libstdc++
stl_deque.h
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1 // Deque implementation -*- C++ -*-
2 
3 // Copyright (C) 2001-2017 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>
60 #include <bits/stl_iterator_base_types.h>
61 #include <bits/stl_iterator_base_funcs.h>
62 #if __cplusplus >= 201103L
63 #include <initializer_list>
64 #endif
65 
66 #include <debug/assertions.h>
67 
68 namespace std _GLIBCXX_VISIBILITY(default)
69 {
70 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
71 
72  /**
73  * @brief This function controls the size of memory nodes.
74  * @param __size The size of an element.
75  * @return The number (not byte size) of elements per node.
76  *
77  * This function started off as a compiler kludge from SGI, but
78  * seems to be a useful wrapper around a repeated constant
79  * expression. The @b 512 is tunable (and no other code needs to
80  * change), but no investigation has been done since inheriting the
81  * SGI code. Touch _GLIBCXX_DEQUE_BUF_SIZE only if you know what
82  * you are doing, however: changing it breaks the binary
83  * compatibility!!
84  */
85 
86 #ifndef _GLIBCXX_DEQUE_BUF_SIZE
87 #define _GLIBCXX_DEQUE_BUF_SIZE 512
88 #endif
89 
90  _GLIBCXX_CONSTEXPR inline size_t
91  __deque_buf_size(size_t __size)
92  { return (__size < _GLIBCXX_DEQUE_BUF_SIZE
93  ? size_t(_GLIBCXX_DEQUE_BUF_SIZE / __size) : size_t(1)); }
94 
95 
96  /**
97  * @brief A deque::iterator.
98  *
99  * Quite a bit of intelligence here. Much of the functionality of
100  * deque is actually passed off to this class. A deque holds two
101  * of these internally, marking its valid range. Access to
102  * elements is done as offsets of either of those two, relying on
103  * operator overloading in this class.
104  *
105  * All the functions are op overloads except for _M_set_node.
106  */
107  template<typename _Tp, typename _Ref, typename _Ptr>
108  struct _Deque_iterator
109  {
110 #if __cplusplus < 201103L
111  typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator;
112  typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
113  typedef _Tp* _Elt_pointer;
114  typedef _Tp** _Map_pointer;
115 #else
116  private:
117  template<typename _Up>
118  using __ptr_to = typename pointer_traits<_Ptr>::template rebind<_Up>;
119  template<typename _CvTp>
120  using __iter = _Deque_iterator<_Tp, _CvTp&, __ptr_to<_CvTp>>;
121  public:
122  typedef __iter<_Tp> iterator;
123  typedef __iter<const _Tp> const_iterator;
124  typedef __ptr_to<_Tp> _Elt_pointer;
125  typedef __ptr_to<_Elt_pointer> _Map_pointer;
126 #endif
127 
128  static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
129  { return __deque_buf_size(sizeof(_Tp)); }
130 
131  typedef std::random_access_iterator_tag iterator_category;
132  typedef _Tp value_type;
133  typedef _Ptr pointer;
134  typedef _Ref reference;
135  typedef size_t size_type;
136  typedef ptrdiff_t difference_type;
137  typedef _Deque_iterator _Self;
138 
139  _Elt_pointer _M_cur;
140  _Elt_pointer _M_first;
141  _Elt_pointer _M_last;
142  _Map_pointer _M_node;
143 
144  _Deque_iterator(_Elt_pointer __x, _Map_pointer __y) _GLIBCXX_NOEXCEPT
145  : _M_cur(__x), _M_first(*__y),
146  _M_last(*__y + _S_buffer_size()), _M_node(__y) { }
147 
148  _Deque_iterator() _GLIBCXX_NOEXCEPT
149  : _M_cur(), _M_first(), _M_last(), _M_node() { }
150 
151  _Deque_iterator(const iterator& __x) _GLIBCXX_NOEXCEPT
152  : _M_cur(__x._M_cur), _M_first(__x._M_first),
153  _M_last(__x._M_last), _M_node(__x._M_node) { }
154 
155  iterator
156  _M_const_cast() const _GLIBCXX_NOEXCEPT
157  { return iterator(_M_cur, _M_node); }
158 
159  reference
160  operator*() const _GLIBCXX_NOEXCEPT
161  { return *_M_cur; }
162 
163  pointer
164  operator->() const _GLIBCXX_NOEXCEPT
165  { return _M_cur; }
166 
167  _Self&
168  operator++() _GLIBCXX_NOEXCEPT
169  {
170  ++_M_cur;
171  if (_M_cur == _M_last)
172  {
173  _M_set_node(_M_node + 1);
174  _M_cur = _M_first;
175  }
176  return *this;
177  }
178 
179  _Self
180  operator++(int) _GLIBCXX_NOEXCEPT
181  {
182  _Self __tmp = *this;
183  ++*this;
184  return __tmp;
185  }
186 
187  _Self&
188  operator--() _GLIBCXX_NOEXCEPT
189  {
190  if (_M_cur == _M_first)
191  {
192  _M_set_node(_M_node - 1);
193  _M_cur = _M_last;
194  }
195  --_M_cur;
196  return *this;
197  }
198 
199  _Self
200  operator--(int) _GLIBCXX_NOEXCEPT
201  {
202  _Self __tmp = *this;
203  --*this;
204  return __tmp;
205  }
206 
207  _Self&
208  operator+=(difference_type __n) _GLIBCXX_NOEXCEPT
209  {
210  const difference_type __offset = __n + (_M_cur - _M_first);
211  if (__offset >= 0 && __offset < difference_type(_S_buffer_size()))
212  _M_cur += __n;
213  else
214  {
215  const difference_type __node_offset =
216  __offset > 0 ? __offset / difference_type(_S_buffer_size())
217  : -difference_type((-__offset - 1)
218  / _S_buffer_size()) - 1;
219  _M_set_node(_M_node + __node_offset);
220  _M_cur = _M_first + (__offset - __node_offset
221  * difference_type(_S_buffer_size()));
222  }
223  return *this;
224  }
225 
226  _Self
227  operator+(difference_type __n) const _GLIBCXX_NOEXCEPT
228  {
229  _Self __tmp = *this;
230  return __tmp += __n;
231  }
232 
233  _Self&
234  operator-=(difference_type __n) _GLIBCXX_NOEXCEPT
235  { return *this += -__n; }
236 
237  _Self
238  operator-(difference_type __n) const _GLIBCXX_NOEXCEPT
239  {
240  _Self __tmp = *this;
241  return __tmp -= __n;
242  }
243 
244  reference
245  operator[](difference_type __n) const _GLIBCXX_NOEXCEPT
246  { return *(*this + __n); }
247 
248  /**
249  * Prepares to traverse new_node. Sets everything except
250  * _M_cur, which should therefore be set by the caller
251  * immediately afterwards, based on _M_first and _M_last.
