File Coverage

/usr/include/c++/5/bits/stl_deque.h
Criterion Covered Total %
statement 0 136 0.0
branch 0 84 0.0
condition n/a
subroutine n/a
pod n/a
total 0 220 0.0


line stmt bran cond sub pod time code
1             // Deque implementation -*- C++ -*-
2              
3             // Copyright (C) 2001-2015 Free Software Foundation, Inc.
4             //
5             // This file is part of the GNU ISO C++ Library. This library is free
6             // software; you can redistribute it and/or modify it under the
7             // terms of the GNU General Public License as published by the
8             // Free Software Foundation; either version 3, or (at your option)
9             // any later version.
10              
11             // This library is distributed in the hope that it will be useful,
12             // but WITHOUT ANY WARRANTY; without even the implied warranty of
13             // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14             // GNU General Public License for more details.
15              
16             // Under Section 7 of GPL version 3, you are granted additional
17             // permissions described in the GCC Runtime Library Exception, version
18             // 3.1, as published by the Free Software Foundation.
19              
20             // You should have received a copy of the GNU General Public License and
21             // a copy of the GCC Runtime Library Exception along with this program;
22             // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23             // .
24              
25             /*
26             *
27             * Copyright (c) 1994
28             * Hewlett-Packard Company
29             *
30             * Permission to use, copy, modify, distribute and sell this software
31             * and its documentation for any purpose is hereby granted without fee,
32             * provided that the above copyright notice appear in all copies and
33             * that both that copyright notice and this permission notice appear
34             * in supporting documentation. Hewlett-Packard Company makes no
35             * representations about the suitability of this software for any
36             * purpose. It is provided "as is" without express or implied warranty.
37             *
38             *
39             * Copyright (c) 1997
40             * Silicon Graphics Computer Systems, Inc.
41             *
42             * Permission to use, copy, modify, distribute and sell this software
43             * and its documentation for any purpose is hereby granted without fee,
44             * provided that the above copyright notice appear in all copies and
45             * that both that copyright notice and this permission notice appear
46             * in supporting documentation. Silicon Graphics makes no
47             * representations about the suitability of this software for any
48             * purpose. It is provided "as is" without express or implied warranty.
49             */
50              
51             /** @file bits/stl_deque.h
52             * This is an internal header file, included by other library headers.
53             * Do not attempt to use it directly. @headername{deque}
54             */
55              
56             #ifndef _STL_DEQUE_H
57             #define _STL_DEQUE_H 1
58              
59             #include
60             #include
61             #include
62             #if __cplusplus >= 201103L
63             #include
64             #endif
65              
66             namespace std _GLIBCXX_VISIBILITY(default)
67             {
68             _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
69              
70             /**
71             * @brief This function controls the size of memory nodes.
72             * @param __size The size of an element.
73             * @return The number (not byte size) of elements per node.
74             *
75             * This function started off as a compiler kludge from SGI, but
76             * seems to be a useful wrapper around a repeated constant
77             * expression. The @b 512 is tunable (and no other code needs to
78             * change), but no investigation has been done since inheriting the
79             * SGI code. Touch _GLIBCXX_DEQUE_BUF_SIZE only if you know what
80             * you are doing, however: changing it breaks the binary
81             * compatibility!!
82             */
83              
84             #ifndef _GLIBCXX_DEQUE_BUF_SIZE
85             #define _GLIBCXX_DEQUE_BUF_SIZE 512
86             #endif
87              
88             _GLIBCXX_CONSTEXPR inline size_t
89 0           __deque_buf_size(size_t __size)
90             { return (__size < _GLIBCXX_DEQUE_BUF_SIZE
91 0 0         ? size_t(_GLIBCXX_DEQUE_BUF_SIZE / __size) : size_t(1)); }
92              
93              
94             /**
95             * @brief A deque::iterator.
96             *
97             * Quite a bit of intelligence here. Much of the functionality of
98             * deque is actually passed off to this class. A deque holds two
99             * of these internally, marking its valid range. Access to
100             * elements is done as offsets of either of those two, relying on
101             * operator overloading in this class.
102             *
103             * All the functions are op overloads except for _M_set_node.
104             */
105             template
106             struct _Deque_iterator
107             {
108             #if __cplusplus < 201103L
109             typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator;
110             typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
111             typedef _Tp* _Elt_pointer;
112             typedef _Tp** _Map_pointer;
113             #else
114             private:
115             template
116             using __ptr_to = typename pointer_traits<_Ptr>::template rebind<_Up>;
117             template
118             using __iter = _Deque_iterator<_Tp, _CvTp&, __ptr_to<_CvTp>>;
119             public:
120             typedef __iter<_Tp> iterator;
121             typedef __iter const_iterator;
122             typedef __ptr_to<_Tp> _Elt_pointer;
123             typedef __ptr_to<_Elt_pointer> _Map_pointer;
124             #endif
125              
126 0           static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
127 0           { return __deque_buf_size(sizeof(_Tp)); }
128              
129             typedef std::random_access_iterator_tag iterator_category;
130             typedef _Tp value_type;
131             typedef _Ptr pointer;
132             typedef _Ref reference;
133             typedef size_t size_type;
134             typedef ptrdiff_t difference_type;
135             typedef _Deque_iterator _Self;
136              
137             _Elt_pointer _M_cur;
138             _Elt_pointer _M_first;
139             _Elt_pointer _M_last;
140             _Map_pointer _M_node;
141              
142             _Deque_iterator(_Elt_pointer __x, _Map_pointer __y) _GLIBCXX_NOEXCEPT
143             : _M_cur(__x), _M_first(*__y),
144             _M_last(*__y + _S_buffer_size()), _M_node(__y) { }
145              
146 0           _Deque_iterator() _GLIBCXX_NOEXCEPT
147 0           : _M_cur(), _M_first(), _M_last(), _M_node() { }
148              
149 0           _Deque_iterator(const iterator& __x) _GLIBCXX_NOEXCEPT
150             : _M_cur(__x._M_cur), _M_first(__x._M_first),
151 0           _M_last(__x._M_last), _M_node(__x._M_node) { }
152              
153             iterator
154             _M_const_cast() const _GLIBCXX_NOEXCEPT
155             { return iterator(_M_cur, _M_node); }
156              
157             reference
158 0           operator*() const _GLIBCXX_NOEXCEPT
159 0           { return *_M_cur; }
160              
161             pointer
162             operator->() const _GLIBCXX_NOEXCEPT
163             { return _M_cur; }
164              
165             _Self&
166             operator++() _GLIBCXX_NOEXCEPT
167             {
168             ++_M_cur;
169             if (_M_cur == _M_last)
170             {
171             _M_set_node(_M_node + 1);
172             _M_cur = _M_first;
173             }
174             return *this;
175             }
176              
177             _Self
178             operator++(int) _GLIBCXX_NOEXCEPT
179             {
180             _Self __tmp = *this;
181             ++*this;
182             return __tmp;
183             }
184              
185             _Self&
186 0           operator--() _GLIBCXX_NOEXCEPT
187             {
188 0 0         if (_M_cur == _M_first)
    0          
189             {
190 0           _M_set_node(_M_node - 1);
191 0           _M_cur = _M_last;
192             }
193 0           --_M_cur;
194 0           return *this;
195             }
196              
197             _Self
198             operator--(int) _GLIBCXX_NOEXCEPT
199             {
200             _Self __tmp = *this;
201             --*this;
202             return __tmp;
203             }
204              
205             _Self&
206             operator+=(difference_type __n) _GLIBCXX_NOEXCEPT
207             {
208             const difference_type __offset = __n + (_M_cur - _M_first);
209             if (__offset >= 0 && __offset < difference_type(_S_buffer_size()))
210             _M_cur += __n;
211             else
212             {
213             const difference_type __node_offset =
214             __offset > 0 ? __offset / difference_type(_S_buffer_size())
215             : -difference_type((-__offset - 1)
216             / _S_buffer_size()) - 1;
217             _M_set_node(_M_node + __node_offset);
218             _M_cur = _M_first + (__offset - __node_offset
219             * difference_type(_S_buffer_size()));
220             }
221             return *this;
222             }
223              
224             _Self
225             operator+(difference_type __n) const _GLIBCXX_NOEXCEPT
226             {
227             _Self __tmp = *this;
228             return __tmp += __n;
229             }
230              
231             _Self&
232             operator-=(difference_type __n) _GLIBCXX_NOEXCEPT
233             { return *this += -__n; }
234              
235             _Self
236             operator-(difference_type __n) const _GLIBCXX_NOEXCEPT
237             {
238             _Self __tmp = *this;
239             return __tmp -= __n;
240             }
241              
242             reference
243             operator[](difference_type __n) const _GLIBCXX_NOEXCEPT
244             { return *(*this + __n); }
245              
246             /**
247             * Prepares to traverse new_node. Sets everything except
248             * _M_cur, which should therefore be set by the caller
249             * immediately afterwards, based on _M_first and _M_last.
