCPP_STD_VER >= 14
1149        _NOEXCEPT
1150#else
1151        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
1152                    __is_nothrow_swappable<allocator_type>::value)
1153#endif
1154{
1155    __map_.swap(__c.__map_);
1156    _VSTD::swap(__start_, __c.__start_);
1157    _VSTD::swap(size(), __c.size());
1158    __swap_allocator(__alloc(), __c.__alloc());
1159}
1160
1161template <class _Tp, class _Allocator>
1162void
1163__deque_base<_Tp, _Allocator>::clear() _NOEXCEPT
1164{
1165    allocator_type& __a = __alloc();
1166    for (iterator __i = begin(), __e = end(); __i != __e; ++__i)
1167        __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
1168    size() = 0;
1169    while (__map_.size() > 2)
1170    {
1171        __alloc_traits::deallocate(__a, __map_.front(), __block_size);
1172        __map_.pop_front();
1173    }
1174    switch (__map_.size())
1175    {
1176    case 1:
1177        __start_ = __block_size / 2;
1178        break;
1179    case 2:
1180        __start_ = __block_size;
1181        break;
1182    }
1183}
1184
1185template <class _Tp, class _Allocator /*= allocator<_Tp>*/>
1186class _LIBCPP_TEMPLATE_VIS deque
1187    : private __deque_base<_Tp, _Allocator>
1188{
1189public:
1190    // types:
1191
1192    typedef _Tp value_type;
1193    typedef _Allocator allocator_type;
1194
1195    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
1196                  "Allocator::value_type must be same type as value_type");
1197
1198    typedef __deque_base<value_type, allocator_type> __base;
1199
1200    typedef typename __base::__alloc_traits        __alloc_traits;
1201    typedef typename __base::reference             reference;
1202    typedef typename __base::const_reference       const_reference;
1203    typedef typename __base::iterator              iterator;
1204    typedef typename __base::const_iterator        const_iterator;
1205    typedef typename __base::size_type             size_type;
1206    typedef typename __base::difference_type       difference_type;
1207
1208    typedef typename __base::pointer               pointer;
1209    typedef typename __base::const_pointer         const_pointer;
1210    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
1211    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
1212
1213    // construct/copy/destroy:
1214    _LIBCPP_INLINE_VISIBILITY
1215    deque()
1216        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
1217        {}
1218    _LIBCPP_INLINE_VISIBILITY explicit deque(const allocator_type& __a) : __base(__a) {}
1219    explicit deque(size_type __n);
1220#if _LIBCPP_STD_VER > 11
1221    explicit deque(size_type __n, const _Allocator& __a);
1222#endif
1223    deque(size_type __n, const value_type& __v);
1224    deque(size_type __n, const value_type& __v, const allocator_type& __a);
1225    template <class _InputIter>
1226        deque(_InputIter __f, _InputIter __l,
1227              typename enable_if<__is_input_iterator<_InputIter>::value>::type* = 0);
1228    template <class _InputIter>
1229        deque(_InputIter __f, _InputIter __l, const allocator_type& __a,
1230              typename enable_if<__is_input_iterator<_InputIter>::value>::type* = 0);
1231    deque(const deque& __c);
1232    deque(const deque& __c, const allocator_type& __a);
1233#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1234    deque(initializer_list<value_type> __il);
1235    deque(initializer_list<value_type> __il, const allocator_type& __a);
1236#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1237
1238    deque& operator=(const deque& __c);
1239#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1240    _LIBCPP_INLINE_VISIBILITY
1241    deque& operator=(initializer_list<value_type> __il) {assign(__il); return *this;}
1242#endif   // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1243
1244#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1245    _LIBCPP_INLINE_VISIBILITY
1246    deque(deque&& __c) _NOEXCEPT_(is_nothrow_move_constructible<__base>::value);
1247    _LIBCPP_INLINE_VISIBILITY
1248    deque(deque&& __c, const allocator_type& __a);
1249    _LIBCPP_INLINE_VISIBILITY
1250    deque& operator=(deque&& __c)
1251        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
1252                   is_nothrow_move_assignable<allocator_type>::value);
1253#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1254
1255    template <class _InputIter>
1256        void assign(_InputIter __f, _InputIter __l,
1257                    typename enable_if<__is_input_iterator<_InputIter>::value &&
1258                                      !__is_random_access_iterator<_InputIter>::value>::type* = 0);
1259    template <class _RAIter>
1260        void assign(_RAIter __f, _RAIter __l,
1261                    typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
1262    void assign(size_type __n, const value_type& __v);
1263#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1264    _LIBCPP_INLINE_VISIBILITY
1265    void assign(initializer_list<value_type> __il) {assign(__il.begin(), __il.end());}
1266#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1267
1268    _LIBCPP_INLINE_VISIBILITY
1269    allocator_type get_allocator() const _NOEXCEPT;
1270
1271    // iterators:
1272
1273    _LIBCPP_INLINE_VISIBILITY
1274    iterator       begin() _NOEXCEPT       {return __base::begin();}
1275    _LIBCPP_INLINE_VISIBILITY
1276    const_iterator begin() const _NOEXCEPT {return __base::begin();}
1277    _LIBCPP_INLINE_VISIBILITY
1278    iterator       end() _NOEXCEPT         {return __base::end();}
1279    _LIBCPP_INLINE_VISIBILITY
1280    const_iterator end()   const _NOEXCEPT {return __base::end();}
1281
1282    _LIBCPP_INLINE_VISIBILITY
1283    reverse_iterator       rbegin() _NOEXCEPT
1284        {return       reverse_iterator(__base::end());}
1285    _LIBCPP_INLINE_VISIBILITY
1286    const_reverse_iterator rbegin() const _NOEXCEPT
1287        {return const_reverse_iterator(__base::end());}
1288    _LIBCPP_INLINE_VISIBILITY
1289    reverse_iterator       rend() _NOEXCEPT
1290        {return       reverse_iterator(__base::begin());}
1291    _LIBCPP_INLINE_VISIBILITY
1292    const_reverse_iterator rend()   const _NOEXCEPT
1293        {return const_reverse_iterator(__base::begin());}
1294
1295    _LIBCPP_INLINE_VISIBILITY
1296    const_iterator         cbegin()  const _NOEXCEPT
1297        {return __base::begin();}
1298    _LIBCPP_INLINE_VISIBILITY
1299    const_iterator         cend()    const _NOEXCEPT
1300        {return __base::end();}
1301    _LIBCPP_INLINE_VISIBILITY
1302    const_reverse_iterator crbegin() const _NOEXCEPT
1303        {return const_reverse_iterator(__base::end());}
1304    _LIBCPP_INLINE_VISIBILITY
1305    const_reverse_iterator crend()   const _NOEXCEPT
1306        {return const_reverse_iterator(__base::begin());}
1307
1308    // capacity:
1309    _LIBCPP_INLINE_VISIBILITY
1310    size_type size() const _NOEXCEPT {return __base::size();}
1311    _LIBCPP_INLINE_VISIBILITY
1312    size_type max_size() const _NOEXCEPT
1313        {return std::min<size_type>(
1314            __alloc_traits::max_size(__base::__alloc()),
1315            numeric_limits<difference_type>::max());}
1316    void resize(size_type __n);
1317    void resize(size_type __n, const value_type& __v);
1318    void shrink_to_fit() _NOEXCEPT;
1319    _LIBCPP_INLINE_VISIBILITY
1320    bool empty() const _NOEXCEPT {return __base::size() == 0;}
1321
1322    // element access:
1323    _LIBCPP_INLINE_VISIBILITY
1324    reference operator[](size_type __i);
1325    _LIBCPP_INLINE_VISIBILITY
1326    const_reference operator[](size_type __i) const;
1327    _LIBCPP_INLINE_VISIBILITY
1328    reference at(size_type __i);
1329    _LIBCPP_INLINE_VISIBILITY
1330    const_reference at(size_type __i) const;
1331    _LIBCPP_INLINE_VISIBILITY
1332    reference front();
1333    _LIBCPP_INLINE_VISIBILITY
1334    const_reference front() const;
1335    _LIBCPP_INLINE_VISIBILITY
1336    reference back();
1337    _LIBCPP_INLINE_VISIBILITY
1338    const_reference back() const;
1339
1340    // 23.2.2.3 modifiers:
1341    void push_front(const value_type& __v);
1342    void push_back(const value_type& __v);
1343#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1344#ifndef _LIBCPP_HAS_NO_VARIADICS
1345    template <class... _Args> reference emplace_front(_Args&&... __args);
1346    template <class... _Args> reference emplace_back(_Args&&... __args);
1347    template <class... _Args> iterator emplace(const_iterator __p, _Args&&... __args);
1348#endif  // _LIBCPP_HAS_NO_VARIADICS
1349    void push_front(value_type&& __v);
1350    void push_back(value_type&& __v);
