libstdc++
stl_deque.h
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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 // <http://www.gnu.org/licenses/>.
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 <bits/concept_check.h>
62 #if __cplusplus >= 201103L
63 #include <initializer_list>
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  __deque_buf_size(size_t __size)
90  { return (__size < _GLIBCXX_DEQUE_BUF_SIZE
91  ? 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<typename _Tp, typename _Ref, typename _Ptr>
107  {
108 #if __cplusplus < 201103L
111  typedef _Tp* _Elt_pointer;
112  typedef _Tp** _Map_pointer;
113 #else
114  private:
115  template<typename _Up>
116  using __ptr_to = typename pointer_traits<_Ptr>::template rebind<_Up>;
117  template<typename _CvTp>
119  public:
120  typedef __iter<_Tp> iterator;
121  typedef __iter<const _Tp> const_iterator;
122  typedef __ptr_to<_Tp> _Elt_pointer;
123  typedef __ptr_to<_Elt_pointer> _Map_pointer;
124 #endif
125 
126  static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
127  { return __deque_buf_size(sizeof(_Tp)); }
128 
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  _Deque_iterator() _GLIBCXX_NOEXCEPT
147  : _M_cur(), _M_first(), _M_last(), _M_node() { }
148 
149  _Deque_iterator(const iterator& __x) _GLIBCXX_NOEXCEPT
150  : _M_cur(__x._M_cur), _M_first(__x._M_first),
151  _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  operator*() const _GLIBCXX_NOEXCEPT
159  { 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  operator--() _GLIBCXX_NOEXCEPT
187  {
188  if (_M_cur == _M_first)
189  {
190  _M_set_node(_M_node - 1);
191  _M_cur = _M_last;
192  }
193  --_M_cur;
194  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  _M_set_node(_Map_pointer __new_node) _GLIBCXX_NOEXCEPT
253  {
254  _M_node = __new_node;
255  _M_first = *__new_node;
256  _M_last = _M_first + difference_type(_S_buffer_size());
257  }
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<typename _Tp, typename _Ref, typename _Ptr>
264  inline bool
265  operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
266  const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
267  { return __x._M_cur == __y._M_cur; }
268 
269  template<typename _Tp, typename _RefL, typename _PtrL,
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<typename _Tp, typename _Ref, typename _Ptr>
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<typename _Tp, typename _RefL, typename _PtrL,
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<typename _Tp, typename _Ref, typename _Ptr>
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<typename _Tp, typename _RefL, typename _PtrL,
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<typename _Tp, typename _Ref, typename _Ptr>
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<typename _Tp, typename _RefL, typename _PtrL,
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<typename _Tp, typename _Ref, typename _Ptr>
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<typename _Tp, typename _RefL, typename _PtrL,
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<typename _Tp, typename _Ref, typename _Ptr>
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<typename _Tp, typename _RefL, typename _PtrL,
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<typename _Tp, typename _Ref, typename _Ptr>
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<typename _Tp, typename _RefL, typename _PtrL,
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<typename _Tp, typename _Ref, typename _Ptr>
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<typename _Tp>
377  void
378  fill(const _Deque_iterator<_Tp, _Tp&, _Tp*>&,
379  const _Deque_iterator<_Tp, _Tp&, _Tp*>&, const _Tp&);
380 
381  template<typename _Tp>
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<typename _Tp>
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<typename _Tp>
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<typename _Tp>
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<typename _Tp>
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<typename _Tp>
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<typename _Tp>
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<typename _Tp>
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<typename _Tp, typename _Alloc>
459  {
460  protected:
462  rebind<_Tp>::other _Tp_alloc_type;
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;
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 
487 
488  _Deque_base()
489  : _M_impl()
490  { _M_initialize_map(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  _Deque_base(_Deque_base&& __x, true_type)
510  : _M_impl(std::move(__x._M_get_Tp_allocator()))
511  {
513  if (__x._M_impl._M_map)
514  this->_M_impl._M_swap_data(__x._M_impl);
515  }
516 
517  _Deque_base(_Deque_base&& __x)
518  : _Deque_base(std::move(__x),
519  __gnu_cxx::__allocator_always_compares_equal<_Alloc>{})
520  { }
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  {
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  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  _Deque_impl()
557  : _Tp_alloc_type(), _M_map(), _M_map_size(0),
558  _M_start(), _M_finish()
559  { }
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  _Deque_impl(_Tp_alloc_type&& __a) noexcept
570  : _Tp_alloc_type(std::move(__a)), _M_map(), _M_map_size(0),
571  _M_start(), _M_finish()
572  { }
573 #endif
574 
575  void _M_swap_data(_Deque_impl& __x) _GLIBCXX_NOEXCEPT
576  {
577  using std::swap;
578  swap(this->_M_start, __x._M_start);
579  swap(this->_M_finish, __x._M_finish);
580  swap(this->_M_map, __x._M_map);
581  swap(this->_M_map_size, __x._M_map_size);
582  }
583  };
584 
585  _Tp_alloc_type&
586  _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT
587  { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); }
588 
589  const _Tp_alloc_type&
590  _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT
591  { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); }
592 
593  _Map_alloc_type
594  _M_get_map_allocator() const _GLIBCXX_NOEXCEPT
595  { return _Map_alloc_type(_M_get_Tp_allocator()); }
596 
597  _Ptr
598  _M_allocate_node()
599  {
601  return _Traits::allocate(_M_impl, __deque_buf_size(sizeof(_Tp)));
602  }
603 
604  void
605  _M_deallocate_node(_Ptr __p) _GLIBCXX_NOEXCEPT
606  {
608  _Traits::deallocate(_M_impl, __p, __deque_buf_size(sizeof(_Tp)));
609  }
610 
611  _Map_pointer
612  _M_allocate_map(size_t __n)
613  {
614  _Map_alloc_type __map_alloc = _M_get_map_allocator();
615  return _Map_alloc_traits::allocate(__map_alloc, __n);
616  }
617 
618  void
619  _M_deallocate_map(_Map_pointer __p, size_t __n) _GLIBCXX_NOEXCEPT
620  {
621  _Map_alloc_type __map_alloc = _M_get_map_allocator();
622  _Map_alloc_traits::deallocate(__map_alloc, __p, __n);
623  }
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  // Now safe to modify current allocator and perform non-throwing swaps.
649  _Deque_impl __ret{std::move(_M_get_Tp_allocator())};
650  _M_impl._M_swap_data(__ret);
651  _M_impl._M_swap_data(__empty._M_impl);
652  return __ret;
653  }
654 #endif
655  };
656 
657  template<typename _Tp, typename _Alloc>
659  ~_Deque_base() _GLIBCXX_NOEXCEPT
660  {
661  if (this->_M_impl._M_map)
662  {
663  _M_destroy_nodes(this->_M_impl._M_start._M_node,
664  this->_M_impl._M_finish._M_node + 1);
665  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
666  }
667  }
668 
669  /**
670  * @brief Layout storage.
671  * @param __num_elements The count of T's for which to allocate space
672  * at first.
673  * @return Nothing.
674  *
675  * The initial underlying memory layout is a bit complicated...
676  */
677  template<typename _Tp, typename _Alloc>
678  void
680  _M_initialize_map(size_t __num_elements)
681  {
682  const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
683  + 1);
684 
685  this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
686  size_t(__num_nodes + 2));
687  this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
688 
689  // For "small" maps (needing less than _M_map_size nodes), allocation
690  // starts in the middle elements and grows outwards. So nstart may be
691  // the beginning of _M_map, but for small maps it may be as far in as
692  // _M_map+3.
693 
694  _Map_pointer __nstart = (this->_M_impl._M_map
695  + (this->_M_impl._M_map_size - __num_nodes) / 2);
696  _Map_pointer __nfinish = __nstart + __num_nodes;
697 
698  __try
699  { _M_create_nodes(__nstart, __nfinish); }
700  __catch(...)
701  {
702  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
703  this->_M_impl._M_map = _Map_pointer();
704  this->_M_impl._M_map_size = 0;
705  __throw_exception_again;
706  }
707 
708  this->_M_impl._M_start._M_set_node(__nstart);
709  this->_M_impl._M_finish._M_set_node(__nfinish - 1);
710  this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
711  this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
712  + __num_elements
713  % __deque_buf_size(sizeof(_Tp)));
714  }
715 
716  template<typename _Tp, typename _Alloc>
717  void
719  _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish)
720  {
721  _Map_pointer __cur;
722  __try
723  {
724  for (__cur = __nstart; __cur < __nfinish; ++__cur)
725  *__cur = this->_M_allocate_node();
726  }
727  __catch(...)
728  {
729  _M_destroy_nodes(__nstart, __cur);
730  __throw_exception_again;
731  }
732  }
733 
734  template<typename _Tp, typename _Alloc>
735  void
736  _Deque_base<_Tp, _Alloc>::
737  _M_destroy_nodes(_Map_pointer __nstart,
738  _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT
739  {
740  for (_Map_pointer __n = __nstart; __n < __nfinish; ++__n)
741  _M_deallocate_node(*__n);
742  }
743 
744  /**
745  * @brief A standard container using fixed-size memory allocation and
746  * constant-time manipulation of elements at either end.