250             */
251             void
252 0           _M_set_node(_Map_pointer __new_node) _GLIBCXX_NOEXCEPT
253             {
254 0           _M_node = __new_node;
255 0           _M_first = *__new_node;
256 0           _M_last = _M_first + difference_type(_S_buffer_size());
257 0           }
258             };
259              
260             // Note: we also provide overloads whose operands are of the same type in
261             // order to avoid ambiguous overload resolution when std::rel_ops operators
262             // are in scope (for additional details, see libstdc++/3628)
263             template
264             inline bool
265 0           operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
266             const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
267 0           { return __x._M_cur == __y._M_cur; }
268              
269             template
270             typename _RefR, typename _PtrR>
271             inline bool
272             operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
273             const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
274             { return __x._M_cur == __y._M_cur; }
275              
276             template
277             inline bool
278             operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
279             const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
280             { return !(__x == __y); }
281              
282             template
283             typename _RefR, typename _PtrR>
284             inline bool
285             operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
286             const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
287             { return !(__x == __y); }
288              
289             template
290             inline bool
291             operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
292             const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
293             { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
294             : (__x._M_node < __y._M_node); }
295              
296             template
297             typename _RefR, typename _PtrR>
298             inline bool
299             operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
300             const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
301             { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
302             : (__x._M_node < __y._M_node); }
303              
304             template
305             inline bool
306             operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
307             const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
308             { return __y < __x; }
309              
310             template
311             typename _RefR, typename _PtrR>
312             inline bool
313             operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
314             const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
315             { return __y < __x; }
316              
317             template
318             inline bool
319             operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
320             const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
321             { return !(__y < __x); }
322              
323             template
324             typename _RefR, typename _PtrR>
325             inline bool
326             operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
327             const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
328             { return !(__y < __x); }
329              
330             template
331             inline bool
332             operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
333             const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
334             { return !(__x < __y); }
335              
336             template
337             typename _RefR, typename _PtrR>
338             inline bool
339             operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
340             const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
341             { return !(__x < __y); }
342              
343             // _GLIBCXX_RESOLVE_LIB_DEFECTS
344             // According to the resolution of DR179 not only the various comparison
345             // operators but also operator- must accept mixed iterator/const_iterator
346             // parameters.
347             template
348             inline typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
349             operator-(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
350             const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
351             {
352             return typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
353             (_Deque_iterator<_Tp, _Ref, _Ptr>::_S_buffer_size())
354             * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
355             + (__y._M_last - __y._M_cur);
356             }
357              
358             template
359             typename _RefR, typename _PtrR>
360             inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
361             operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
362             const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
363             {
364             return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
365             (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size())
366             * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
367             + (__y._M_last - __y._M_cur);
368             }
369              
370             template
371             inline _Deque_iterator<_Tp, _Ref, _Ptr>
372             operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x)
373             _GLIBCXX_NOEXCEPT
374             { return __x + __n; }
375              
376             template
377             void
378             fill(const _Deque_iterator<_Tp, _Tp&, _Tp*>&,
379             const _Deque_iterator<_Tp, _Tp&, _Tp*>&, const _Tp&);
380              
381             template
382             _Deque_iterator<_Tp, _Tp&, _Tp*>
383             copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
384             _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
385             _Deque_iterator<_Tp, _Tp&, _Tp*>);
386              
387             template
388             inline _Deque_iterator<_Tp, _Tp&, _Tp*>
389             copy(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
390             _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
391             _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
392             { return std::copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first),
393             _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last),
394             __result); }
395              
396             template
397             _Deque_iterator<_Tp, _Tp&, _Tp*>
398             copy_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
399             _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
400             _Deque_iterator<_Tp, _Tp&, _Tp*>);
401              
402             template
403             inline _Deque_iterator<_Tp, _Tp&, _Tp*>
404             copy_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
405             _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
406             _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
407             { return std::copy_backward(_Deque_iterator<_Tp,
408             const _Tp&, const _Tp*>(__first),
409             _Deque_iterator<_Tp,
410             const _Tp&, const _Tp*>(__last),
411             __result); }
412              
413             #if __cplusplus >= 201103L
414             template
415             _Deque_iterator<_Tp, _Tp&, _Tp*>
416             move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
417             _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
418             _Deque_iterator<_Tp, _Tp&, _Tp*>);
419              
420             template
421             inline _Deque_iterator<_Tp, _Tp&, _Tp*>
422             move(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
423             _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
424             _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
425             { return std::move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first),
426             _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last),
427             __result); }
428              
429             template
430             _Deque_iterator<_Tp, _Tp&, _Tp*>
431             move_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
432             _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
433             _Deque_iterator<_Tp, _Tp&, _Tp*>);
434              
435             template
436             inline _Deque_iterator<_Tp, _Tp&, _Tp*>
437             move_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
438             _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
439             _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
440             { return std::move_backward(_Deque_iterator<_Tp,
441             const _Tp&, const _Tp*>(__first),
442             _Deque_iterator<_Tp,
443             const _Tp&, const _Tp*>(__last),
444             __result); }
445             #endif
446              
447             /**
448             * Deque base class. This class provides the unified face for %deque's
449             * allocation. This class's constructor and destructor allocate and
450             * deallocate (but do not initialize) storage. This makes %exception
451             * safety easier.
452             *
453             * Nothing in this class ever constructs or destroys an actual Tp element.
454             * (Deque handles that itself.) Only/All memory management is performed
455             * here.
456             */
457             template
458             class _Deque_base
459             {
460             protected:
461             typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
462             rebind<_Tp>::other _Tp_alloc_type;
463             typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Alloc_traits;
464              
465             #if __cplusplus < 201103L
466             typedef _Tp* _Ptr;
467             typedef const _Tp* _Ptr_const;
468             #else
469             typedef typename _Alloc_traits::pointer _Ptr;
470             typedef typename _Alloc_traits::const_pointer _Ptr_const;
471             #endif
472              
473             typedef typename _Alloc_traits::template rebind<_Ptr>::other
474             _Map_alloc_type;
475             typedef __gnu_cxx::__alloc_traits<_Map_alloc_type> _Map_alloc_traits;
476              
477             public:
478             typedef _Alloc allocator_type;
479             typedef typename _Alloc_traits::size_type size_type;
480              
481             allocator_type
482             get_allocator() const _GLIBCXX_NOEXCEPT
483             { return allocator_type(_M_get_Tp_allocator()); }
484              
485             typedef _Deque_iterator<_Tp, _Tp&, _Ptr> iterator;
486             typedef _Deque_iterator<_Tp, const _Tp&, _Ptr_const> const_iterator;
487              
488 0           _Deque_base()
489 0           : _M_impl()
490 0 0         { _M_initialize_map(0); }
    0          
    0          
491              
492             _Deque_base(size_t __num_elements)
493             : _M_impl()
494             { _M_initialize_map(__num_elements); }
495              
496             _Deque_base(const allocator_type& __a, size_t __num_elements)
497             : _M_impl(__a)
498             { _M_initialize_map(__num_elements); }
499              
500             _Deque_base(const allocator_type& __a)
501             : _M_impl(__a)
502             { /* Caller must initialize map. */ }
503              
504             #if __cplusplus >= 201103L
505             _Deque_base(_Deque_base&& __x, false_type)
506             : _M_impl(__x._M_move_impl())
507             { }
508              
509 0           _Deque_base(_Deque_base&& __x, true_type)
510 0           : _M_impl(std::move(__x._M_get_Tp_allocator()))
511             {
512 0 0         _M_initialize_map(0);
    0          
    0          
513 0 0         if (__x._M_impl._M_map)
    0          
    0          
514 0           this->_M_impl._M_swap_data(__x._M_impl);
515 0           }
516              
517 0           _Deque_base(_Deque_base&& __x)
518 0           : _Deque_base(std::move(__x),
519 0 0         __gnu_cxx::__allocator_always_compares_equal<_Alloc>{})
    0          
    0          
520 0           { }
521              
522             _Deque_base(_Deque_base&& __x, const allocator_type& __a, size_type __n)
523             : _M_impl(__a)
524             {
525             if (__x.get_allocator() == __a)
526             {
527             if (__x._M_impl._M_map)
528             {
529             _M_initialize_map(0);
530             this->_M_impl._M_swap_data(__x._M_impl);
531             }
532             }
533             else
534             {
535             _M_initialize_map(__n);
536             }
537             }
538             #endif
539              
540             ~_Deque_base() _GLIBCXX_NOEXCEPT;
541              
542             protected:
543             typedef typename iterator::_Map_pointer _Map_pointer;
544              
545             //This struct encapsulates the implementation of the std::deque
546             //standard container and at the same time makes use of the EBO
547             //for empty allocators.
548 0           struct _Deque_impl
549             : public _Tp_alloc_type
550             {
551             _Map_pointer _M_map;
552             size_t _M_map_size;
553             iterator _M_start;
554             iterator _M_finish;
555              
556 0           _Deque_impl()
557             : _Tp_alloc_type(), _M_map(), _M_map_size(0),
558 0           _M_start(), _M_finish()
559 0           { }
560              
561             _Deque_impl(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT
562             : _Tp_alloc_type(__a), _M_map(), _M_map_size(0),
563             _M_start(), _M_finish()
564             { }
565              
566             #if __cplusplus >= 201103L
567             _Deque_impl(_Deque_impl&&) = default;
568              
569 0           _Deque_impl(_Tp_alloc_type&& __a) noexcept
570 0           : _Tp_alloc_type(std::move(__a)), _M_map(), _M_map_size(0),
571 0           _M_start(), _M_finish()
572 0           { }
573             #endif
574              
575 0           void _M_swap_data(_Deque_impl& __x) _GLIBCXX_NOEXCEPT
576             {
577             using std::swap;
578 0           swap(this->_M_start, __x._M_start);
579 0           swap(this->_M_finish, __x._M_finish);
580 0           swap(this->_M_map, __x._M_map);
581 0           swap(this->_M_map_size, __x._M_map_size);
582 0           }
583             };
584              
585             _Tp_alloc_type&
586 0           _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT
587 0           { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); }
588              
589             const _Tp_alloc_type&
590 0           _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT
591 0           { return *static_cast(&this->_M_impl); }
592              
593             _Map_alloc_type
594 0           _M_get_map_allocator() const _GLIBCXX_NOEXCEPT
595 0           { return _Map_alloc_type(_M_get_Tp_allocator()); }
596              
597             _Ptr
598 0           _M_allocate_node()
599             {
600             typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
601 0           return _Traits::allocate(_M_impl, __deque_buf_size(sizeof(_Tp)));
602             }
603              
604             void
605 0           _M_deallocate_node(_Ptr __p) _GLIBCXX_NOEXCEPT
606             {
607             typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
608 0           _Traits::deallocate(_M_impl, __p, __deque_buf_size(sizeof(_Tp)));
609 0           }
610              
611             _Map_pointer
612 0           _M_allocate_map(size_t __n)
613             {
614 0           _Map_alloc_type __map_alloc = _M_get_map_allocator();
615 0 0         return _Map_alloc_traits::allocate(__map_alloc, __n);
    0          
    0          
616             }
617              
618             void
619 0           _M_deallocate_map(_Map_pointer __p, size_t __n) _GLIBCXX_NOEXCEPT
620             {
621 0           _Map_alloc_type __map_alloc = _M_get_map_allocator();
622 0           _Map_alloc_traits::deallocate(__map_alloc, __p, __n);
623 0           }
624              
625             protected:
626             void _M_initialize_map(size_t);
627             void _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish);
628             void _M_destroy_nodes(_Map_pointer __nstart,
629             _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT;
630             enum { _S_initial_map_size = 8 };
631              
632             _Deque_impl _M_impl;
633              
634             #if __cplusplus >= 201103L
635             private:
636             _Deque_impl
637             _M_move_impl()
638             {
639             if (!_M_impl._M_map)
640             return std::move(_M_impl);
641              
642             // Create a copy of the current allocator.