1351    iterator insert(const_iterator __p, value_type&& __v);
1352#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1353    iterator insert(const_iterator __p, const value_type& __v);
1354    iterator insert(const_iterator __p, size_type __n, const value_type& __v);
1355    template <class _InputIter>
1356        iterator insert(const_iterator __p, _InputIter __f, _InputIter __l,
1357                         typename enable_if<__is_input_iterator<_InputIter>::value
1358                                         &&!__is_forward_iterator<_InputIter>::value>::type* = 0);
1359    template <class _ForwardIterator>
1360        iterator insert(const_iterator __p, _ForwardIterator __f, _ForwardIterator __l,
1361                               typename enable_if<__is_forward_iterator<_ForwardIterator>::value
1362                                         &&!__is_bidirectional_iterator<_ForwardIterator>::value>::type* = 0);
1363    template <class _BiIter>
1364        iterator insert(const_iterator __p, _BiIter __f, _BiIter __l,
1365                         typename enable_if<__is_bidirectional_iterator<_BiIter>::value>::type* = 0);
1366#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1367    _LIBCPP_INLINE_VISIBILITY
1368    iterator insert(const_iterator __p, initializer_list<value_type> __il)
1369        {return insert(__p, __il.begin(), __il.end());}
1370#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1371    void pop_front();
1372    void pop_back();
1373    iterator erase(const_iterator __p);
1374    iterator erase(const_iterator __f, const_iterator __l);
1375
1376    _LIBCPP_INLINE_VISIBILITY
1377    void swap(deque& __c)
1378#if _LIBCPP_STD_VER >= 14
1379        _NOEXCEPT;
1380#else
1381        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
1382                   __is_nothrow_swappable<allocator_type>::value);
1383#endif
1384    _LIBCPP_INLINE_VISIBILITY
1385    void clear() _NOEXCEPT;
1386
1387    _LIBCPP_INLINE_VISIBILITY
1388    bool __invariants() const {return __base::__invariants();}
1389private:
1390    typedef typename __base::__map_const_pointer __map_const_pointer;
1391
1392    _LIBCPP_INLINE_VISIBILITY
1393    static size_type __recommend_blocks(size_type __n)
1394    {
1395        return __n / __base::__block_size + (__n % __base::__block_size != 0);
1396    }
1397    _LIBCPP_INLINE_VISIBILITY
1398    size_type __capacity() const
1399    {
1400        return __base::__map_.size() == 0 ? 0 : __base::__map_.size() * __base::__block_size - 1;
1401    }
1402    _LIBCPP_INLINE_VISIBILITY
1403    size_type __front_spare() const
1404    {
1405        return __base::__start_;
1406    }
1407    _LIBCPP_INLINE_VISIBILITY
1408    size_type __back_spare() const
1409    {
1410        return __capacity() - (__base::__start_ + __base::size());
1411    }
1412
1413    template <class _InpIter>
1414        void __append(_InpIter __f, _InpIter __l,
1415                 typename enable_if<__is_input_iterator<_InpIter>::value &&
1416                                   !__is_forward_iterator<_InpIter>::value>::type* = 0);
1417    template <class _ForIter>
1418        void __append(_ForIter __f, _ForIter __l,
1419                      typename enable_if<__is_forward_iterator<_ForIter>::value>::type* = 0);
1420    void __append(size_type __n);
1421    void __append(size_type __n, const value_type& __v);
1422    void __erase_to_end(const_iterator __f);
1423    void __add_front_capacity();
1424    void __add_front_capacity(size_type __n);
1425    void __add_back_capacity();
1426    void __add_back_capacity(size_type __n);
1427    iterator __move_and_check(iterator __f, iterator __l, iterator __r,
1428                              const_pointer& __vt);
1429    iterator __move_backward_and_check(iterator __f, iterator __l, iterator __r,
1430                                       const_pointer& __vt);
1431    void __move_construct_and_check(iterator __f, iterator __l,
1432                                    iterator __r, const_pointer& __vt);
1433    void __move_construct_backward_and_check(iterator __f, iterator __l,
1434                                             iterator __r, const_pointer& __vt);
1435
1436    _LIBCPP_INLINE_VISIBILITY
1437    void __copy_assign_alloc(const deque& __c)
1438        {__copy_assign_alloc(__c, integral_constant<bool,
1439                      __alloc_traits::propagate_on_container_copy_assignment::value>());}
1440
1441    _LIBCPP_INLINE_VISIBILITY
1442    void __copy_assign_alloc(const deque& __c, true_type)
1443        {
1444            if (__base::__alloc() != __c.__alloc())
1445            {
1446                clear();
1447                shrink_to_fit();
1448            }
1449            __base::__alloc() = __c.__alloc();
1450            __base::__map_.__alloc() = __c.__map_.__alloc();
1451        }
1452
1453    _LIBCPP_INLINE_VISIBILITY
1454    void __copy_assign_alloc(const deque&, false_type)
1455        {}
1456
1457    void __move_assign(deque& __c, true_type)
1458        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
1459    void __move_assign(deque& __c, false_type);
1460};
1461
1462template <class _Tp, class _Allocator>
1463deque<_Tp, _Allocator>::deque(size_type __n)
1464{
1465    if (__n > 0)
1466        __append(__n);
1467}
1468
1469#if _LIBCPP_STD_VER > 11
1470template <class _Tp, class _Allocator>
1471deque<_Tp, _Allocator>::deque(size_type __n, const _Allocator& __a)
1472    : __base(__a)
1473{
1474    if (__n > 0)
1475        __append(__n);
1476}
1477#endif
1478
1479template <class _Tp, class _Allocator>
1480deque<_Tp, _Allocator>::deque(size_type __n, const value_type& __v)
1481{
1482    if (__n > 0)
1483        __append(__n, __v);
1484}
1485
1486template <class _Tp, class _Allocator>
1487deque<_Tp, _Allocator>::deque(size_type __n, const value_type& __v, const allocator_type& __a)
1488    : __base(__a)
1489{
1490    if (__n > 0)
1491        __append(__n, __v);
1492}
1493
1494template <class _Tp, class _Allocator>
1495template <class _InputIter>
1496deque<_Tp, _Allocator>::deque(_InputIter __f, _InputIter __l,
1497              typename enable_if<__is_input_iterator<_InputIter>::value>::type*)
1498{
1499    __append(__f, __l);
1500}
1501
1502template <class _Tp, class _Allocator>
1503template <class _InputIter>
1504deque<_Tp, _Allocator>::deque(_InputIter __f, _InputIter __l, const allocator_type& __a,
1505              typename enable_if<__is_input_iterator<_InputIter>::value>::type*)
1506    : __base(__a)
1507{
1508    __append(__f, __l);
1509}
1510
1511template <class _Tp, class _Allocator>
1512deque<_Tp, _Allocator>::deque(const deque& __c)
1513    : __base(__alloc_traits::select_on_container_copy_construction(__c.__alloc()))
1514{
1515    __append(__c.begin(), __c.end());
1516}
1517
1518template <class _Tp, class _Allocator>
1519deque<_Tp, _Allocator>::deque(const deque& __c, const allocator_type& __a)
1520    : __base(__a)
1521{
1522    __append(__c.begin(), __c.end());
1523}
1524
1525#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1526
1527template <class _Tp, class _Allocator>
1528deque<_Tp, _Allocator>::deque(initializer_list<value_type> __il)
1529{
1530    __append(__il.begin(), __il.end());
1531}
1532
1533template <class _Tp, class _Allocator>
1534deque<_Tp, _Allocator>::deque(initializer_list<value_type> __il, const allocator_type& __a)
1535    : __base(__a)
1536{
1537    __append(__il.begin(), __il.end());
1538}
1539
1540#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
1541
1542template <class _Tp, class _Allocator>
1543deque<_Tp, _Allocator>&
1544deque<_Tp, _Allocator>::operator=(const deque& __c)
1545{
1546    if (this != &__c)
1547    {
1548        __copy_assign_alloc(__c);
1549        assign(__c.begin(), __c.end());
1550    }
1551    return *this;
1552}
1553
1554#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1555
1556template <class _Tp, class _Allocator>
1557inline
1558deque<_Tp, _Allocator>::deque(deque&& __c)
1559    _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
1560    : __base(_VSTD::move(__c))
1561{
1562}
1563
1564template <class _Tp, class _Allocator>
1565inline
1566deque<_Tp, _Allocator>::deque(deque&& __c, const allocator_type& __a)
1567    : __base(_VSTD::move(__c), __a)
1568{
1569    if (__a != __c.__alloc())
1570    {
1571        typedef move_iterator<iterator> _Ip;
1572        assign(_Ip(__c.begin()), _Ip(__c.end()));
1573    }
1574}
1575
1576template <class _Tp, class _Allocator>
1577inline
1578deque<_Tp, _Allocator>&
1579deque<_Tp, _Allocator>::operator=(deque&& __c)
1580        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
1581                   is_nothrow_move_assignable<allocator_type>::value)
1582{
1583    __move_assign(__c, integral_constant<bool,