747  *
748  * @ingroup sequences
749  *
750  * @tparam _Tp Type of element.
751  * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
752  *
753  * Meets the requirements of a <a href="tables.html#65">container</a>, a
754  * <a href="tables.html#66">reversible container</a>, and a
755  * <a href="tables.html#67">sequence</a>, including the
756  * <a href="tables.html#68">optional sequence requirements</a>.
757  *
758  * In previous HP/SGI versions of deque, there was an extra template
759  * parameter so users could control the node size. This extension turned
760  * out to violate the C++ standard (it can be detected using template
761  * template parameters), and it was removed.
762  *
763  * Here's how a deque<Tp> manages memory. Each deque has 4 members:
764  *
765  * - Tp** _M_map
766  * - size_t _M_map_size
767  * - iterator _M_start, _M_finish
768  *
769  * map_size is at least 8. %map is an array of map_size
770  * pointers-to-@a nodes. (The name %map has nothing to do with the
771  * std::map class, and @b nodes should not be confused with
772  * std::list's usage of @a node.)
773  *
774  * A @a node has no specific type name as such, but it is referred
775  * to as @a node in this file. It is a simple array-of-Tp. If Tp
776  * is very large, there will be one Tp element per node (i.e., an
777  * @a array of one). For non-huge Tp's, node size is inversely
778  * related to Tp size: the larger the Tp, the fewer Tp's will fit
779  * in a node. The goal here is to keep the total size of a node
780  * relatively small and constant over different Tp's, to improve
781  * allocator efficiency.
782  *
783  * Not every pointer in the %map array will point to a node. If
784  * the initial number of elements in the deque is small, the
785  * /middle/ %map pointers will be valid, and the ones at the edges
786  * will be unused. This same situation will arise as the %map
787  * grows: available %map pointers, if any, will be on the ends. As
788  * new nodes are created, only a subset of the %map's pointers need
789  * to be copied @a outward.
790  *
791  * Class invariants:
792  * - For any nonsingular iterator i:
793  * - i.node points to a member of the %map array. (Yes, you read that
794  * correctly: i.node does not actually point to a node.) The member of
795  * the %map array is what actually points to the node.
796  * - i.first == *(i.node) (This points to the node (first Tp element).)
797  * - i.last == i.first + node_size
798  * - i.cur is a pointer in the range [i.first, i.last). NOTE:
799  * the implication of this is that i.cur is always a dereferenceable
800  * pointer, even if i is a past-the-end iterator.
801  * - Start and Finish are always nonsingular iterators. NOTE: this
802  * means that an empty deque must have one node, a deque with <N
803  * elements (where N is the node buffer size) must have one node, a
804  * deque with N through (2N-1) elements must have two nodes, etc.
805  * - For every node other than start.node and finish.node, every
806  * element in the node is an initialized object. If start.node ==
807  * finish.node, then [start.cur, finish.cur) are initialized
808  * objects, and the elements outside that range are uninitialized
809  * storage. Otherwise, [start.cur, start.last) and [finish.first,
810  * finish.cur) are initialized objects, and [start.first, start.cur)
811  * and [finish.cur, finish.last) are uninitialized storage.
812  * - [%map, %map + map_size) is a valid, non-empty range.
813  * - [start.node, finish.node] is a valid range contained within
814  * [%map, %map + map_size).
815  * - A pointer in the range [%map, %map + map_size) points to an allocated
816  * node if and only if the pointer is in the range
817  * [start.node, finish.node].
818  *
819  * Here's the magic: nothing in deque is @b aware of the discontiguous
820  * storage!
821  *
822  * The memory setup and layout occurs in the parent, _Base, and the iterator
823  * class is entirely responsible for @a leaping from one node to the next.
824  * All the implementation routines for deque itself work only through the
825  * start and finish iterators. This keeps the routines simple and sane,
826  * and we can use other standard algorithms as well.
827  */
828  template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
829  class deque : protected _Deque_base<_Tp, _Alloc>
830  {
831  // concept requirements
832  typedef typename _Alloc::value_type _Alloc_value_type;
833  __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
834  __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
835 
837  typedef typename _Base::_Tp_alloc_type _Tp_alloc_type;
838  typedef typename _Base::_Alloc_traits _Alloc_traits;
839  typedef typename _Base::_Map_pointer _Map_pointer;
840 
841  public:
842  typedef _Tp value_type;
843  typedef typename _Alloc_traits::pointer pointer;
844  typedef typename _Alloc_traits::const_pointer const_pointer;
845  typedef typename _Alloc_traits::reference reference;
846  typedef typename _Alloc_traits::const_reference const_reference;
847  typedef typename _Base::iterator iterator;
848  typedef typename _Base::const_iterator const_iterator;
851  typedef size_t size_type;
852  typedef ptrdiff_t difference_type;
853  typedef _Alloc allocator_type;
854 
855  protected:
856  static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
857  { return __deque_buf_size(sizeof(_Tp)); }
858 
859  // Functions controlling memory layout, and nothing else.
861  using _Base::_M_create_nodes;
862  using _Base::_M_destroy_nodes;
863  using _Base::_M_allocate_node;
864  using _Base::_M_deallocate_node;
865  using _Base::_M_allocate_map;
866  using _Base::_M_deallocate_map;
867  using _Base::_M_get_Tp_allocator;
868 
869  /**
870  * A total of four data members accumulated down the hierarchy.
871  * May be accessed via _M_impl.*
872  */
873  using _Base::_M_impl;
874 
875  public:
876  // [23.2.1.1] construct/copy/destroy
877  // (assign() and get_allocator() are also listed in this section)
878 
879  /**
880  * @brief Creates a %deque with no elements.
881  */
882  deque() : _Base() { }
883 
884  /**
885  * @brief Creates a %deque with no elements.
886  * @param __a An allocator object.
887  */
888  explicit
889  deque(const allocator_type& __a)
890  : _Base(__a, 0) { }
891 
892 #if __cplusplus >= 201103L
893  /**
894  * @brief Creates a %deque with default constructed elements.
895  * @param __n The number of elements to initially create.
896  *
897  * This constructor fills the %deque with @a n default
898  * constructed elements.
899  */
900  explicit
901  deque(size_type __n, const allocator_type& __a = allocator_type())
902  : _Base(__a, __n)
903  { _M_default_initialize(); }
904 
905  /**
906  * @brief Creates a %deque with copies of an exemplar element.
907  * @param __n The number of elements to initially create.
908  * @param __value An element to copy.
909  * @param __a An allocator.
910  *
911  * This constructor fills the %deque with @a __n copies of @a __value.
912  */
913  deque(size_type __n, const value_type& __value,
914  const allocator_type& __a = allocator_type())
915  : _Base(__a, __n)
916  { _M_fill_initialize(__value); }
917 #else
918  /**
919  * @brief Creates a %deque with copies of an exemplar element.
920  * @param __n The number of elements to initially create.
921  * @param __value An element to copy.
922  * @param __a An allocator.
923  *
924  * This constructor fills the %deque with @a __n copies of @a __value.
925  */
926  explicit
927  deque(size_type __n, const value_type& __value = value_type(),
928  const allocator_type& __a = allocator_type())
929  : _Base(__a, __n)
930  { _M_fill_initialize(__value); }
931 #endif
932 
933  /**
934  * @brief %Deque copy constructor.
935  * @param __x A %deque of identical element and allocator types.
936  *
937  * The newly-created %deque uses a copy of the allocation object used
938  * by @a __x.
939  */
940  deque(const deque& __x)
941  : _Base(_Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()),
942  __x.size())
943  { std::__uninitialized_copy_a(__x.begin(), __x.end(),
944  this->_M_impl._M_start,
945  _M_get_Tp_allocator()); }
946 
947 #if __cplusplus >= 201103L
948  /**
949  * @brief %Deque move constructor.
950  * @param __x A %deque of identical element and allocator types.
951  *
952  * The newly-created %deque contains the exact contents of @a __x.
953  * The contents of @a __x are a valid, but unspecified %deque.
954  */
955  deque(deque&& __x)
956  : _Base(std::move(__x)) { }
957 
958  /// Copy constructor with alternative allocator
959  deque(const deque& __x, const allocator_type& __a)
960  : _Base(__a, __x.size())
961  { std::__uninitialized_copy_a(__x.begin(), __x.end(),
962  this->_M_impl._M_start,
963  _M_get_Tp_allocator()); }
964 
965  /// Move constructor with alternative allocator
966  deque(deque&& __x, const allocator_type& __a)
967  : _Base(std::move(__x), __a, __x.size())
968  {
969  if (__x.get_allocator() != __a)
970  {
971  std::__uninitialized_move_a(__x.begin(), __x.end(),
972  this->_M_impl._M_start,
973  _M_get_Tp_allocator());
974  __x.clear();
975  }
976  }
977 
978  /**
979  * @brief Builds a %deque from an initializer list.
980  * @param __l An initializer_list.
