xref: /freebsd-12.1/contrib/libc++/include/deque (revision 540d2a8b)
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);  // reference in C++17
114    template <class... Args> reference emplace_back(Args&&... args);   // reference in C++17
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_CXX03_LANG
972    __deque_base(__deque_base&& __c)
973        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
974    __deque_base(__deque_base&& __c, const allocator_type& __a);
975#endif  // _LIBCPP_CXX03_LANG
976
977    void swap(__deque_base& __c)
978#if _LIBCPP_STD_VER >= 14
979        _NOEXCEPT;
980#else
981        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
982                    __is_nothrow_swappable<allocator_type>::value);
983#endif
984protected:
985    void clear() _NOEXCEPT;
986
987    bool __invariants() const;
988
989    _LIBCPP_INLINE_VISIBILITY
990    void __move_assign(__deque_base& __c)
991        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
992                   is_nothrow_move_assignable<allocator_type>::value)
993    {
994        __map_ = _VSTD::move(__c.__map_);
995        __start_ = __c.__start_;
996        size() = __c.size();
997        __move_assign_alloc(__c);
998        __c.__start_ = __c.size() = 0;
999    }
1000
1001    _LIBCPP_INLINE_VISIBILITY
1002    void __move_assign_alloc(__deque_base& __c)
1003        _NOEXCEPT_(!__alloc_traits::propagate_on_container_move_assignment::value ||
1004                   is_nothrow_move_assignable<allocator_type>::value)
1005        {__move_assign_alloc(__c, integral_constant<bool,
1006                      __alloc_traits::propagate_on_container_move_assignment::value>());}
1007
1008private:
1009    _LIBCPP_INLINE_VISIBILITY
1010    void __move_assign_alloc(__deque_base& __c, true_type)
1011        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
1012        {
1013            __alloc() = _VSTD::move(__c.__alloc());
1014        }
1015
1016    _LIBCPP_INLINE_VISIBILITY
1017    void __move_assign_alloc(__deque_base&, false_type) _NOEXCEPT
1018        {}
1019};
1020
1021template <class _Tp, class _Allocator>
1022const typename __deque_base<_Tp, _Allocator>::difference_type
1023    __deque_base<_Tp, _Allocator>::__block_size =
1024        __deque_block_size<value_type, difference_type>::value;
1025
1026template <class _Tp, class _Allocator>
1027bool
1028__deque_base<_Tp, _Allocator>::__invariants() const
1029{
1030    if (!__map_.__invariants())
1031        return false;
1032    if (__map_.size() >= size_type(-1) / __block_size)
1033        return false;
1034    for (typename __map::const_iterator __i = __map_.begin(), __e = __map_.end();
1035         __i != __e; ++__i)
1036        if (*__i == nullptr)
1037            return false;
1038    if (__map_.size() != 0)
1039    {
1040        if (size() >= __map_.size() * __block_size)
1041            return false;
1042        if (__start_ >= __map_.size() * __block_size - size())
1043            return false;
1044    }
1045    else
1046    {
1047        if (size() != 0)
1048            return false;
1049        if (__start_ != 0)
1050            return false;
1051    }
1052    return true;
1053}
1054
1055template <class _Tp, class _Allocator>
1056typename __deque_base<_Tp, _Allocator>::iterator
1057__deque_base<_Tp, _Allocator>::begin() _NOEXCEPT
1058{
1059    __map_pointer __mp = __map_.begin() + __start_ / __block_size;
1060    return iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
1061}
1062
1063template <class _Tp, class _Allocator>
1064typename __deque_base<_Tp, _Allocator>::const_iterator
1065__deque_base<_Tp, _Allocator>::begin() const _NOEXCEPT
1066{
1067    __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __start_ / __block_size);
1068    return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
1069}
1070
1071template <class _Tp, class _Allocator>
1072typename __deque_base<_Tp, _Allocator>::iterator
1073__deque_base<_Tp, _Allocator>::end() _NOEXCEPT
1074{
1075    size_type __p = size() + __start_;
1076    __map_pointer __mp = __map_.begin() + __p / __block_size;
1077    return iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
1078}
1079
1080template <class _Tp, class _Allocator>
1081typename __deque_base<_Tp, _Allocator>::const_iterator
1082__deque_base<_Tp, _Allocator>::end() const _NOEXCEPT
1083{
1084    size_type __p = size() + __start_;
1085    __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __p / __block_size);
1086    return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
1087}
1088
1089template <class _Tp, class _Allocator>
1090inline
1091__deque_base<_Tp, _Allocator>::__deque_base()
1092    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
1093    : __start_(0), __size_(0) {}
1094
1095template <class _Tp, class _Allocator>
1096inline
1097__deque_base<_Tp, _Allocator>::__deque_base(const allocator_type& __a)
1098    : __map_(__pointer_allocator(__a)), __start_(0), __size_(0, __a) {}
1099
1100template <class _Tp, class _Allocator>
1101__deque_base<_Tp, _Allocator>::~__deque_base()
1102{
1103    clear();
1104    typename __map::iterator __i = __map_.begin();
1105    typename __map::iterator __e = __map_.end();
1106    for (; __i != __e; ++__i)
1107        __alloc_traits::deallocate(__alloc(), *__i, __block_size);
1108}
1109
1110#ifndef _LIBCPP_CXX03_LANG
1111
1112template <class _Tp, class _Allocator>
1113__deque_base<_Tp, _Allocator>::__deque_base(__deque_base&& __c)
1114    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
1115    : __map_(_VSTD::move(__c.__map_)),
1116      __start_(_VSTD::move(__c.__start_)),
1117      __size_(_VSTD::move(__c.__size_))
1118{
1119    __c.__start_ = 0;
1120    __c.size() = 0;
1121}
1122
1123template <class _Tp, class _Allocator>
1124__deque_base<_Tp, _Allocator>::__deque_base(__deque_base&& __c, const allocator_type& __a)
1125    : __map_(_VSTD::move(__c.__map_), __pointer_allocator(__a)),
1126      __start_(_VSTD::move(__c.__start_)),
1127      __size_(_VSTD::move(__c.size()), __a)
1128{
1129    if (__a == __c.__alloc())
1130    {
1131        __c.__start_ = 0;
1132        __c.size() = 0;
1133    }
1134    else
1135    {
1136        __map_.clear();
1137        __start_ = 0;
1138        size() = 0;
1139    }
1140}
1141
1142#endif  // _LIBCPP_CXX03_LANG
1143
1144template <class _Tp, class _Allocator>
1145void
1146__deque_base<_Tp, _Allocator>::swap(__deque_base& __c)
1147#if _LIBCPP_STD_VER >= 14
1148        _NOEXCEPT
1149#else
1150        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
1151                    __is_nothrow_swappable<allocator_type>::value)
1152#endif
1153{
1154    __map_.swap(__c.__map_);
1155    _VSTD::swap(__start_, __c.__start_);
1156    _VSTD::swap(size(), __c.size());
1157    __swap_allocator(__alloc(), __c.__alloc());
1158}
1159
1160template <class _Tp, class _Allocator>
1161void
1162__deque_base<_Tp, _Allocator>::clear() _NOEXCEPT
1163{
1164    allocator_type& __a = __alloc();
1165    for (iterator __i = begin(), __e = end(); __i != __e; ++__i)
1166        __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
1167    size() = 0;
1168    while (__map_.size() > 2)
1169    {
1170        __alloc_traits::deallocate(__a, __map_.front(), __block_size);
1171        __map_.pop_front();
1172    }
1173    switch (__map_.size())
1174    {
1175    case 1:
1176        __start_ = __block_size / 2;
1177        break;
1178    case 2:
1179        __start_ = __block_size;
1180        break;
1181    }
1182}
1183
1184template <class _Tp, class _Allocator /*= allocator<_Tp>*/>
1185class _LIBCPP_TEMPLATE_VIS deque
1186    : private __deque_base<_Tp, _Allocator>
1187{
1188public:
1189    // types:
1190
1191    typedef _Tp value_type;
1192    typedef _Allocator allocator_type;
1193
1194    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
1195                  "Allocator::value_type must be same type as value_type");
1196
1197    typedef __deque_base<value_type, allocator_type> __base;
1198
1199    typedef typename __base::__alloc_traits        __alloc_traits;
1200    typedef typename __base::reference             reference;
1201    typedef typename __base::const_reference       const_reference;
1202    typedef typename __base::iterator              iterator;
1203    typedef typename __base::const_iterator        const_iterator;
1204    typedef typename __base::size_type             size_type;
1205    typedef typename __base::difference_type       difference_type;
1206
1207    typedef typename __base::pointer               pointer;
1208    typedef typename __base::const_pointer         const_pointer;
1209    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
1210    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
1211
1212    // construct/copy/destroy:
1213    _LIBCPP_INLINE_VISIBILITY
1214    deque()
1215        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
1216        {}
1217    _LIBCPP_INLINE_VISIBILITY explicit deque(const allocator_type& __a) : __base(__a) {}
1218    explicit deque(size_type __n);
1219#if _LIBCPP_STD_VER > 11
1220    explicit deque(size_type __n, const _Allocator& __a);
1221#endif
1222    deque(size_type __n, const value_type& __v);
1223    deque(size_type __n, const value_type& __v, const allocator_type& __a);