252  */
253  void
254  _M_set_node(_Map_pointer __new_node) _GLIBCXX_NOEXCEPT
255  {
256  _M_node = __new_node;
257  _M_first = *__new_node;
258  _M_last = _M_first + difference_type(_S_buffer_size());
259  }
260  };
261 
262  // Note: we also provide overloads whose operands are of the same type in
263  // order to avoid ambiguous overload resolution when std::rel_ops operators
264  // are in scope (for additional details, see libstdc++/3628)
265  template<typename _Tp, typename _Ref, typename _Ptr>
266  inline bool
267  operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
268  const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
269  { return __x._M_cur == __y._M_cur; }
270 
271  template<typename _Tp, typename _RefL, typename _PtrL,
272  typename _RefR, typename _PtrR>
273  inline bool
274  operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
275  const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
276  { return __x._M_cur == __y._M_cur; }
277 
278  template<typename _Tp, typename _Ref, typename _Ptr>
279  inline bool
280  operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
281  const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
282  { return !(__x == __y); }
283 
284  template<typename _Tp, typename _RefL, typename _PtrL,
285  typename _RefR, typename _PtrR>
286  inline bool
287  operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
288  const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
289  { return !(__x == __y); }
290 
291  template<typename _Tp, typename _Ref, typename _Ptr>
292  inline bool
293  operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
294  const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
295  { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
296  : (__x._M_node < __y._M_node); }
297 
298  template<typename _Tp, typename _RefL, typename _PtrL,
299  typename _RefR, typename _PtrR>
300  inline bool
301  operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
302  const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
303  { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
304  : (__x._M_node < __y._M_node); }
305 
306  template<typename _Tp, typename _Ref, typename _Ptr>
307  inline bool
308  operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
309  const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
310  { return __y < __x; }
311 
312  template<typename _Tp, typename _RefL, typename _PtrL,
313  typename _RefR, typename _PtrR>
314  inline bool
315  operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
316  const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
317  { return __y < __x; }
318 
319  template<typename _Tp, typename _Ref, typename _Ptr>
320  inline bool
321  operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
322  const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
323  { return !(__y < __x); }
324 
325  template<typename _Tp, typename _RefL, typename _PtrL,
326  typename _RefR, typename _PtrR>
327  inline bool
328  operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
329  const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
330  { return !(__y < __x); }
331 
332  template<typename _Tp, typename _Ref, typename _Ptr>
333  inline bool
334  operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
335  const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
336  { return !(__x < __y); }
337 
338  template<typename _Tp, typename _RefL, typename _PtrL,
339  typename _RefR, typename _PtrR>
340  inline bool
341  operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
342  const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
343  { return !(__x < __y); }
344 
345  // _GLIBCXX_RESOLVE_LIB_DEFECTS
346  // According to the resolution of DR179 not only the various comparison
347  // operators but also operator- must accept mixed iterator/const_iterator
348  // parameters.
349  template<typename _Tp, typename _Ref, typename _Ptr>
350  inline typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
351  operator-(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
352  const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
353  {
354  return typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
355  (_Deque_iterator<_Tp, _Ref, _Ptr>::_S_buffer_size())
356  * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
357  + (__y._M_last - __y._M_cur);
358  }
359 
360  template<typename _Tp, typename _RefL, typename _PtrL,
361  typename _RefR, typename _PtrR>
362  inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
363  operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
364  const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
365  {
366  return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
367  (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size())
368  * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
369  + (__y._M_last - __y._M_cur);
370  }
371 
372  template<typename _Tp, typename _Ref, typename _Ptr>
373  inline _Deque_iterator<_Tp, _Ref, _Ptr>
374  operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x)
375  _GLIBCXX_NOEXCEPT
376  { return __x + __n; }
377 
378  template<typename _Tp>
379  void
380  fill(const _Deque_iterator<_Tp, _Tp&, _Tp*>&,
381  const _Deque_iterator<_Tp, _Tp&, _Tp*>&, const _Tp&);
382 
383  template<typename _Tp>
384  _Deque_iterator<_Tp, _Tp&, _Tp*>
385  copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
386  _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
387  _Deque_iterator<_Tp, _Tp&, _Tp*>);
388 
389  template<typename _Tp>
390  inline _Deque_iterator<_Tp, _Tp&, _Tp*>
391  copy(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
392  _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
393  _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
394  { return std::copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first),
395  _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last),
396  __result); }
397 
398  template<typename _Tp>
399  _Deque_iterator<_Tp, _Tp&, _Tp*>
400  copy_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
401  _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
402  _Deque_iterator<_Tp, _Tp&, _Tp*>);
403 
404  template<typename _Tp>
405  inline _Deque_iterator<_Tp, _Tp&, _Tp*>
406  copy_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
407  _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
408  _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
409  { return std::copy_backward(_Deque_iterator<_Tp,
410  const _Tp&, const _Tp*>(__first),
411  _Deque_iterator<_Tp,
412  const _Tp&, const _Tp*>(__last),
413  __result); }
414 
415 #if __cplusplus >= 201103L
416  template<typename _Tp>
417  _Deque_iterator<_Tp, _Tp&, _Tp*>
418  move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
419  _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
420  _Deque_iterator<_Tp, _Tp&, _Tp*>);
421 
422  template<typename _Tp>
423  inline _Deque_iterator<_Tp, _Tp&, _Tp*>
424  move(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
425  _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
426  _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
427  { return std::move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first),
428  _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last),
429  __result); }
430 
431  template<typename _Tp>
432  _Deque_iterator<_Tp, _Tp&, _Tp*>
433  move_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
434  _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
435  _Deque_iterator<_Tp, _Tp&, _Tp*>);
436 
437  template<typename _Tp>
438  inline _Deque_iterator<_Tp, _Tp&, _Tp*>
439  move_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
440  _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
441  _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
442  { return std::move_backward(_Deque_iterator<_Tp,
443  const _Tp&, const _Tp*>(__first),
444  _Deque_iterator<_Tp,
445  const _Tp&, const _Tp*>(__last),
446  __result); }
447 #endif
448 
449  /**
450  * Deque base class. This class provides the unified face for %deque's
451  * allocation. This class's constructor and destructor allocate and
452  * deallocate (but do not initialize) storage. This makes %exception
453  * safety easier.
454  *
455  * Nothing in this class ever constructs or destroys an actual Tp element.
456  * (Deque handles that itself.) Only/All memory management is performed
457  * here.