643             _Tp_alloc_type __alloc{_M_get_Tp_allocator()};
644             // Put that copy in a moved-from state.
645             _Tp_alloc_type __sink __attribute((__unused__)) {std::move(__alloc)};
646             // Create an empty map that allocates using the moved-from allocator.
647             _Deque_base __empty{__alloc};
648             __empty._M_initialize_map(0);
649             // Now safe to modify current allocator and perform non-throwing swaps.
650             _Deque_impl __ret{std::move(_M_get_Tp_allocator())};
651             _M_impl._M_swap_data(__ret);
652             _M_impl._M_swap_data(__empty._M_impl);
653             return __ret;
654             }
655             #endif
656             };
657              
658             template
659 0           _Deque_base<_Tp, _Alloc>::
660             ~_Deque_base() _GLIBCXX_NOEXCEPT
661             {
662 0 0         if (this->_M_impl._M_map)
    0          
    0          
663             {
664 0           _M_destroy_nodes(this->_M_impl._M_start._M_node,
665 0           this->_M_impl._M_finish._M_node + 1);
666 0           _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
667             }
668 0           }
669              
670             /**
671             * @brief Layout storage.
672             * @param __num_elements The count of T's for which to allocate space
673             * at first.
674             * @return Nothing.
675             *
676             * The initial underlying memory layout is a bit complicated...
677             */
678             template
679             void
680 0           _Deque_base<_Tp, _Alloc>::
681             _M_initialize_map(size_t __num_elements)
682             {
683 0           const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
684 0           + 1);
685              
686 0           this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
687 0           size_t(__num_nodes + 2));
688 0           this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
689              
690             // For "small" maps (needing less than _M_map_size nodes), allocation
691             // starts in the middle elements and grows outwards. So nstart may be
692             // the beginning of _M_map, but for small maps it may be as far in as
693             // _M_map+3.
694              
695             _Map_pointer __nstart = (this->_M_impl._M_map
696 0           + (this->_M_impl._M_map_size - __num_nodes) / 2);
697 0           _Map_pointer __nfinish = __nstart + __num_nodes;
698              
699             __try
700 0 0         { _M_create_nodes(__nstart, __nfinish); }
    0          
    0          
701             __catch(...)
702             {
703             _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
704             this->_M_impl._M_map = _Map_pointer();
705             this->_M_impl._M_map_size = 0;
706             __throw_exception_again;
707             }
708              
709 0           this->_M_impl._M_start._M_set_node(__nstart);
710 0           this->_M_impl._M_finish._M_set_node(__nfinish - 1);
711 0           this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
712 0           this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
713 0           + __num_elements
714 0           % __deque_buf_size(sizeof(_Tp)));
715 0           }
716              
717             template
718             void
719 0           _Deque_base<_Tp, _Alloc>::
720             _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish)
721             {
722             _Map_pointer __cur;
723             __try
724             {
725 0 0         for (__cur = __nstart; __cur < __nfinish; ++__cur)
    0          
    0          
726 0 0         *__cur = this->_M_allocate_node();
    0          
    0          
727             }
728             __catch(...)
729             {
730             _M_destroy_nodes(__nstart, __cur);
731             __throw_exception_again;
732             }
733 0           }
734              
735             template
736             void
737 0           _Deque_base<_Tp, _Alloc>::
738             _M_destroy_nodes(_Map_pointer __nstart,
739             _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT
740             {
741 0 0         for (_Map_pointer __n = __nstart; __n < __nfinish; ++__n)
    0          
    0          
742 0           _M_deallocate_node(*__n);
743 0           }
744              
745             /**
746             * @brief A standard container using fixed-size memory allocation and
747             * constant-time manipulation of elements at either end.
748             *
749             * @ingroup sequences
750             *
751             * @tparam _Tp Type of element.
752             * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
753             *
754             * Meets the requirements of a container, a
755             * reversible container, and a
756             * sequence, including the
757             * optional sequence requirements.
758             *
759             * In previous HP/SGI versions of deque, there was an extra template
760             * parameter so users could control the node size. This extension turned
761             * out to violate the C++ standard (it can be detected using template
762             * template parameters), and it was removed.
763             *
764             * Here's how a deque manages memory. Each deque has 4 members:
765             *
766             * - Tp** _M_map
767             * - size_t _M_map_size
768             * - iterator _M_start, _M_finish
769             *
770             * map_size is at least 8. %map is an array of map_size
771             * pointers-to-@a nodes. (The name %map has nothing to do with the
772             * std::map class, and @b nodes should not be confused with
773             * std::list's usage of @a node.)
774             *
775             * A @a node has no specific type name as such, but it is referred
776             * to as @a node in this file. It is a simple array-of-Tp. If Tp
777             * is very large, there will be one Tp element per node (i.e., an
778             * @a array of one). For non-huge Tp's, node size is inversely
779             * related to Tp size: the larger the Tp, the fewer Tp's will fit
780             * in a node. The goal here is to keep the total size of a node
781             * relatively small and constant over different Tp's, to improve
782             * allocator efficiency.
783             *
784             * Not every pointer in the %map array will point to a node. If
785             * the initial number of elements in the deque is small, the
786             * /middle/ %map pointers will be valid, and the ones at the edges
787             * will be unused. This same situation will arise as the %map
788             * grows: available %map pointers, if any, will be on the ends. As
789             * new nodes are created, only a subset of the %map's pointers need
790             * to be copied @a outward.
791             *
792             * Class invariants:
793             * - For any nonsingular iterator i:
794             * - i.node points to a member of the %map array. (Yes, you read that
795             * correctly: i.node does not actually point to a node.) The member of
796             * the %map array is what actually points to the node.
797             * - i.first == *(i.node) (This points to the node (first Tp element).)
798             * - i.last == i.first + node_size
799             * - i.cur is a pointer in the range [i.first, i.last). NOTE:
800             * the implication of this is that i.cur is always a dereferenceable
801             * pointer, even if i is a past-the-end iterator.
802             * - Start and Finish are always nonsingular iterators. NOTE: this
803             * means that an empty deque must have one node, a deque with
804             * elements (where N is the node buffer size) must have one node, a
805             * deque with N through (2N-1) elements must have two nodes, etc.
806             * - For every node other than start.node and finish.node, every
807             * element in the node is an initialized object. If start.node ==
808             * finish.node, then [start.cur, finish.cur) are initialized
809             * objects, and the elements outside that range are uninitialized
810             * storage. Otherwise, [start.cur, start.last) and [finish.first,
811             * finish.cur) are initialized objects, and [start.first, start.cur)
812             * and [finish.cur, finish.last) are uninitialized storage.
813             * - [%map, %map + map_size) is a valid, non-empty range.
814             * - [start.node, finish.node] is a valid range contained within
815             * [%map, %map + map_size).
816             * - A pointer in the range [%map, %map + map_size) points to an allocated
817             * node if and only if the pointer is in the range
818             * [start.node, finish.node].
819             *
820             * Here's the magic: nothing in deque is @b aware of the discontiguous
821             * storage!
822             *
823             * The memory setup and layout occurs in the parent, _Base, and the iterator
824             * class is entirely responsible for @a leaping from one node to the next.
825             * All the implementation routines for deque itself work only through the
826             * start and finish iterators. This keeps the routines simple and sane,
827             * and we can use other standard algorithms as well.
828             */
829             template >
830             class deque : protected _Deque_base<_Tp, _Alloc>
831             {
832             // concept requirements
833             typedef typename _Alloc::value_type _Alloc_value_type;
834             __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
835             __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
836              
837             typedef _Deque_base<_Tp, _Alloc> _Base;
838             typedef typename _Base::_Tp_alloc_type _Tp_alloc_type;
839             typedef typename _Base::_Alloc_traits _Alloc_traits;
840             typedef typename _Base::_Map_pointer _Map_pointer;
841              
842             public:
843             typedef _Tp value_type;
844             typedef typename _Alloc_traits::pointer pointer;
845             typedef typename _Alloc_traits::const_pointer const_pointer;
846             typedef typename _Alloc_traits::reference reference;
847             typedef typename _Alloc_traits::const_reference const_reference;
848             typedef typename _Base::iterator iterator;
849             typedef typename _Base::const_iterator const_iterator;
850             typedef std::reverse_iterator const_reverse_iterator;
851             typedef std::reverse_iterator reverse_iterator;
852             typedef size_t size_type;
853             typedef ptrdiff_t difference_type;
854             typedef _Alloc allocator_type;
855              
856             protected:
857             static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
858             { return __deque_buf_size(sizeof(_Tp)); }
859              
860             // Functions controlling memory layout, and nothing else.