1224    template <class _InputIter>
1225        deque(_InputIter __f, _InputIter __l,
1226              typename enable_if<__is_input_iterator<_InputIter>::value>::type* = 0);
1227    template <class _InputIter>
1228        deque(_InputIter __f, _InputIter __l, const allocator_type& __a,
1229              typename enable_if<__is_input_iterator<_InputIter>::value>::type* = 0);
1230    deque(const deque& __c);
1231    deque(const deque& __c, const allocator_type& __a);
1232
1233    deque& operator=(const deque& __c);
1234
1235#ifndef _LIBCPP_CXX03_LANG
1236    deque(initializer_list<value_type> __il);
1237    deque(initializer_list<value_type> __il, const allocator_type& __a);
1238
1239    _LIBCPP_INLINE_VISIBILITY
1240    deque& operator=(initializer_list<value_type> __il) {assign(__il); return *this;}
1241
1242    _LIBCPP_INLINE_VISIBILITY
1243    deque(deque&& __c) _NOEXCEPT_(is_nothrow_move_constructible<__base>::value);
1244    _LIBCPP_INLINE_VISIBILITY
1245    deque(deque&& __c, const allocator_type& __a);
1246    _LIBCPP_INLINE_VISIBILITY
1247    deque& operator=(deque&& __c)
1248        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
1249                   is_nothrow_move_assignable<allocator_type>::value);
1250
1251    _LIBCPP_INLINE_VISIBILITY
1252    void assign(initializer_list<value_type> __il) {assign(__il.begin(), __il.end());}
1253#endif  // _LIBCPP_CXX03_LANG
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
1264    _LIBCPP_INLINE_VISIBILITY
1265    allocator_type get_allocator() const _NOEXCEPT;
1266
1267    // iterators:
1268
1269    _LIBCPP_INLINE_VISIBILITY
1270    iterator       begin() _NOEXCEPT       {return __base::begin();}
1271    _LIBCPP_INLINE_VISIBILITY
1272    const_iterator begin() const _NOEXCEPT {return __base::begin();}
1273    _LIBCPP_INLINE_VISIBILITY
1274    iterator       end() _NOEXCEPT         {return __base::end();}
1275    _LIBCPP_INLINE_VISIBILITY
1276    const_iterator end()   const _NOEXCEPT {return __base::end();}
1277
1278    _LIBCPP_INLINE_VISIBILITY
1279    reverse_iterator       rbegin() _NOEXCEPT
1280        {return       reverse_iterator(__base::end());}
1281    _LIBCPP_INLINE_VISIBILITY
1282    const_reverse_iterator rbegin() const _NOEXCEPT
1283        {return const_reverse_iterator(__base::end());}
1284    _LIBCPP_INLINE_VISIBILITY
1285    reverse_iterator       rend() _NOEXCEPT
1286        {return       reverse_iterator(__base::begin());}
1287    _LIBCPP_INLINE_VISIBILITY
1288    const_reverse_iterator rend()   const _NOEXCEPT
1289        {return const_reverse_iterator(__base::begin());}
1290
1291    _LIBCPP_INLINE_VISIBILITY
1292    const_iterator         cbegin()  const _NOEXCEPT
1293        {return __base::begin();}
1294    _LIBCPP_INLINE_VISIBILITY
1295    const_iterator         cend()    const _NOEXCEPT
1296        {return __base::end();}
1297    _LIBCPP_INLINE_VISIBILITY
1298    const_reverse_iterator crbegin() const _NOEXCEPT
1299        {return const_reverse_iterator(__base::end());}
1300    _LIBCPP_INLINE_VISIBILITY
1301    const_reverse_iterator crend()   const _NOEXCEPT
1302        {return const_reverse_iterator(__base::begin());}
1303
1304    // capacity:
1305    _LIBCPP_INLINE_VISIBILITY
1306    size_type size() const _NOEXCEPT {return __base::size();}
1307    _LIBCPP_INLINE_VISIBILITY
1308    size_type max_size() const _NOEXCEPT
1309        {return std::min<size_type>(
1310            __alloc_traits::max_size(__base::__alloc()),
1311            numeric_limits<difference_type>::max());}
1312    void resize(size_type __n);
1313    void resize(size_type __n, const value_type& __v);
1314    void shrink_to_fit() _NOEXCEPT;
1315    _LIBCPP_INLINE_VISIBILITY
1316    bool empty() const _NOEXCEPT {return __base::size() == 0;}
1317
1318    // element access:
1319    _LIBCPP_INLINE_VISIBILITY
1320    reference operator[](size_type __i);
1321    _LIBCPP_INLINE_VISIBILITY
1322    const_reference operator[](size_type __i) const;
1323    _LIBCPP_INLINE_VISIBILITY
1324    reference at(size_type __i);
1325    _LIBCPP_INLINE_VISIBILITY
1326    const_reference at(size_type __i) const;
1327    _LIBCPP_INLINE_VISIBILITY
1328    reference front();
1329    _LIBCPP_INLINE_VISIBILITY
1330    const_reference front() const;
1331    _LIBCPP_INLINE_VISIBILITY
1332    reference back();
1333    _LIBCPP_INLINE_VISIBILITY
1334    const_reference back() const;
1335
1336    // 23.2.2.3 modifiers:
1337    void push_front(const value_type& __v);
1338    void push_back(const value_type& __v);
1339#ifndef _LIBCPP_CXX03_LANG
1340#if _LIBCPP_STD_VER > 14
1341    template <class... _Args> reference emplace_front(_Args&&... __args);
1342    template <class... _Args> reference emplace_back (_Args&&... __args);
1343#else
1344    template <class... _Args> void      emplace_front(_Args&&... __args);
1345    template <class... _Args> void      emplace_back (_Args&&... __args);
1346#endif
1347    template <class... _Args> iterator emplace(const_iterator __p, _Args&&... __args);
1348
1349    void push_front(value_type&& __v);
1350    void push_back(value_type&& __v);
1351    iterator insert(const_iterator __p, value_type&& __v);
1352
1353    _LIBCPP_INLINE_VISIBILITY
1354    iterator insert(const_iterator __p, initializer_list<value_type> __il)
1355        {return insert(__p, __il.begin(), __il.end());}
1356#endif  // _LIBCPP_CXX03_LANG
1357
1358    iterator insert(const_iterator __p, const value_type& __v);
1359    iterator insert(const_iterator __p, size_type __n, const value_type& __v);
1360    template <class _InputIter>
1361        iterator insert(const_iterator __p, _InputIter __f, _InputIter __l,
1362                         typename enable_if<__is_input_iterator<_InputIter>::value
1363                                         &&!__is_forward_iterator<_InputIter>::value>::type* = 0);
1364    template <class _ForwardIterator>
1365        iterator insert(const_iterator __p, _ForwardIterator __f, _ForwardIterator __l,
1366                               typename enable_if<__is_forward_iterator<_ForwardIterator>::value
1367                                         &&!__is_bidirectional_iterator<_ForwardIterator>::value>::type* = 0);
1368    template <class _BiIter>
1369        iterator insert(const_iterator __p, _BiIter __f, _BiIter __l,
1370                         typename enable_if<__is_bidirectional_iterator<_BiIter>::value>::type* = 0);
1371
1372    void pop_front();
1373    void pop_back();
1374    iterator erase(const_iterator __p);
1375    iterator erase(const_iterator __f, const_iterator __l);
1376
1377    _LIBCPP_INLINE_VISIBILITY
1378    void swap(deque& __c)
1379#if _LIBCPP_STD_VER >= 14
1380        _NOEXCEPT;
1381#else
1382        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
1383                   __is_nothrow_swappable<allocator_type>::value);
1384#endif
1385    _LIBCPP_INLINE_VISIBILITY
1386    void clear() _NOEXCEPT;
1387
1388    _LIBCPP_INLINE_VISIBILITY
1389    bool __invariants() const {return __base::__invariants();}
1390private:
1391    typedef typename __base::__map_const_pointer __map_const_pointer;
1392
1393    _LIBCPP_INLINE_VISIBILITY
1394    static size_type __recommend_blocks(size_type __n)
1395    {
1396        return __n / __base::__block_size + (__n % __base::__block_size != 0);
1397    }
1398    _LIBCPP_INLINE_VISIBILITY
1399    size_type __capacity() const
1400    {
1401        return __base::__map_.size() == 0 ? 0 : __base::__map_.size() * __base::__block_size - 1;
1402    }
1403    _LIBCPP_INLINE_VISIBILITY
1404    size_type __front_spare() const
1405    {
1406        return __base::__start_;
1407    }
1408    _LIBCPP_INLINE_VISIBILITY
1409    size_type __back_spare() const
1410    {
1411        return __capacity() - (__base::__start_ + __base::size());
1412    }
1413
1414    template <class _InpIter>
1415        void __append(_InpIter __f, _InpIter __l,
1416                 typename enable_if<__is_input_iterator<_InpIter>::value &&
1417                                   !__is_forward_iterator<_InpIter>::value>::type* = 0);
1418    template <class _ForIter>
1419        void __append(_ForIter __f, _ForIter __l,
1420                      typename enable_if<__is_forward_iterator<_ForIter>::value>::type* = 0);
1421    void __append(size_type __n);
1422    void __append(size_type __n, const value_type& __v);
1423    void __erase_to_end(const_iterator __f);
1424    void __add_front_capacity();
1425    void __add_front_capacity(size_type __n);
1426    void __add_back_capacity();
1427    void __add_back_capacity(size_type __n);
1428    iterator __move_and_check(iterator __f, iterator __l, iterator __r,
1429                              const_pointer& __vt);
1430    iterator __move_backward_and_check(iterator __f, iterator __l, iterator __r,
1431                                       const_pointer& __vt);
1432    void __move_construct_and_check(iterator __f, iterator __l,
1433                                    iterator __r, const_pointer& __vt);
1434    void __move_construct_backward_and_check(iterator __f, iterator __l,
1435                                             iterator __r, const_pointer& __vt);
1436
1437    _LIBCPP_INLINE_VISIBILITY