1584          __alloc_traits::propagate_on_container_move_assignment::value>());
1585    return *this;
1586}
1587
1588template <class _Tp, class _Allocator>
1589void
1590deque<_Tp, _Allocator>::__move_assign(deque& __c, false_type)
1591{
1592    if (__base::__alloc() != __c.__alloc())
1593    {
1594        typedef move_iterator<iterator> _Ip;
1595        assign(_Ip(__c.begin()), _Ip(__c.end()));
1596    }
1597    else
1598        __move_assign(__c, true_type());
1599}
1600
1601template <class _Tp, class _Allocator>
1602void
1603deque<_Tp, _Allocator>::__move_assign(deque& __c, true_type)
1604    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
1605{
1606    clear();
1607    shrink_to_fit();
1608    __base::__move_assign(__c);
1609}
1610
1611#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1612
1613template <class _Tp, class _Allocator>
1614template <class _InputIter>
1615void
1616deque<_Tp, _Allocator>::assign(_InputIter __f, _InputIter __l,
1617                               typename enable_if<__is_input_iterator<_InputIter>::value &&
1618                                                 !__is_random_access_iterator<_InputIter>::value>::type*)
1619{
1620    iterator __i = __base::begin();
1621    iterator __e = __base::end();
1622    for (; __f != __l && __i != __e; ++__f, (void) ++__i)
1623        *__i = *__f;
1624    if (__f != __l)
1625        __append(__f, __l);
1626    else
1627        __erase_to_end(__i);
1628}
1629
1630template <class _Tp, class _Allocator>
1631template <class _RAIter>
1632void
1633deque<_Tp, _Allocator>::assign(_RAIter __f, _RAIter __l,
1634                               typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
1635{
1636    if (static_cast<size_type>(__l - __f) > __base::size())
1637    {
1638        _RAIter __m = __f + __base::size();
1639        _VSTD::copy(__f, __m, __base::begin());
1640        __append(__m, __l);
1641    }
1642    else
1643        __erase_to_end(_VSTD::copy(__f, __l, __base::begin()));
1644}
1645
1646template <class _Tp, class _Allocator>
1647void
1648deque<_Tp, _Allocator>::assign(size_type __n, const value_type& __v)
1649{
1650    if (__n > __base::size())
1651    {
1652        _VSTD::fill_n(__base::begin(), __base::size(), __v);
1653        __n -= __base::size();
1654        __append(__n, __v);
1655    }
1656    else
1657        __erase_to_end(_VSTD::fill_n(__base::begin(), __n, __v));
1658}
1659
1660template <class _Tp, class _Allocator>
1661inline
1662_Allocator
1663deque<_Tp, _Allocator>::get_allocator() const _NOEXCEPT
1664{
1665    return __base::__alloc();
1666}
1667
1668template <class _Tp, class _Allocator>
1669void
1670deque<_Tp, _Allocator>::resize(size_type __n)
1671{
1672    if (__n > __base::size())
1673        __append(__n - __base::size());
1674    else if (__n < __base::size())
1675        __erase_to_end(__base::begin() + __n);
1676}
1677
1678template <class _Tp, class _Allocator>
1679void
1680deque<_Tp, _Allocator>::resize(size_type __n, const value_type& __v)
1681{
1682    if (__n > __base::size())
1683        __append(__n - __base::size(), __v);
1684    else if (__n < __base::size())
1685        __erase_to_end(__base::begin() + __n);
1686}
1687
1688template <class _Tp, class _Allocator>
1689void
1690deque<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
1691{
1692    allocator_type& __a = __base::__alloc();
1693    if (empty())
1694    {
1695        while (__base::__map_.size() > 0)
1696        {
1697            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
1698            __base::__map_.pop_back();
1699        }
1700        __base::__start_ = 0;
1701    }
1702    else
1703    {
1704        if (__front_spare() >= __base::__block_size)
1705        {
1706            __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
1707            __base::__map_.pop_front();
1708            __base::__start_ -= __base::__block_size;
1709        }
1710        if (__back_spare() >= __base::__block_size)
1711        {
1712            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
1713            __base::__map_.pop_back();
1714        }
1715    }
1716    __base::__map_.shrink_to_fit();
1717}
1718
1719template <class _Tp, class _Allocator>
1720inline
1721typename deque<_Tp, _Allocator>::reference
1722deque<_Tp, _Allocator>::operator[](size_type __i)
1723{
1724    size_type __p = __base::__start_ + __i;
1725    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1726}
1727
1728template <class _Tp, class _Allocator>
1729inline
1730typename deque<_Tp, _Allocator>::const_reference
1731deque<_Tp, _Allocator>::operator[](size_type __i) const
1732{
1733    size_type __p = __base::__start_ + __i;
1734    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1735}
1736
1737template <class _Tp, class _Allocator>
1738inline
1739typename deque<_Tp, _Allocator>::reference
1740deque<_Tp, _Allocator>::at(size_type __i)
1741{
1742    if (__i >= __base::size())
1743        __base::__throw_out_of_range();
1744    size_type __p = __base::__start_ + __i;
1745    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1746}
1747
1748template <class _Tp, class _Allocator>
1749inline
1750typename deque<_Tp, _Allocator>::const_reference
1751deque<_Tp, _Allocator>::at(size_type __i) const
1752{
1753    if (__i >= __base::size())
1754        __base::__throw_out_of_range();
1755    size_type __p = __base::__start_ + __i;
1756    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1757}
1758
1759template <class _Tp, class _Allocator>
1760inline
1761typename deque<_Tp, _Allocator>::reference
1762deque<_Tp, _Allocator>::front()
1763{
1764    return *(*(__base::__map_.begin() + __base::__start_ / __base::__block_size)
1765                                      + __base::__start_ % __base::__block_size);
1766}
1767
1768template <class _Tp, class _Allocator>
1769inline
1770typename deque<_Tp, _Allocator>::const_reference
1771deque<_Tp, _Allocator>::front() const
1772{
1773    return *(*(__base::__map_.begin() + __base::__start_ / __base::__block_size)
1774                                      + __base::__start_ % __base::__block_size);
1775}
1776
1777template <class _Tp, class _Allocator>
1778inline
1779typename deque<_Tp, _Allocator>::reference
1780deque<_Tp, _Allocator>::back()
1781{
1782    size_type __p = __base::size() + __base::__start_ - 1;
1783    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1784}
1785
1786template <class _Tp, class _Allocator>
1787inline
1788typename deque<_Tp, _Allocator>::const_reference
1789deque<_Tp, _Allocator>::back() const
1790{
1791    size_type __p = __base::size() + __base::__start_ - 1;
1792    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1793}
1794
1795template <class _Tp, class _Allocator>
1796void
1797deque<_Tp, _Allocator>::push_back(const value_type& __v)
1798{
1799    allocator_type& __a = __base::__alloc();
1800    if (__back_spare() == 0)
1801        __add_back_capacity();
1802    // __back_spare() >= 1
1803    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), __v);
1804    ++__base::size();
1805}
1806
1807#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1808
1809template <class _Tp, class _Allocator>
1810void
1811deque<_Tp, _Allocator>::push_back(value_type&& __v)
1812{
1813    allocator_type& __a = __base::__alloc();
1814    if (__back_spare() == 0)
1815        __add_back_capacity();
1816    // __back_spare() >= 1
1817    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::move(__v));
1818    ++__base::size();
1819}
1820
1821#ifndef _LIBCPP_HAS_NO_VARIADICS
1822
1823template <class _Tp, class _Allocator>
1824template <class... _Args>
1825typename deque<_Tp, _Allocator>::reference
1826deque<_Tp, _Allocator>::emplace_back(_Args&&... __args)
1827{
1828    allocator_type& __a = __base::__alloc();
1829    if (__back_spare() == 0)
1830        __add_back_capacity();
1831    // __back_spare() >= 1
1832    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()),
1833                              _VSTD::forward<_Args>(__args)...);
1834    ++__base::size();
1835    return *--__base::end();
1836}
1837
1838#endif  // _LIBCPP_HAS_NO_VARIADICS
1839#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1840
1841template <class _Tp, class _Allocator>
1842void
1843deque<_Tp, _Allocator>::push_front(const value_type& __v)
1844{
1845    allocator_type& __a = __base::__alloc();
1846    if (__front_spare() == 0)
1847        __add_front_capacity();
1848    // __front_spare() >= 1
1849    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), __v);
1850    --__base::__start_;
1851    ++__base::size();
1852}
1853
1854#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1855
1856template <class _Tp, class _Allocator>