861             using _Base::_M_initialize_map;
862             using _Base::_M_create_nodes;
863             using _Base::_M_destroy_nodes;
864             using _Base::_M_allocate_node;
865             using _Base::_M_deallocate_node;
866             using _Base::_M_allocate_map;
867             using _Base::_M_deallocate_map;
868             using _Base::_M_get_Tp_allocator;
869              
870             /**
871             * A total of four data members accumulated down the hierarchy.
872             * May be accessed via _M_impl.*
873             */
874             using _Base::_M_impl;
875              
876             public:
877             // [23.2.1.1] construct/copy/destroy
878             // (assign() and get_allocator() are also listed in this section)
879              
880             /**
881             * @brief Creates a %deque with no elements.
882             */
883 0           deque() : _Base() { }
884              
885             /**
886             * @brief Creates a %deque with no elements.
887             * @param __a An allocator object.
888             */
889             explicit
890             deque(const allocator_type& __a)
891             : _Base(__a, 0) { }
892              
893             #if __cplusplus >= 201103L
894             /**
895             * @brief Creates a %deque with default constructed elements.
896             * @param __n The number of elements to initially create.
897             *
898             * This constructor fills the %deque with @a n default
899             * constructed elements.
900             */
901             explicit
902             deque(size_type __n, const allocator_type& __a = allocator_type())
903             : _Base(__a, __n)
904             { _M_default_initialize(); }
905              
906             /**
907             * @brief Creates a %deque with copies of an exemplar element.
908             * @param __n The number of elements to initially create.
909             * @param __value An element to copy.
910             * @param __a An allocator.
911             *
912             * This constructor fills the %deque with @a __n copies of @a __value.
913             */
914             deque(size_type __n, const value_type& __value,
915             const allocator_type& __a = allocator_type())
916             : _Base(__a, __n)
917             { _M_fill_initialize(__value); }
918             #else
919             /**
920             * @brief Creates a %deque with copies of an exemplar element.
921             * @param __n The number of elements to initially create.
922             * @param __value An element to copy.
923             * @param __a An allocator.
924             *
925             * This constructor fills the %deque with @a __n copies of @a __value.
926             */
927             explicit
928             deque(size_type __n, const value_type& __value = value_type(),
929             const allocator_type& __a = allocator_type())
930             : _Base(__a, __n)
931             { _M_fill_initialize(__value); }
932             #endif
933              
934             /**
935             * @brief %Deque copy constructor.
936             * @param __x A %deque of identical element and allocator types.
937             *
938             * The newly-created %deque uses a copy of the allocation object used
939             * by @a __x.
940             */
941             deque(const deque& __x)
942             : _Base(_Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()),
943             __x.size())
944             { std::__uninitialized_copy_a(__x.begin(), __x.end(),
945             this->_M_impl._M_start,
946             _M_get_Tp_allocator()); }
947              
948             #if __cplusplus >= 201103L
949             /**
950             * @brief %Deque move constructor.
951             * @param __x A %deque of identical element and allocator types.
952             *
953             * The newly-created %deque contains the exact contents of @a __x.
954             * The contents of @a __x are a valid, but unspecified %deque.
955             */
956 0           deque(deque&& __x)
957 0           : _Base(std::move(__x)) { }
958              
959             /// Copy constructor with alternative allocator
960             deque(const deque& __x, const allocator_type& __a)
961             : _Base(__a, __x.size())
962             { std::__uninitialized_copy_a(__x.begin(), __x.end(),
963             this->_M_impl._M_start,
964             _M_get_Tp_allocator()); }
965              
966             /// Move constructor with alternative allocator
967             deque(deque&& __x, const allocator_type& __a)
968             : _Base(std::move(__x), __a, __x.size())
969             {
970             if (__x.get_allocator() != __a)
971             {
972             std::__uninitialized_move_a(__x.begin(), __x.end(),
973             this->_M_impl._M_start,
974             _M_get_Tp_allocator());
975             __x.clear();
976             }
977             }
978              
979             /**
980             * @brief Builds a %deque from an initializer list.
981             * @param __l An initializer_list.
982             * @param __a An allocator object.
983             *
984             * Create a %deque consisting of copies of the elements in the
985             * initializer_list @a __l.
986             *
987             * This will call the element type's copy constructor N times
988             * (where N is __l.size()) and do no memory reallocation.
989             */
990             deque(initializer_list __l,
991             const allocator_type& __a = allocator_type())
992             : _Base(__a)
993             {
994             _M_range_initialize(__l.begin(), __l.end(),
995             random_access_iterator_tag());
996             }
997             #endif
998              
999             /**
1000             * @brief Builds a %deque from a range.
1001             * @param __first An input iterator.
1002             * @param __last An input iterator.
1003             * @param __a An allocator object.
1004             *
1005             * Create a %deque consisting of copies of the elements from [__first,
1006             * __last).
1007             *
1008             * If the iterators are forward, bidirectional, or random-access, then
1009             * this will call the elements' copy constructor N times (where N is
1010             * distance(__first,__last)) and do no memory reallocation. But if only
1011             * input iterators are used, then this will do at most 2N calls to the
1012             * copy constructor, and logN memory reallocations.
1013             */
1014             #if __cplusplus >= 201103L
1015             template
1016             typename = std::_RequireInputIter<_InputIterator>>
1017             deque(_InputIterator __first, _InputIterator __last,
1018             const allocator_type& __a = allocator_type())
1019             : _Base(__a)
1020             { _M_initialize_dispatch(__first, __last, __false_type()); }
1021             #else
1022             template
1023             deque(_InputIterator __first, _InputIterator __last,
1024             const allocator_type& __a = allocator_type())
1025             : _Base(__a)
1026             {
1027             // Check whether it's an integral type. If so, it's not an iterator.
1028             typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1029             _M_initialize_dispatch(__first, __last, _Integral());
1030             }
1031             #endif
1032              
1033             /**
1034             * The dtor only erases the elements, and note that if the elements
1035             * themselves are pointers, the pointed-to memory is not touched in any
1036             * way. Managing the pointer is the user's responsibility.
1037             */
1038 0           ~deque()
1039 0           { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); }
1040              
1041             /**
1042             * @brief %Deque assignment operator.
1043             * @param __x A %deque of identical element and allocator types.
1044             *
1045             * All the elements of @a x are copied, but unlike the copy constructor,
1046             * the allocator object is not copied.
1047             */
1048             deque&
1049             operator=(const deque& __x);
1050              
1051             #if __cplusplus >= 201103L
1052             /**
1053             * @brief %Deque move assignment operator.
1054             * @param __x A %deque of identical element and allocator types.
1055             *
1056             * The contents of @a __x are moved into this deque (without copying,
1057             * if the allocators permit it).
1058             * @a __x is a valid, but unspecified %deque.
1059             */
1060             deque&
1061             operator=(deque&& __x) noexcept(_Alloc_traits::_S_always_equal())
1062             {
1063             constexpr bool __always_equal = _Alloc_traits::_S_always_equal();
1064             _M_move_assign1(std::move(__x),
1065             integral_constant());
1066             return *this;
1067             }
1068              
1069             /**
1070             * @brief Assigns an initializer list to a %deque.
1071             * @param __l An initializer_list.
1072             *
1073             * This function fills a %deque with copies of the elements in the
1074             * initializer_list @a __l.
1075             *
1076             * Note that the assignment completely changes the %deque and that the
1077             * resulting %deque's size is the same as the number of elements
1078             * assigned. Old data may be lost.
1079             */
1080             deque&
1081             operator=(initializer_list __l)
1082             {
1083             this->assign(__l.begin(), __l.end());
1084             return *this;
1085             }
1086             #endif
1087              
1088             /**
1089             * @brief Assigns a given value to a %deque.
1090             * @param __n Number of elements to be assigned.
1091             * @param __val Value to be assigned.
1092             *
1093             * This function fills a %deque with @a n copies of the given
1094             * value. Note that the assignment completely changes the
1095             * %deque and that the resulting %deque's size is the same as
1096             * the number of elements assigned. Old data may be lost.
1097             */
1098             void
1099             assign(size_type __n, const value_type& __val)
1100             { _M_fill_assign(__n, __val); }
1101              
1102             /**
1103             * @brief Assigns a range to a %deque.
1104             * @param __first An input iterator.
1105             * @param __last An input iterator.
1106             *
1107             * This function fills a %deque with copies of the elements in the
1108             * range [__first,__last).
1109             *
1110             * Note that the assignment completely changes the %deque and that the
1111             * resulting %deque's size is the same as the number of elements
1112             * assigned. Old data may be lost.
1113             */
1114             #if __cplusplus >= 201103L
1115             template
1116             typename = std::_RequireInputIter<_InputIterator>>
1117             void
1118             assign(_InputIterator __first, _InputIterator __last)
1119             { _M_assign_dispatch(__first, __last, __false_type()); }
1120             #else
1121             template
1122             void
1123             assign(_InputIterator __first, _InputIterator __last)
1124             {
1125             typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1126             _M_assign_dispatch(__first, __last, _Integral());
1127             }
1128             #endif
1129              
1130             #if __cplusplus >= 201103L
1131             /**
1132             * @brief Assigns an initializer list to a %deque.
1133             * @param __l An initializer_list.
1134             *
1135             * This function fills a %deque with copies of the elements in the
1136             * initializer_list @a __l.
1137             *
1138             * Note that the assignment completely changes the %deque and that the
1139             * resulting %deque's size is the same as the number of elements
1140             * assigned. Old data may be lost.