1438    void __copy_assign_alloc(const deque& __c)
1439        {__copy_assign_alloc(__c, integral_constant<bool,
1440                      __alloc_traits::propagate_on_container_copy_assignment::value>());}
1441
1442    _LIBCPP_INLINE_VISIBILITY
1443    void __copy_assign_alloc(const deque& __c, true_type)
1444        {
1445            if (__base::__alloc() != __c.__alloc())
1446            {
1447                clear();
1448                shrink_to_fit();
1449            }
1450            __base::__alloc() = __c.__alloc();
1451            __base::__map_.__alloc() = __c.__map_.__alloc();
1452        }
1453
1454    _LIBCPP_INLINE_VISIBILITY
1455    void __copy_assign_alloc(const deque&, false_type)
1456        {}
1457
1458    void __move_assign(deque& __c, true_type)
1459        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
1460    void __move_assign(deque& __c, false_type);
1461};
1462
1463template <class _Tp, class _Allocator>
1464deque<_Tp, _Allocator>::deque(size_type __n)
1465{
1466    if (__n > 0)
1467        __append(__n);
1468}
1469
1470#if _LIBCPP_STD_VER > 11
1471template <class _Tp, class _Allocator>
1472deque<_Tp, _Allocator>::deque(size_type __n, const _Allocator& __a)
1473    : __base(__a)
1474{
1475    if (__n > 0)
1476        __append(__n);
1477}
1478#endif
1479
1480template <class _Tp, class _Allocator>
1481deque<_Tp, _Allocator>::deque(size_type __n, const value_type& __v)
1482{
1483    if (__n > 0)
1484        __append(__n, __v);
1485}
1486
1487template <class _Tp, class _Allocator>
1488deque<_Tp, _Allocator>::deque(size_type __n, const value_type& __v, const allocator_type& __a)
1489    : __base(__a)
1490{
1491    if (__n > 0)
1492        __append(__n, __v);
1493}
1494
1495template <class _Tp, class _Allocator>
1496template <class _InputIter>
1497deque<_Tp, _Allocator>::deque(_InputIter __f, _InputIter __l,
1498              typename enable_if<__is_input_iterator<_InputIter>::value>::type*)
1499{
1500    __append(__f, __l);
1501}
1502
1503template <class _Tp, class _Allocator>
1504template <class _InputIter>
1505deque<_Tp, _Allocator>::deque(_InputIter __f, _InputIter __l, const allocator_type& __a,
1506              typename enable_if<__is_input_iterator<_InputIter>::value>::type*)
1507    : __base(__a)
1508{
1509    __append(__f, __l);
1510}
1511
1512template <class _Tp, class _Allocator>
1513deque<_Tp, _Allocator>::deque(const deque& __c)
1514    : __base(__alloc_traits::select_on_container_copy_construction(__c.__alloc()))
1515{
1516    __append(__c.begin(), __c.end());
1517}
1518
1519template <class _Tp, class _Allocator>
1520deque<_Tp, _Allocator>::deque(const deque& __c, const allocator_type& __a)
1521    : __base(__a)
1522{
1523    __append(__c.begin(), __c.end());
1524}
1525
1526template <class _Tp, class _Allocator>
1527deque<_Tp, _Allocator>&
1528deque<_Tp, _Allocator>::operator=(const deque& __c)
1529{
1530    if (this != &__c)
1531    {
1532        __copy_assign_alloc(__c);
1533        assign(__c.begin(), __c.end());
1534    }
1535    return *this;
1536}
1537
1538#ifndef _LIBCPP_CXX03_LANG
1539
1540template <class _Tp, class _Allocator>
1541deque<_Tp, _Allocator>::deque(initializer_list<value_type> __il)
1542{
1543    __append(__il.begin(), __il.end());
1544}
1545
1546template <class _Tp, class _Allocator>
1547deque<_Tp, _Allocator>::deque(initializer_list<value_type> __il, const allocator_type& __a)
1548    : __base(__a)
1549{
1550    __append(__il.begin(), __il.end());
1551}
1552
1553template <class _Tp, class _Allocator>
1554inline
1555deque<_Tp, _Allocator>::deque(deque&& __c)
1556    _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
1557    : __base(_VSTD::move(__c))
1558{
1559}
1560
1561template <class _Tp, class _Allocator>
1562inline
1563deque<_Tp, _Allocator>::deque(deque&& __c, const allocator_type& __a)
1564    : __base(_VSTD::move(__c), __a)
1565{
1566    if (__a != __c.__alloc())
1567    {
1568        typedef move_iterator<iterator> _Ip;
1569        assign(_Ip(__c.begin()), _Ip(__c.end()));
1570    }
1571}
1572
1573template <class _Tp, class _Allocator>
1574inline
1575deque<_Tp, _Allocator>&
1576deque<_Tp, _Allocator>::operator=(deque&& __c)
1577        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
1578                   is_nothrow_move_assignable<allocator_type>::value)
1579{
1580    __move_assign(__c, integral_constant<bool,
1581          __alloc_traits::propagate_on_container_move_assignment::value>());
1582    return *this;
1583}
1584
1585template <class _Tp, class _Allocator>
1586void
1587deque<_Tp, _Allocator>::__move_assign(deque& __c, false_type)
1588{
1589    if (__base::__alloc() != __c.__alloc())
1590    {
1591        typedef move_iterator<iterator> _Ip;
1592        assign(_Ip(__c.begin()), _Ip(__c.end()));
1593    }
1594    else
1595        __move_assign(__c, true_type());
1596}
1597
1598template <class _Tp, class _Allocator>
1599void
1600deque<_Tp, _Allocator>::__move_assign(deque& __c, true_type)
1601    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
1602{
1603    clear();
1604    shrink_to_fit();
1605    __base::__move_assign(__c);
1606}
1607
1608#endif  // _LIBCPP_CXX03_LANG
1609
1610template <class _Tp, class _Allocator>
1611template <class _InputIter>
1612void
1613deque<_Tp, _Allocator>::assign(_InputIter __f, _InputIter __l,
1614                               typename enable_if<__is_input_iterator<_InputIter>::value &&
1615                                                 !__is_random_access_iterator<_InputIter>::value>::type*)
1616{
1617    iterator __i = __base::begin();
1618    iterator __e = __base::end();
1619    for (; __f != __l && __i != __e; ++__f, (void) ++__i)
1620        *__i = *__f;
1621    if (__f != __l)
1622        __append(__f, __l);
1623    else
1624        __erase_to_end(__i);
1625}
1626
1627template <class _Tp, class _Allocator>
1628template <class _RAIter>
1629void
1630deque<_Tp, _Allocator>::assign(_RAIter __f, _RAIter __l,
1631                               typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
1632{
1633    if (static_cast<size_type>(__l - __f) > __base::size())
1634    {
1635        _RAIter __m = __f + __base::size();
1636        _VSTD::copy(__f, __m, __base::begin());
1637        __append(__m, __l);
1638    }
1639    else
1640        __erase_to_end(_VSTD::copy(__f, __l, __base::begin()));
1641}
1642
1643template <class _Tp, class _Allocator>
1644void
1645deque<_Tp, _Allocator>::assign(size_type __n, const value_type& __v)
1646{
1647    if (__n > __base::size())
1648    {
1649        _VSTD::fill_n(__base::begin(), __base::size(), __v);
1650        __n -= __base::size();
1651        __append(__n, __v);
1652    }
1653    else
1654        __erase_to_end(_VSTD::fill_n(__base::begin(), __n, __v));
1655}
1656
1657template <class _Tp, class _Allocator>
1658inline
1659_Allocator
1660deque<_Tp, _Allocator>::get_allocator() const _NOEXCEPT
1661{
1662    return __base::__alloc();
1663}
1664
1665template <class _Tp, class _Allocator>
1666void
1667deque<_Tp, _Allocator>::resize(size_type __n)
1668{
1669    if (__n > __base::size())
1670        __append(__n - __base::size());
1671    else if (__n < __base::size())
1672        __erase_to_end(__base::begin() + __n);
1673}
1674
1675template <class _Tp, class _Allocator>
1676void
1677deque<_Tp, _Allocator>::resize(size_type __n, const value_type& __v)
1678{
1679    if (__n > __base::size())
1680        __append(__n - __base::size(), __v);
1681    else if (__n < __base::size())
1682        __erase_to_end(__base::begin() + __n);
1683}
1684
1685template <class _Tp, class _Allocator>
1686void
1687deque<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
1688{
1689    allocator_type& __a = __base::__alloc();
1690    if (empty())
1691    {
1692        while (__base::__map_.size() > 0)
1693        {
1694            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
1695            __base::__map_.pop_back();
1696        }
1697        __base::__start_ = 0;
1698    }
1699    else
1700    {
1701        if (__front_spare() >= __base::__block_size)
1702        {
1703            __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
1704            __base::__map_.pop_front();
1705            __base::__start_ -= __base::__block_size;
1706        }
1707        if (__back_spare() >= __base::__block_size)
1708        {
1709            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
1710            __base::__map_.pop_back();
1711        }
1712    }
1713    __base::__map_.shrink_to_fit();
1714}
1715
1716template <class _Tp, class _Allocator>
1717inline
1718typename deque<_Tp, _Allocator>::reference
1719deque<_Tp, _Allocator>::operator[](size_type __i)
1720{
1721    size_type __p = __base::__start_ + __i;
1722    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1723}
1724
1725template <class _Tp, class _Allocator>
1726inline
1727typename deque<_Tp, _Allocator>::const_reference
1728deque<_Tp, _Allocator>::operator[](size_type __i) const
1729{
1730    size_type __p = __base::__start_ + __i;
1731    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1732}
1733
1734template <class _Tp, class _Allocator>
1735inline
1736typename deque<_Tp, _Allocator>::reference
1737deque<_Tp, _Allocator>::at(size_type __i)