1857void
1858deque<_Tp, _Allocator>::push_front(value_type&& __v)
1859{
1860    allocator_type& __a = __base::__alloc();
1861    if (__front_spare() == 0)
1862        __add_front_capacity();
1863    // __front_spare() >= 1
1864    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::move(__v));
1865    --__base::__start_;
1866    ++__base::size();
1867}
1868
1869#ifndef _LIBCPP_HAS_NO_VARIADICS
1870
1871template <class _Tp, class _Allocator>
1872template <class... _Args>
1873typename deque<_Tp, _Allocator>::reference
1874deque<_Tp, _Allocator>::emplace_front(_Args&&... __args)
1875{
1876    allocator_type& __a = __base::__alloc();
1877    if (__front_spare() == 0)
1878        __add_front_capacity();
1879    // __front_spare() >= 1
1880    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::forward<_Args>(__args)...);
1881    --__base::__start_;
1882    ++__base::size();
1883    return *__base::begin();
1884}
1885
1886#endif  // _LIBCPP_HAS_NO_VARIADICS
1887#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1888
1889template <class _Tp, class _Allocator>
1890typename deque<_Tp, _Allocator>::iterator
1891deque<_Tp, _Allocator>::insert(const_iterator __p, const value_type& __v)
1892{
1893    size_type __pos = __p - __base::begin();
1894    size_type __to_end = __base::size() - __pos;
1895    allocator_type& __a = __base::__alloc();
1896    if (__pos < __to_end)
1897    {   // insert by shifting things backward
1898        if (__front_spare() == 0)
1899            __add_front_capacity();
1900        // __front_spare() >= 1
1901        if (__pos == 0)
1902        {
1903            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), __v);
1904            --__base::__start_;
1905            ++__base::size();
1906        }
1907        else
1908        {
1909            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
1910            iterator __b = __base::begin();
1911            iterator __bm1 = _VSTD::prev(__b);
1912            if (__vt == pointer_traits<const_pointer>::pointer_to(*__b))
1913                __vt = pointer_traits<const_pointer>::pointer_to(*__bm1);
1914            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
1915            --__base::__start_;
1916            ++__base::size();
1917            if (__pos > 1)
1918                __b = __move_and_check(_VSTD::next(__b), __b + __pos, __b, __vt);
1919            *__b = *__vt;
1920        }
1921    }
1922    else
1923    {   // insert by shifting things forward
1924        if (__back_spare() == 0)
1925            __add_back_capacity();
1926        // __back_capacity >= 1
1927        size_type __de = __base::size() - __pos;
1928        if (__de == 0)
1929        {
1930            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), __v);
1931            ++__base::size();
1932        }
1933        else
1934        {
1935            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
1936            iterator __e = __base::end();
1937            iterator __em1 = _VSTD::prev(__e);
1938            if (__vt == pointer_traits<const_pointer>::pointer_to(*__em1))
1939                __vt = pointer_traits<const_pointer>::pointer_to(*__e);
1940            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
1941            ++__base::size();
1942            if (__de > 1)
1943                __e = __move_backward_and_check(__e - __de, __em1, __e, __vt);
1944            *--__e = *__vt;
1945        }
1946    }
1947    return __base::begin() + __pos;
1948}
1949
1950#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1951
1952template <class _Tp, class _Allocator>
1953typename deque<_Tp, _Allocator>::iterator
1954deque<_Tp, _Allocator>::insert(const_iterator __p, value_type&& __v)
1955{
1956    size_type __pos = __p - __base::begin();
1957    size_type __to_end = __base::size() - __pos;
1958    allocator_type& __a = __base::__alloc();
1959    if (__pos < __to_end)
1960    {   // insert by shifting things backward
1961        if (__front_spare() == 0)
1962            __add_front_capacity();
1963        // __front_spare() >= 1
1964        if (__pos == 0)
1965        {
1966            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::move(__v));
1967            --__base::__start_;
1968            ++__base::size();
1969        }
1970        else
1971        {
1972            iterator __b = __base::begin();
1973            iterator __bm1 = _VSTD::prev(__b);
1974            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
1975            --__base::__start_;
1976            ++__base::size();
1977            if (__pos > 1)
1978                __b = _VSTD::move(_VSTD::next(__b), __b + __pos, __b);
1979            *__b = _VSTD::move(__v);
1980        }
1981    }
1982    else
1983    {   // insert by shifting things forward
1984        if (__back_spare() == 0)
1985            __add_back_capacity();
1986        // __back_capacity >= 1
1987        size_type __de = __base::size() - __pos;
1988        if (__de == 0)
1989        {
1990            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::move(__v));
1991            ++__base::size();
1992        }
1993        else
1994        {
1995            iterator __e = __base::end();
1996            iterator __em1 = _VSTD::prev(__e);
1997            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
1998            ++__base::size();
1999            if (__de > 1)
2000                __e = _VSTD::move_backward(__e - __de, __em1, __e);
2001            *--__e = _VSTD::move(__v);
2002        }
2003    }
2004    return __base::begin() + __pos;
2005}
2006
2007#ifndef _LIBCPP_HAS_NO_VARIADICS
2008
2009template <class _Tp, class _Allocator>
2010template <class... _Args>
2011typename deque<_Tp, _Allocator>::iterator
2012deque<_Tp, _Allocator>::emplace(const_iterator __p, _Args&&... __args)
2013{
2014    size_type __pos = __p - __base::begin();
2015    size_type __to_end = __base::size() - __pos;
2016    allocator_type& __a = __base::__alloc();
2017    if (__pos < __to_end)
2018    {   // insert by shifting things backward
2019        if (__front_spare() == 0)
2020            __add_front_capacity();
2021        // __front_spare() >= 1
2022        if (__pos == 0)
2023        {
2024            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::forward<_Args>(__args)...);
2025            --__base::__start_;
2026            ++__base::size();
2027        }
2028        else
2029        {
2030            __temp_value<value_type, _Allocator> __tmp(this->__alloc(), _VSTD::forward<_Args>(__args)...);
2031            iterator __b = __base::begin();
2032            iterator __bm1 = _VSTD::prev(__b);
2033            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
2034            --__base::__start_;
2035            ++__base::size();
2036            if (__pos > 1)
2037                __b = _VSTD::move(_VSTD::next(__b), __b + __pos, __b);
2038            *__b = _VSTD::move(__tmp.get());
2039        }
2040    }
2041    else
2042    {   // insert by shifting things forward
2043        if (__back_spare() == 0)
2044            __add_back_capacity();
2045        // __back_capacity >= 1
2046        size_type __de = __base::size() - __pos;
2047        if (__de == 0)
2048        {
2049            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::forward<_Args>(__args)...);
2050            ++__base::size();
2051        }
2052        else
2053        {
2054            __temp_value<value_type, _Allocator> __tmp(this->__alloc(), _VSTD::forward<_Args>(__args)...);
2055            iterator __e = __base::end();
2056            iterator __em1 = _VSTD::prev(__e);
2057            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
2058            ++__base::size();
2059            if (__de > 1)
2060                __e = _VSTD::move_backward(__e - __de, __em1, __e);
2061            *--__e = _VSTD::move(__tmp.get());
2062        }
2063    }
2064    return __base::begin() + __pos;
2065}
2066
2067#endif  // _LIBCPP_HAS_NO_VARIADICS
2068#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2069
2070template <class _Tp, class _Allocator>
2071typename deque<_Tp, _Allocator>::iterator
2072deque<_Tp, _Allocator>::insert(const_iterator __p, size_type __n, const value_type& __v)
2073{
2074    size_type __pos = __p - __base::begin();
2075    size_type __to_end = __base::size() - __pos;
2076    allocator_type& __a = __base::__alloc();
2077    if (__pos < __to_end)
2078    {   // insert by shifting things backward
2079        if (__n > __front_spare())
2080            __add_front_capacity(__n - __front_spare());
2081        // __n <= __front_spare()
2082        iterator __old_begin = __base::begin();
2083        iterator __i = __old_begin;
2084        if (__n > __pos)