1141             */
1142             void
1143             assign(initializer_list __l)
1144             { this->assign(__l.begin(), __l.end()); }
1145             #endif
1146              
1147             /// Get a copy of the memory allocation object.
1148             allocator_type
1149             get_allocator() const _GLIBCXX_NOEXCEPT
1150             { return _Base::get_allocator(); }
1151              
1152             // iterators
1153             /**
1154             * Returns a read/write iterator that points to the first element in the
1155             * %deque. Iteration is done in ordinary element order.
1156             */
1157             iterator
1158 0           begin() _GLIBCXX_NOEXCEPT
1159 0           { return this->_M_impl._M_start; }
1160              
1161             /**
1162             * Returns a read-only (constant) iterator that points to the first
1163             * element in the %deque. Iteration is done in ordinary element order.
1164             */
1165             const_iterator
1166             begin() const _GLIBCXX_NOEXCEPT
1167             { return this->_M_impl._M_start; }
1168              
1169             /**
1170             * Returns a read/write iterator that points one past the last
1171             * element in the %deque. Iteration is done in ordinary
1172             * element order.
1173             */
1174             iterator
1175 0           end() _GLIBCXX_NOEXCEPT
1176 0           { return this->_M_impl._M_finish; }
1177              
1178             /**
1179             * Returns a read-only (constant) iterator that points one past
1180             * the last element in the %deque. Iteration is done in
1181             * ordinary element order.
1182             */
1183             const_iterator
1184             end() const _GLIBCXX_NOEXCEPT
1185             { return this->_M_impl._M_finish; }
1186              
1187             /**
1188             * Returns a read/write reverse iterator that points to the
1189             * last element in the %deque. Iteration is done in reverse
1190             * element order.
1191             */
1192             reverse_iterator
1193             rbegin() _GLIBCXX_NOEXCEPT
1194             { return reverse_iterator(this->_M_impl._M_finish); }
1195              
1196             /**
1197             * Returns a read-only (constant) reverse iterator that points
1198             * to the last element in the %deque. Iteration is done in
1199             * reverse element order.
1200             */
1201             const_reverse_iterator
1202             rbegin() const _GLIBCXX_NOEXCEPT
1203             { return const_reverse_iterator(this->_M_impl._M_finish); }
1204              
1205             /**
1206             * Returns a read/write reverse iterator that points to one
1207             * before the first element in the %deque. Iteration is done
1208             * in reverse element order.
1209             */
1210             reverse_iterator
1211             rend() _GLIBCXX_NOEXCEPT
1212             { return reverse_iterator(this->_M_impl._M_start); }
1213              
1214             /**
1215             * Returns a read-only (constant) reverse iterator that points
1216             * to one before the first element in the %deque. Iteration is
1217             * done in reverse element order.
1218             */
1219             const_reverse_iterator
1220             rend() const _GLIBCXX_NOEXCEPT
1221             { return const_reverse_iterator(this->_M_impl._M_start); }
1222              
1223             #if __cplusplus >= 201103L
1224             /**
1225             * Returns a read-only (constant) iterator that points to the first
1226             * element in the %deque. Iteration is done in ordinary element order.
1227             */
1228             const_iterator
1229             cbegin() const noexcept
1230             { return this->_M_impl._M_start; }
1231              
1232             /**
1233             * Returns a read-only (constant) iterator that points one past
1234             * the last element in the %deque. Iteration is done in
1235             * ordinary element order.
1236             */
1237             const_iterator
1238             cend() const noexcept
1239             { return this->_M_impl._M_finish; }
1240              
1241             /**
1242             * Returns a read-only (constant) reverse iterator that points
1243             * to the last element in the %deque. Iteration is done in
1244             * reverse element order.
1245             */
1246             const_reverse_iterator
1247             crbegin() const noexcept
1248             { return const_reverse_iterator(this->_M_impl._M_finish); }
1249              
1250             /**
1251             * Returns a read-only (constant) reverse iterator that points
1252             * to one before the first element in the %deque. Iteration is
1253             * done in reverse element order.
1254             */
1255             const_reverse_iterator
1256             crend() const noexcept
1257             { return const_reverse_iterator(this->_M_impl._M_start); }
1258             #endif
1259              
1260             // [23.2.1.2] capacity
1261             /** Returns the number of elements in the %deque. */
1262             size_type
1263             size() const _GLIBCXX_NOEXCEPT
1264             { return this->_M_impl._M_finish - this->_M_impl._M_start; }
1265              
1266             /** Returns the size() of the largest possible %deque. */
1267             size_type
1268             max_size() const _GLIBCXX_NOEXCEPT
1269             { return _Alloc_traits::max_size(_M_get_Tp_allocator()); }
1270              
1271             #if __cplusplus >= 201103L
1272             /**
1273             * @brief Resizes the %deque to the specified number of elements.
1274             * @param __new_size Number of elements the %deque should contain.
1275             *
1276             * This function will %resize the %deque to the specified
1277             * number of elements. If the number is smaller than the
1278             * %deque's current size the %deque is truncated, otherwise
1279             * default constructed elements are appended.
1280             */
1281             void
1282             resize(size_type __new_size)
1283             {
1284             const size_type __len = size();
1285             if (__new_size > __len)
1286             _M_default_append(__new_size - __len);
1287             else if (__new_size < __len)
1288             _M_erase_at_end(this->_M_impl._M_start
1289             + difference_type(__new_size));
1290             }
1291              
1292             /**
1293             * @brief Resizes the %deque to the specified number of elements.
1294             * @param __new_size Number of elements the %deque should contain.
1295             * @param __x Data with which new elements should be populated.
1296             *
1297             * This function will %resize the %deque to the specified
1298             * number of elements. If the number is smaller than the
1299             * %deque's current size the %deque is truncated, otherwise the
1300             * %deque is extended and new elements are populated with given
1301             * data.
1302             */
1303             void
1304             resize(size_type __new_size, const value_type& __x)
1305             {
1306             const size_type __len = size();
1307             if (__new_size > __len)
1308             insert(this->_M_impl._M_finish, __new_size - __len, __x);
1309             else if (__new_size < __len)
1310             _M_erase_at_end(this->_M_impl._M_start
1311             + difference_type(__new_size));
1312             }
1313             #else
1314             /**
1315             * @brief Resizes the %deque to the specified number of elements.
1316             * @param __new_size Number of elements the %deque should contain.
1317             * @param __x Data with which new elements should be populated.
1318             *
1319             * This function will %resize the %deque to the specified
1320             * number of elements. If the number is smaller than the
1321             * %deque's current size the %deque is truncated, otherwise the
1322             * %deque is extended and new elements are populated with given
1323             * data.
1324             */
1325             void
1326             resize(size_type __new_size, value_type __x = value_type())
1327             {
1328             const size_type __len = size();
1329             if (__new_size > __len)
1330             insert(this->_M_impl._M_finish, __new_size - __len, __x);
1331             else if (__new_size < __len)
1332             _M_erase_at_end(this->_M_impl._M_start
1333             + difference_type(__new_size));
1334             }
1335             #endif
1336              
1337             #if __cplusplus >= 201103L
1338             /** A non-binding request to reduce memory use. */
1339             void
1340             shrink_to_fit() noexcept
1341             { _M_shrink_to_fit(); }
1342             #endif
1343              
1344             /**
1345             * Returns true if the %deque is empty. (Thus begin() would
1346             * equal end().)
1347             */
1348             bool
1349 0           empty() const _GLIBCXX_NOEXCEPT
1350 0           { return this->_M_impl._M_finish == this->_M_impl._M_start; }
1351              
1352             // element access
1353             /**
1354             * @brief Subscript access to the data contained in the %deque.
1355             * @param __n The index of the element for which data should be
1356             * accessed.
1357             * @return Read/write reference to data.
1358             *
1359             * This operator allows for easy, array-style, data access.
1360             * Note that data access with this operator is unchecked and
1361             * out_of_range lookups are not defined. (For checked lookups
1362             * see at().)
1363             */
1364             reference
1365             operator[](size_type __n) _GLIBCXX_NOEXCEPT
1366             { return this->_M_impl._M_start[difference_type(__n)]; }
1367              
1368             /**
1369             * @brief Subscript access to the data contained in the %deque.
1370             * @param __n The index of the element for which data should be
1371             * accessed.
1372             * @return Read-only (constant) reference to data.
1373             *
1374             * This operator allows for easy, array-style, data access.
1375             * Note that data access with this operator is unchecked and
1376             * out_of_range lookups are not defined. (For checked lookups
1377             * see at().)
1378             */
1379             const_reference
1380             operator[](size_type __n) const _GLIBCXX_NOEXCEPT
1381             { return this->_M_impl._M_start[difference_type(__n)]; }
1382              
1383             protected:
1384             /// Safety check used only from at().
1385             void
1386             _M_range_check(size_type __n) const
1387             {
1388             if (__n >= this->size())
1389             __throw_out_of_range_fmt(__N("deque::_M_range_check: __n "
1390             "(which is %zu)>= this->size() "
1391             "(which is %zu)"),
1392             __n, this->size());
1393             }
1394              
1395             public:
1396             /**
1397             * @brief Provides access to the data contained in the %deque.
1398             * @param __n The index of the element for which data should be
1399             * accessed.
1400             * @return Read/write reference to data.
1401             * @throw std::out_of_range If @a __n is an invalid index.
1402             *
1403             * This function provides for safer data access. The parameter
1404             * is first checked that it is in the range of the deque. The
1405             * function throws out_of_range if the check fails.
1406             */
1407             reference
1408             at(size_type __n)
1409             {
1410             _M_range_check(__n);
1411             return (*this)[__n];
1412             }
1413              
1414             /**
1415             * @brief Provides access to the data contained in the %deque.