981  * @param __a An allocator object.
982  *
983  * Create a %deque consisting of copies of the elements in the
984  * initializer_list @a __l.
985  *
986  * This will call the element type's copy constructor N times
987  * (where N is __l.size()) and do no memory reallocation.
988  */
989  deque(initializer_list<value_type> __l,
990  const allocator_type& __a = allocator_type())
991  : _Base(__a)
992  {
993  _M_range_initialize(__l.begin(), __l.end(),
995  }
996 #endif
997 
998  /**
999  * @brief Builds a %deque from a range.
1000  * @param __first An input iterator.
1001  * @param __last An input iterator.
1002  * @param __a An allocator object.
1003  *
1004  * Create a %deque consisting of copies of the elements from [__first,
1005  * __last).
1006  *
1007  * If the iterators are forward, bidirectional, or random-access, then
1008  * this will call the elements' copy constructor N times (where N is
1009  * distance(__first,__last)) and do no memory reallocation. But if only
1010  * input iterators are used, then this will do at most 2N calls to the
1011  * copy constructor, and logN memory reallocations.
1012  */
1013 #if __cplusplus >= 201103L
1014  template<typename _InputIterator,
1015  typename = std::_RequireInputIter<_InputIterator>>
1016  deque(_InputIterator __first, _InputIterator __last,
1017  const allocator_type& __a = allocator_type())
1018  : _Base(__a)
1019  { _M_initialize_dispatch(__first, __last, __false_type()); }
1020 #else
1021  template<typename _InputIterator>
1022  deque(_InputIterator __first, _InputIterator __last,
1023  const allocator_type& __a = allocator_type())
1024  : _Base(__a)
1025  {
1026  // Check whether it's an integral type. If so, it's not an iterator.
1027  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1028  _M_initialize_dispatch(__first, __last, _Integral());
1029  }
1030 #endif
1031 
1032  /**
1033  * The dtor only erases the elements, and note that if the elements
1034  * themselves are pointers, the pointed-to memory is not touched in any
1035  * way. Managing the pointer is the user's responsibility.
1036  */
1038  { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); }
1039 
1040  /**
1041  * @brief %Deque assignment operator.
1042  * @param __x A %deque of identical element and allocator types.
1043  *
1044  * All the elements of @a x are copied, but unlike the copy constructor,
1045  * the allocator object is not copied.
1046  */
1047  deque&
1048  operator=(const deque& __x);
1049 
1050 #if __cplusplus >= 201103L
1051  /**
1052  * @brief %Deque move assignment operator.
1053  * @param __x A %deque of identical element and allocator types.
1054  *
1055  * The contents of @a __x are moved into this deque (without copying,
1056  * if the allocators permit it).
1057  * @a __x is a valid, but unspecified %deque.
1058  */
1059  deque&
1060  operator=(deque&& __x) noexcept(_Alloc_traits::_S_always_equal())
1061  {
1062  constexpr bool __always_equal = _Alloc_traits::_S_always_equal();
1063  _M_move_assign1(std::move(__x),
1064  integral_constant<bool, __always_equal>());
1065  return *this;
1066  }
1067 
1068  /**
1069  * @brief Assigns an initializer list to a %deque.
1070  * @param __l An initializer_list.
1071  *
1072  * This function fills a %deque with copies of the elements in the
1073  * initializer_list @a __l.
1074  *
1075  * Note that the assignment completely changes the %deque and that the
1076  * resulting %deque's size is the same as the number of elements
1077  * assigned. Old data may be lost.
1078  */
1079  deque&
1080  operator=(initializer_list<value_type> __l)
1081  {
1082  this->assign(__l.begin(), __l.end());
1083  return *this;
1084  }
1085 #endif
1086 
1087  /**
1088  * @brief Assigns a given value to a %deque.
1089  * @param __n Number of elements to be assigned.
1090  * @param __val Value to be assigned.
1091  *
1092  * This function fills a %deque with @a n copies of the given
1093  * value. Note that the assignment completely changes the
1094  * %deque and that the resulting %deque's size is the same as
1095  * the number of elements assigned. Old data may be lost.
1096  */
1097  void
1098  assign(size_type __n, const value_type& __val)
1099  { _M_fill_assign(__n, __val); }
1100 
1101  /**
1102  * @brief Assigns a range to a %deque.
1103  * @param __first An input iterator.
1104  * @param __last An input iterator.
1105  *
1106  * This function fills a %deque with copies of the elements in the
1107  * range [__first,__last).
1108  *
1109  * Note that the assignment completely changes the %deque and that the
1110  * resulting %deque's size is the same as the number of elements
1111  * assigned. Old data may be lost.
1112  */
1113 #if __cplusplus >= 201103L
1114  template<typename _InputIterator,
1115  typename = std::_RequireInputIter<_InputIterator>>
1116  void
1117  assign(_InputIterator __first, _InputIterator __last)
1118  { _M_assign_dispatch(__first, __last, __false_type()); }
1119 #else
1120  template<typename _InputIterator>
1121  void
1122  assign(_InputIterator __first, _InputIterator __last)
1123  {
1124  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1125  _M_assign_dispatch(__first, __last, _Integral());
1126  }
1127 #endif
1128 
1129 #if __cplusplus >= 201103L
1130  /**
1131  * @brief Assigns an initializer list to a %deque.
1132  * @param __l An initializer_list.
1133  *
1134  * This function fills a %deque with copies of the elements in the
1135  * initializer_list @a __l.
1136  *
1137  * Note that the assignment completely changes the %deque and that the
1138  * resulting %deque's size is the same as the number of elements
1139  * assigned. Old data may be lost.
1140  */
1141  void
1142  assign(initializer_list<value_type> __l)
1143  { this->assign(__l.begin(), __l.end()); }
1144 #endif
1145 
1146  /// Get a copy of the memory allocation object.
1147  allocator_type
1148  get_allocator() const _GLIBCXX_NOEXCEPT
1149  { return _Base::get_allocator(); }
1150 
1151  // iterators
1152  /**
1153  * Returns a read/write iterator that points to the first element in the
1154  * %deque. Iteration is done in ordinary element order.
1155  */
1156  iterator
1157  begin() _GLIBCXX_NOEXCEPT
1158  { return this->_M_impl._M_start; }
1159 
1160  /**
1161  * Returns a read-only (constant) iterator that points to the first
1162  * element in the %deque. Iteration is done in ordinary element order.
1163  */
1164  const_iterator
1165  begin() const _GLIBCXX_NOEXCEPT
1166  { return this->_M_impl._M_start; }
1167 
1168  /**
1169  * Returns a read/write iterator that points one past the last
1170  * element in the %deque. Iteration is done in ordinary
1171  * element order.
1172  */
1173  iterator
1174  end() _GLIBCXX_NOEXCEPT
1175  { return this->_M_impl._M_finish; }
1176 
1177  /**
1178  * Returns a read-only (constant) iterator that points one past
1179  * the last element in the %deque. Iteration is done in
1180  * ordinary element order.
1181  */
1182  const_iterator
1183  end() const _GLIBCXX_NOEXCEPT
1184  { return this->_M_impl._M_finish; }
1185 
1186  /**
1187  * Returns a read/write reverse iterator that points to the
1188  * last element in the %deque. Iteration is done in reverse
1189  * element order.
1190  */
1191  reverse_iterator
1192  rbegin() _GLIBCXX_NOEXCEPT
1193  { return reverse_iterator(this->_M_impl._M_finish); }
1194 
1195  /**
1196  * Returns a read-only (constant) reverse iterator that points
1197  * to the last element in the %deque. Iteration is done in
1198  * reverse element order.
1199  */
1200  const_reverse_iterator
1201  rbegin() const _GLIBCXX_NOEXCEPT
1202  { return const_reverse_iterator(this->_M_impl._M_finish); }
1203 
1204  /**
1205  * Returns a read/write reverse iterator that points to one
1206  * before the first element in the %deque. Iteration is done
1207  * in reverse element order.
1208  */
1209  reverse_iterator
1210  rend() _GLIBCXX_NOEXCEPT
1211  { return reverse_iterator(this->_M_impl._M_start); }
1212 
1213  /**
1214  * Returns a read-only (constant) reverse iterator that points
1215  * to one before the first element in the %deque. Iteration is
1216  * done in reverse element order.
1217  */
1218  const_reverse_iterator
1219  rend() const _GLIBCXX_NOEXCEPT
1220  { return const_reverse_iterator(this->_M_impl._M_start); }
1221 
1222 #if __cplusplus >= 201103L
1223  /**
1224  * Returns a read-only (constant) iterator that points to the first
1225  * element in the %deque. Iteration is done in ordinary element order.
1226  */
1227  const_iterator
1228  cbegin() const noexcept
1229  { return this->_M_impl._M_start; }
1230 
1231  /**
1232  * Returns a read-only (constant) iterator that points one past
1233  * the last element in the %deque. Iteration is done in
1234  * ordinary element order.