1738{
1739    if (__i >= __base::size())
1740        __base::__throw_out_of_range();
1741    size_type __p = __base::__start_ + __i;
1742    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1743}
1744
1745template <class _Tp, class _Allocator>
1746inline
1747typename deque<_Tp, _Allocator>::const_reference
1748deque<_Tp, _Allocator>::at(size_type __i) const
1749{
1750    if (__i >= __base::size())
1751        __base::__throw_out_of_range();
1752    size_type __p = __base::__start_ + __i;
1753    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1754}
1755
1756template <class _Tp, class _Allocator>
1757inline
1758typename deque<_Tp, _Allocator>::reference
1759deque<_Tp, _Allocator>::front()
1760{
1761    return *(*(__base::__map_.begin() + __base::__start_ / __base::__block_size)
1762                                      + __base::__start_ % __base::__block_size);
1763}
1764
1765template <class _Tp, class _Allocator>
1766inline
1767typename deque<_Tp, _Allocator>::const_reference
1768deque<_Tp, _Allocator>::front() const
1769{
1770    return *(*(__base::__map_.begin() + __base::__start_ / __base::__block_size)
1771                                      + __base::__start_ % __base::__block_size);
1772}
1773
1774template <class _Tp, class _Allocator>
1775inline
1776typename deque<_Tp, _Allocator>::reference
1777deque<_Tp, _Allocator>::back()
1778{
1779    size_type __p = __base::size() + __base::__start_ - 1;
1780    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1781}
1782
1783template <class _Tp, class _Allocator>
1784inline
1785typename deque<_Tp, _Allocator>::const_reference
1786deque<_Tp, _Allocator>::back() const
1787{
1788    size_type __p = __base::size() + __base::__start_ - 1;
1789    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
1790}
1791
1792template <class _Tp, class _Allocator>
1793void
1794deque<_Tp, _Allocator>::push_back(const value_type& __v)
1795{
1796    allocator_type& __a = __base::__alloc();
1797    if (__back_spare() == 0)
1798        __add_back_capacity();
1799    // __back_spare() >= 1
1800    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), __v);
1801    ++__base::size();
1802}
1803
1804template <class _Tp, class _Allocator>
1805void
1806deque<_Tp, _Allocator>::push_front(const value_type& __v)
1807{
1808    allocator_type& __a = __base::__alloc();
1809    if (__front_spare() == 0)
1810        __add_front_capacity();
1811    // __front_spare() >= 1
1812    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), __v);
1813    --__base::__start_;
1814    ++__base::size();
1815}
1816
1817#ifndef _LIBCPP_CXX03_LANG
1818template <class _Tp, class _Allocator>
1819void
1820deque<_Tp, _Allocator>::push_back(value_type&& __v)
1821{
1822    allocator_type& __a = __base::__alloc();
1823    if (__back_spare() == 0)
1824        __add_back_capacity();
1825    // __back_spare() >= 1
1826    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::move(__v));
1827    ++__base::size();
1828}
1829
1830template <class _Tp, class _Allocator>
1831template <class... _Args>
1832#if _LIBCPP_STD_VER > 14
1833typename deque<_Tp, _Allocator>::reference
1834#else
1835void
1836#endif
1837deque<_Tp, _Allocator>::emplace_back(_Args&&... __args)
1838{
1839    allocator_type& __a = __base::__alloc();
1840    if (__back_spare() == 0)
1841        __add_back_capacity();
1842    // __back_spare() >= 1
1843    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()),
1844                              _VSTD::forward<_Args>(__args)...);
1845    ++__base::size();
1846#if _LIBCPP_STD_VER > 14
1847    return *--__base::end();
1848#endif
1849}
1850
1851template <class _Tp, class _Allocator>
1852void
1853deque<_Tp, _Allocator>::push_front(value_type&& __v)
1854{
1855    allocator_type& __a = __base::__alloc();
1856    if (__front_spare() == 0)
1857        __add_front_capacity();
1858    // __front_spare() >= 1
1859    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::move(__v));
1860    --__base::__start_;
1861    ++__base::size();
1862}
1863
1864
1865template <class _Tp, class _Allocator>
1866template <class... _Args>
1867#if _LIBCPP_STD_VER > 14
1868typename deque<_Tp, _Allocator>::reference
1869#else
1870void
1871#endif
1872deque<_Tp, _Allocator>::emplace_front(_Args&&... __args)
1873{
1874    allocator_type& __a = __base::__alloc();
1875    if (__front_spare() == 0)
1876        __add_front_capacity();
1877    // __front_spare() >= 1
1878    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::forward<_Args>(__args)...);
1879    --__base::__start_;
1880    ++__base::size();
1881#if _LIBCPP_STD_VER > 14
1882    return *__base::begin();
1883#endif
1884}
1885
1886template <class _Tp, class _Allocator>
1887typename deque<_Tp, _Allocator>::iterator
1888deque<_Tp, _Allocator>::insert(const_iterator __p, value_type&& __v)
1889{
1890    size_type __pos = __p - __base::begin();
1891    size_type __to_end = __base::size() - __pos;
1892    allocator_type& __a = __base::__alloc();
1893    if (__pos < __to_end)
1894    {   // insert by shifting things backward
1895        if (__front_spare() == 0)
1896            __add_front_capacity();
1897        // __front_spare() >= 1
1898        if (__pos == 0)
1899        {
1900            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::move(__v));
1901            --__base::__start_;
1902            ++__base::size();
1903        }
1904        else
1905        {
1906            iterator __b = __base::begin();
1907            iterator __bm1 = _VSTD::prev(__b);
1908            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
1909            --__base::__start_;
1910            ++__base::size();
1911            if (__pos > 1)
1912                __b = _VSTD::move(_VSTD::next(__b), __b + __pos, __b);
1913            *__b = _VSTD::move(__v);
1914        }
1915    }
1916    else
1917    {   // insert by shifting things forward
1918        if (__back_spare() == 0)
1919            __add_back_capacity();
1920        // __back_capacity >= 1
1921        size_type __de = __base::size() - __pos;
1922        if (__de == 0)
1923        {
1924            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::move(__v));
1925            ++__base::size();
1926        }
1927        else
1928        {
1929            iterator __e = __base::end();
1930            iterator __em1 = _VSTD::prev(__e);
1931            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
1932            ++__base::size();
1933            if (__de > 1)
1934                __e = _VSTD::move_backward(__e - __de, __em1, __e);
1935            *--__e = _VSTD::move(__v);
1936        }
1937    }
1938    return __base::begin() + __pos;
1939}
1940
1941template <class _Tp, class _Allocator>
1942template <class... _Args>
1943typename deque<_Tp, _Allocator>::iterator
1944deque<_Tp, _Allocator>::emplace(const_iterator __p, _Args&&... __args)
1945{
1946    size_type __pos = __p - __base::begin();
1947    size_type __to_end = __base::size() - __pos;
1948    allocator_type& __a = __base::__alloc();
1949    if (__pos < __to_end)
1950    {   // insert by shifting things backward
1951        if (__front_spare() == 0)
1952            __add_front_capacity();
1953        // __front_spare() >= 1
1954        if (__pos == 0)
1955        {
1956            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::forward<_Args>(__args)...);
1957            --__base::__start_;
1958            ++__base::size();
1959        }
1960        else
1961        {
1962            __temp_value<value_type, _Allocator> __tmp(this->__alloc(), _VSTD::forward<_Args>(__args)...);
1963            iterator __b = __base::begin();
1964            iterator __bm1 = _VSTD::prev(__b);
1965            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
1966            --__base::__start_;
1967            ++__base::size();
1968            if (__pos > 1)
1969                __b = _VSTD::move(_VSTD::next(__b), __b + __pos, __b);
1970            *__b = _VSTD::move(__tmp.get());
1971        }
1972    }
1973    else
1974    {   // insert by shifting things forward
1975        if (__back_spare() == 0)
1976            __add_back_capacity();
1977        // __back_capacity >= 1
1978        size_type __de = __base::size() - __pos;
1979        if (__de == 0)
1980        {
1981            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::forward<_Args>(__args)...);
1982            ++__base::size();
1983        }
1984        else
1985        {
1986            __temp_value<value_type, _Allocator> __tmp(this->__alloc(), _VSTD::forward<_Args>(__args)...);
1987            iterator __e = __base::end();
1988            iterator __em1 = _VSTD::prev(__e);
1989            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
1990            ++__base::size();
1991            if (__de > 1)
1992                __e = _VSTD::move_backward(__e - __de, __em1, __e);
1993            *--__e = _VSTD::move(__tmp.get());
1994        }
1995    }
1996    return __base::begin() + __pos;
1997}
1998
1999#endif  // _LIBCPP_CXX03_LANG
2000
2001
2002template <class _Tp, class _Allocator>
2003typename deque<_Tp, _Allocator>::iterator
2004deque<_Tp, _Allocator>::insert(const_iterator __p, const value_type& __v)
2005{