1416             * @param __n The index of the element for which data should be
1417             * accessed.
1418             * @return Read-only (constant) reference to data.
1419             * @throw std::out_of_range If @a __n is an invalid index.
1420             *
1421             * This function provides for safer data access. The parameter is first
1422             * checked that it is in the range of the deque. The function throws
1423             * out_of_range if the check fails.
1424             */
1425             const_reference
1426             at(size_type __n) const
1427             {
1428             _M_range_check(__n);
1429             return (*this)[__n];
1430             }
1431              
1432             /**
1433             * Returns a read/write reference to the data at the first
1434             * element of the %deque.
1435             */
1436             reference
1437             front() _GLIBCXX_NOEXCEPT
1438             { return *begin(); }
1439              
1440             /**
1441             * Returns a read-only (constant) reference to the data at the first
1442             * element of the %deque.
1443             */
1444             const_reference
1445             front() const _GLIBCXX_NOEXCEPT
1446             { return *begin(); }
1447              
1448             /**
1449             * Returns a read/write reference to the data at the last element of the
1450             * %deque.
1451             */
1452             reference
1453 0           back() _GLIBCXX_NOEXCEPT
1454             {
1455 0           iterator __tmp = end();
1456 0           --__tmp;
1457 0           return *__tmp;
1458             }
1459              
1460             /**
1461             * Returns a read-only (constant) reference to the data at the last
1462             * element of the %deque.
1463             */
1464             const_reference
1465             back() const _GLIBCXX_NOEXCEPT
1466             {
1467             const_iterator __tmp = end();
1468             --__tmp;
1469             return *__tmp;
1470             }
1471              
1472             // [23.2.1.2] modifiers
1473             /**
1474             * @brief Add data to the front of the %deque.
1475             * @param __x Data to be added.
1476             *
1477             * This is a typical stack operation. The function creates an
1478             * element at the front of the %deque and assigns the given
1479             * data to it. Due to the nature of a %deque this operation
1480             * can be done in constant time.
1481             */
1482             void
1483             push_front(const value_type& __x)
1484             {
1485             if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
1486             {
1487             _Alloc_traits::construct(this->_M_impl,
1488             this->_M_impl._M_start._M_cur - 1,
1489             __x);
1490             --this->_M_impl._M_start._M_cur;
1491             }
1492             else
1493             _M_push_front_aux(__x);
1494             }
1495              
1496             #if __cplusplus >= 201103L
1497             void
1498             push_front(value_type&& __x)
1499             { emplace_front(std::move(__x)); }
1500              
1501             template
1502             void
1503             emplace_front(_Args&&... __args);
1504             #endif
1505              
1506             /**
1507             * @brief Add data to the end of the %deque.
1508             * @param __x Data to be added.
1509             *
1510             * This is a typical stack operation. The function creates an
1511             * element at the end of the %deque and assigns the given data
1512             * to it. Due to the nature of a %deque this operation can be
1513             * done in constant time.
1514             */
1515             void
1516 0           push_back(const value_type& __x)
1517             {
1518 0 0         if (this->_M_impl._M_finish._M_cur
    0          
    0          
1519 0           != this->_M_impl._M_finish._M_last - 1)
1520             {
1521 0           _Alloc_traits::construct(this->_M_impl,
1522             this->_M_impl._M_finish._M_cur, __x);
1523 0           ++this->_M_impl._M_finish._M_cur;
1524             }
1525             else
1526 0           _M_push_back_aux(__x);
1527 0           }
1528              
1529             #if __cplusplus >= 201103L
1530             void
1531 0           push_back(value_type&& __x)
1532 0           { emplace_back(std::move(__x)); }
1533              
1534             template
1535             void
1536             emplace_back(_Args&&... __args);
1537             #endif
1538              
1539             /**
1540             * @brief Removes first element.
1541             *
1542             * This is a typical stack operation. It shrinks the %deque by one.
1543             *
1544             * Note that no data is returned, and if the first element's data is
1545             * needed, it should be retrieved before pop_front() is called.
1546             */
1547             void
1548             pop_front() _GLIBCXX_NOEXCEPT
1549             {
1550             if (this->_M_impl._M_start._M_cur
1551             != this->_M_impl._M_start._M_last - 1)
1552             {
1553             _Alloc_traits::destroy(this->_M_impl,
1554             this->_M_impl._M_start._M_cur);
1555             ++this->_M_impl._M_start._M_cur;
1556             }
1557             else
1558             _M_pop_front_aux();
1559             }
1560              
1561             /**
1562             * @brief Removes last element.
1563             *
1564             * This is a typical stack operation. It shrinks the %deque by one.
1565             *
1566             * Note that no data is returned, and if the last element's data is
1567             * needed, it should be retrieved before pop_back() is called.
1568             */
1569             void
1570 0           pop_back() _GLIBCXX_NOEXCEPT
1571             {
1572 0 0         if (this->_M_impl._M_finish._M_cur
    0          
    0          
1573 0           != this->_M_impl._M_finish._M_first)
1574             {
1575 0           --this->_M_impl._M_finish._M_cur;
1576 0           _Alloc_traits::destroy(this->_M_impl,
1577             this->_M_impl._M_finish._M_cur);
1578             }
1579             else
1580 0           _M_pop_back_aux();
1581 0           }
1582              
1583             #if __cplusplus >= 201103L
1584             /**
1585             * @brief Inserts an object in %deque before specified iterator.
1586             * @param __position A const_iterator into the %deque.
1587             * @param __args Arguments.
1588             * @return An iterator that points to the inserted data.
1589             *
1590             * This function will insert an object of type T constructed
1591             * with T(std::forward(args)...) before the specified location.
1592             */
1593             template
1594             iterator
1595             emplace(const_iterator __position, _Args&&... __args);
1596              
1597             /**
1598             * @brief Inserts given value into %deque before specified iterator.
1599             * @param __position A const_iterator into the %deque.
1600             * @param __x Data to be inserted.
1601             * @return An iterator that points to the inserted data.
1602             *
1603             * This function will insert a copy of the given value before the
1604             * specified location.
1605             */
1606             iterator
1607             insert(const_iterator __position, const value_type& __x);
1608             #else
1609             /**
1610             * @brief Inserts given value into %deque before specified iterator.
1611             * @param __position An iterator into the %deque.
1612             * @param __x Data to be inserted.
1613             * @return An iterator that points to the inserted data.
1614             *
1615             * This function will insert a copy of the given value before the
1616             * specified location.
1617             */
1618             iterator
1619             insert(iterator __position, const value_type& __x);
1620             #endif
1621              
1622             #if __cplusplus >= 201103L
1623             /**
1624             * @brief Inserts given rvalue into %deque before specified iterator.
1625             * @param __position A const_iterator into the %deque.
1626             * @param __x Data to be inserted.
1627             * @return An iterator that points to the inserted data.
1628             *
1629             * This function will insert a copy of the given rvalue before the
1630             * specified location.
1631             */
1632             iterator
1633             insert(const_iterator __position, value_type&& __x)
1634             { return emplace(__position, std::move(__x)); }
1635              
1636             /**
1637             * @brief Inserts an initializer list into the %deque.
1638             * @param __p An iterator into the %deque.
1639             * @param __l An initializer_list.
1640             *
1641             * This function will insert copies of the data in the
1642             * initializer_list @a __l into the %deque before the location
1643             * specified by @a __p. This is known as list insert.
1644             */
1645             iterator
1646             insert(const_iterator __p, initializer_list __l)
1647             { return this->insert(__p, __l.begin(), __l.end()); }
1648             #endif
1649              
1650             #if __cplusplus >= 201103L
1651             /**
1652             * @brief Inserts a number of copies of given data into the %deque.
1653             * @param __position A const_iterator into the %deque.
1654             * @param __n Number of elements to be inserted.
1655             * @param __x Data to be inserted.
1656             * @return An iterator that points to the inserted data.
1657             *
1658             * This function will insert a specified number of copies of the given
1659             * data before the location specified by @a __position.
1660             */
1661             iterator
1662             insert(const_iterator __position, size_type __n, const value_type& __x)
1663             {
1664             difference_type __offset = __position - cbegin();
1665             _M_fill_insert(__position._M_const_cast(), __n, __x);
1666             return begin() + __offset;
1667             }
1668             #else
1669             /**
1670             * @brief Inserts a number of copies of given data into the %deque.
1671             * @param __position An iterator into the %deque.
1672             * @param __n Number of elements to be inserted.
1673             * @param __x Data to be inserted.
1674             *
1675             * This function will insert a specified number of copies of the given
1676             * data before the location specified by @a __position.
1677             */
1678             void
1679             insert(iterator __position, size_type __n, const value_type& __x)
1680             { _M_fill_insert(__position, __n, __x); }
1681             #endif
1682              
1683             #if __cplusplus >= 201103L
1684             /**
1685             * @brief Inserts a range into the %deque.
1686             * @param __position A const_iterator into the %deque.
1687             * @param __first An input iterator.
1688             * @param __last An input iterator.
1689             * @return An iterator that points to the inserted data.
1690             *
1691             * This function will insert copies of the data in the range
1692             * [__first,__last) into the %deque before the location specified
1693             * by @a __position. This is known as range insert.
1694             */
1695             template
1696             typename = std::_RequireInputIter<_InputIterator>>
1697             iterator
1698             insert(const_iterator __position, _InputIterator __first,
1699             _InputIterator __last)
1700             {
1701             difference_type __offset = __position - cbegin();
1702             _M_insert_dispatch(__position._M_const_cast(),
1703             __first, __last, __false_type());
1704             return begin() + __offset;
1705             }
1706             #else
1707             /**
1708             * @brief Inserts a range into the %deque.