1235  */
1236  const_iterator
1237  cend() const noexcept
1238  { return this->_M_impl._M_finish; }
1239 
1240  /**
1241  * Returns a read-only (constant) reverse iterator that points
1242  * to the last element in the %deque. Iteration is done in
1243  * reverse element order.
1244  */
1245  const_reverse_iterator
1246  crbegin() const noexcept
1247  { return const_reverse_iterator(this->_M_impl._M_finish); }
1248 
1249  /**
1250  * Returns a read-only (constant) reverse iterator that points
1251  * to one before the first element in the %deque. Iteration is
1252  * done in reverse element order.
1253  */
1254  const_reverse_iterator
1255  crend() const noexcept
1256  { return const_reverse_iterator(this->_M_impl._M_start); }
1257 #endif
1258 
1259  // [23.2.1.2] capacity
1260  /** Returns the number of elements in the %deque. */
1261  size_type
1262  size() const _GLIBCXX_NOEXCEPT
1263  { return this->_M_impl._M_finish - this->_M_impl._M_start; }
1264 
1265  /** Returns the size() of the largest possible %deque. */
1266  size_type
1267  max_size() const _GLIBCXX_NOEXCEPT
1268  { return _Alloc_traits::max_size(_M_get_Tp_allocator()); }
1269 
1270 #if __cplusplus >= 201103L
1271  /**
1272  * @brief Resizes the %deque to the specified number of elements.
1273  * @param __new_size Number of elements the %deque should contain.
1274  *
1275  * This function will %resize the %deque to the specified
1276  * number of elements. If the number is smaller than the
1277  * %deque's current size the %deque is truncated, otherwise
1278  * default constructed elements are appended.
1279  */
1280  void
1281  resize(size_type __new_size)
1282  {
1283  const size_type __len = size();
1284  if (__new_size > __len)
1285  _M_default_append(__new_size - __len);
1286  else if (__new_size < __len)
1287  _M_erase_at_end(this->_M_impl._M_start
1288  + difference_type(__new_size));
1289  }
1290 
1291  /**
1292  * @brief Resizes the %deque to the specified number of elements.
1293  * @param __new_size Number of elements the %deque should contain.
1294  * @param __x Data with which new elements should be populated.
1295  *
1296  * This function will %resize the %deque to the specified
1297  * number of elements. If the number is smaller than the
1298  * %deque's current size the %deque is truncated, otherwise the
1299  * %deque is extended and new elements are populated with given
1300  * data.
1301  */
1302  void
1303  resize(size_type __new_size, const value_type& __x)
1304  {
1305  const size_type __len = size();
1306  if (__new_size > __len)
1307  insert(this->_M_impl._M_finish, __new_size - __len, __x);
1308  else if (__new_size < __len)
1309  _M_erase_at_end(this->_M_impl._M_start
1310  + difference_type(__new_size));
1311  }
1312 #else
1313  /**
1314  * @brief Resizes the %deque to the specified number of elements.
1315  * @param __new_size Number of elements the %deque should contain.
1316  * @param __x Data with which new elements should be populated.
1317  *
1318  * This function will %resize the %deque to the specified
1319  * number of elements. If the number is smaller than the
1320  * %deque's current size the %deque is truncated, otherwise the
1321  * %deque is extended and new elements are populated with given
1322  * data.
1323  */
1324  void
1325  resize(size_type __new_size, value_type __x = value_type())
1326  {
1327  const size_type __len = size();
1328  if (__new_size > __len)
1329  insert(this->_M_impl._M_finish, __new_size - __len, __x);
1330  else if (__new_size < __len)
1331  _M_erase_at_end(this->_M_impl._M_start
1332  + difference_type(__new_size));
1333  }
1334 #endif
1335 
1336 #if __cplusplus >= 201103L
1337  /** A non-binding request to reduce memory use. */
1338  void
1339  shrink_to_fit() noexcept
1340  { _M_shrink_to_fit(); }
1341 #endif
1342 
1343  /**
1344  * Returns true if the %deque is empty. (Thus begin() would
1345  * equal end().)
1346  */
1347  bool
1348  empty() const _GLIBCXX_NOEXCEPT
1349  { return this->_M_impl._M_finish == this->_M_impl._M_start; }
1350 
1351  // element access
1352  /**
1353  * @brief Subscript access to the data contained in the %deque.
1354  * @param __n The index of the element for which data should be
1355  * accessed.
1356  * @return Read/write reference to data.
1357  *
1358  * This operator allows for easy, array-style, data access.
1359  * Note that data access with this operator is unchecked and
1360  * out_of_range lookups are not defined. (For checked lookups
1361  * see at().)
1362  */
1363  reference
1364  operator[](size_type __n) _GLIBCXX_NOEXCEPT
1365  { return this->_M_impl._M_start[difference_type(__n)]; }
1366 
1367  /**
1368  * @brief Subscript access to the data contained in the %deque.
1369  * @param __n The index of the element for which data should be
1370  * accessed.
1371  * @return Read-only (constant) reference to data.
1372  *
1373  * This operator allows for easy, array-style, data access.
1374  * Note that data access with this operator is unchecked and
1375  * out_of_range lookups are not defined. (For checked lookups
1376  * see at().)
1377  */
1378  const_reference
1379  operator[](size_type __n) const _GLIBCXX_NOEXCEPT
1380  { return this->_M_impl._M_start[difference_type(__n)]; }
1381 
1382  protected:
1383  /// Safety check used only from at().
1384  void
1385  _M_range_check(size_type __n) const
1386  {
1387  if (__n >= this->size())
1388  __throw_out_of_range_fmt(__N("deque::_M_range_check: __n "
1389  "(which is %zu)>= this->size() "
1390  "(which is %zu)"),
1391  __n, this->size());
1392  }
1393 
1394  public:
1395  /**
1396  * @brief Provides access to the data contained in the %deque.
1397  * @param __n The index of the element for which data should be
1398  * accessed.
1399  * @return Read/write reference to data.
1400  * @throw std::out_of_range If @a __n is an invalid index.
1401  *
1402  * This function provides for safer data access. The parameter
1403  * is first checked that it is in the range of the deque. The
1404  * function throws out_of_range if the check fails.
1405  */
1406  reference
1407  at(size_type __n)
1408  {
1409  _M_range_check(__n);
1410  return (*this)[__n];
1411  }
1412 
1413  /**
1414  * @brief Provides access to the data contained in the %deque.
1415  * @param __n The index of the element for which data should be
1416  * accessed.
1417  * @return Read-only (constant) reference to data.
1418  * @throw std::out_of_range If @a __n is an invalid index.
1419  *
1420  * This function provides for safer data access. The parameter is first
1421  * checked that it is in the range of the deque. The function throws
1422  * out_of_range if the check fails.
1423  */
1424  const_reference
1425  at(size_type __n) const
1426  {
1427  _M_range_check(__n);
1428  return (*this)[__n];
1429  }
1430 
1431  /**
1432  * Returns a read/write reference to the data at the first
1433  * element of the %deque.
1434  */
1435  reference
1436  front() _GLIBCXX_NOEXCEPT
1437  { return *begin(); }
1438 
1439  /**
1440  * Returns a read-only (constant) reference to the data at the first
1441  * element of the %deque.
1442  */
1443  const_reference
1444  front() const _GLIBCXX_NOEXCEPT
1445  { return *begin(); }
1446 
1447  /**
1448  * Returns a read/write reference to the data at the last element of the
1449  * %deque.
1450  */
1451  reference
1452  back() _GLIBCXX_NOEXCEPT
1453  {
1454  iterator __tmp = end();
1455  --__tmp;
1456  return *__tmp;
1457  }
1458 
1459  /**
1460  * Returns a read-only (constant) reference to the data at the last
1461  * element of the %deque.
1462  */
1463  const_reference
1464  back() const _GLIBCXX_NOEXCEPT
1465  {
1466  const_iterator __tmp = end();
1467  --__tmp;
1468  return *__tmp;
1469  }
1470 
1471  // [23.2.1.2] modifiers
1472  /**
1473  * @brief Add data to the front of the %deque.
1474  * @param __x Data to be added.
1475  *
1476  * This is a typical stack operation. The function creates an
1477  * element at the front of the %deque and assigns the given
1478  * data to it. Due to the nature of a %deque this operation
1479  * can be done in constant time.
1480  */
1481  void
1482  push_front(const value_type& __x)
1483  {
1484  if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
1485  {
1486  _Alloc_traits::construct(this->_M_impl,
1487  this->_M_impl._M_start._M_cur - 1,
1488  __x);
1489  --this->_M_impl._M_start._M_cur;
1490  }
1491  else
1492  _M_push_front_aux(__x);
1493  }
1494 
1495 #if __cplusplus >= 201103L
1496  void
1497  push_front(value_type&& __x)
1498  { emplace_front(std::move(__x)); }
1499 
1500  template<typename... _Args>
1501  void
1502  emplace_front(_Args&&... __args);
1503 #endif
1504 
1505  /**
1506  * @brief Add data to the end of the %deque.
1507  * @param __x Data to be added.
1508  *
1509  * This is a typical stack operation. The function creates an
1510  * element at the end of the %deque and assigns the given data
1511  * to it. Due to the nature of a %deque this operation can be
1512  * done in constant time.