2006    size_type __pos = __p - __base::begin();
2007    size_type __to_end = __base::size() - __pos;
2008    allocator_type& __a = __base::__alloc();
2009    if (__pos < __to_end)
2010    {   // insert by shifting things backward
2011        if (__front_spare() == 0)
2012            __add_front_capacity();
2013        // __front_spare() >= 1
2014        if (__pos == 0)
2015        {
2016            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), __v);
2017            --__base::__start_;
2018            ++__base::size();
2019        }
2020        else
2021        {
2022            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
2023            iterator __b = __base::begin();
2024            iterator __bm1 = _VSTD::prev(__b);
2025            if (__vt == pointer_traits<const_pointer>::pointer_to(*__b))
2026                __vt = pointer_traits<const_pointer>::pointer_to(*__bm1);
2027            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
2028            --__base::__start_;
2029            ++__base::size();
2030            if (__pos > 1)
2031                __b = __move_and_check(_VSTD::next(__b), __b + __pos, __b, __vt);
2032            *__b = *__vt;
2033        }
2034    }
2035    else
2036    {   // insert by shifting things forward
2037        if (__back_spare() == 0)
2038            __add_back_capacity();
2039        // __back_capacity >= 1
2040        size_type __de = __base::size() - __pos;
2041        if (__de == 0)
2042        {
2043            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), __v);
2044            ++__base::size();
2045        }
2046        else
2047        {
2048            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
2049            iterator __e = __base::end();
2050            iterator __em1 = _VSTD::prev(__e);
2051            if (__vt == pointer_traits<const_pointer>::pointer_to(*__em1))
2052                __vt = pointer_traits<const_pointer>::pointer_to(*__e);
2053            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
2054            ++__base::size();
2055            if (__de > 1)
2056                __e = __move_backward_and_check(__e - __de, __em1, __e, __vt);
2057            *--__e = *__vt;
2058        }
2059    }
2060    return __base::begin() + __pos;
2061}
2062
2063template <class _Tp, class _Allocator>
2064typename deque<_Tp, _Allocator>::iterator
2065deque<_Tp, _Allocator>::insert(const_iterator __p, size_type __n, const value_type& __v)
2066{
2067    size_type __pos = __p - __base::begin();
2068    size_type __to_end = __base::size() - __pos;
2069    allocator_type& __a = __base::__alloc();
2070    if (__pos < __to_end)
2071    {   // insert by shifting things backward
2072        if (__n > __front_spare())
2073            __add_front_capacity(__n - __front_spare());
2074        // __n <= __front_spare()
2075        iterator __old_begin = __base::begin();
2076        iterator __i = __old_begin;
2077        if (__n > __pos)
2078        {
2079            for (size_type __m = __n - __pos; __m; --__m, --__base::__start_, ++__base::size())
2080                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), __v);
2081            __n = __pos;
2082        }
2083        if (__n > 0)
2084        {
2085            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
2086            iterator __obn = __old_begin + __n;
2087            __move_construct_backward_and_check(__old_begin, __obn, __i, __vt);
2088            if (__n < __pos)
2089                __old_begin = __move_and_check(__obn, __old_begin + __pos, __old_begin, __vt);
2090            _VSTD::fill_n(__old_begin, __n, *__vt);
2091        }
2092    }
2093    else
2094    {   // insert by shifting things forward
2095        size_type __back_capacity = __back_spare();
2096        if (__n > __back_capacity)
2097            __add_back_capacity(__n - __back_capacity);
2098        // __n <= __back_capacity
2099        iterator __old_end = __base::end();
2100        iterator __i = __old_end;
2101        size_type __de = __base::size() - __pos;
2102        if (__n > __de)
2103        {
2104            for (size_type __m = __n - __de; __m; --__m, ++__i, ++__base::size())
2105                __alloc_traits::construct(__a, _VSTD::addressof(*__i), __v);
2106            __n = __de;
2107        }
2108        if (__n > 0)
2109        {
2110            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
2111            iterator __oen = __old_end - __n;
2112            __move_construct_and_check(__oen, __old_end, __i, __vt);
2113            if (__n < __de)
2114                __old_end = __move_backward_and_check(__old_end - __de, __oen, __old_end, __vt);
2115            _VSTD::fill_n(__old_end - __n, __n, *__vt);
2116        }
2117    }
2118    return __base::begin() + __pos;
2119}
2120
2121template <class _Tp, class _Allocator>
2122template <class _InputIter>
2123typename deque<_Tp, _Allocator>::iterator
2124deque<_Tp, _Allocator>::insert(const_iterator __p, _InputIter __f, _InputIter __l,
2125                               typename enable_if<__is_input_iterator<_InputIter>::value
2126                                               &&!__is_forward_iterator<_InputIter>::value>::type*)
2127{
2128    __split_buffer<value_type, allocator_type&> __buf(__base::__alloc());
2129    __buf.__construct_at_end(__f, __l);
2130    typedef typename __split_buffer<value_type, allocator_type&>::iterator __bi;
2131    return insert(__p, move_iterator<__bi>(__buf.begin()), move_iterator<__bi>(__buf.end()));
2132}
2133
2134template <class _Tp, class _Allocator>
2135template <class _ForwardIterator>
2136typename deque<_Tp, _Allocator>::iterator
2137deque<_Tp, _Allocator>::insert(const_iterator __p, _ForwardIterator __f, _ForwardIterator __l,
2138                               typename enable_if<__is_forward_iterator<_ForwardIterator>::value
2139                                               &&!__is_bidirectional_iterator<_ForwardIterator>::value>::type*)
2140{
2141    size_type __n = _VSTD::distance(__f, __l);
2142    __split_buffer<value_type, allocator_type&> __buf(__n, 0, __base::__alloc());
2143    __buf.__construct_at_end(__f, __l);
2144    typedef typename __split_buffer<value_type, allocator_type&>::iterator __fwd;
2145    return insert(__p, move_iterator<__fwd>(__buf.begin()), move_iterator<__fwd>(__buf.end()));
2146}
2147
2148template <class _Tp, class _Allocator>
2149template <class _BiIter>
2150typename deque<_Tp, _Allocator>::iterator
2151deque<_Tp, _Allocator>::insert(const_iterator __p, _BiIter __f, _BiIter __l,
2152                               typename enable_if<__is_bidirectional_iterator<_BiIter>::value>::type*)
2153{
2154    size_type __n = _VSTD::distance(__f, __l);
2155    size_type __pos = __p - __base::begin();
2156    size_type __to_end = __base::size() - __pos;
2157    allocator_type& __a = __base::__alloc();
2158    if (__pos < __to_end)
2159    {   // insert by shifting things backward
2160        if (__n > __front_spare())
2161            __add_front_capacity(__n - __front_spare());
2162        // __n <= __front_spare()
2163        iterator __old_begin = __base::begin();
2164        iterator __i = __old_begin;
2165        _BiIter __m = __f;
2166        if (__n > __pos)
2167        {
2168            __m = __pos < __n / 2 ? _VSTD::prev(__l, __pos) : _VSTD::next(__f, __n - __pos);
2169            for (_BiIter __j = __m; __j != __f; --__base::__start_, ++__base::size())
2170                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), *--__j);
2171            __n = __pos;
2172        }
2173        if (__n > 0)
2174        {
2175            iterator __obn = __old_begin + __n;
2176            for (iterator __j = __obn; __j != __old_begin;)
2177            {
2178                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), _VSTD::move(*--__j));
2179                --__base::__start_;
2180                ++__base::size();
2181            }
2182            if (__n < __pos)
2183                __old_begin = _VSTD::move(__obn, __old_begin + __pos, __old_begin);
2184            _VSTD::copy(__m, __l, __old_begin);
2185        }
2186    }
2187    else
2188    {   // insert by shifting things forward
2189        size_type __back_capacity = __back_spare();
2190        if (__n > __back_capacity)
2191            __add_back_capacity(__n - __back_capacity);
2192        // __n <= __back_capacity
2193        iterator __old_end = __base::end();
2194        iterator __i = __old_end;
2195        _BiIter __m = __l;
2196        size_type __de = __base::size() - __pos;
2197        if (__n > __de)
2198        {
2199            __m = __de < __n / 2 ? _VSTD::next(__f, __de) : _VSTD::prev(__l, __n - __de);
2200            for (_BiIter __j = __m; __j != __l; ++__i, (void) ++__j, ++__base::size())
2201                __alloc_traits::construct(__a, _VSTD::addressof(*__i), *__j);
2202            __n = __de;
2203        }
2204        if (__n > 0)
2205        {
2206            iterator __oen = __old_end - __n;
2207            for (iterator __j = __oen; __j != __old_end; ++__i, ++__j, ++__base::size())
2208                __alloc_traits::construct(__a, _VSTD::addressof(*__i), _VSTD::move(*__j));
2209            if (__n < __de)