2085        {
2086            for (size_type __m = __n - __pos; __m; --__m, --__base::__start_, ++__base::size())
2087                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), __v);
2088            __n = __pos;
2089        }
2090        if (__n > 0)
2091        {
2092            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
2093            iterator __obn = __old_begin + __n;
2094            __move_construct_backward_and_check(__old_begin, __obn, __i, __vt);
2095            if (__n < __pos)
2096                __old_begin = __move_and_check(__obn, __old_begin + __pos, __old_begin, __vt);
2097            _VSTD::fill_n(__old_begin, __n, *__vt);
2098        }
2099    }
2100    else
2101    {   // insert by shifting things forward
2102        size_type __back_capacity = __back_spare();
2103        if (__n > __back_capacity)
2104            __add_back_capacity(__n - __back_capacity);
2105        // __n <= __back_capacity
2106        iterator __old_end = __base::end();
2107        iterator __i = __old_end;
2108        size_type __de = __base::size() - __pos;
2109        if (__n > __de)
2110        {
2111            for (size_type __m = __n - __de; __m; --__m, ++__i, ++__base::size())
2112                __alloc_traits::construct(__a, _VSTD::addressof(*__i), __v);
2113            __n = __de;
2114        }
2115        if (__n > 0)
2116        {
2117            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
2118            iterator __oen = __old_end - __n;
2119            __move_construct_and_check(__oen, __old_end, __i, __vt);
2120            if (__n < __de)
2121                __old_end = __move_backward_and_check(__old_end - __de, __oen, __old_end, __vt);
2122            _VSTD::fill_n(__old_end - __n, __n, *__vt);
2123        }
2124    }
2125    return __base::begin() + __pos;
2126}
2127
2128template <class _Tp, class _Allocator>
2129template <class _InputIter>
2130typename deque<_Tp, _Allocator>::iterator
2131deque<_Tp, _Allocator>::insert(const_iterator __p, _InputIter __f, _InputIter __l,
2132                               typename enable_if<__is_input_iterator<_InputIter>::value
2133                                               &&!__is_forward_iterator<_InputIter>::value>::type*)
2134{
2135    __split_buffer<value_type, allocator_type&> __buf(__base::__alloc());
2136    __buf.__construct_at_end(__f, __l);
2137    typedef typename __split_buffer<value_type, allocator_type&>::iterator __bi;
2138    return insert(__p, move_iterator<__bi>(__buf.begin()), move_iterator<__bi>(__buf.end()));
2139}
2140
2141template <class _Tp, class _Allocator>
2142template <class _ForwardIterator>
2143typename deque<_Tp, _Allocator>::iterator
2144deque<_Tp, _Allocator>::insert(const_iterator __p, _ForwardIterator __f, _ForwardIterator __l,
2145                               typename enable_if<__is_forward_iterator<_ForwardIterator>::value
2146                                               &&!__is_bidirectional_iterator<_ForwardIterator>::value>::type*)
2147{
2148    size_type __n = _VSTD::distance(__f, __l);
2149    __split_buffer<value_type, allocator_type&> __buf(__n, 0, __base::__alloc());
2150    __buf.__construct_at_end(__f, __l);
2151    typedef typename __split_buffer<value_type, allocator_type&>::iterator __fwd;
2152    return insert(__p, move_iterator<__fwd>(__buf.begin()), move_iterator<__fwd>(__buf.end()));
2153}
2154
2155template <class _Tp, class _Allocator>
2156template <class _BiIter>
2157typename deque<_Tp, _Allocator>::iterator
2158deque<_Tp, _Allocator>::insert(const_iterator __p, _BiIter __f, _BiIter __l,
2159                               typename enable_if<__is_bidirectional_iterator<_BiIter>::value>::type*)
2160{
2161    size_type __n = _VSTD::distance(__f, __l);
2162    size_type __pos = __p - __base::begin();
2163    size_type __to_end = __base::size() - __pos;
2164    allocator_type& __a = __base::__alloc();
2165    if (__pos < __to_end)
2166    {   // insert by shifting things backward
2167        if (__n > __front_spare())
2168            __add_front_capacity(__n - __front_spare());
2169        // __n <= __front_spare()
2170        iterator __old_begin = __base::begin();
2171        iterator __i = __old_begin;
2172        _BiIter __m = __f;
2173        if (__n > __pos)
2174        {
2175            __m = __pos < __n / 2 ? _VSTD::prev(__l, __pos) : _VSTD::next(__f, __n - __pos);
2176            for (_BiIter __j = __m; __j != __f; --__base::__start_, ++__base::size())
2177                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), *--__j);
2178            __n = __pos;
2179        }
2180        if (__n > 0)
2181        {
2182            iterator __obn = __old_begin + __n;
2183            for (iterator __j = __obn; __j != __old_begin;)
2184            {
2185                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), _VSTD::move(*--__j));
2186                --__base::__start_;
2187                ++__base::size();
2188            }
2189            if (__n < __pos)
2190                __old_begin = _VSTD::move(__obn, __old_begin + __pos, __old_begin);
2191            _VSTD::copy(__m, __l, __old_begin);
2192        }
2193    }
2194    else
2195    {   // insert by shifting things forward
2196        size_type __back_capacity = __back_spare();
2197        if (__n > __back_capacity)
2198            __add_back_capacity(__n - __back_capacity);
2199        // __n <= __back_capacity
2200        iterator __old_end = __base::end();
2201        iterator __i = __old_end;
2202        _BiIter __m = __l;
2203        size_type __de = __base::size() - __pos;
2204        if (__n > __de)
2205        {
2206            __m = __de < __n / 2 ? _VSTD::next(__f, __de) : _VSTD::prev(__l, __n - __de);
2207            for (_BiIter __j = __m; __j != __l; ++__i, (void) ++__j, ++__base::size())
2208                __alloc_traits::construct(__a, _VSTD::addressof(*__i), *__j);
2209            __n = __de;
2210        }
2211        if (__n > 0)
2212        {
2213            iterator __oen = __old_end - __n;
2214            for (iterator __j = __oen; __j != __old_end; ++__i, ++__j, ++__base::size())
2215                __alloc_traits::construct(__a, _VSTD::addressof(*__i), _VSTD::move(*__j));
2216            if (__n < __de)
2217                __old_end = _VSTD::move_backward(__old_end - __de, __oen, __old_end);
2218            _VSTD::copy_backward(__f, __m, __old_end);
2219        }
2220    }
2221    return __base::begin() + __pos;
2222}
2223
2224template <class _Tp, class _Allocator>
2225template <class _InpIter>
2226void
2227deque<_Tp, _Allocator>::__append(_InpIter __f, _InpIter __l,
2228                                 typename enable_if<__is_input_iterator<_InpIter>::value &&
2229                                                   !__is_forward_iterator<_InpIter>::value>::type*)
2230{
2231    for (; __f != __l; ++__f)
2232        push_back(*__f);
2233}
2234
2235template <class _Tp, class _Allocator>
2236template <class _ForIter>
2237void
2238deque<_Tp, _Allocator>::__append(_ForIter __f, _ForIter __l,
2239                                 typename enable_if<__is_forward_iterator<_ForIter>::value>::type*)
2240{
2241    size_type __n = _VSTD::distance(__f, __l);
2242    allocator_type& __a = __base::__alloc();
2243    size_type __back_capacity = __back_spare();
2244    if (__n > __back_capacity)
2245        __add_back_capacity(__n - __back_capacity);
2246    // __n <= __back_capacity
2247    for (iterator __i = __base::end(); __f != __l; ++__i, (void) ++__f, ++__base::size())
2248        __alloc_traits::construct(__a, _VSTD::addressof(*__i), *__f);
2249}
2250
2251template <class _Tp, class _Allocator>
2252void
2253deque<_Tp, _Allocator>::__append(size_type __n)
2254{
2255    allocator_type& __a = __base::__alloc();
2256    size_type __back_capacity = __back_spare();
2257    if (__n > __back_capacity)
2258        __add_back_capacity(__n - __back_capacity);
2259    // __n <= __back_capacity
2260    for (iterator __i = __base::end(); __n; --__n, ++__i, ++__base::size())
2261        __alloc_traits::construct(__a, _VSTD::addressof(*__i));
2262}
2263
2264template <class _Tp, class _Allocator>
2265void
2266deque<_Tp, _Allocator>::__append(size_type __n, const value_type& __v)
2267{
2268    allocator_type& __a = __base::__alloc();
2269    size_type __back_capacity = __back_spare();
2270    if (__n > __back_capacity)
2271        __add_back_capacity(__n - __back_capacity);
2272    // __n <= __back_capacity
2273    for (iterator __i = __base::end(); __n; --__n, ++__i, ++__base::size())
2274        __alloc_traits::construct(__a, _VSTD::addressof(*__i), __v);
2275}
2276
2277// Create front capacity for one block of elements.