1513  */
1514  void
1515  push_back(const value_type& __x)
1516  {
1517  if (this->_M_impl._M_finish._M_cur
1518  != this->_M_impl._M_finish._M_last - 1)
1519  {
1520  _Alloc_traits::construct(this->_M_impl,
1521  this->_M_impl._M_finish._M_cur, __x);
1522  ++this->_M_impl._M_finish._M_cur;
1523  }
1524  else
1525  _M_push_back_aux(__x);
1526  }
1527 
1528 #if __cplusplus >= 201103L
1529  void
1530  push_back(value_type&& __x)
1531  { emplace_back(std::move(__x)); }
1532 
1533  template<typename... _Args>
1534  void
1535  emplace_back(_Args&&... __args);
1536 #endif
1537 
1538  /**
1539  * @brief Removes first element.
1540  *
1541  * This is a typical stack operation. It shrinks the %deque by one.
1542  *
1543  * Note that no data is returned, and if the first element's data is
1544  * needed, it should be retrieved before pop_front() is called.
1545  */
1546  void
1547  pop_front() _GLIBCXX_NOEXCEPT
1548  {
1549  if (this->_M_impl._M_start._M_cur
1550  != this->_M_impl._M_start._M_last - 1)
1551  {
1552  _Alloc_traits::destroy(this->_M_impl,
1553  this->_M_impl._M_start._M_cur);
1554  ++this->_M_impl._M_start._M_cur;
1555  }
1556  else
1557  _M_pop_front_aux();
1558  }
1559 
1560  /**
1561  * @brief Removes last element.
1562  *
1563  * This is a typical stack operation. It shrinks the %deque by one.
1564  *
1565  * Note that no data is returned, and if the last element's data is
1566  * needed, it should be retrieved before pop_back() is called.
1567  */
1568  void
1569  pop_back() _GLIBCXX_NOEXCEPT
1570  {
1571  if (this->_M_impl._M_finish._M_cur
1572  != this->_M_impl._M_finish._M_first)
1573  {
1574  --this->_M_impl._M_finish._M_cur;
1575  _Alloc_traits::destroy(this->_M_impl,
1576  this->_M_impl._M_finish._M_cur);
1577  }
1578  else
1579  _M_pop_back_aux();
1580  }
1581 
1582 #if __cplusplus >= 201103L
1583  /**
1584  * @brief Inserts an object in %deque before specified iterator.
1585  * @param __position A const_iterator into the %deque.
1586  * @param __args Arguments.
1587  * @return An iterator that points to the inserted data.
1588  *
1589  * This function will insert an object of type T constructed
1590  * with T(std::forward<Args>(args)...) before the specified location.
1591  */
1592  template<typename... _Args>
1593  iterator
1594  emplace(const_iterator __position, _Args&&... __args);
1595 
1596  /**
1597  * @brief Inserts given value into %deque before specified iterator.
1598  * @param __position A const_iterator into the %deque.
1599  * @param __x Data to be inserted.
1600  * @return An iterator that points to the inserted data.
1601  *
1602  * This function will insert a copy of the given value before the
1603  * specified location.
1604  */
1605  iterator
1606  insert(const_iterator __position, const value_type& __x);
1607 #else
1608  /**
1609  * @brief Inserts given value into %deque before specified iterator.
1610  * @param __position An iterator into the %deque.
1611  * @param __x Data to be inserted.
1612  * @return An iterator that points to the inserted data.
1613  *
1614  * This function will insert a copy of the given value before the
1615  * specified location.
1616  */
1617  iterator
1618  insert(iterator __position, const value_type& __x);
1619 #endif
1620 
1621 #if __cplusplus >= 201103L
1622  /**
1623  * @brief Inserts given rvalue into %deque before specified iterator.
1624  * @param __position A const_iterator into the %deque.
1625  * @param __x Data to be inserted.
1626  * @return An iterator that points to the inserted data.
1627  *
1628  * This function will insert a copy of the given rvalue before the
1629  * specified location.
1630  */
1631  iterator
1632  insert(const_iterator __position, value_type&& __x)
1633  { return emplace(__position, std::move(__x)); }
1634 
1635  /**
1636  * @brief Inserts an initializer list into the %deque.
1637  * @param __p An iterator into the %deque.
1638  * @param __l An initializer_list.
1639  *
1640  * This function will insert copies of the data in the
1641  * initializer_list @a __l into the %deque before the location
1642  * specified by @a __p. This is known as <em>list insert</em>.
1643  */
1644  iterator
1645  insert(const_iterator __p, initializer_list<value_type> __l)
1646  { return this->insert(__p, __l.begin(), __l.end()); }
1647 #endif
1648 
1649 #if __cplusplus >= 201103L
1650  /**
1651  * @brief Inserts a number of copies of given data into the %deque.
1652  * @param __position A const_iterator into the %deque.
1653  * @param __n Number of elements to be inserted.
1654  * @param __x Data to be inserted.
1655  * @return An iterator that points to the inserted data.
1656  *
1657  * This function will insert a specified number of copies of the given
1658  * data before the location specified by @a __position.
1659  */
1660  iterator
1661  insert(const_iterator __position, size_type __n, const value_type& __x)
1662  {
1663  difference_type __offset = __position - cbegin();
1664  _M_fill_insert(__position._M_const_cast(), __n, __x);
1665  return begin() + __offset;
1666  }
1667 #else
1668  /**
1669  * @brief Inserts a number of copies of given data into the %deque.
1670  * @param __position An iterator into the %deque.
1671  * @param __n Number of elements to be inserted.
1672  * @param __x Data to be inserted.
1673  *
1674  * This function will insert a specified number of copies of the given
1675  * data before the location specified by @a __position.
1676  */
1677  void
1678  insert(iterator __position, size_type __n, const value_type& __x)
1679  { _M_fill_insert(__position, __n, __x); }
1680 #endif
1681 
1682 #if __cplusplus >= 201103L
1683  /**
1684  * @brief Inserts a range into the %deque.
1685  * @param __position A const_iterator into the %deque.
1686  * @param __first An input iterator.
1687  * @param __last An input iterator.
1688  * @return An iterator that points to the inserted data.
1689  *
1690  * This function will insert copies of the data in the range
1691  * [__first,__last) into the %deque before the location specified
1692  * by @a __position. This is known as <em>range insert</em>.
1693  */
1694  template<typename _InputIterator,
1695  typename = std::_RequireInputIter<_InputIterator>>
1696  iterator
1697  insert(const_iterator __position, _InputIterator __first,
1698  _InputIterator __last)
1699  {
1700  difference_type __offset = __position - cbegin();
1701  _M_insert_dispatch(__position._M_const_cast(),
1702  __first, __last, __false_type());
1703  return begin() + __offset;
1704  }
1705 #else
1706  /**
1707  * @brief Inserts a range into the %deque.
1708  * @param __position An iterator into the %deque.
1709  * @param __first An input iterator.
1710  * @param __last An input iterator.
1711  *
1712  * This function will insert copies of the data in the range
1713  * [__first,__last) into the %deque before the location specified
1714  * by @a __position. This is known as <em>range insert</em>.
1715  */
1716  template<typename _InputIterator>
1717  void
1718  insert(iterator __position, _InputIterator __first,
1719  _InputIterator __last)
1720  {
1721  // Check whether it's an integral type. If so, it's not an iterator.
1722  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1723  _M_insert_dispatch(__position, __first, __last, _Integral());
1724  }
1725 #endif
1726 
1727  /**
1728  * @brief Remove element at given position.
1729  * @param __position Iterator pointing to element to be erased.
1730  * @return An iterator pointing to the next element (or end()).
1731  *
1732  * This function will erase the element at the given position and thus
1733  * shorten the %deque by one.
1734  *
1735  * The user is cautioned that
1736  * this function only erases the element, and that if the element is
1737  * itself a pointer, the pointed-to memory is not touched in any way.
1738  * Managing the pointer is the user's responsibility.
1739  */
1740  iterator
1741 #if __cplusplus >= 201103L
1742  erase(const_iterator __position)
1743 #else
1744  erase(iterator __position)
1745 #endif
1746  { return _M_erase(__position._M_const_cast()); }
1747 
1748  /**
1749  * @brief Remove a range of elements.
1750  * @param __first Iterator pointing to the first element to be erased.
1751  * @param __last Iterator pointing to one past the last element to be
1752  * erased.
1753  * @return An iterator pointing to the element pointed to by @a last
1754  * prior to erasing (or end()).
1755  *
1756  * This function will erase the elements in the range
1757  * [__first,__last) and shorten the %deque accordingly.
1758  *
1759  * The user is cautioned that
1760  * this function only erases the elements, and that if the elements
1761  * themselves are pointers, the pointed-to memory is not touched in any
1762  * way. Managing the pointer is the user's responsibility.