2210                __old_end = _VSTD::move_backward(__old_end - __de, __oen, __old_end);
2211            _VSTD::copy_backward(__f, __m, __old_end);
2212        }
2213    }
2214    return __base::begin() + __pos;
2215}
2216
2217template <class _Tp, class _Allocator>
2218template <class _InpIter>
2219void
2220deque<_Tp, _Allocator>::__append(_InpIter __f, _InpIter __l,
2221                                 typename enable_if<__is_input_iterator<_InpIter>::value &&
2222                                                   !__is_forward_iterator<_InpIter>::value>::type*)
2223{
2224    for (; __f != __l; ++__f)
2225        push_back(*__f);
2226}
2227
2228template <class _Tp, class _Allocator>
2229template <class _ForIter>
2230void
2231deque<_Tp, _Allocator>::__append(_ForIter __f, _ForIter __l,
2232                                 typename enable_if<__is_forward_iterator<_ForIter>::value>::type*)
2233{
2234    size_type __n = _VSTD::distance(__f, __l);
2235    allocator_type& __a = __base::__alloc();
2236    size_type __back_capacity = __back_spare();
2237    if (__n > __back_capacity)
2238        __add_back_capacity(__n - __back_capacity);
2239    // __n <= __back_capacity
2240    for (iterator __i = __base::end(); __f != __l; ++__i, (void) ++__f, ++__base::size())
2241        __alloc_traits::construct(__a, _VSTD::addressof(*__i), *__f);
2242}
2243
2244template <class _Tp, class _Allocator>
2245void
2246deque<_Tp, _Allocator>::__append(size_type __n)
2247{
2248    allocator_type& __a = __base::__alloc();
2249    size_type __back_capacity = __back_spare();
2250    if (__n > __back_capacity)
2251        __add_back_capacity(__n - __back_capacity);
2252    // __n <= __back_capacity
2253    for (iterator __i = __base::end(); __n; --__n, ++__i, ++__base::size())
2254        __alloc_traits::construct(__a, _VSTD::addressof(*__i));
2255}
2256
2257template <class _Tp, class _Allocator>
2258void
2259deque<_Tp, _Allocator>::__append(size_type __n, const value_type& __v)
2260{
2261    allocator_type& __a = __base::__alloc();
2262    size_type __back_capacity = __back_spare();
2263    if (__n > __back_capacity)
2264        __add_back_capacity(__n - __back_capacity);
2265    // __n <= __back_capacity
2266    for (iterator __i = __base::end(); __n; --__n, ++__i, ++__base::size())
2267        __alloc_traits::construct(__a, _VSTD::addressof(*__i), __v);
2268}
2269
2270// Create front capacity for one block of elements.
2271// Strong guarantee.  Either do it or don't touch anything.
2272template <class _Tp, class _Allocator>
2273void
2274deque<_Tp, _Allocator>::__add_front_capacity()
2275{
2276    allocator_type& __a = __base::__alloc();
2277    if (__back_spare() >= __base::__block_size)
2278    {
2279        __base::__start_ += __base::__block_size;
2280        pointer __pt = __base::__map_.back();
2281        __base::__map_.pop_back();
2282        __base::__map_.push_front(__pt);
2283    }
2284    // Else if __base::__map_.size() < __base::__map_.capacity() then we need to allocate 1 buffer
2285    else if (__base::__map_.size() < __base::__map_.capacity())
2286    {   // we can put the new buffer into the map, but don't shift things around
2287        // until all buffers are allocated.  If we throw, we don't need to fix
2288        // anything up (any added buffers are undetectible)
2289        if (__base::__map_.__front_spare() > 0)
2290            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
2291        else
2292        {
2293            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2294            // Done allocating, reorder capacity
2295            pointer __pt = __base::__map_.back();
2296            __base::__map_.pop_back();
2297            __base::__map_.push_front(__pt);
2298        }
2299        __base::__start_ = __base::__map_.size() == 1 ?
2300                               __base::__block_size / 2 :
2301                               __base::__start_ + __base::__block_size;
2302    }
2303    // Else need to allocate 1 buffer, *and* we need to reallocate __map_.
2304    else
2305    {
2306        __split_buffer<pointer, typename __base::__pointer_allocator&>
2307            __buf(max<size_type>(2 * __base::__map_.capacity(), 1),
2308                  0, __base::__map_.__alloc());
2309
2310        typedef __allocator_destructor<_Allocator> _Dp;
2311        unique_ptr<pointer, _Dp> __hold(
2312            __alloc_traits::allocate(__a, __base::__block_size),
2313                _Dp(__a, __base::__block_size));
2314        __buf.push_back(__hold.get());
2315        __hold.release();
2316
2317        for (typename __base::__map_pointer __i = __base::__map_.begin();
2318                __i != __base::__map_.end(); ++__i)
2319            __buf.push_back(*__i);
2320        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
2321        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
2322        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
2323        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
2324        __base::__start_ = __base::__map_.size() == 1 ?
2325                               __base::__block_size / 2 :
2326                               __base::__start_ + __base::__block_size;
2327    }
2328}
2329
2330// Create front capacity for __n elements.
2331// Strong guarantee.  Either do it or don't touch anything.
2332template <class _Tp, class _Allocator>
2333void
2334deque<_Tp, _Allocator>::__add_front_capacity(size_type __n)
2335{
2336    allocator_type& __a = __base::__alloc();
2337    size_type __nb = __recommend_blocks(__n + __base::__map_.empty());
2338    // Number of unused blocks at back:
2339    size_type __back_capacity = __back_spare() / __base::__block_size;
2340    __back_capacity = _VSTD::min(__back_capacity, __nb);  // don't take more than you need
2341    __nb -= __back_capacity;  // number of blocks need to allocate
2342    // If __nb == 0, then we have sufficient capacity.
2343    if (__nb == 0)
2344    {
2345        __base::__start_ += __base::__block_size * __back_capacity;
2346        for (; __back_capacity > 0; --__back_capacity)
2347        {
2348            pointer __pt = __base::__map_.back();
2349            __base::__map_.pop_back();
2350            __base::__map_.push_front(__pt);
2351        }
2352    }
2353    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
2354    else if (__nb <= __base::__map_.capacity() - __base::__map_.size())
2355    {   // we can put the new buffers into the map, but don't shift things around
2356        // until all buffers are allocated.  If we throw, we don't need to fix
2357        // anything up (any added buffers are undetectible)
2358        for (; __nb > 0; --__nb, __base::__start_ += __base::__block_size - (__base::__map_.size() == 1))
2359        {
2360            if (__base::__map_.__front_spare() == 0)
2361                break;
2362            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
2363        }
2364        for (; __nb > 0; --__nb, ++__back_capacity)
2365            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2366        // Done allocating, reorder capacity
2367        __base::__start_ += __back_capacity * __base::__block_size;
2368        for (; __back_capacity > 0; --__back_capacity)
2369        {
2370            pointer __pt = __base::__map_.back();
2371            __base::__map_.pop_back();
2372            __base::__map_.push_front(__pt);
2373        }
2374    }
2375    // Else need to allocate __nb buffers, *and* we need to reallocate __map_.
2376    else
2377    {
2378        size_type __ds = (__nb + __back_capacity) * __base::__block_size - __base::__map_.empty();
2379        __split_buffer<pointer, typename __base::__pointer_allocator&>
2380            __buf(max<size_type>(2* __base::__map_.capacity(),
2381                                 __nb + __base::__map_.size()),
2382                  0, __base::__map_.__alloc());
2383#ifndef _LIBCPP_NO_EXCEPTIONS
2384        try
2385        {
2386#endif  // _LIBCPP_NO_EXCEPTIONS
2387            for (; __nb > 0; --__nb)
2388                __buf.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2389#ifndef _LIBCPP_NO_EXCEPTIONS
2390        }
2391        catch (...)
2392        {
2393            for (typename __base::__map_pointer __i = __buf.begin();
2394                    __i != __buf.end(); ++__i)
2395                __alloc_traits::deallocate(__a, *__i, __base::__block_size);
2396            throw;
2397        }
2398#endif  // _LIBCPP_NO_EXCEPTIONS
2399        for (; __back_capacity > 0; --__back_capacity)
2400        {
2401            __buf.push_back(__base::__map_.back());
2402            __base::__map_.pop_back();
2403        }
2404        for (typename __base::__map_pointer __i = __base::__map_.begin();
2405                __i != __base::__map_.end(); ++__i)
2406            __buf.push_back(*__i);
2407        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
2408        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
2409        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
2410        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
2411        __base::__start_ += __ds;
2412    }
2413}
2414
2415// Create back capacity for one block of elements.