2278// Strong guarantee.  Either do it or don't touch anything.
2279template <class _Tp, class _Allocator>
2280void
2281deque<_Tp, _Allocator>::__add_front_capacity()
2282{
2283    allocator_type& __a = __base::__alloc();
2284    if (__back_spare() >= __base::__block_size)
2285    {
2286        __base::__start_ += __base::__block_size;
2287        pointer __pt = __base::__map_.back();
2288        __base::__map_.pop_back();
2289        __base::__map_.push_front(__pt);
2290    }
2291    // Else if __base::__map_.size() < __base::__map_.capacity() then we need to allocate 1 buffer
2292    else if (__base::__map_.size() < __base::__map_.capacity())
2293    {   // we can put the new buffer into the map, but don't shift things around
2294        // until all buffers are allocated.  If we throw, we don't need to fix
2295        // anything up (any added buffers are undetectible)
2296        if (__base::__map_.__front_spare() > 0)
2297            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
2298        else
2299        {
2300            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2301            // Done allocating, reorder capacity
2302            pointer __pt = __base::__map_.back();
2303            __base::__map_.pop_back();
2304            __base::__map_.push_front(__pt);
2305        }
2306        __base::__start_ = __base::__map_.size() == 1 ?
2307                               __base::__block_size / 2 :
2308                               __base::__start_ + __base::__block_size;
2309    }
2310    // Else need to allocate 1 buffer, *and* we need to reallocate __map_.
2311    else
2312    {
2313        __split_buffer<pointer, typename __base::__pointer_allocator&>
2314            __buf(max<size_type>(2 * __base::__map_.capacity(), 1),
2315                  0, __base::__map_.__alloc());
2316
2317        typedef __allocator_destructor<_Allocator> _Dp;
2318        unique_ptr<pointer, _Dp> __hold(
2319            __alloc_traits::allocate(__a, __base::__block_size),
2320                _Dp(__a, __base::__block_size));
2321        __buf.push_back(__hold.get());
2322        __hold.release();
2323
2324        for (typename __base::__map_pointer __i = __base::__map_.begin();
2325                __i != __base::__map_.end(); ++__i)
2326            __buf.push_back(*__i);
2327        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
2328        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
2329        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
2330        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
2331        __base::__start_ = __base::__map_.size() == 1 ?
2332                               __base::__block_size / 2 :
2333                               __base::__start_ + __base::__block_size;
2334    }
2335}
2336
2337// Create front capacity for __n elements.
2338// Strong guarantee.  Either do it or don't touch anything.
2339template <class _Tp, class _Allocator>
2340void
2341deque<_Tp, _Allocator>::__add_front_capacity(size_type __n)
2342{
2343    allocator_type& __a = __base::__alloc();
2344    size_type __nb = __recommend_blocks(__n + __base::__map_.empty());
2345    // Number of unused blocks at back:
2346    size_type __back_capacity = __back_spare() / __base::__block_size;
2347    __back_capacity = _VSTD::min(__back_capacity, __nb);  // don't take more than you need
2348    __nb -= __back_capacity;  // number of blocks need to allocate
2349    // If __nb == 0, then we have sufficient capacity.
2350    if (__nb == 0)
2351    {
2352        __base::__start_ += __base::__block_size * __back_capacity;
2353        for (; __back_capacity > 0; --__back_capacity)
2354        {
2355            pointer __pt = __base::__map_.back();
2356            __base::__map_.pop_back();
2357            __base::__map_.push_front(__pt);
2358        }
2359    }
2360    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
2361    else if (__nb <= __base::__map_.capacity() - __base::__map_.size())
2362    {   // we can put the new buffers into the map, but don't shift things around
2363        // until all buffers are allocated.  If we throw, we don't need to fix
2364        // anything up (any added buffers are undetectible)
2365        for (; __nb > 0; --__nb, __base::__start_ += __base::__block_size - (__base::__map_.size() == 1))
2366        {
2367            if (__base::__map_.__front_spare() == 0)
2368                break;
2369            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
2370        }
2371        for (; __nb > 0; --__nb, ++__back_capacity)
2372            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2373        // Done allocating, reorder capacity
2374        __base::__start_ += __back_capacity * __base::__block_size;
2375        for (; __back_capacity > 0; --__back_capacity)
2376        {
2377            pointer __pt = __base::__map_.back();
2378            __base::__map_.pop_back();
2379            __base::__map_.push_front(__pt);
2380        }
2381    }
2382    // Else need to allocate __nb buffers, *and* we need to reallocate __map_.
2383    else
2384    {
2385        size_type __ds = (__nb + __back_capacity) * __base::__block_size - __base::__map_.empty();
2386        __split_buffer<pointer, typename __base::__pointer_allocator&>
2387            __buf(max<size_type>(2* __base::__map_.capacity(),
2388                                 __nb + __base::__map_.size()),
2389                  0, __base::__map_.__alloc());
2390#ifndef _LIBCPP_NO_EXCEPTIONS
2391        try
2392        {
2393#endif  // _LIBCPP_NO_EXCEPTIONS
2394            for (; __nb > 0; --__nb)
2395                __buf.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2396#ifndef _LIBCPP_NO_EXCEPTIONS
2397        }
2398        catch (...)
2399        {
2400            for (typename __base::__map_pointer __i = __buf.begin();
2401                    __i != __buf.end(); ++__i)
2402                __alloc_traits::deallocate(__a, *__i, __base::__block_size);
2403            throw;
2404        }
2405#endif  // _LIBCPP_NO_EXCEPTIONS
2406        for (; __back_capacity > 0; --__back_capacity)
2407        {
2408            __buf.push_back(__base::__map_.back());
2409            __base::__map_.pop_back();
2410        }
2411        for (typename __base::__map_pointer __i = __base::__map_.begin();
2412                __i != __base::__map_.end(); ++__i)
2413            __buf.push_back(*__i);
2414        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
2415        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
2416        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
2417        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
2418        __base::__start_ += __ds;
2419    }
2420}
2421
2422// Create back capacity for one block of elements.
2423// Strong guarantee.  Either do it or don't touch anything.
2424template <class _Tp, class _Allocator>
2425void
2426deque<_Tp, _Allocator>::__add_back_capacity()
2427{
2428    allocator_type& __a = __base::__alloc();
2429    if (__front_spare() >= __base::__block_size)
2430    {
2431        __base::__start_ -= __base::__block_size;
2432        pointer __pt = __base::__map_.front();
2433        __base::__map_.pop_front();
2434        __base::__map_.push_back(__pt);
2435    }
2436    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
2437    else if (__base::__map_.size() < __base::__map_.capacity())
2438    {   // we can put the new buffer into the map, but don't shift things around
2439        // until it is allocated.  If we throw, we don't need to fix
2440        // anything up (any added buffers are undetectible)
2441        if (__base::__map_.__back_spare() != 0)
2442            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2443        else
2444        {
2445            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
2446            // Done allocating, reorder capacity
2447            pointer __pt = __base::__map_.front();
2448            __base::__map_.pop_front();
2449            __base::__map_.push_back(__pt);
2450        }
2451    }
2452    // Else need to allocate 1 buffer, *and* we need to reallocate __map_.