1763  */
1764  iterator
1765 #if __cplusplus >= 201103L
1766  erase(const_iterator __first, const_iterator __last)
1767 #else
1768  erase(iterator __first, iterator __last)
1769 #endif
1770  { return _M_erase(__first._M_const_cast(), __last._M_const_cast()); }
1771 
1772  /**
1773  * @brief Swaps data with another %deque.
1774  * @param __x A %deque of the same element and allocator types.
1775  *
1776  * This exchanges the elements between two deques in constant time.
1777  * (Four pointers, so it should be quite fast.)
1778  * Note that the global std::swap() function is specialized such that
1779  * std::swap(d1,d2) will feed to this function.
1780  */
1781  void
1782  swap(deque& __x)
1783 #if __cplusplus >= 201103L
1784  noexcept(_Alloc_traits::_S_nothrow_swap())
1785 #endif
1786  {
1787  _M_impl._M_swap_data(__x._M_impl);
1788  _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(),
1789  __x._M_get_Tp_allocator());
1790  }
1791 
1792  /**
1793  * Erases all the elements. Note that this function only erases the
1794  * elements, and that if the elements themselves are pointers, the
1795  * pointed-to memory is not touched in any way. Managing the pointer is
1796  * the user's responsibility.
1797  */
1798  void
1799  clear() _GLIBCXX_NOEXCEPT
1800  { _M_erase_at_end(begin()); }
1801 
1802  protected:
1803  // Internal constructor functions follow.
1804 
1805  // called by the range constructor to implement [23.1.1]/9
1806 
1807  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1808  // 438. Ambiguity in the "do the right thing" clause
1809  template<typename _Integer>
1810  void
1811  _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
1812  {
1813  _M_initialize_map(static_cast<size_type>(__n));
1814  _M_fill_initialize(__x);
1815  }
1816 
1817  // called by the range constructor to implement [23.1.1]/9
1818  template<typename _InputIterator>
1819  void
1820  _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
1821  __false_type)
1822  {
1823  typedef typename std::iterator_traits<_InputIterator>::
1824  iterator_category _IterCategory;
1825  _M_range_initialize(__first, __last, _IterCategory());
1826  }
1827 
1828  // called by the second initialize_dispatch above
1829  //@{
1830  /**
1831  * @brief Fills the deque with whatever is in [first,last).
1832  * @param __first An input iterator.
1833  * @param __last An input iterator.
1834  * @return Nothing.
1835  *
1836  * If the iterators are actually forward iterators (or better), then the
1837  * memory layout can be done all at once. Else we move forward using
1838  * push_back on each value from the iterator.
1839  */
1840  template<typename _InputIterator>
1841  void
1842  _M_range_initialize(_InputIterator __first, _InputIterator __last,
1844 
1845  // called by the second initialize_dispatch above
1846  template<typename _ForwardIterator>
1847  void
1848  _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
1850  //@}
1851 
1852  /**
1853  * @brief Fills the %deque with copies of value.
1854  * @param __value Initial value.
1855  * @return Nothing.
1856  * @pre _M_start and _M_finish have already been initialized,
1857  * but none of the %deque's elements have yet been constructed.
1858  *
1859  * This function is called only when the user provides an explicit size
1860  * (with or without an explicit exemplar value).
1861  */
1862  void
1863  _M_fill_initialize(const value_type& __value);
1864 
1865 #if __cplusplus >= 201103L
1866  // called by deque(n).
1867  void
1868  _M_default_initialize();
1869 #endif
1870 
1871  // Internal assign functions follow. The *_aux functions do the actual
1872  // assignment work for the range versions.
1873 
1874  // called by the range assign to implement [23.1.1]/9
1875 
1876  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1877  // 438. Ambiguity in the "do the right thing" clause
1878  template<typename _Integer>
1879  void
1880  _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
1881  { _M_fill_assign(__n, __val); }
1882 
1883  // called by the range assign to implement [23.1.1]/9
1884  template<typename _InputIterator>
1885  void
1886  _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
1887  __false_type)
1888  {
1889  typedef typename std::iterator_traits<_InputIterator>::
1890  iterator_category _IterCategory;
1891  _M_assign_aux(__first, __last, _IterCategory());
1892  }
1893 
1894  // called by the second assign_dispatch above
1895  template<typename _InputIterator>
1896  void
1897  _M_assign_aux(_InputIterator __first, _InputIterator __last,
1899 
1900  // called by the second assign_dispatch above
1901  template<typename _ForwardIterator>
1902  void
1903  _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
1905  {
1906  const size_type __len = std::distance(__first, __last);
1907  if (__len > size())
1908  {
1909  _ForwardIterator __mid = __first;
1910  std::advance(__mid, size());
1911  std::copy(__first, __mid, begin());
1912  insert(end(), __mid, __last);
1913  }
1914  else
1915  _M_erase_at_end(std::copy(__first, __last, begin()));
1916  }
1917 
1918  // Called by assign(n,t), and the range assign when it turns out
1919  // to be the same thing.
1920  void
1921  _M_fill_assign(size_type __n, const value_type& __val)
1922  {
1923  if (__n > size())
1924  {
1925  std::fill(begin(), end(), __val);
1926  insert(end(), __n - size(), __val);
1927  }
1928  else
1929  {
1930  _M_erase_at_end(begin() + difference_type(__n));
1931  std::fill(begin(), end(), __val);
1932  }
1933  }
1934 
1935  //@{
1936  /// Helper functions for push_* and pop_*.
1937 #if __cplusplus < 201103L
1938  void _M_push_back_aux(const value_type&);
1939 
1940  void _M_push_front_aux(const value_type&);
1941 #else
1942  template<typename... _Args>
1943  void _M_push_back_aux(_Args&&... __args);
1944 
1945  template<typename... _Args>
1946  void _M_push_front_aux(_Args&&... __args);
1947 #endif
1948 
1949  void _M_pop_back_aux();
1950 
1951  void _M_pop_front_aux();
1952  //@}
1953 
1954  // Internal insert functions follow. The *_aux functions do the actual
1955  // insertion work when all shortcuts fail.
1956 
1957  // called by the range insert to implement [23.1.1]/9
1958 
1959  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1960  // 438. Ambiguity in the "do the right thing" clause
1961  template<typename _Integer>
1962  void
1963  _M_insert_dispatch(iterator __pos,
1964  _Integer __n, _Integer __x, __true_type)
1965  { _M_fill_insert(__pos, __n, __x); }
1966 
1967  // called by the range insert to implement [23.1.1]/9
1968  template<typename _InputIterator>
1969  void
1970  _M_insert_dispatch(iterator __pos,
1971  _InputIterator __first, _InputIterator __last,
1972  __false_type)
1973  {
1974  typedef typename std::iterator_traits<_InputIterator>::
1975  iterator_category _IterCategory;
1976  _M_range_insert_aux(__pos, __first, __last, _IterCategory());
1977  }
1978 
1979  // called by the second insert_dispatch above
1980  template<typename _InputIterator>
1981  void
1982  _M_range_insert_aux(iterator __pos, _InputIterator __first,
1983  _InputIterator __last, std::input_iterator_tag);
1984 
1985  // called by the second insert_dispatch above
1986  template<typename _ForwardIterator>
1987  void
1988  _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
1989  _ForwardIterator __last, std::forward_iterator_tag);
1990 
1991  // Called by insert(p,n,x), and the range insert when it turns out to be
1992  // the same thing. Can use fill functions in optimal situations,
1993  // otherwise passes off to insert_aux(p,n,x).
1994  void
1995  _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
1996 
1997  // called by insert(p,x)
1998 #if __cplusplus < 201103L
1999  iterator
2000  _M_insert_aux(iterator __pos, const value_type& __x);
2001 #else
2002  template<typename... _Args>
2003  iterator
2004  _M_insert_aux(iterator __pos, _Args&&... __args);
2005 #endif
2006 
2007  // called by insert(p,n,x) via fill_insert
2008  void
2009  _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
2010 
2011  // called by range_insert_aux for forward iterators
2012  template<typename _ForwardIterator>
2013  void
2014  _M_insert_aux(iterator __pos,
2015  _ForwardIterator __first, _ForwardIterator __last,
2016  size_type __n);
2017 
2018 
2019  // Internal erase functions follow.
2020 
2021  void
2022  _M_destroy_data_aux(iterator __first, iterator __last);
2023 
2024  // Called by ~deque().
2025  // NB: Doesn't deallocate the nodes.
2026  template<typename _Alloc1>
2027  void
2028  _M_destroy_data(iterator __first, iterator __last, const _Alloc1&)
2029  { _M_destroy_data_aux(__first, __last); }
2030 
2031  void
2032  _M_destroy_data(iterator __first, iterator __last,
2033  const std::allocator<_Tp>&)
2034  {
2035  if (!__has_trivial_destructor(value_type))
2036  _M_destroy_data_aux(__first, __last);
2037  }
2038 
2039  // Called by erase(q1, q2).
2040  void
2041  _M_erase_at_begin(iterator __pos)
2042  {
2043  _M_destroy_data(begin(), __pos, _M_get_Tp_allocator());
2044  _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node);
2045  this->_M_impl._M_start = __pos;
2046  }
2047 
2048  // Called by erase(q1, q2), resize(), clear(), _M_assign_aux,
2049  // _M_fill_assign, operator=.