2416// Strong guarantee.  Either do it or don't touch anything.
2417template <class _Tp, class _Allocator>
2418void
2419deque<_Tp, _Allocator>::__add_back_capacity()
2420{
2421    allocator_type& __a = __base::__alloc();
2422    if (__front_spare() >= __base::__block_size)
2423    {
2424        __base::__start_ -= __base::__block_size;
2425        pointer __pt = __base::__map_.front();
2426        __base::__map_.pop_front();
2427        __base::__map_.push_back(__pt);
2428    }
2429    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
2430    else if (__base::__map_.size() < __base::__map_.capacity())
2431    {   // we can put the new buffer into the map, but don't shift things around
2432        // until it is allocated.  If we throw, we don't need to fix
2433        // anything up (any added buffers are undetectible)
2434        if (__base::__map_.__back_spare() != 0)
2435            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2436        else
2437        {
2438            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
2439            // Done allocating, reorder capacity
2440            pointer __pt = __base::__map_.front();
2441            __base::__map_.pop_front();
2442            __base::__map_.push_back(__pt);
2443        }
2444    }
2445    // Else need to allocate 1 buffer, *and* we need to reallocate __map_.
2446    else
2447    {
2448        __split_buffer<pointer, typename __base::__pointer_allocator&>
2449            __buf(max<size_type>(2* __base::__map_.capacity(), 1),
2450                  __base::__map_.size(),
2451                  __base::__map_.__alloc());
2452
2453        typedef __allocator_destructor<_Allocator> _Dp;
2454        unique_ptr<pointer, _Dp> __hold(
2455            __alloc_traits::allocate(__a, __base::__block_size),
2456                _Dp(__a, __base::__block_size));
2457        __buf.push_back(__hold.get());
2458        __hold.release();
2459
2460        for (typename __base::__map_pointer __i = __base::__map_.end();
2461                __i != __base::__map_.begin();)
2462            __buf.push_front(*--__i);
2463        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
2464        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
2465        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
2466        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
2467    }
2468}
2469
2470// Create back capacity for __n elements.
2471// Strong guarantee.  Either do it or don't touch anything.
2472template <class _Tp, class _Allocator>
2473void
2474deque<_Tp, _Allocator>::__add_back_capacity(size_type __n)
2475{
2476    allocator_type& __a = __base::__alloc();
2477    size_type __nb = __recommend_blocks(__n + __base::__map_.empty());
2478    // Number of unused blocks at front:
2479    size_type __front_capacity = __front_spare() / __base::__block_size;
2480    __front_capacity = _VSTD::min(__front_capacity, __nb);  // don't take more than you need
2481    __nb -= __front_capacity;  // number of blocks need to allocate
2482    // If __nb == 0, then we have sufficient capacity.
2483    if (__nb == 0)
2484    {
2485        __base::__start_ -= __base::__block_size * __front_capacity;
2486        for (; __front_capacity > 0; --__front_capacity)
2487        {
2488            pointer __pt = __base::__map_.front();
2489            __base::__map_.pop_front();
2490            __base::__map_.push_back(__pt);
2491        }
2492    }
2493    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
2494    else if (__nb <= __base::__map_.capacity() - __base::__map_.size())
2495    {   // we can put the new buffers into the map, but don't shift things around
2496        // until all buffers are allocated.  If we throw, we don't need to fix
2497        // anything up (any added buffers are undetectible)
2498        for (; __nb > 0; --__nb)
2499        {
2500            if (__base::__map_.__back_spare() == 0)
2501                break;
2502            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2503        }
2504        for (; __nb > 0; --__nb, ++__front_capacity, __base::__start_ +=
2505                                 __base::__block_size - (__base::__map_.size() == 1))
2506            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
2507        // Done allocating, reorder capacity
2508        __base::__start_ -= __base::__block_size * __front_capacity;
2509        for (; __front_capacity > 0; --__front_capacity)
2510        {
2511            pointer __pt = __base::__map_.front();
2512            __base::__map_.pop_front();
2513            __base::__map_.push_back(__pt);
2514        }
2515    }
2516    // Else need to allocate __nb buffers, *and* we need to reallocate __map_.
2517    else
2518    {
2519        size_type __ds = __front_capacity * __base::__block_size;
2520        __split_buffer<pointer, typename __base::__pointer_allocator&>
2521            __buf(max<size_type>(2* __base::__map_.capacity(),
2522                                 __nb + __base::__map_.size()),
2523                  __base::__map_.size() - __front_capacity,
2524                  __base::__map_.__alloc());
2525#ifndef _LIBCPP_NO_EXCEPTIONS
2526        try
2527        {
2528#endif  // _LIBCPP_NO_EXCEPTIONS
2529            for (; __nb > 0; --__nb)
2530                __buf.push_back(__alloc_traits::allocate(__a, __base::__block_size));
2531#ifndef _LIBCPP_NO_EXCEPTIONS
2532        }
2533        catch (...)
2534        {
2535            for (typename __base::__map_pointer __i = __buf.begin();
2536                    __i != __buf.end(); ++__i)
2537                __alloc_traits::deallocate(__a, *__i, __base::__block_size);
2538            throw;
2539        }
2540#endif  // _LIBCPP_NO_EXCEPTIONS
2541        for (; __front_capacity > 0; --__front_capacity)
2542        {
2543            __buf.push_back(__base::__map_.front());
2544            __base::__map_.pop_front();
2545        }
2546        for (typename __base::__map_pointer __i = __base::__map_.end();
2547                __i != __base::__map_.begin();)
2548            __buf.push_front(*--__i);
2549        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
2550        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
2551        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
2552        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
2553        __base::__start_ -= __ds;
2554    }
2555}
2556
2557template <class _Tp, class _Allocator>
2558void
2559deque<_Tp, _Allocator>::pop_front()
2560{
2561    allocator_type& __a = __base::__alloc();
2562    __alloc_traits::destroy(__a, __to_raw_pointer(*(__base::__map_.begin() +
2563                                                    __base::__start_ / __base::__block_size) +
2564                                                    __base::__start_ % __base::__block_size));
2565    --__base::size();
2566    if (++__base::__start_ >= 2 * __base::__block_size)
2567    {
2568        __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
2569        __base::__map_.pop_front();
2570        __base::__start_ -= __base::__block_size;
2571    }
2572}
2573
2574template <class _Tp, class _Allocator>
2575void
2576deque<_Tp, _Allocator>::pop_back()
2577{
2578    allocator_type& __a = __base::__alloc();
2579    size_type __p = __base::size() + __base::__start_ - 1;
2580    __alloc_traits::destroy(__a, __to_raw_pointer(*(__base::__map_.begin() +
2581                                                    __p / __base::__block_size) +
2582                                                    __p % __base::__block_size));
2583    --__base::size();
2584    if (__back_spare() >= 2 * __base::__block_size)
2585    {
2586        __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
2587        __base::__map_.pop_back();
2588    }
2589}
2590
2591// move assign [__f, __l) to [__r, __r + (__l-__f)).
2592// If __vt points into [__f, __l), then subtract (__f - __r) from __vt.
2593template <class _Tp, class _Allocator>
2594typename deque<_Tp, _Allocator>::iterator
2595deque<_Tp, _Allocator>::__move_and_check(iterator __f, iterator __l, iterator __r,
2596                                         const_pointer& __vt)
2597{
2598    // as if
2599    //   for (; __f != __l; ++__f, ++__r)
2600    //       *__r = _VSTD::move(*__f);
2601    difference_type __n = __l - __f;
2602    while (__n > 0)
2603    {
2604        pointer __fb = __f.__ptr_;
2605        pointer __fe = *__f.__m_iter_ + __base::__block_size;
2606        difference_type __bs = __fe - __fb;
2607        if (__bs > __n)
2608        {
2609            __bs = __n;
2610            __fe = __fb + __bs;
2611        }
2612        if (__fb <= __vt && __vt < __fe)
2613            __vt = (const_iterator(static_cast<__map_const_pointer>(__f.__m_iter_), __vt) -= __f - __r).__ptr_;
2614        __r = _VSTD::move(__fb, __fe, __r);
2615        __n -= __bs;
2616        __f += __bs;
2617    }
2618    return __r;
2619}
2620
2621// move assign [__f, __l) to [__r - (__l-__f), __r) backwards.
2622// If __vt points into [__f, __l), then add (__r - __l) to __vt.
2623template <class _Tp, class _Allocator>
2624typename deque<_Tp, _Allocator>::iterator
2625deque<_Tp, _Allocator>::__move_backward_and_check(iterator __f, iterator __l, iterator __r,
2626                                                  const_pointer& __vt)
2627{
2628    // as if
2629    //   while (__f != __l)
2630    //       *--__r = _VSTD::move(*--__l);
2631    difference_type __n = __l - __f;
2632    while (__n > 0)
2633    {
2634        --__l;
2635        pointer __lb = *__l.__m_iter_;
2636        pointer __le = __l.__ptr_ + 1;
2637        difference_type __bs = __le - __lb;
2638        if (__bs > __n)
2639        {
2640            __bs = __n;
2641            __lb = __le - __bs;
2642        }
2643        if (__lb <= __vt && __vt < __le)
2644            __vt = (const_iterator(static_cast<__map_const_pointer>(__l.__m_iter_), __vt) += __r - __l - 1).__ptr_;
2645        __r = _VSTD::move_backward(__lb, __le, __r);
2646        __n -= __bs;
2647        __l -= __bs - 1;
2648    }
2649    return __r;
2650}
2651
2652// move construct [__f, __l) to [__r, __r + (__l-__f)).