458  */
459  template<typename _Tp, typename _Alloc>
460  class _Deque_base
461  {
462  protected:
463  typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
464  rebind<_Tp>::other _Tp_alloc_type;
465  typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Alloc_traits;
466 
467 #if __cplusplus < 201103L
468  typedef _Tp* _Ptr;
469  typedef const _Tp* _Ptr_const;
470 #else
471  typedef typename _Alloc_traits::pointer _Ptr;
472  typedef typename _Alloc_traits::const_pointer _Ptr_const;
473 #endif
474 
475  typedef typename _Alloc_traits::template rebind<_Ptr>::other
476  _Map_alloc_type;
477  typedef __gnu_cxx::__alloc_traits<_Map_alloc_type> _Map_alloc_traits;
478 
479  public:
480  typedef _Alloc allocator_type;
481  typedef typename _Alloc_traits::size_type size_type;
482 
483  allocator_type
484  get_allocator() const _GLIBCXX_NOEXCEPT
485  { return allocator_type(_M_get_Tp_allocator()); }
486 
487  typedef _Deque_iterator<_Tp, _Tp&, _Ptr> iterator;
488  typedef _Deque_iterator<_Tp, const _Tp&, _Ptr_const> const_iterator;
489 
490  _Deque_base()
491  : _M_impl()
492  { _M_initialize_map(0); }
493 
494  _Deque_base(size_t __num_elements)
495  : _M_impl()
496  { _M_initialize_map(__num_elements); }
497 
498  _Deque_base(const allocator_type& __a, size_t __num_elements)
499  : _M_impl(__a)
500  { _M_initialize_map(__num_elements); }
501 
502  _Deque_base(const allocator_type& __a)
503  : _M_impl(__a)
504  { /* Caller must initialize map. */ }
505 
506 #if __cplusplus >= 201103L
507  _Deque_base(_Deque_base&& __x, false_type)
508  : _M_impl(__x._M_move_impl())
509  { }
510 
511  _Deque_base(_Deque_base&& __x, true_type)
512  : _M_impl(std::move(__x._M_get_Tp_allocator()))
513  {
514  _M_initialize_map(0);
515  if (__x._M_impl._M_map)
516  this->_M_impl._M_swap_data(__x._M_impl);
517  }
518 
519  _Deque_base(_Deque_base&& __x)
520  : _Deque_base(std::move(__x), typename _Alloc_traits::is_always_equal{})
521  { }
522 
523  _Deque_base(_Deque_base&& __x, const allocator_type& __a, size_type __n)
524  : _M_impl(__a)
525  {
526  if (__x.get_allocator() == __a)
527  {
528  if (__x._M_impl._M_map)
529  {
530  _M_initialize_map(0);
531  this->_M_impl._M_swap_data(__x._M_impl);
532  }
533  }
534  else
535  {
536  _M_initialize_map(__n);
537  }
538  }
539 #endif
540 
541  ~_Deque_base() _GLIBCXX_NOEXCEPT;
542 
543  protected:
544  typedef typename iterator::_Map_pointer _Map_pointer;
545 
546  //This struct encapsulates the implementation of the std::deque
547  //standard container and at the same time makes use of the EBO
548  //for empty allocators.
549  struct _Deque_impl
550  : public _Tp_alloc_type
551  {
552  _Map_pointer _M_map;
553  size_t _M_map_size;
554  iterator _M_start;
555  iterator _M_finish;
556 
557  _Deque_impl()
558  : _Tp_alloc_type(), _M_map(), _M_map_size(0),
559  _M_start(), _M_finish()
560  { }
561 
562  _Deque_impl(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT
563  : _Tp_alloc_type(__a), _M_map(), _M_map_size(0),
564  _M_start(), _M_finish()
565  { }
566 
567 #if __cplusplus >= 201103L
568  _Deque_impl(_Deque_impl&&) = default;
569 
570  _Deque_impl(_Tp_alloc_type&& __a) noexcept
571  : _Tp_alloc_type(std::move(__a)), _M_map(), _M_map_size(0),
572  _M_start(), _M_finish()
573  { }
574 #endif
575 
576  void _M_swap_data(_Deque_impl& __x) _GLIBCXX_NOEXCEPT
577  {
578  using std::swap;
579  swap(this->_M_start, __x._M_start);
580  swap(this->_M_finish, __x._M_finish);
581  swap(this->_M_map, __x._M_map);
582  swap(this->_M_map_size, __x._M_map_size);
583  }
584  };
585 
586  _Tp_alloc_type&
587  _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT
588  { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); }
589 
590  const _Tp_alloc_type&
591  _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT
592  { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); }
593 
594  _Map_alloc_type
595  _M_get_map_allocator() const _GLIBCXX_NOEXCEPT
596  { return _Map_alloc_type(_M_get_Tp_allocator()); }
597 
598  _Ptr
599  _M_allocate_node()
600  {
601  typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
602  return _Traits::allocate(_M_impl, __deque_buf_size(sizeof(_Tp)));
603  }
604 
605  void
606  _M_deallocate_node(_Ptr __p) _GLIBCXX_NOEXCEPT
607  {
608  typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
609  _Traits::deallocate(_M_impl, __p, __deque_buf_size(sizeof(_Tp)));
610  }
611 
612  _Map_pointer
613  _M_allocate_map(size_t __n)
614  {
615  _Map_alloc_type __map_alloc = _M_get_map_allocator();
616  return _Map_alloc_traits::allocate(__map_alloc, __n);
617  }
618 
619  void
620  _M_deallocate_map(_Map_pointer __p, size_t __n) _GLIBCXX_NOEXCEPT
621  {
622  _Map_alloc_type __map_alloc = _M_get_map_allocator();
623  _Map_alloc_traits::deallocate(__map_alloc, __p, __n);
624  }
625 
626  protected:
627  void _M_initialize_map(size_t);
628  void _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish);
629  void _M_destroy_nodes(_Map_pointer __nstart,
630  _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT;
631  enum { _S_initial_map_size = 8 };
632 
633  _Deque_impl _M_impl;
634 
635 #if __cplusplus >= 201103L
636  private:
637  _Deque_impl
638  _M_move_impl()
639  {
640  if (!_M_impl._M_map)
641  return std::move(_M_impl);
642 
643  // Create a copy of the current allocator.
644  _Tp_alloc_type __alloc{_M_get_Tp_allocator()};
645  // Put that copy in a moved-from state.
646  _Tp_alloc_type __sink __attribute((__unused__)) {std::move(__alloc)};
647  // Create an empty map that allocates using the moved-from allocator.
648  _Deque_base __empty{__alloc};
649  __empty._M_initialize_map(0);
650  // Now safe to modify current allocator and perform non-throwing swaps.
651  _Deque_impl __ret{std::move(_M_get_Tp_allocator())};
652  _M_impl._M_swap_data(__ret);
653  _M_impl._M_swap_data(__empty._M_impl);
654  return __ret;
655  }
656 #endif
657  };
658 
659  template<typename _Tp, typename _Alloc>
660  _Deque_base<_Tp, _Alloc>::
661  ~_Deque_base() _GLIBCXX_NOEXCEPT
662  {
663  if (this->_M_impl._M_map)
664  {
665  _M_destroy_nodes(this->_M_impl._M_start._M_node,
666  this->_M_impl._M_finish._M_node + 1);
667  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
668  }
669  }
670 
671  /**
672  * @brief Layout storage.
673  * @param __num_elements The count of T's for which to allocate space
674  * at first.
675  * @return Nothing.
676  *
677  * The initial underlying memory layout is a bit complicated...
678  */
679  template<typename _Tp, typename _Alloc>
680  void
681  _Deque_base<_Tp, _Alloc>::
682  _M_initialize_map(size_t __num_elements)
683  {
684  const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
685  + 1);
686 
687  this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
688  size_t(__num_nodes + 2));
689  this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
690 
691  // For "small" maps (needing less than _M_map_size nodes), allocation
692  // starts in the middle elements and grows outwards. So nstart may be
693  // the beginning of _M_map, but for small maps it may be as far in as
694  // _M_map+3.