2050  void
2051  _M_erase_at_end(iterator __pos)
2052  {
2053  _M_destroy_data(__pos, end(), _M_get_Tp_allocator());
2054  _M_destroy_nodes(__pos._M_node + 1,
2055  this->_M_impl._M_finish._M_node + 1);
2056  this->_M_impl._M_finish = __pos;
2057  }
2058 
2059  iterator
2060  _M_erase(iterator __pos);
2061 
2062  iterator
2063  _M_erase(iterator __first, iterator __last);
2064 
2065 #if __cplusplus >= 201103L
2066  // Called by resize(sz).
2067  void
2068  _M_default_append(size_type __n);
2069 
2070  bool
2071  _M_shrink_to_fit();
2072 #endif
2073 
2074  //@{
2075  /// Memory-handling helpers for the previous internal insert functions.
2076  iterator
2078  {
2079  const size_type __vacancies = this->_M_impl._M_start._M_cur
2080  - this->_M_impl._M_start._M_first;
2081  if (__n > __vacancies)
2082  _M_new_elements_at_front(__n - __vacancies);
2083  return this->_M_impl._M_start - difference_type(__n);
2084  }
2085 
2086  iterator
2088  {
2089  const size_type __vacancies = (this->_M_impl._M_finish._M_last
2090  - this->_M_impl._M_finish._M_cur) - 1;
2091  if (__n > __vacancies)
2092  _M_new_elements_at_back(__n - __vacancies);
2093  return this->_M_impl._M_finish + difference_type(__n);
2094  }
2095 
2096  void
2097  _M_new_elements_at_front(size_type __new_elements);
2098 
2099  void
2100  _M_new_elements_at_back(size_type __new_elements);
2101  //@}
2102 
2103 
2104  //@{
2105  /**
2106  * @brief Memory-handling helpers for the major %map.
2107  *
2108  * Makes sure the _M_map has space for new nodes. Does not
2109  * actually add the nodes. Can invalidate _M_map pointers.
2110  * (And consequently, %deque iterators.)
2111  */
2112  void
2113  _M_reserve_map_at_back(size_type __nodes_to_add = 1)
2114  {
2115  if (__nodes_to_add + 1 > this->_M_impl._M_map_size
2116  - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
2117  _M_reallocate_map(__nodes_to_add, false);
2118  }
2119 
2120  void
2121  _M_reserve_map_at_front(size_type __nodes_to_add = 1)
2122  {
2123  if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
2124  - this->_M_impl._M_map))
2125  _M_reallocate_map(__nodes_to_add, true);
2126  }
2127 
2128  void
2129  _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
2130  //@}
2131 
2132 #if __cplusplus >= 201103L
2133  // Constant-time, nothrow move assignment when source object's memory
2134  // can be moved because the allocators are equal.
2135  void
2136  _M_move_assign1(deque&& __x, /* always equal: */ true_type) noexcept
2137  {
2138  this->_M_impl._M_swap_data(__x._M_impl);
2139  __x.clear();
2140  std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator());
2141  }
2142 
2143  void
2144  _M_move_assign1(deque&& __x, /* always equal: */ false_type)
2145  {
2146  constexpr bool __move_storage =
2147  _Alloc_traits::_S_propagate_on_move_assign();
2148  _M_move_assign2(std::move(__x),
2149  integral_constant<bool, __move_storage>());
2150  }
2151 
2152  // Destroy all elements and deallocate all memory, then replace
2153  // with elements created from __args.
2154  template<typename... _Args>
2155  void
2156  _M_replace_map(_Args&&... __args)
2157  {
2158  // Create new data first, so if allocation fails there are no effects.
2159  deque __newobj(std::forward<_Args>(__args)...);
2160  // Free existing storage using existing allocator.
2161  clear();
2162  _M_deallocate_node(*begin()._M_node); // one node left after clear()
2163  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
2164  this->_M_impl._M_map = nullptr;
2165  this->_M_impl._M_map_size = 0;
2166  // Take ownership of replacement memory.
2167  this->_M_impl._M_swap_data(__newobj._M_impl);
2168  }
2169 
2170  // Do move assignment when the allocator propagates.
2171  void
2172  _M_move_assign2(deque&& __x, /* propagate: */ true_type)
2173  {
2174  // Make a copy of the original allocator state.
2175  auto __alloc = __x._M_get_Tp_allocator();
2176  // The allocator propagates so storage can be moved from __x,
2177  // leaving __x in a valid empty state with a moved-from allocator.
2178  _M_replace_map(std::move(__x));
2179  // Move the corresponding allocator state too.
2180  _M_get_Tp_allocator() = std::move(__alloc);
2181  }
2182 
2183  // Do move assignment when it may not be possible to move source
2184  // object's memory, resulting in a linear-time operation.
2185  void
2186  _M_move_assign2(deque&& __x, /* propagate: */ false_type)
2187  {
2188  if (__x._M_get_Tp_allocator() == this->_M_get_Tp_allocator())
2189  {
2190  // The allocators are equal so storage can be moved from __x,
2191  // leaving __x in a valid empty state with its current allocator.
2192  _M_replace_map(std::move(__x), __x.get_allocator());
2193  }
2194  else
2195  {
2196  // The rvalue's allocator cannot be moved and is not equal,
2197  // so we need to individually move each element.
2198  this->assign(std::__make_move_if_noexcept_iterator(__x.begin()),
2199  std::__make_move_if_noexcept_iterator(__x.end()));
2200  __x.clear();
2201  }
2202  }
2203 #endif
2204  };
2205 
2206 
2207  /**
2208  * @brief Deque equality comparison.
2209  * @param __x A %deque.
2210  * @param __y A %deque of the same type as @a __x.
2211  * @return True iff the size and elements of the deques are equal.
2212  *
2213  * This is an equivalence relation. It is linear in the size of the
2214  * deques. Deques are considered equivalent if their sizes are equal,
2215  * and if corresponding elements compare equal.
2216  */
2217  template<typename _Tp, typename _Alloc>
2218  inline bool
2219  operator==(const deque<_Tp, _Alloc>& __x,
2220  const deque<_Tp, _Alloc>& __y)
2221  { return __x.size() == __y.size()
2222  && std::equal(__x.begin(), __x.end(), __y.begin()); }
2223 
2224  /**
2225  * @brief Deque ordering relation.
2226  * @param __x A %deque.
2227  * @param __y A %deque of the same type as @a __x.
2228  * @return True iff @a x is lexicographically less than @a __y.
2229  *
2230  * This is a total ordering relation. It is linear in the size of the
2231  * deques. The elements must be comparable with @c <.
2232  *
2233  * See std::lexicographical_compare() for how the determination is made.
2234  */
2235  template<typename _Tp, typename _Alloc>
2236  inline bool
2237  operator<(const deque<_Tp, _Alloc>& __x,
2238  const deque<_Tp, _Alloc>& __y)
2239  { return std::lexicographical_compare(__x.begin(), __x.end(),
2240  __y.begin(), __y.end()); }
2241 
2242  /// Based on operator==
2243  template<typename _Tp, typename _Alloc>
2244  inline bool
2245  operator!=(const deque<_Tp, _Alloc>& __x,
2246  const deque<_Tp, _Alloc>& __y)
2247  { return !(__x == __y); }
2248 
2249  /// Based on operator<
2250  template<typename _Tp, typename _Alloc>
2251  inline bool
2253  const deque<_Tp, _Alloc>& __y)
2254  { return __y < __x; }
2255 
2256  /// Based on operator<
2257  template<typename _Tp, typename _Alloc>
2258  inline bool
2259  operator<=(const deque<_Tp, _Alloc>& __x,
2260  const deque<_Tp, _Alloc>& __y)
2261  { return !(__y < __x); }
2262 
2263  /// Based on operator<
2264  template<typename _Tp, typename _Alloc>
2265  inline bool
2267  const deque<_Tp, _Alloc>& __y)
2268  { return !(__x < __y); }
2269 
2270  /// See std::deque::swap().
2271  template<typename _Tp, typename _Alloc>
2272  inline void
2274  { __x.swap(__y); }
2275 
2276 #undef _GLIBCXX_DEQUE_BUF_SIZE
2277 
2278 _GLIBCXX_END_NAMESPACE_CONTAINER
2279 } // namespace std
2280 
2281 #endif /* _STL_DEQUE_H */
void swap(_Tp &, _Tp &) noexcept(__and_< is_nothrow_move_constructible< _Tp >, is_nothrow_move_assignable< _Tp >>::value)
Swaps two values.
Definition: move.h:176
reverse_iterator rend() noexcept
Definition: stl_deque.h:1210
const_iterator cbegin() const noexcept
Definition: stl_deque.h:1228
iterator end() noexcept
Definition: stl_deque.h:1174
deque(deque &&__x)
Deque move constructor.
Definition: stl_deque.h:955
void resize(size_type __new_size)
Resizes the deque to the specified number of elements.