2653// If __vt points into [__f, __l), then add (__r - __f) to __vt.
2654template <class _Tp, class _Allocator>
2655void
2656deque<_Tp, _Allocator>::__move_construct_and_check(iterator __f, iterator __l,
2657                                                   iterator __r, const_pointer& __vt)
2658{
2659    allocator_type& __a = __base::__alloc();
2660    // as if
2661    //   for (; __f != __l; ++__r, ++__f, ++__base::size())
2662    //       __alloc_traits::construct(__a, _VSTD::addressof(*__r), _VSTD::move(*__f));
2663    difference_type __n = __l - __f;
2664    while (__n > 0)
2665    {
2666        pointer __fb = __f.__ptr_;
2667        pointer __fe = *__f.__m_iter_ + __base::__block_size;
2668        difference_type __bs = __fe - __fb;
2669        if (__bs > __n)
2670        {
2671            __bs = __n;
2672            __fe = __fb + __bs;
2673        }
2674        if (__fb <= __vt && __vt < __fe)
2675            __vt = (const_iterator(static_cast<__map_const_pointer>(__f.__m_iter_), __vt) += __r - __f).__ptr_;
2676        for (; __fb != __fe; ++__fb, ++__r, ++__base::size())
2677            __alloc_traits::construct(__a, _VSTD::addressof(*__r), _VSTD::move(*__fb));
2678        __n -= __bs;
2679        __f += __bs;
2680    }
2681}
2682
2683// move construct [__f, __l) to [__r - (__l-__f), __r) backwards.
2684// If __vt points into [__f, __l), then subtract (__l - __r) from __vt.
2685template <class _Tp, class _Allocator>
2686void
2687deque<_Tp, _Allocator>::__move_construct_backward_and_check(iterator __f, iterator __l,
2688                                                            iterator __r, const_pointer& __vt)
2689{
2690    allocator_type& __a = __base::__alloc();
2691    // as if
2692    //   for (iterator __j = __l; __j != __f;)
2693    //   {
2694    //       __alloc_traitsconstruct(__a, _VSTD::addressof(*--__r), _VSTD::move(*--__j));
2695    //       --__base::__start_;
2696    //       ++__base::size();
2697    //   }
2698    difference_type __n = __l - __f;
2699    while (__n > 0)
2700    {
2701        --__l;
2702        pointer __lb = *__l.__m_iter_;
2703        pointer __le = __l.__ptr_ + 1;
2704        difference_type __bs = __le - __lb;
2705        if (__bs > __n)
2706        {
2707            __bs = __n;
2708            __lb = __le - __bs;
2709        }
2710        if (__lb <= __vt && __vt < __le)
2711            __vt = (const_iterator(static_cast<__map_const_pointer>(__l.__m_iter_), __vt) -= __l - __r + 1).__ptr_;
2712        while (__le != __lb)
2713        {
2714            __alloc_traits::construct(__a, _VSTD::addressof(*--__r), _VSTD::move(*--__le));
2715            --__base::__start_;
2716            ++__base::size();
2717        }
2718        __n -= __bs;
2719        __l -= __bs - 1;
2720    }
2721}
2722
2723template <class _Tp, class _Allocator>
2724typename deque<_Tp, _Allocator>::iterator
2725deque<_Tp, _Allocator>::erase(const_iterator __f)
2726{
2727    iterator __b = __base::begin();
2728    difference_type __pos = __f - __b;
2729    iterator __p = __b + __pos;
2730    allocator_type& __a = __base::__alloc();
2731    if (static_cast<size_t>(__pos) <= (__base::size() - 1) / 2)
2732    {   // erase from front
2733        _VSTD::move_backward(__b, __p, _VSTD::next(__p));
2734        __alloc_traits::destroy(__a, _VSTD::addressof(*__b));
2735        --__base::size();
2736        ++__base::__start_;
2737        if (__front_spare() >= 2 * __base::__block_size)
2738        {
2739            __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
2740            __base::__map_.pop_front();
2741            __base::__start_ -= __base::__block_size;
2742        }
2743    }
2744    else
2745    {   // erase from back
2746        iterator __i = _VSTD::move(_VSTD::next(__p), __base::end(), __p);
2747        __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
2748        --__base::size();
2749        if (__back_spare() >= 2 * __base::__block_size)
2750        {
2751            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
2752            __base::__map_.pop_back();
2753        }
2754    }
2755    return __base::begin() + __pos;
2756}
2757
2758template <class _Tp, class _Allocator>
2759typename deque<_Tp, _Allocator>::iterator
2760deque<_Tp, _Allocator>::erase(const_iterator __f, const_iterator __l)
2761{
2762    difference_type __n = __l - __f;
2763    iterator __b = __base::begin();
2764    difference_type __pos = __f - __b;
2765    iterator __p = __b + __pos;
2766    if (__n > 0)
2767    {
2768        allocator_type& __a = __base::__alloc();
2769        if (static_cast<size_t>(__pos) <= (__base::size() - __n) / 2)
2770        {   // erase from front
2771            iterator __i = _VSTD::move_backward(__b, __p, __p + __n);
2772            for (; __b != __i; ++__b)
2773                __alloc_traits::destroy(__a, _VSTD::addressof(*__b));
2774            __base::size() -= __n;
2775            __base::__start_ += __n;
2776            while (__front_spare() >= 2 * __base::__block_size)
2777            {
2778                __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
2779                __base::__map_.pop_front();
2780                __base::__start_ -= __base::__block_size;
2781            }
2782        }
2783        else
2784        {   // erase from back
2785            iterator __i = _VSTD::move(__p + __n, __base::end(), __p);
2786            for (iterator __e = __base::end(); __i != __e; ++__i)
2787                __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
2788            __base::size() -= __n;
2789            while (__back_spare() >= 2 * __base::__block_size)
2790            {
2791                __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
2792                __base::__map_.pop_back();
2793            }
2794        }
2795    }
2796    return __base::begin() + __pos;
2797}
2798
2799template <class _Tp, class _Allocator>
2800void
2801deque<_Tp, _Allocator>::__erase_to_end(const_iterator __f)
2802{
2803    iterator __e = __base::end();
2804    difference_type __n = __e - __f;
2805    if (__n > 0)
2806    {
2807        allocator_type& __a = __base::__alloc();
2808        iterator __b = __base::begin();
2809        difference_type __pos = __f - __b;
2810        for (iterator __p = __b + __pos; __p != __e; ++__p)
2811            __alloc_traits::destroy(__a, _VSTD::addressof(*__p));
2812        __base::size() -= __n;
2813        while (__back_spare() >= 2 * __base::__block_size)
2814        {
2815            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
2816            __base::__map_.pop_back();
2817        }
2818    }
2819}
2820
2821template <class _Tp, class _Allocator>
2822inline
2823void
2824deque<_Tp, _Allocator>::swap(deque& __c)
2825#if _LIBCPP_STD_VER >= 14
2826        _NOEXCEPT
2827#else
2828        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
2829                    __is_nothrow_swappable<allocator_type>::value)
2830#endif
2831{
2832    __base::swap(__c);
2833}
2834
2835template <class _Tp, class _Allocator>
2836inline
2837void
2838deque<_Tp, _Allocator>::clear() _NOEXCEPT
2839{
2840    __base::clear();
2841}
2842
2843template <class _Tp, class _Allocator>
2844inline _LIBCPP_INLINE_VISIBILITY
2845bool
2846operator==(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2847{
2848    const typename deque<_Tp, _Allocator>::size_type __sz = __x.size();
2849    return __sz == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
2850}
2851
2852template <class _Tp, class _Allocator>
2853inline _LIBCPP_INLINE_VISIBILITY
2854bool
2855operator!=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2856{
2857    return !(__x == __y);
2858}
2859
2860template <class _Tp, class _Allocator>
2861inline _LIBCPP_INLINE_VISIBILITY
2862bool
2863operator< (const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2864{
2865    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
2866}
2867
2868template <class _Tp, class _Allocator>
2869inline _LIBCPP_INLINE_VISIBILITY
2870bool
2871operator> (const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2872{
2873    return __y < __x;
2874}
2875
2876template <class _Tp, class _Allocator>
2877inline _LIBCPP_INLINE_VISIBILITY
2878bool
2879operator>=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2880{
2881    return !(__x < __y);
2882}
2883
2884template <class _Tp, class _Allocator>
2885inline _LIBCPP_INLINE_VISIBILITY
2886bool
2887operator<=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
2888{
2889    return !(__y < __x);
2890}
2891
2892template <class _Tp, class _Allocator>
2893inline _LIBCPP_INLINE_VISIBILITY
2894void
2895swap(deque<_Tp, _Allocator>& __x, deque<_Tp, _Allocator>& __y)
2896    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
2897{
2898    __x.swap(__y);
2899}
2900
2901_LIBCPP_END_NAMESPACE_STD
2902
2903#endif  // _LIBCPP_DEQUE
2904