695 
696  _Map_pointer __nstart = (this->_M_impl._M_map
697  + (this->_M_impl._M_map_size - __num_nodes) / 2);
698  _Map_pointer __nfinish = __nstart + __num_nodes;
699 
700  __try
701  { _M_create_nodes(__nstart, __nfinish); }
702  __catch(...)
703  {
704  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
705  this->_M_impl._M_map = _Map_pointer();
706  this->_M_impl._M_map_size = 0;
707  __throw_exception_again;
708  }
709 
710  this->_M_impl._M_start._M_set_node(__nstart);
711  this->_M_impl._M_finish._M_set_node(__nfinish - 1);
712  this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
713  this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
714  + __num_elements
715  % __deque_buf_size(sizeof(_Tp)));
716  }
717 
718  template<typename _Tp, typename _Alloc>
719  void
720  _Deque_base<_Tp, _Alloc>::
721  _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish)
722  {
723  _Map_pointer __cur;
724  __try
725  {
726  for (__cur = __nstart; __cur < __nfinish; ++__cur)
727  *__cur = this->_M_allocate_node();
728  }
729  __catch(...)
730  {
731  _M_destroy_nodes(__nstart, __cur);
732  __throw_exception_again;
733  }
734  }
735 
736  template<typename _Tp, typename _Alloc>
737  void
738  _Deque_base<_Tp, _Alloc>::
739  _M_destroy_nodes(_Map_pointer __nstart,
740  _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT
741  {
742  for (_Map_pointer __n = __nstart; __n < __nfinish; ++__n)
743  _M_deallocate_node(*__n);
744  }
745 
746  /**
747  * @brief A standard container using fixed-size memory allocation and
748  * constant-time manipulation of elements at either end.
749  *
750  * @ingroup sequences
751  *
752  * @tparam _Tp Type of element.
753  * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
754  *
755  * Meets the requirements of a <a href="tables.html#65">container</a>, a
756  * <a href="tables.html#66">reversible container</a>, and a
757  * <a href="tables.html#67">sequence</a>, including the
758  * <a href="tables.html#68">optional sequence requirements</a>.
759  *
760  * In previous HP/SGI versions of deque, there was an extra template
761  * parameter so users could control the node size. This extension turned
762  * out to violate the C++ standard (it can be detected using template
763  * template parameters), and it was removed.
764  *
765  * Here's how a deque<Tp> manages memory. Each deque has 4 members:
766  *
767  * - Tp** _M_map
768  * - size_t _M_map_size
769  * - iterator _M_start, _M_finish
770  *
771  * map_size is at least 8. %map is an array of map_size
772  * pointers-to-@a nodes. (The name %map has nothing to do with the
773  * std::map class, and @b nodes should not be confused with
774  * std::list's usage of @a node.)
775  *
776  * A @a node has no specific type name as such, but it is referred
777  * to as @a node in this file. It is a simple array-of-Tp. If Tp
778  * is very large, there will be one Tp element per node (i.e., an
779  * @a array of one). For non-huge Tp's, node size is inversely
780  * related to Tp size: the larger the Tp, the fewer Tp's will fit
781  * in a node. The goal here is to keep the total size of a node
782  * relatively small and constant over different Tp's, to improve
783  * allocator efficiency.
784  *
785  * Not every pointer in the %map array will point to a node. If
786  * the initial number of elements in the deque is small, the
787  * /middle/ %map pointers will be valid, and the ones at the edges
788  * will be unused. This same situation will arise as the %map
789  * grows: available %map pointers, if any, will be on the ends. As
790  * new nodes are created, only a subset of the %map's pointers need
791  * to be copied @a outward.
792  *
793  * Class invariants:
794  * - For any nonsingular iterator i:
795  * - i.node points to a member of the %map array. (Yes, you read that
796  * correctly: i.node does not actually point to a node.) The member of
797  * the %map array is what actually points to the node.
798  * - i.first == *(i.node) (This points to the node (first Tp element).)
799  * - i.last == i.first + node_size
800  * - i.cur is a pointer in the range [i.first, i.last). NOTE:
801  * the implication of this is that i.cur is always a dereferenceable
802  * pointer, even if i is a past-the-end iterator.
803  * - Start and Finish are always nonsingular iterators. NOTE: this
804  * means that an empty deque must have one node, a deque with <N
805  * elements (where N is the node buffer size) must have one node, a
806  * deque with N through (2N-1) elements must have two nodes, etc.
807  * - For every node other than start.node and finish.node, every
808  * element in the node is an initialized object. If start.node ==
809  * finish.node, then [start.cur, finish.cur) are initialized
810  * objects, and the elements outside that range are uninitialized
811  * storage. Otherwise, [start.cur, start.last) and [finish.first,
812  * finish.cur) are initialized objects, and [start.first, start.cur)
813  * and [finish.cur, finish.last) are uninitialized storage.
814  * - [%map, %map + map_size) is a valid, non-empty range.
815  * - [start.node, finish.node] is a valid range contained within
816  * [%map, %map + map_size).
817  * - A pointer in the range [%map, %map + map_size) points to an allocated
818  * node if and only if the pointer is in the range
819  * [start.node, finish.node].
820  *
821  * Here's the magic: nothing in deque is @b aware of the discontiguous
822  * storage!
823  *
824  * The memory setup and layout occurs in the parent, _Base, and the iterator
825  * class is entirely responsible for @a leaping from one node to the next.
826  * All the implementation routines for deque itself work only through the
827  * start and finish iterators. This keeps the routines simple and sane,
828  * and we can use other standard algorithms as well.
829  */
830  template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
831  class deque : protected _Deque_base<_Tp, _Alloc>
832  {
833 #ifdef _GLIBCXX_CONCEPT_CHECKS
834  // concept requirements
835  typedef typename _Alloc::value_type _Alloc_value_type;
836 # if __cplusplus < 201103L
837  __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
838 # endif
839  __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
840 #endif
841 
842  typedef _Deque_base<_Tp, _Alloc> _Base;
843  typedef typename _Base::_Tp_alloc_type _Tp_alloc_type;
844  typedef typename _Base::_Alloc_traits _Alloc_traits;
845  typedef typename _Base::_Map_pointer _Map_pointer;
846 
847  public:
848  typedef _Tp value_type;
849  typedef typename _Alloc_traits::pointer pointer;
850  typedef typename _Alloc_traits::const_pointer const_pointer;
851  typedef typename _Alloc_traits::reference reference;
852  typedef typename _Alloc_traits::const_reference const_reference;
853  typedef typename _Base::iterator iterator;
854  typedef typename _Base::const_iterator const_iterator;
855  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
856  typedef std::reverse_iterator<iterator> reverse_iterator;
857  typedef size_t size_type;
858  typedef ptrdiff_t difference_type;
859  typedef _Alloc allocator_type;
860 
861  protected:
862  static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
863  { return __deque_buf_size(sizeof(_Tp)); }
864 
865  // Functions controlling memory layout, and nothing else.
866  using _Base::_M_initialize_map;
867  using _Base::_M_create_nodes;
868  using _Base::_M_destroy_nodes;
869  using _Base::_M_allocate_node;
870  using _Base::_M_deallocate_node;
871  using _Base::_M_allocate_map;
872  using _Base::_M_deallocate_map;
873  using _Base::_M_get_Tp_allocator;
874 
875  /**
876  * A total of four data members accumulated down the hierarchy.