2453    else
2454    {
2455        __split_buffer<pointer, typename __base::__pointer_allocator&>
2456            __buf(max<size_type>(2* __base::__map_.capacity(), 1),
2457                  __base::__map_.size(),
2458                  __base::__map_.__alloc());
2459
2460        typedef __allocator_destructor<_Allocator> _Dp;
2461        unique_ptr<pointer, _Dp> __hold(
2462            __alloc_traits::allocate(__a, __base::__block_size),
2463                _Dp(__a, __base::__block_size));
2464        __buf.push_back(__hold.get());
2465        __hold.release();
2466
2467        for (typename __base::__map_pointer __i = __base::__map_.end();
2468                __i != __base::__map_.begin();)
2469            __buf.push_front(*--__i);
2470        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
2471        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
2472        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
2473        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
2474    }
2475}
2476
2477// Create back capacity for __n elements.
2478// Strong guarantee.  Either do it or don't touch anything.
2479template <class _Tp, class _Allocator>
2480void
2481deque<_Tp, _Allocator>::__add_back_capacity(size_type __n)
2482{
2483    allocator_type& __a = __base::__alloc();
2484    size_type __nb = __recommend_blocks(__n + __base::__map_.empty());
2485    // Number of unused blocks at front:
2486    size_type __front_capacity = __front_spare() / __base::__block_size;
2487    __front_capacity = _VSTD::min(__front_capacity, __nb);  // don't take more than you need
2488    __nb -= __front_capacity;  // number of blocks need to allocate
2489    // If __nb == 0, then we have sufficient capacity.
2490    if (__nb == 0)
2491    {
2492        __base::__start_ -= __base::__block_size * __front_capacity;
2493        for (; __front_capacity > 0; --__front_capacity)
2494        {
2495            pointer __pt = __base::__map_.front();
2496            __base::__map_.pop_front();
2497            __base::__map_.push_back(__pt);
2498        }
2499    }
2500    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
2501    else if (__nb <= __base::__map_.capacity() - __base::__map_.size())
2502    {   // we can put the new buffers into the map, but don't shift things around
2503        // until all buffers are allocated.  If we throw, we don't need to fix
2504        // anything up (any added buffers are undetectible)
2505        for (; __nb > 0; --__nb)
2506        {
2507            if (__base::__map_.__back_spare() == 0)
2508                break;
2509            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2510        }
2511        for (; __nb > 0; --__nb, ++__front_capacity, __base::__start_ +=
2512                                 __base::__block_size - (__base::__map_.size() == 1))
2513            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
2514        // Done allocating, reorder capacity
2515        __base::__start_ -= __base::__block_size * __front_capacity;
2516        for (; __front_capacity > 0; --__front_capacity)
2517        {
2518            pointer __pt = __base::__map_.front();
2519            __base::__map_.pop_front();
2520            __base::__map_.push_back(__pt);
2521        }
2522    }
2523    // Else need to allocate __nb buffers, *and* we need to reallocate __map_.
2524    else
2525    {
2526        size_type __ds = __front_capacity * __base::__block_size;
2527        __split_buffer<pointer, typename __base::__pointer_allocator&>
2528            __buf(max<size_type>(2* __base::__map_.capacity(),
2529                                 __nb + __base::__map_.size()),
2530                  __base::__map_.size() - __front_capacity,
2531                  __base::__map_.__alloc());
2532#ifndef _LIBCPP_NO_EXCEPTIONS
2533        try
2534        {
2535#endif  // _LIBCPP_NO_EXCEPTIONS
2536            for (; __nb > 0; --__nb)
2537                __buf.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2538#ifndef _LIBCPP_NO_EXCEPTIONS
2539        }
2540        catch (...)
2541        {
2542            for (typename __base::__map_pointer __i = __buf.begin();
2543                    __i != __buf.end(); ++__i)
2544                __alloc_traits::deallocate(__a, *__i, __base::__block_size);
2545            throw;
2546        }
2547#endif  // _LIBCPP_NO_EXCEPTIONS
2548        for (; __front_capacity > 0; --__front_capacity)
2549        {
2550            __buf.push_back(__base::__map_.front());
2551            __base::__map_.pop_front();
2552        }
2553        for (typename __base::__map_pointer __i = __base::__map_.end();
2554                __i != __base::__map_.begin();)
2555            __buf.push_front(*--__i);
2556        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
2557        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
2558        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
2559        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
2560        __base::__start_ -= __ds;
2561    }
2562}
2563
2564template <class _Tp, class _Allocator>
2565void
2566deque<_Tp, _Allocator>::pop_front()
2567{
2568    allocator_type& __a = __base::__alloc();
2569    __alloc_traits::destroy(__a, __to_raw_pointer(*(__base::__map_.begin() +
2570                                                    __base::__start_ / __base::__block_size) +
2571                                                    __base::__start_ % __base::__block_size));
2572    --__base::size();
2573    if (++__base::__start_ >= 2 * __base::__block_size)
2574    {
2575        __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
2576        __base::__map_.pop_front();
2577        __base::__start_ -= __base::__block_size;
2578    }
2579}
2580
2581template <class _Tp, class _Allocator>
2582void
2583deque<_Tp, _Allocator>::pop_back()
2584{
2585    allocator_type& __a = __base::__alloc();
2586    size_type __p = __base::size() + __base::__start_ - 1;
2587    __alloc_traits::destroy(__a, __to_raw_pointer(*(__base::__map_.begin() +
2588                                                    __p / __base::__block_size) +
2589                                                    __p % __base::__block_size));
2590    --__base::size();
2591    if (__back_spare() >= 2 * __base::__block_size)
2592    {
2593        __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
2594        __base::__map_.pop_back();
2595    }
2596}
2597
2598// move assign [__f, __l) to [__r, __r + (__l-__f)).
2599// If __vt points into [__f, __l), then subtract (__f - __r) from __vt.
2600template <class _Tp, class _Allocator>
2601typename deque<_Tp, _Allocator>::iterator
2602deque<_Tp, _Allocator>::__move_and_check(iterator __f, iterator __l, iterator __r,
2603                                         const_pointer& __vt)
2604{
2605    // as if
2606    //   for (; __f != __l; ++__f, ++__r)
2607    //       *__r = _VSTD::move(*__f);
2608    difference_type __n = __l - __f;
2609    while (__n > 0)
2610    {
2611        pointer __fb = __f.__ptr_;
2612        pointer __fe = *__f.__m_iter_ + __base::__block_size;
2613        difference_type __bs = __fe - __fb;
2614        if (__bs > __n)
2615        {
2616            __bs = __n;
2617            __fe = __fb + __bs;
2618        }
2619        if (__fb <= __vt && __vt < __fe)
2620            __vt = (const_iterator(static_cast<__map_const_pointer>(__f.__m_iter_), __vt) -= __f - __r).__ptr_;
2621        __r = _VSTD::move(__fb, __fe, __r);
2622        __n -= __bs;
2623        __f += __bs;
2624    }
2625    return __r;
2626}
2627
2628// move assign [__f, __l) to [__r - (__l-__f), __r) backwards.
2629// If __vt points into [__f, __l), then add (__r - __l) to __vt.
2630template <class _Tp, class _Allocator>
2631typename deque<_Tp, _Allocator>::iterator
2632deque<_Tp, _Allocator>::__move_backward_and_check(iterator __f, iterator __l, iterator __r,
2633                                                  const_pointer& __vt)
2634{
2635    // as if
2636    //   while (__f != __l)
2637    //       *--__r = _VSTD::move(*--__l);
2638    difference_type __n = __l - __f;
2639    while (__n > 0)
2640    {
2641        --__l;
2642        pointer __lb = *__l.__m_iter_;
2643        pointer __le = __l.__ptr_ + 1;
2644        difference_type __bs = __le - __lb;
2645        if (__bs > __n)
2646        {
2647            __bs = __n;
2648            __lb = __le - __bs;
2649        }
2650        if (__lb <= __vt && __vt < __le)
2651            __vt = (const_iterator(static_cast<__map_const_pointer>(__l.__m_iter_), __vt) += __r - __l - 1).__ptr_;
2652        __r = _VSTD::move_backward(__lb, __le, __r);
2653        __n -= __bs;
2654        __l -= __bs - 1;
2655    }
2656    return __r;
2657}
2658
2659// move construct [__f, __l) to [__r, __r + (__l-__f)).
2660// If __vt points into [__f, __l), then add (__r - __f) to __vt.