1709             * @param __position An iterator into the %deque.
1710             * @param __first An input iterator.
1711             * @param __last An input iterator.
1712             *
1713             * This function will insert copies of the data in the range
1714             * [__first,__last) into the %deque before the location specified
1715             * by @a __position. This is known as range insert.
1716             */
1717             template
1718             void
1719             insert(iterator __position, _InputIterator __first,
1720             _InputIterator __last)
1721             {
1722             // Check whether it's an integral type. If so, it's not an iterator.
1723             typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1724             _M_insert_dispatch(__position, __first, __last, _Integral());
1725             }
1726             #endif
1727              
1728             /**
1729             * @brief Remove element at given position.
1730             * @param __position Iterator pointing to element to be erased.
1731             * @return An iterator pointing to the next element (or end()).
1732             *
1733             * This function will erase the element at the given position and thus
1734             * shorten the %deque by one.
1735             *
1736             * The user is cautioned that
1737             * this function only erases the element, and that if the element is
1738             * itself a pointer, the pointed-to memory is not touched in any way.
1739             * Managing the pointer is the user's responsibility.
1740             */
1741             iterator
1742             #if __cplusplus >= 201103L
1743             erase(const_iterator __position)
1744             #else
1745             erase(iterator __position)
1746             #endif
1747             { return _M_erase(__position._M_const_cast()); }
1748              
1749             /**
1750             * @brief Remove a range of elements.
1751             * @param __first Iterator pointing to the first element to be erased.
1752             * @param __last Iterator pointing to one past the last element to be
1753             * erased.
1754             * @return An iterator pointing to the element pointed to by @a last
1755             * prior to erasing (or end()).
1756             *
1757             * This function will erase the elements in the range
1758             * [__first,__last) and shorten the %deque accordingly.
1759             *
1760             * The user is cautioned that
1761             * this function only erases the elements, and that if the elements
1762             * themselves are pointers, the pointed-to memory is not touched in any
1763             * way. Managing the pointer is the user's responsibility.
1764             */
1765             iterator
1766             #if __cplusplus >= 201103L
1767             erase(const_iterator __first, const_iterator __last)
1768             #else
1769             erase(iterator __first, iterator __last)
1770             #endif
1771             { return _M_erase(__first._M_const_cast(), __last._M_const_cast()); }
1772              
1773             /**
1774             * @brief Swaps data with another %deque.
1775             * @param __x A %deque of the same element and allocator types.
1776             *
1777             * This exchanges the elements between two deques in constant time.
1778             * (Four pointers, so it should be quite fast.)
1779             * Note that the global std::swap() function is specialized such that
1780             * std::swap(d1,d2) will feed to this function.
1781             */
1782             void
1783             swap(deque& __x)
1784             #if __cplusplus >= 201103L
1785             noexcept(_Alloc_traits::_S_nothrow_swap())
1786             #endif
1787             {
1788             _M_impl._M_swap_data(__x._M_impl);
1789             _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(),
1790             __x._M_get_Tp_allocator());
1791             }
1792              
1793             /**
1794             * Erases all the elements. Note that this function only erases the
1795             * elements, and that if the elements themselves are pointers, the
1796             * pointed-to memory is not touched in any way. Managing the pointer is
1797             * the user's responsibility.
1798             */
1799             void
1800             clear() _GLIBCXX_NOEXCEPT
1801             { _M_erase_at_end(begin()); }
1802              
1803             protected:
1804             // Internal constructor functions follow.
1805              
1806             // called by the range constructor to implement [23.1.1]/9
1807              
1808             // _GLIBCXX_RESOLVE_LIB_DEFECTS
1809             // 438. Ambiguity in the "do the right thing" clause
1810             template
1811             void
1812             _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
1813             {
1814             _M_initialize_map(static_cast(__n));
1815             _M_fill_initialize(__x);
1816             }
1817              
1818             // called by the range constructor to implement [23.1.1]/9
1819             template
1820             void
1821             _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
1822             __false_type)
1823             {
1824             typedef typename std::iterator_traits<_InputIterator>::
1825             iterator_category _IterCategory;
1826             _M_range_initialize(__first, __last, _IterCategory());
1827             }
1828              
1829             // called by the second initialize_dispatch above
1830             //@{
1831             /**
1832             * @brief Fills the deque with whatever is in [first,last).
1833             * @param __first An input iterator.
1834             * @param __last An input iterator.
1835             * @return Nothing.
1836             *
1837             * If the iterators are actually forward iterators (or better), then the
1838             * memory layout can be done all at once. Else we move forward using
1839             * push_back on each value from the iterator.
1840             */
1841             template
1842             void
1843             _M_range_initialize(_InputIterator __first, _InputIterator __last,
1844             std::input_iterator_tag);
1845              
1846             // called by the second initialize_dispatch above
1847             template
1848             void
1849             _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
1850             std::forward_iterator_tag);
1851             //@}
1852              
1853             /**
1854             * @brief Fills the %deque with copies of value.
1855             * @param __value Initial value.
1856             * @return Nothing.
1857             * @pre _M_start and _M_finish have already been initialized,
1858             * but none of the %deque's elements have yet been constructed.
1859             *
1860             * This function is called only when the user provides an explicit size
1861             * (with or without an explicit exemplar value).
1862             */
1863             void
1864             _M_fill_initialize(const value_type& __value);
1865              
1866             #if __cplusplus >= 201103L
1867             // called by deque(n).
1868             void
1869             _M_default_initialize();
1870             #endif
1871              
1872             // Internal assign functions follow. The *_aux functions do the actual
1873             // assignment work for the range versions.
1874              
1875             // called by the range assign to implement [23.1.1]/9
1876              
1877             // _GLIBCXX_RESOLVE_LIB_DEFECTS
1878             // 438. Ambiguity in the "do the right thing" clause
1879             template
1880             void
1881             _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
1882             { _M_fill_assign(__n, __val); }
1883              
1884             // called by the range assign to implement [23.1.1]/9
1885             template
1886             void
1887             _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
1888             __false_type)
1889             {
1890             typedef typename std::iterator_traits<_InputIterator>::
1891             iterator_category _IterCategory;
1892             _M_assign_aux(__first, __last, _IterCategory());
1893             }
1894              
1895             // called by the second assign_dispatch above
1896             template
1897             void
1898             _M_assign_aux(_InputIterator __first, _InputIterator __last,
1899             std::input_iterator_tag);
1900              
1901             // called by the second assign_dispatch above
1902             template
1903             void
1904             _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
1905             std::forward_iterator_tag)
1906             {
1907             const size_type __len = std::distance(__first, __last);
1908             if (__len > size())
1909             {
1910             _ForwardIterator __mid = __first;
1911             std::advance(__mid, size());
1912             std::copy(__first, __mid, begin());
1913             insert(end(), __mid, __last);
1914             }
1915             else
1916             _M_erase_at_end(std::copy(__first, __last, begin()));
1917             }
1918              
1919             // Called by assign(n,t), and the range assign when it turns out
1920             // to be the same thing.
1921             void
1922             _M_fill_assign(size_type __n, const value_type& __val)
1923             {
1924             if (__n > size())
1925             {
1926             std::fill(begin(), end(), __val);
1927             insert(end(), __n - size(), __val);
1928             }
1929             else
1930             {
1931             _M_erase_at_end(begin() + difference_type(__n));
1932             std::fill(begin(), end(), __val);
1933             }
1934             }
1935              
1936             //@{
1937             /// Helper functions for push_* and pop_*.
1938             #if __cplusplus < 201103L
1939             void _M_push_back_aux(const value_type&);
1940              
1941             void _M_push_front_aux(const value_type&);
1942             #else
1943             template
1944             void _M_push_back_aux(_Args&&... __args);
1945              
1946             template
1947             void _M_push_front_aux(_Args&&... __args);
1948             #endif
1949              
1950             void _M_pop_back_aux();
1951              
1952             void _M_pop_front_aux();
1953             //@}
1954              
1955             // Internal insert functions follow. The *_aux functions do the actual
1956             // insertion work when all shortcuts fail.
1957              
1958             // called by the range insert to implement [23.1.1]/9
1959              
1960             // _GLIBCXX_RESOLVE_LIB_DEFECTS
1961             // 438. Ambiguity in the "do the right thing" clause
1962             template
1963             void
1964             _M_insert_dispatch(iterator __pos,
1965             _Integer __n, _Integer __x, __true_type)
1966             { _M_fill_insert(__pos, __n, __x); }
1967              
1968             // called by the range insert to implement [23.1.1]/9
1969             template
1970             void
1971             _M_insert_dispatch(iterator __pos,
1972             _InputIterator __first, _InputIterator __last,
1973             __false_type)
1974             {
1975             typedef typename std::iterator_traits<_InputIterator>::
1976             iterator_category _IterCategory;
1977             _M_range_insert_aux(__pos, __first, __last, _IterCategory());
1978             }
1979              
1980             // called by the second insert_dispatch above
1981             template
1982             void
1983             _M_range_insert_aux(iterator __pos, _InputIterator __first,
1984             _InputIterator __last, std::input_iterator_tag);
1985              
1986             // called by the second insert_dispatch above
1987             template
1988             void
1989             _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
1990             _ForwardIterator __last, std::forward_iterator_tag);
1991              
1992             // Called by insert(p,n,x), and the range insert when it turns out to be
1993             // the same thing. Can use fill functions in optimal situations,
1994             // otherwise passes off to insert_aux(p,n,x).