877  * May be accessed via _M_impl.*
878  */
879  using _Base::_M_impl;
880 
881  public:
882  // [23.2.1.1] construct/copy/destroy
883  // (assign() and get_allocator() are also listed in this section)
884 
885  /**
886  * @brief Creates a %deque with no elements.
887  */
888  deque() : _Base() { }
889 
890  /**
891  * @brief Creates a %deque with no elements.
892  * @param __a An allocator object.
893  */
894  explicit
895  deque(const allocator_type& __a)
896  : _Base(__a, 0) { }
897 
898 #if __cplusplus >= 201103L
899  /**
900  * @brief Creates a %deque with default constructed elements.
901  * @param __n The number of elements to initially create.
902  * @param __a An allocator.
903  *
904  * This constructor fills the %deque with @a n default
905  * constructed elements.
906  */
907  explicit
908  deque(size_type __n, const allocator_type& __a = allocator_type())
909  : _Base(__a, __n)
910  { _M_default_initialize(); }
911 
912  /**
913  * @brief Creates a %deque with copies of an exemplar element.
914  * @param __n The number of elements to initially create.
915  * @param __value An element to copy.
916  * @param __a An allocator.
917  *
918  * This constructor fills the %deque with @a __n copies of @a __value.
919  */
920  deque(size_type __n, const value_type& __value,
921  const allocator_type& __a = allocator_type())
922  : _Base(__a, __n)
923  { _M_fill_initialize(__value); }
924 #else
925  /**
926  * @brief Creates a %deque with copies of an exemplar element.
927  * @param __n The number of elements to initially create.
928  * @param __value An element to copy.
929  * @param __a An allocator.
930  *
931  * This constructor fills the %deque with @a __n copies of @a __value.
932  */
933  explicit
934  deque(size_type __n, const value_type& __value = value_type(),
935  const allocator_type& __a = allocator_type())
936  : _Base(__a, __n)
937  { _M_fill_initialize(__value); }
938 #endif
939 
940  /**
941  * @brief %Deque copy constructor.
942  * @param __x A %deque of identical element and allocator types.
943  *
944  * The newly-created %deque uses a copy of the allocator object used
945  * by @a __x (unless the allocator traits dictate a different object).
946  */
947  deque(const deque& __x)
948  : _Base(_Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()),
949  __x.size())
950  { std::__uninitialized_copy_a(__x.begin(), __x.end(),
951  this->_M_impl._M_start,
952  _M_get_Tp_allocator()); }
953 
954 #if __cplusplus >= 201103L
955  /**
956  * @brief %Deque move constructor.
957  * @param __x A %deque of identical element and allocator types.
958  *
959  * The newly-created %deque contains the exact contents of @a __x.
960  * The contents of @a __x are a valid, but unspecified %deque.
961  */
962  deque(deque&& __x)
963  : _Base(std::move(__x)) { }
964 
965  /// Copy constructor with alternative allocator
966  deque(const deque& __x, const allocator_type& __a)
967  : _Base(__a, __x.size())
968  { std::__uninitialized_copy_a(__x.begin(), __x.end(),
969  this->_M_impl._M_start,
970  _M_get_Tp_allocator()); }
971 
972  /// Move constructor with alternative allocator
973  deque(deque&& __x, const allocator_type& __a)
974  : _Base(std::move(__x), __a, __x.size())
975  {
976  if (__x.get_allocator() != __a)
977  {
978  std::__uninitialized_move_a(__x.begin(), __x.end(),
979  this->_M_impl._M_start,
980  _M_get_Tp_allocator());
981  __x.clear();
982  }
983  }
984 
985  /**
986  * @brief Builds a %deque from an initializer list.
987  * @param __l An initializer_list.
988  * @param __a An allocator object.
989  *
990  * Create a %deque consisting of copies of the elements in the
991  * initializer_list @a __l.
992  *
993  * This will call the element type's copy constructor N times
994  * (where N is __l.size()) and do no memory reallocation.
995  */
996  deque(initializer_list<value_type> __l,
997  const allocator_type& __a = allocator_type())
998  : _Base(__a)
999  {
1000  _M_range_initialize(__l.begin(), __l.end(),
1001  random_access_iterator_tag());
1002  }
1003 #endif
1004 
1005  /**
1006  * @brief Builds a %deque from a range.
1007  * @param __first An input iterator.
1008  * @param __last An input iterator.
1009  * @param __a An allocator object.
1010  *
1011  * Create a %deque consisting of copies of the elements from [__first,
1012  * __last).
1013  *
1014  * If the iterators are forward, bidirectional, or random-access, then
1015  * this will call the elements' copy constructor N times (where N is
1016  * distance(__first,__last)) and do no memory reallocation. But if only
1017  * input iterators are used, then this will do at most 2N calls to the
1018  * copy constructor, and logN memory reallocations.
1019  */
1020 #if __cplusplus >= 201103L
1021  template<typename _InputIterator,
1022  typename = std::_RequireInputIter<_InputIterator>>
1023  deque(_InputIterator __first, _InputIterator __last,
1024  const allocator_type& __a = allocator_type())
1025  : _Base(__a)
1026  { _M_initialize_dispatch(__first, __last, __false_type()); }
1027 #else
1028  template<typename _InputIterator>
1029  deque(_InputIterator __first, _InputIterator __last,
1030  const allocator_type& __a = allocator_type())
1031  : _Base(__a)
1032  {
1033  // Check whether it's an integral type. If so, it's not an iterator.
1034  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1035  _M_initialize_dispatch(__first, __last, _Integral());
1036  }
1037 #endif
1038 
1039  /**
1040  * The dtor only erases the elements, and note that if the elements
1041  * themselves are pointers, the pointed-to memory is not touched in any
1042  * way. Managing the pointer is the user's responsibility.
1043  */
1044  ~deque()
1045  { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); }
1046 
1047  /**
1048  * @brief %Deque assignment operator.
1049  * @param __x A %deque of identical element and allocator types.
1050  *
1051  * All the elements of @a x are copied.
1052  *
1053  * The newly-created %deque uses a copy of the allocator object used
1054  * by @a __x (unless the allocator traits dictate a different object).
1055  */
1056  deque&
1057  operator=(const deque& __x);
1058 
1059 #if __cplusplus >= 201103L
1060  /**
1061  * @brief %Deque move assignment operator.
1062  * @param __x A %deque of identical element and allocator types.
1063  *
1064  * The contents of @a __x are moved into this deque (without copying,
1065  * if the allocators permit it).
1066  * @a __x is a valid, but unspecified %deque.
1067  */
1068  deque&
1069  operator=(deque&& __x) noexcept(_Alloc_traits::_S_always_equal())
1070  {
1071  using __always_equal = typename _Alloc_traits::is_always_equal;
1072  _M_move_assign1(std::move(__x), __always_equal{});
1073  return *this;
1074  }
1075 
1076  /**
1077  * @brief Assigns an initializer list to a %deque.