2661template <class _Tp, class _Allocator>
2662void
2663deque<_Tp, _Allocator>::__move_construct_and_check(iterator __f, iterator __l,
2664                                                   iterator __r, const_pointer& __vt)
2665{
2666    allocator_type& __a = __base::__alloc();
2667    // as if
2668    //   for (; __f != __l; ++__r, ++__f, ++__base::size())
2669    //       __alloc_traits::construct(__a, _VSTD::addressof(*__r), _VSTD::move(*__f));
2670    difference_type __n = __l - __f;
2671    while (__n > 0)
2672    {
2673        pointer __fb = __f.__ptr_;
2674        pointer __fe = *__f.__m_iter_ + __base::__block_size;
2675        difference_type __bs = __fe - __fb;
2676        if (__bs > __n)
2677        {
2678            __bs = __n;
2679            __fe = __fb + __bs;
2680        }
2681        if (__fb <= __vt && __vt < __fe)
2682            __vt = (const_iterator(static_cast<__map_const_pointer>(__f.__m_iter_), __vt) += __r - __f).__ptr_;
2683        for (; __fb != __fe; ++__fb, ++__r, ++__base::size())
2684            __alloc_traits::construct(__a, _VSTD::addressof(*__r), _VSTD::move(*__fb));
2685        __n -= __bs;
2686        __f += __bs;
2687    }
2688}
2689
2690// move construct [__f, __l) to [__r - (__l-__f), __r) backwards.
2691// If __vt points into [__f, __l), then subtract (__l - __r) from __vt.
2692template <class _Tp, class _Allocator>
2693void
2694deque<_Tp, _Allocator>::__move_construct_backward_and_check(iterator __f, iterator __l,
2695                                                            iterator __r, const_pointer& __vt)
2696{
2697    allocator_type& __a = __base::__alloc();
2698    // as if
2699    //   for (iterator __j = __l; __j != __f;)
2700    //   {
2701    //       __alloc_traitsconstruct(__a, _VSTD::addressof(*--__r), _VSTD::move(*--__j));
2702    //       --__base::__start_;
2703    //       ++__base::size();
2704    //   }
2705    difference_type __n = __l - __f;
2706    while (__n > 0)
2707    {
2708        --__l;
2709        pointer __lb = *__l.__m_iter_;
2710        pointer __le = __l.__ptr_ + 1;
2711        difference_type __bs = __le - __lb;
2712        if (__bs > __n)
2713        {
2714            __bs = __n;
2715            __lb = __le - __bs;
2716        }
2717        if (__lb <= __vt && __vt < __le)
2718            __vt = (const_iterator(static_cast<__map_const_pointer>(__l.__m_iter_), __vt) -= __l - __r + 1).__ptr_;
2719        while (__le != __lb)
2720        {
2721            __alloc_traits::construct(__a, _VSTD::addressof(*--__r), _VSTD::move(*--__le));
2722            --__base::__start_;
2723            ++__base::size();
2724        }
2725        __n -= __bs;
2726        __l -= __bs - 1;
2727    }
2728}
2729
2730template <class _Tp, class _Allocator>
2731typename deque<_Tp, _Allocator>::iterator
2732deque<_Tp, _Allocator>::erase(const_iterator __f)
2733{
2734    iterator __b = __base::begin();
2735    difference_type __pos = __f - __b;
2736    iterator __p = __b + __pos;
2737    allocator_type& __a = __base::__alloc();
2738    if (static_cast<size_t>(__pos) <= (__base::size() - 1) / 2)
2739    {   // erase from front
2740        _VSTD::move_backward(__b, __p, _VSTD::next(__p));
2741        __alloc_traits::destroy(__a, _VSTD::addressof(*__b));
2742        --__base::size();
2743        ++__base::__start_;
2744        if (__front_spare() >= 2 * __base::__block_size)
2745        {
2746            __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
2747            __base::__map_.pop_front();
2748            __base::__start_ -= __base::__block_size;
2749        }
2750    }
2751    else
2752    {   // erase from back
2753        iterator __i = _VSTD::move(_VSTD::next(__p), __base::end(), __p);
2754        __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
2755        --__base::size();
2756        if (__back_spare() >= 2 * __base::__block_size)
2757        {
2758            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
2759            __base::__map_.pop_back();
2760        }
2761    }
2762    return __base::begin() + __pos;
2763}
2764
2765template <class _Tp, class _Allocator>
2766typename deque<_Tp, _Allocator>::iterator
2767deque<_Tp, _Allocator>::erase(const_iterator __f, const_iterator __l)
2768{
2769    difference_type __n = __l - __f;
2770    iterator __b = __base::begin();
2771    difference_type __pos = __f - __b;
2772    iterator __p = __b + __pos;
2773    if (__n > 0)
2774    {
2775        allocator_type& __a = __base::__alloc();
2776        if (static_cast<size_t>(__pos) <= (__base::size() - __n) / 2)
2777        {   // erase from front
2778            iterator __i = _VSTD::move_backward(__b, __p, __p + __n);
2779            for (; __b != __i; ++__b)
2780                __alloc_traits::destroy(__a, _VSTD::addressof(*__b));
2781            __base::size() -= __n;
2782            __base::__start_ += __n;
2783            while (__front_spare() >= 2 * __base::__block_size)
2784            {
2785                __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
2786                __base::__map_.pop_front();
2787                __base::__start_ -= __base::__block_size;
2788            }
2789        }
2790        else
2791        {   // erase from back
2792            iterator __i = _VSTD::move(__p + __n, __base::end(), __p);
2793            for (iterator __e = __base::end(); __i != __e; ++__i)
2794                __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
2795            __base::size() -= __n;
2796            while (__back_spare() >= 2 * __base::__block_size)
2797            {
2798                __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
2799                __base::__map_.pop_back();
2800            }
2801        }
2802    }
2803    return __base::begin() + __pos;
2804}
2805
2806template <class _Tp, class _Allocator>
2807void
2808deque<_Tp, _Allocator>::__erase_to_end(const_iterator __f)
2809{
2810    iterator __e = __base::end();
2811    difference_type __n = __e - __f;
2812    if (__n > 0)
2813    {
2814        allocator_type& __a = __base::__alloc();
2815        iterator __b = __base::begin();
2816        difference_type __pos = __f - __b;
2817        for (iterator __p = __b + __pos; __p != __e; ++__p)
2818            __alloc_traits::destroy(__a, _VSTD::addressof(*__p));
2819        __base::size() -= __n;
2820        while (__back_spare() >= 2 * __base::__block_size)
2821        {
2822            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
2823            __base::__map_.pop_back();
2824        }
2825    }
2826}
2827
2828template <class _Tp, class _Allocator>
2829inline
2830void
2831deque<_Tp, _Allocator>::swap(deque& __c)
2832#if _LIBCPP_STD_VER >= 14
2833        _NOEXCEPT
2834#else
2835        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
2836                    __is_nothrow_swappable<allocator_type>::value)
2837#endif
2838{
2839    __base::swap(__c);
2840}
2841
2842template <class _Tp, class _Allocator>
2843inline
2844void
2845deque<_Tp, _Allocator>::clear() _NOEXCEPT
2846{
2847    __base::clear();
2848}
2849
2850template <class _Tp, class _Allocator>
2851inline _LIBCPP_INLINE_VISIBILITY
2852bool
2853operator==(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2854{
2855    const typename deque<_Tp, _Allocator>::size_type __sz = __x.size();
2856    return __sz == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
2857}
2858
2859template <class _Tp, class _Allocator>
2860inline _LIBCPP_INLINE_VISIBILITY
2861bool
2862operator!=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2863{
2864    return !(__x == __y);
2865}
2866
2867template <class _Tp, class _Allocator>
2868inline _LIBCPP_INLINE_VISIBILITY
2869bool
2870operator< (const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2871{
2872    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
2873}
2874
2875template <class _Tp, class _Allocator>
2876inline _LIBCPP_INLINE_VISIBILITY
2877bool
2878operator> (const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2879{
2880    return __y < __x;
2881}
2882
2883template <class _Tp, class _Allocator>
2884inline _LIBCPP_INLINE_VISIBILITY
2885bool
2886operator>=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2887{
2888    return !(__x < __y);
2889}
2890
2891template <class _Tp, class _Allocator>
2892inline _LIBCPP_INLINE_VISIBILITY
2893bool
2894operator<=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2895{
2896    return !(__y < __x);
2897}
2898
2899template <class _Tp, class _Allocator>
2900inline _LIBCPP_INLINE_VISIBILITY
2901void
2902swap(deque<_Tp, _Allocator>& __x, deque<_Tp, _Allocator>& __y)
2903    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
2904{
2905    __x.swap(__y);
2906}
2907
2908_LIBCPP_END_NAMESPACE_STD
2909
2910#endif  // _LIBCPP_DEQUE
2911