1995             void
1996             _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
1997              
1998             // called by insert(p,x)
1999             #if __cplusplus < 201103L
2000             iterator
2001             _M_insert_aux(iterator __pos, const value_type& __x);
2002             #else
2003             template
2004             iterator
2005             _M_insert_aux(iterator __pos, _Args&&... __args);
2006             #endif
2007              
2008             // called by insert(p,n,x) via fill_insert
2009             void
2010             _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
2011              
2012             // called by range_insert_aux for forward iterators
2013             template
2014             void
2015             _M_insert_aux(iterator __pos,
2016             _ForwardIterator __first, _ForwardIterator __last,
2017             size_type __n);
2018              
2019              
2020             // Internal erase functions follow.
2021              
2022             void
2023             _M_destroy_data_aux(iterator __first, iterator __last);
2024              
2025             // Called by ~deque().
2026             // NB: Doesn't deallocate the nodes.
2027             template
2028             void
2029             _M_destroy_data(iterator __first, iterator __last, const _Alloc1&)
2030             { _M_destroy_data_aux(__first, __last); }
2031              
2032             void
2033 0           _M_destroy_data(iterator __first, iterator __last,
2034             const std::allocator<_Tp>&)
2035             {
2036             if (!__has_trivial_destructor(value_type))
2037             _M_destroy_data_aux(__first, __last);
2038 0           }
2039              
2040             // Called by erase(q1, q2).
2041             void
2042             _M_erase_at_begin(iterator __pos)
2043             {
2044             _M_destroy_data(begin(), __pos, _M_get_Tp_allocator());
2045             _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node);
2046             this->_M_impl._M_start = __pos;
2047             }
2048              
2049             // Called by erase(q1, q2), resize(), clear(), _M_assign_aux,
2050             // _M_fill_assign, operator=.
2051             void
2052             _M_erase_at_end(iterator __pos)
2053             {
2054             _M_destroy_data(__pos, end(), _M_get_Tp_allocator());
2055             _M_destroy_nodes(__pos._M_node + 1,
2056             this->_M_impl._M_finish._M_node + 1);
2057             this->_M_impl._M_finish = __pos;
2058             }
2059              
2060             iterator
2061             _M_erase(iterator __pos);
2062              
2063             iterator
2064             _M_erase(iterator __first, iterator __last);
2065              
2066             #if __cplusplus >= 201103L
2067             // Called by resize(sz).
2068             void
2069             _M_default_append(size_type __n);
2070              
2071             bool
2072             _M_shrink_to_fit();
2073             #endif
2074              
2075             //@{
2076             /// Memory-handling helpers for the previous internal insert functions.
2077             iterator
2078             _M_reserve_elements_at_front(size_type __n)
2079             {
2080             const size_type __vacancies = this->_M_impl._M_start._M_cur
2081             - this->_M_impl._M_start._M_first;
2082             if (__n > __vacancies)
2083             _M_new_elements_at_front(__n - __vacancies);
2084             return this->_M_impl._M_start - difference_type(__n);
2085             }
2086              
2087             iterator
2088             _M_reserve_elements_at_back(size_type __n)
2089             {
2090             const size_type __vacancies = (this->_M_impl._M_finish._M_last
2091             - this->_M_impl._M_finish._M_cur) - 1;
2092             if (__n > __vacancies)
2093             _M_new_elements_at_back(__n - __vacancies);
2094             return this->_M_impl._M_finish + difference_type(__n);
2095             }
2096              
2097             void
2098             _M_new_elements_at_front(size_type __new_elements);
2099              
2100             void
2101             _M_new_elements_at_back(size_type __new_elements);
2102             //@}
2103              
2104              
2105             //@{
2106             /**
2107             * @brief Memory-handling helpers for the major %map.
2108             *
2109             * Makes sure the _M_map has space for new nodes. Does not
2110             * actually add the nodes. Can invalidate _M_map pointers.
2111             * (And consequently, %deque iterators.)
2112             */
2113             void
2114 0           _M_reserve_map_at_back(size_type __nodes_to_add = 1)
2115             {
2116 0 0         if (__nodes_to_add + 1 > this->_M_impl._M_map_size
    0          
    0          
2117 0           - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
2118 0           _M_reallocate_map(__nodes_to_add, false);
2119 0           }
2120              
2121             void
2122             _M_reserve_map_at_front(size_type __nodes_to_add = 1)
2123             {
2124             if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
2125             - this->_M_impl._M_map))
2126             _M_reallocate_map(__nodes_to_add, true);
2127             }
2128              
2129             void
2130             _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
2131             //@}
2132              
2133             #if __cplusplus >= 201103L
2134             // Constant-time, nothrow move assignment when source object's memory
2135             // can be moved because the allocators are equal.
2136             void
2137             _M_move_assign1(deque&& __x, /* always equal: */ true_type) noexcept
2138             {
2139             this->_M_impl._M_swap_data(__x._M_impl);
2140             __x.clear();
2141             std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator());
2142             }
2143              
2144             void
2145             _M_move_assign1(deque&& __x, /* always equal: */ false_type)
2146             {
2147             constexpr bool __move_storage =
2148             _Alloc_traits::_S_propagate_on_move_assign();
2149             _M_move_assign2(std::move(__x),
2150             integral_constant());
2151             }
2152              
2153             // Destroy all elements and deallocate all memory, then replace
2154             // with elements created from __args.
2155             template
2156             void
2157             _M_replace_map(_Args&&... __args)
2158             {
2159             // Create new data first, so if allocation fails there are no effects.
2160             deque __newobj(std::forward<_Args>(__args)...);
2161             // Free existing storage using existing allocator.
2162             clear();
2163             _M_deallocate_node(*begin()._M_node); // one node left after clear()
2164             _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
2165             this->_M_impl._M_map = nullptr;
2166             this->_M_impl._M_map_size = 0;
2167             // Take ownership of replacement memory.
2168             this->_M_impl._M_swap_data(__newobj._M_impl);
2169             }
2170              
2171             // Do move assignment when the allocator propagates.
2172             void
2173             _M_move_assign2(deque&& __x, /* propagate: */ true_type)
2174             {
2175             // Make a copy of the original allocator state.
2176             auto __alloc = __x._M_get_Tp_allocator();
2177             // The allocator propagates so storage can be moved from __x,
2178             // leaving __x in a valid empty state with a moved-from allocator.
2179             _M_replace_map(std::move(__x));
2180             // Move the corresponding allocator state too.
2181             _M_get_Tp_allocator() = std::move(__alloc);
2182             }
2183              
2184             // Do move assignment when it may not be possible to move source
2185             // object's memory, resulting in a linear-time operation.
2186             void
2187             _M_move_assign2(deque&& __x, /* propagate: */ false_type)
2188             {
2189             if (__x._M_get_Tp_allocator() == this->_M_get_Tp_allocator())
2190             {
2191             // The allocators are equal so storage can be moved from __x,
2192             // leaving __x in a valid empty state with its current allocator.
2193             _M_replace_map(std::move(__x), __x.get_allocator());
2194             }
2195             else
2196             {
2197             // The rvalue's allocator cannot be moved and is not equal,
2198             // so we need to individually move each element.
2199             this->assign(std::__make_move_if_noexcept_iterator(__x.begin()),
2200             std::__make_move_if_noexcept_iterator(__x.end()));
2201             __x.clear();
2202             }
2203             }
2204             #endif
2205             };
2206              
2207              
2208             /**
2209             * @brief Deque equality comparison.
2210             * @param __x A %deque.
2211             * @param __y A %deque of the same type as @a __x.
2212             * @return True iff the size and elements of the deques are equal.
2213             *
2214             * This is an equivalence relation. It is linear in the size of the
2215             * deques. Deques are considered equivalent if their sizes are equal,
2216             * and if corresponding elements compare equal.
2217             */
2218             template
2219             inline bool
2220             operator==(const deque<_Tp, _Alloc>& __x,
2221             const deque<_Tp, _Alloc>& __y)
2222             { return __x.size() == __y.size()
2223             && std::equal(__x.begin(), __x.end(), __y.begin()); }
2224              
2225             /**
2226             * @brief Deque ordering relation.
2227             * @param __x A %deque.
2228             * @param __y A %deque of the same type as @a __x.
2229             * @return True iff @a x is lexicographically less than @a __y.
2230             *
2231             * This is a total ordering relation. It is linear in the size of the
2232             * deques. The elements must be comparable with @c <.
2233             *
2234             * See std::lexicographical_compare() for how the determination is made.
2235             */
2236             template
2237             inline bool
2238             operator<(const deque<_Tp, _Alloc>& __x,
2239             const deque<_Tp, _Alloc>& __y)
2240             { return std::lexicographical_compare(__x.begin(), __x.end(),
2241             __y.begin(), __y.end()); }
2242              
2243             /// Based on operator==
2244             template
2245             inline bool
2246             operator!=(const deque<_Tp, _Alloc>& __x,
2247             const deque<_Tp, _Alloc>& __y)
2248             { return !(__x == __y); }
2249              
2250             /// Based on operator<
2251             template
2252             inline bool
2253             operator>(const deque<_Tp, _Alloc>& __x,
2254             const deque<_Tp, _Alloc>& __y)
2255             { return __y < __x; }
2256              
2257             /// Based on operator<
2258             template
2259             inline bool
2260             operator<=(const deque<_Tp, _Alloc>& __x,
2261             const deque<_Tp, _Alloc>& __y)
2262             { return !(__y < __x); }
2263              
2264             /// Based on operator<
2265             template
2266             inline bool
2267             operator>=(const deque<_Tp, _Alloc>& __x,
2268             const deque<_Tp, _Alloc>& __y)
2269             { return !(__x < __y); }
2270              
2271             /// See std::deque::swap().
2272             template
2273             inline void
2274             swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y)
2275             { __x.swap(__y); }
2276              
2277             #undef _GLIBCXX_DEQUE_BUF_SIZE
2278              
2279             _GLIBCXX_END_NAMESPACE_CONTAINER
2280             } // namespace std
2281              
2282             #endif /* _STL_DEQUE_H */