1078  * @param __l An initializer_list.
1079  *
1080  * This function fills a %deque with copies of the elements in the
1081  * initializer_list @a __l.
1082  *
1083  * Note that the assignment completely changes the %deque and that the
1084  * resulting %deque's size is the same as the number of elements
1085  * assigned.
1086  */
1087  deque&
1088  operator=(initializer_list<value_type> __l)
1089  {
1090  _M_assign_aux(__l.begin(), __l.end(),
1091  random_access_iterator_tag());
1092  return *this;
1093  }
1094 #endif
1095 
1096  /**
1097  * @brief Assigns a given value to a %deque.
1098  * @param __n Number of elements to be assigned.
1099  * @param __val Value to be assigned.
1100  *
1101  * This function fills a %deque with @a n copies of the given
1102  * value. Note that the assignment completely changes the
1103  * %deque and that the resulting %deque's size is the same as
1104  * the number of elements assigned.
1105  */
1106  void
1107  assign(size_type __n, const value_type& __val)
1108  { _M_fill_assign(__n, __val); }
1109 
1110  /**
1111  * @brief Assigns a range to a %deque.
1112  * @param __first An input iterator.
1113  * @param __last An input iterator.
1114  *
1115  * This function fills a %deque with copies of the elements in the
1116  * range [__first,__last).
1117  *
1118  * Note that the assignment completely changes the %deque and that the
1119  * resulting %deque's size is the same as the number of elements
1120  * assigned.
1121  */
1122 #if __cplusplus >= 201103L
1123  template<typename _InputIterator,
1124  typename = std::_RequireInputIter<_InputIterator>>
1125  void
1126  assign(_InputIterator __first, _InputIterator __last)
1127  { _M_assign_dispatch(__first, __last, __false_type()); }
1128 #else
1129  template<typename _InputIterator>
1130  void
1131  assign(_InputIterator __first, _InputIterator __last)
1132  {
1133  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1134  _M_assign_dispatch(__first, __last, _Integral());
1135  }
1136 #endif
1137 
1138 #if __cplusplus >= 201103L
1139  /**
1140  * @brief Assigns an initializer list to a %deque.
1141  * @param __l An initializer_list.
1142  *
1143  * This function fills a %deque with copies of the elements in the
1144  * initializer_list @a __l.
1145  *
1146  * Note that the assignment completely changes the %deque and that the
1147  * resulting %deque's size is the same as the number of elements
1148  * assigned.
1149  */
1150  void
1151  assign(initializer_list<value_type> __l)
1152  { _M_assign_aux(__l.begin(), __l.end(), random_access_iterator_tag()); }
1153 #endif
1154 
1155  /// Get a copy of the memory allocation object.
1156  allocator_type
1157  get_allocator() const _GLIBCXX_NOEXCEPT
1158  { return _Base::get_allocator(); }
1159 
1160  // iterators
1161  /**
1162  * Returns a read/write iterator that points to the first element in the
1163  * %deque. Iteration is done in ordinary element order.
1164  */
1165  iterator
1166  begin() _GLIBCXX_NOEXCEPT
1167  { return this->_M_impl._M_start; }
1168 
1169  /**
1170  * Returns a read-only (constant) iterator that points to the first
1171  * element in the %deque. Iteration is done in ordinary element order.
1172  */
1173  const_iterator
1174  begin() const _GLIBCXX_NOEXCEPT
1175  { return this->_M_impl._M_start; }
1176 
1177  /**
1178  * Returns a read/write iterator that points one past the last
1179  * element in the %deque. Iteration is done in ordinary
1180  * element order.
1181  */
1182  iterator
1183  end() _GLIBCXX_NOEXCEPT
1184  { return this->_M_impl._M_finish; }
1185 
1186  /**
1187  * Returns a read-only (constant) iterator that points one past
1188  * the last element in the %deque. Iteration is done in
1189  * ordinary element order.
1190  */
1191  const_iterator
1192  end() const _GLIBCXX_NOEXCEPT
1193  { return this->_M_impl._M_finish; }
1194 
1195  /**
1196  * Returns a read/write reverse iterator that points to the
1197  * last element in the %deque. Iteration is done in reverse
1198  * element order.
1199  */
1200  reverse_iterator
1201  rbegin() _GLIBCXX_NOEXCEPT
1202  { return reverse_iterator(this->_M_impl._M_finish); }
1203 
1204  /**
1205  * Returns a read-only (constant) reverse iterator that points
1206  * to the last element in the %deque. Iteration is done in
1207  * reverse element order.
1208  */
1209  const_reverse_iterator
1210  rbegin() const _GLIBCXX_NOEXCEPT
1211  { return const_reverse_iterator(this->_M_impl._M_finish); }
1212 
1213  /**
1214  * Returns a read/write reverse iterator that points to one
1215  * before the first element in the %deque. Iteration is done
1216  * in reverse element order.
1217  */
1218  reverse_iterator
1219  rend() _GLIBCXX_NOEXCEPT
1220  { return reverse_iterator(this->_M_impl._M_start); }
1221 
1222  /**
1223  * Returns a read-only (constant) reverse iterator that points
1224  * to one before the first element in the %deque. Iteration is
1225  * done in reverse element order.
1226  */
1227  const_reverse_iterator
1228  rend() const _GLIBCXX_NOEXCEPT
1229  { return const_reverse_iterator(this->_M_impl._M_start); }
1230 
1231 #if __cplusplus >= 201103L
1232  /**
1233  * Returns a read-only (constant) iterator that points to the first
1234  * element in the %deque. Iteration is done in ordinary element order.
1235  */
1236  const_iterator
1237  cbegin() const noexcept
1238  { return this->_M_impl._M_start; }
1239 
1240  /**
1241  * Returns a read-only (constant) iterator that points one past
1242  * the last element in the %deque. Iteration is done in
1243  * ordinary element order.
1244  */
1245  const_iterator
1246  cend() const noexcept
1247  { return this->_M_impl._M_finish; }
1248 
1249  /**
1250  * Returns a read-only (constant) reverse iterator that points
1251  * to the last element in the %deque. Iteration is done in
1252  * reverse element order.
1253  */
1254  const_reverse_iterator
1255  crbegin() const noexcept
1256  { return const_reverse_iterator(this->_M_impl._M_finish); }
1257 
1258  /**
1259  * Returns a read-only (constant) reverse iterator that points
1260  * to one before the first element in the %deque. Iteration is
1261  * done in reverse element order.
1262  */
1263  const_reverse_iterator
1264  crend() const noexcept
1265  { return const_reverse_iterator(this->_M_impl._M_start); }
1266 #endif
1267 
1268  // [23.2.1.2] capacity
1269  /** Returns the number of elements in the %deque. */
1270  size_type
1271  size() const _GLIBCXX_NOEXCEPT
1272  { return this->_M_impl._M_finish - this->_M_impl._M_start; }
1273 
1274  /** Returns the size() of the largest possible %deque. */
1275  size_type
1276  max_size() const _GLIBCXX_NOEXCEPT
1277  { return _Alloc_traits::max_size(_M_get_Tp_allocator()); }
1278 
1279 #if __cplusplus >= 201103L
1280  /**
1281  * @brief Resizes the %deque to the specified number of elements.