Definition: stl_deque.h:1281
void _M_range_check(size_type __n) const
Safety check used only from at().
Definition: stl_deque.h:1385
void _M_set_node(_Map_pointer __new_node) noexcept
Definition: stl_deque.h:252
size_type max_size() const noexcept
Definition: stl_deque.h:1267
reference front() noexcept
Definition: stl_deque.h:1436
Uniform interface to C++98 and C++0x allocators.
reference at(size_type __n)
Provides access to the data contained in the deque.
Definition: stl_deque.h:1407
void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
iterator _M_reserve_elements_at_back(size_type __n)
Memory-handling helpers for the previous internal insert functions.
Definition: stl_deque.h:2087
void assign(initializer_list< value_type > __l)
Assigns an initializer list to a deque.
Definition: stl_deque.h:1142
void _M_push_front_aux(_Args &&...__args)
Helper functions for push_* and pop_*.
const_reverse_iterator rbegin() const noexcept
Definition: stl_deque.h:1201
iterator insert(const_iterator __position, value_type &&__x)
Inserts given rvalue into deque before specified iterator.
Definition: stl_deque.h:1632
bool operator>=(const basic_string< _CharT, _Traits, _Alloc > &__lhs, const basic_string< _CharT, _Traits, _Alloc > &__rhs)
Test if string doesn't precede string.
deque(const deque &__x, const allocator_type &__a)
Copy constructor with alternative allocator.
Definition: stl_deque.h:959
void _M_fill_initialize(const value_type &__value)
Fills the deque with copies of value.
deque(const deque &__x)
Deque copy constructor.
Definition: stl_deque.h:940
Forward iterators support a superset of input iterator operations.
void _M_range_initialize(_InputIterator __first, _InputIterator __last, std::input_iterator_tag)
Fills the deque with whatever is in [first,last).
bool empty() const noexcept
Definition: stl_deque.h:1348
size_type size() const noexcept
Definition: stl_deque.h:1262
void assign(size_type __n, const value_type &__val)
Assigns a given value to a deque.
Definition: stl_deque.h:1098
const_reference at(size_type __n) const
Provides access to the data contained in the deque.
Definition: stl_deque.h:1425
void clear() noexcept
Definition: stl_deque.h:1799
void _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front)
Memory-handling helpers for the major map.
deque(size_type __n, const value_type &__value, const allocator_type &__a=allocator_type())
Creates a deque with copies of an exemplar element.
Definition: stl_deque.h:913
_GLIBCXX14_CONSTEXPR const _Tp & max(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:219
deque(initializer_list< value_type > __l, const allocator_type &__a=allocator_type())
Builds a deque from an initializer list.
Definition: stl_deque.h:989
iterator begin() noexcept
Definition: stl_deque.h:1157
bool equal(_II1 __first1, _II1 __last1, _II2 __first2)
Tests a range for element-wise equality.
const_reference front() const noexcept
Definition: stl_deque.h:1444
const_reverse_iterator crbegin() const noexcept
Definition: stl_deque.h:1246
iterator _M_reserve_elements_at_front(size_type __n)
Memory-handling helpers for the previous internal insert functions.
Definition: stl_deque.h:2077
const_iterator begin() const noexcept
Definition: stl_deque.h:1165
void _M_pop_back_aux()
Helper functions for push_* and pop_*.
_BI2 move_backward(_BI1 __first, _BI1 __last, _BI2 __result)
Moves the range [first,last) into result.
Definition: stl_algobase.h:670
A deque::iterator.
Definition: stl_deque.h:106
const_iterator cend() const noexcept
Definition: stl_deque.h:1237
static pointer allocate(_Alloc &__a, size_type __n)
Allocate memory.
deque(deque &&__x, const allocator_type &__a)
Move constructor with alternative allocator.
Definition: stl_deque.h:966
deque & operator=(deque &&__x) noexcept(_Alloc_traits::_S_always_equal())
Deque move assignment operator.
Definition: stl_deque.h:1060
reference operator[](size_type __n) noexcept
Subscript access to the data contained in the deque.
Definition: stl_deque.h:1364
deque(_InputIterator __first, _InputIterator __last, const allocator_type &__a=allocator_type())
Builds a deque from a range.
Definition: stl_deque.h:1016
bool operator>(const basic_string< _CharT, _Traits, _Alloc > &__lhs, const basic_string< _CharT, _Traits, _Alloc > &__rhs)
Test if string follows string.
deque()
Creates a deque with no elements.
Definition: stl_deque.h:882
deque & operator=(const deque &__x)
Deque assignment operator.
void push_back(const value_type &__x)
Add data to the end of the deque.
Definition: stl_deque.h:1515
void _M_reserve_map_at_front(size_type __nodes_to_add=1)
Memory-handling helpers for the major map.
Definition: stl_deque.h:2121
void _M_reserve_map_at_back(size_type __nodes_to_add=1)
Memory-handling helpers for the major map.
Definition: stl_deque.h:2113
void _M_new_elements_at_front(size_type __new_elements)
Memory-handling helpers for the previous internal insert functions.
void swap(deque &__x) noexcept(_Alloc_traits::_S_nothrow_swap())
Swaps data with another deque.
Definition: stl_deque.h:1782
iterator insert(const_iterator __position, size_type __n, const value_type &__x)
Inserts a number of copies of given data into the deque.
Definition: stl_deque.h:1661
const_iterator end() const noexcept
Definition: stl_deque.h:1183
deque & operator=(initializer_list< value_type > __l)
Assigns an initializer list to a deque.
Definition: stl_deque.h:1080
void _M_push_back_aux(_Args &&...__args)
Helper functions for push_* and pop_*.
void _M_new_elements_at_back(size_type __new_elements)
Memory-handling helpers for the previous internal insert functions.
The standard allocator, as per [20.4].
Definition: allocator.h:92
void resize(size_type __new_size, const value_type &__x)
Resizes the deque to the specified number of elements.
Definition: stl_deque.h:1303
basic_string< _CharT, _Traits, _Alloc > operator+(const basic_string< _CharT, _Traits, _Alloc > &__lhs, const basic_string< _CharT, _Traits, _Alloc > &__rhs)
Concatenate two strings.
void pop_back() noexcept
Removes last element.
Definition: stl_deque.h:1569
iterator erase(const_iterator __first, const_iterator __last)
Remove a range of elements.
Definition: stl_deque.h:1766
allocator_type get_allocator() const noexcept
Get a copy of the memory allocation object.
Definition: stl_deque.h:1148
reverse_iterator rbegin() noexcept
Definition: stl_deque.h:1192
iterator emplace(const_iterator __position, _Args &&...__args)
Inserts an object in deque before specified iterator.
A standard container using fixed-size memory allocation and constant-time manipulation of elements at...
Definition: stl_deque.h:829
void _M_initialize_map(size_t)
Layout storage.
Definition: stl_deque.h:680
deque(const allocator_type &__a)
Creates a deque with no elements.
Definition: stl_deque.h:889
const_reference back() const noexcept
Definition: stl_deque.h:1464
const_reverse_iterator rend() const noexcept
Definition: stl_deque.h:1219
Marking input iterators.
void pop_front() noexcept
Removes first element.
Definition: stl_deque.h:1547
reference back() noexcept
Definition: stl_deque.h:1452
static size_type max_size(const _Tp_alloc_type &__a) noexcept
The maximum supported allocation size.
Uniform interface to all pointer-like types.
Definition: ptr_traits.h:132
const_reverse_iterator crend() const noexcept
Definition: stl_deque.h:1255
void shrink_to_fit() noexcept
Definition: stl_deque.h:1339
iterator insert(const_iterator __position, const value_type &__x)
Inserts given value into deque before specified iterator.
iterator insert(const_iterator __p, initializer_list< value_type > __l)
Inserts an initializer list into the deque.
Definition: stl_deque.h:1645
const_reference operator[](size_type __n) const noexcept
Subscript access to the data contained in the deque.
Definition: stl_deque.h:1379
iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
static void deallocate(_Alloc &__a, pointer __p, size_type __n)
Deallocate memory.
void assign(_InputIterator __first, _InputIterator __last)
Assigns a range to a deque.
Definition: stl_deque.h:1117
void _M_pop_front_aux()
Helper functions for push_* and pop_*.
iterator erase(const_iterator __position)
Remove element at given position.
Definition: stl_deque.h:1742
void push_front(const value_type &__x)
Add data to the front of the deque.
Definition: stl_deque.h:1482
Random-access iterators support a superset of bidirectional iterator operations.
deque(size_type __n, const allocator_type &__a=allocator_type())
Creates a deque with default constructed elements.
Definition: stl_deque.h:901
iterator insert(const_iterator __position, _InputIterator __first, _InputIterator __last)
Inserts a range into the deque.
Definition: stl_deque.h:1697
ISO C++ entities toplevel namespace is std.
bool lexicographical_compare(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2, _Compare __comp)
Performs dictionary comparison on ranges.
#define _GLIBCXX_DEQUE_BUF_SIZE
This function controls the size of memory nodes.
Definition: stl_deque.h:85
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition: move.h:101