1282  * @param __new_size Number of elements the %deque should contain.
1283  *
1284  * This function will %resize the %deque to the specified
1285  * number of elements. If the number is smaller than the
1286  * %deque's current size the %deque is truncated, otherwise
1287  * default constructed elements are appended.
1288  */
1289  void
1290  resize(size_type __new_size)
1291  {
1292  const size_type __len = size();
1293  if (__new_size > __len)
1294  _M_default_append(__new_size - __len);
1295  else if (__new_size < __len)
1296  _M_erase_at_end(this->_M_impl._M_start
1297  + difference_type(__new_size));
1298  }
1299 
1300  /**
1301  * @brief Resizes the %deque to the specified number of elements.
1302  * @param __new_size Number of elements the %deque should contain.
1303  * @param __x Data with which new elements should be populated.
1304  *
1305  * This function will %resize the %deque to the specified
1306  * number of elements. If the number is smaller than the
1307  * %deque's current size the %deque is truncated, otherwise the
1308  * %deque is extended and new elements are populated with given
1309  * data.
1310  */
1311  void
1312  resize(size_type __new_size, const value_type& __x)
1313  {
1314  const size_type __len = size();
1315  if (__new_size > __len)
1316  _M_fill_insert(this->_M_impl._M_finish, __new_size - __len, __x);
1317  else if (__new_size < __len)
1318  _M_erase_at_end(this->_M_impl._M_start
1319  + difference_type(__new_size));
1320  }
1321 #else
1322  /**
1323  * @brief Resizes the %deque to the specified number of elements.
1324  * @param __new_size Number of elements the %deque should contain.
1325  * @param __x Data with which new elements should be populated.
1326  *
1327  * This function will %resize the %deque to the specified
1328  * number of elements. If the number is smaller than the
1329  * %deque's current size the %deque is truncated, otherwise the
1330  * %deque is extended and new elements are populated with given
1331  * data.
1332  */
1333  void
1334  resize(size_type __new_size, value_type __x = value_type())
1335  {
1336  const size_type __len = size();
1337  if (__new_size > __len)
1338  _M_fill_insert(this->_M_impl._M_finish, __new_size - __len, __x);
1339  else if (__new_size < __len)
1340  _M_erase_at_end(this->_M_impl._M_start
1341  + difference_type(__new_size));
1342  }
1343 #endif
1344 
1345 #if __cplusplus >= 201103L
1346  /** A non-binding request to reduce memory use. */
1347  void
1348  shrink_to_fit() noexcept
1349  { _M_shrink_to_fit(); }
1350 #endif
1351 
1352  /**
1353  * Returns true if the %deque is empty. (Thus begin() would
1354  * equal end().)
1355  */
1356  bool
1357  empty() const _GLIBCXX_NOEXCEPT
1358  { return this->_M_impl._M_finish == this->_M_impl._M_start; }
1359 
1360  // element access
1361  /**
1362  * @brief Subscript access to the data contained in the %deque.
1363  * @param __n The index of the element for which data should be
1364  * accessed.
1365  * @return Read/write reference to data.
1366  *
1367  * This operator allows for easy, array-style, data access.
1368  * Note that data access with this operator is unchecked and
1369  * out_of_range lookups are not defined. (For checked lookups
1370  * see at().)
1371  */
1372  reference
1373  operator[](size_type __n) _GLIBCXX_NOEXCEPT
1374  {
1375  __glibcxx_requires_subscript(__n);
1376  return this->_M_impl._M_start[difference_type(__n)];
1377  }
1378 
1379  /**
1380  * @brief Subscript access to the data contained in the %deque.
1381  * @param __n The index of the element for which data should be
1382  * accessed.
1383  * @return Read-only (constant) reference to data.
1384  *
1385  * This operator allows for easy, array-style, data access.
1386  * Note that data access with this operator is unchecked and
1387  * out_of_range lookups are not defined. (For checked lookups
1388  * see at().)
1389  */
1390  const_reference
1391  operator[](size_type __n) const _GLIBCXX_NOEXCEPT
1392  {
1393  __glibcxx_requires_subscript(__n);
1394  return this->_M_impl._M_start[difference_type(__n)];
1395  }
1396 
1397  protected:
1398  /// Safety check used only from at().
1399  void
1400  _M_range_check(size_type __n) const
1401  {
1402  if (__n >= this->size())
1403  __throw_out_of_range_fmt(__N("deque::_M_range_check: __n "
1404  "(which is %zu)>= this->size() "
1405  "(which is %zu)"),
1406  __n, this->size());
1407  }
1408 
1409  public:
1410  /**
1411  * @brief Provides access to the data contained in the %deque.
1412  * @param __n The index of the element for which data should be
1413  * accessed.
1414  * @return Read/write reference to data.
1415  * @throw std::out_of_range If @a __n is an invalid index.
1416  *
1417  * This function provides for safer data access. The parameter
1418  * is first checked that it is in the range of the deque. The
1419  * function throws out_of_range if the check fails.
1420  */
1421  reference
1422  at(size_type __n)
1423  {
1424  _M_range_check(__n);
1425  return (*this)[__n];
1426  }
1427 
1428  /**
1429  * @brief Provides access to the data contained in the %deque.
1430  * @param __n The index of the element for which data should be
1431  * accessed.
1432  * @return Read-only (constant) reference to data.
1433  * @throw std::out_of_range If @a __n is an invalid index.
1434  *
1435  * This function provides for safer data access. The parameter is first
1436  * checked that it is in the range of the deque. The function throws
1437  * out_of_range if the check fails.
1438  */
1439  const_reference
1440  at(size_type __n) const
1441  {
1442  _M_range_check(__n);
1443  return (*this)[__n];
1444  }
1445 
1446  /**
1447  * Returns a read/write reference to the data at the first
1448  * element of the %deque.
1449  */
1450  reference
1451  front() _GLIBCXX_NOEXCEPT
1452  {
1453  __glibcxx_requires_nonempty();
1454  return *begin();
1455  }
1456 
1457  /**
1458  * Returns a read-only (constant) reference to the data at the first
1459  * element of the %deque.
1460  */
1461  const_reference
1462  front() const _GLIBCXX_NOEXCEPT
1463  {
1464  __glibcxx_requires_nonempty();
1465  return *begin();
1466  }
1467 
1468  /**
1469  * Returns a read/write reference to the data at the last element of the
1470  * %deque.
1471  */
1472  reference
1473  back() _GLIBCXX_NOEXCEPT
1474  {
1475  __glibcxx_requires_nonempty();
1476  iterator __tmp = end();
1477  --__tmp;
1478  return *__tmp;
1479  }
1480 
1481  /**
1482  * Returns a read-only (constant) reference to the data at the last
1483  * element of the %deque.
1484  */
1485  const_reference
1486  back() const _GLIBCXX_NOEXCEPT
1487  {
1488  __glibcxx_requires_nonempty();
1489  const_iterator __tmp = end();
1490  --__tmp;
1491  return *__tmp;
1492  }
1493 
1494  // [23.2.1.2] modifiers
1495  /**
1496  * @brief Add data to the front of the %deque.
1497  * @param __x Data to be added.
1498  *
1499  * This is a typical stack operation. The function creates an
1500  * element at the front of the %deque and assigns the given
1501  * data to it. Due to the nature of a %deque this operation
1502  * can be done in constant time.
1503  */
1504  void
1505  push_front(const value_type& __x)
1506  {
1507  if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
1508  {
1509  _Alloc_traits::construct(this->_M_impl,
1510  this->_M_impl._M_start._M_cur - 1,
1511  __x);
1512  --this->_M_impl._M_start._M_cur;
1513  }
1514  else
1515  _M_push_front_aux(__x);
1516  }
1517 
1518 #if __cplusplus >= 201103L
1519  void
1520  push_front(value_type&& __x)
1521  { emplace_front(std::move(__x)); }
1522 
1523  template<typename... _Args>
1524 #if __cplusplus > 201402L
1525  reference
1526 #else
1527  void
1528 #endif
1529  emplace_front(_Args&&... __args);
1530 #endif
1531 
1532  /**
1533  * @brief Add data to the end of the %deque.
1534  * @param __x Data to be added.
1535  *
1536  * This is a typical stack operation. The function creates an
1537  * element at the end of the %deque and assigns the given data
1538  * to it. Due to the nature of a %deque this operation can be
1539  * done in constant time.
1540  */
1541  void
1542  push_back(const value_type& __x)
1543  {
1544  if (this->_M_impl._M_finish._M_cur
1545  != this->_M_impl._M_finish._M_last - 1)
1546  {
1547  _Alloc_traits::construct(this->_M_impl,
1548  this->_M_impl._M_finish._M_cur, __x);
1549  ++this->_M_impl._M_finish._M_cur;
1550  }
1551  else
1552  _M_push_back_aux(__x);
1553  }
1554 
1555 #if __cplusplus >= 201103L
1556  void
1557  push_back(value_type&& __x)
1558  { emplace_back(std::move(__x)); }
1559 
1560  template<typename... _Args>
1561 #if __cplusplus > 201402L
1562  reference
1563 #else
1564  void
1565 #endif
1566  emplace_back(_Args&&... __args);
1567 #endif
1568 
1569  /**
1570  * @brief Removes first element.
1571  *
1572  * This is a typical stack operation. It shrinks the %deque by one.
1573  *
1574  * Note that no data is returned, and if the first element's data is
1575  * needed, it should be retrieved before pop_front() is called.
1576  */
1577  void
1578  pop_front() _GLIBCXX_NOEXCEPT
1579  {
1580  __glibcxx_requires_nonempty();
1581  if (this->_M_impl._M_start._M_cur
1582  != this->_M_impl._M_start._M_last - 1)
1583  {
1584  _Alloc_traits::destroy(this->_M_impl,
1585  this->_M_impl._M_start._M_cur);
1586  ++this->_M_impl._M_start._M_cur;
1587  }
1588  else
1589  _M_pop_front_aux();
1590  }
1591 
1592  /**
1593  * @brief Removes last element.
1594  *
1595  * This is a typical stack operation. It shrinks the %deque by one.
1596  *
1597  * Note that no data is returned, and if the last element's data is
1598  * needed, it should be retrieved before pop_back() is called.
1599  */
1600  void
1601  pop_back() _GLIBCXX_NOEXCEPT
1602  {
1603  __glibcxx_requires_nonempty();
1604  if (this->_M_impl._M_finish._M_cur
1605  != this->_M_impl._M_finish._M_first)
1606  {
1607  --this->_M_impl._M_finish._M_cur;
1608  _Alloc_traits::destroy(this->_M_impl,
1609  this->_M_impl._M_finish._M_cur);
1610  }
1611  else
1612  _M_pop_back_aux();
1613  }
1614 
1615 #if __cplusplus >= 201103L
1616  /**
1617  * @brief Inserts an object in %deque before specified iterator.
1618  * @param __position A const_iterator into the %deque.
1619  * @param __args Arguments.
1620  * @return An iterator that points to the inserted data.
1621  *
1622  * This function will insert an object of type T constructed
1623  * with T(std::forward<Args>(args)...) before the specified location.
1624  */
1625  template<typename... _Args>
1626  iterator
1627  emplace(const_iterator __position, _Args&&... __args);
1628 
1629  /**
1630  * @brief Inserts given value into %deque before specified iterator.
1631  * @param __position A const_iterator into the %deque.
1632  * @param __x Data to be inserted.
1633  * @return An iterator that points to the inserted data.
1634  *
1635  * This function will insert a copy of the given value before the
1636  * specified location.
1637  */
1638  iterator
1639  insert(const_iterator __position, const value_type& __x);
1640 #else
1641  /**
1642  * @brief Inserts given value into %deque before specified iterator.
1643  * @param __position An iterator into the %deque.
1644  * @param __x Data to be inserted.
1645  * @return An iterator that points to the inserted data.
1646  *
1647  * This function will insert a copy of the given value before the
1648  * specified location.
1649  */
1650  iterator
1651  insert(iterator __position, const value_type& __x);
1652 #endif
1653 
1654 #if __cplusplus >= 201103L
1655  /**
1656  * @brief Inserts given rvalue into %deque before specified iterator.
1657  * @param __position A const_iterator into the %deque.
1658  * @param __x Data to be inserted.
1659  * @return An iterator that points to the inserted data.
1660  *
1661  * This function will insert a copy of the given rvalue before the
1662  * specified location.
1663  */
1664  iterator
1665  insert(const_iterator __position, value_type&& __x)
1666  { return emplace(__position, std::move(__x)); }
1667 
1668  /**
1669  * @brief Inserts an initializer list into the %deque.
1670  * @param __p An iterator into the %deque.
1671  * @param __l An initializer_list.
1672  *
1673  * This function will insert copies of the data in the
1674  * initializer_list @a __l into the %deque before the location
1675  * specified by @a __p. This is known as <em>list insert</em>.
1676  */
1677  iterator
1678  insert(const_iterator __p, initializer_list<value_type> __l)
1679  {
1680  auto __offset = __p - cbegin();
1681  _M_range_insert_aux(__p._M_const_cast(), __l.begin(), __l.end(),
1682  std::random_access_iterator_tag());
1683  return begin() + __offset;
1684  }
1685 #endif
1686 
1687 #if __cplusplus >= 201103L
1688  /**
1689  * @brief Inserts a number of copies of given data into the %deque.
1690  * @param __position A const_iterator into the %deque.
1691  * @param __n Number of elements to be inserted.
1692  * @param __x Data to be inserted.
1693  * @return An iterator that points to the inserted data.
1694  *
1695  * This function will insert a specified number of copies of the given
1696  * data before the location specified by @a __position.
1697  */
1698  iterator
1699  insert(const_iterator __position, size_type __n, const value_type& __x)
1700  {
1701  difference_type __offset = __position - cbegin();
1702  _M_fill_insert(__position._M_const_cast(), __n, __x);
1703  return begin() + __offset;
1704  }
1705 #else
1706  /**
1707  * @brief Inserts a number of copies of given data into the %deque.
1708  * @param __position An iterator into the %deque.
1709  * @param __n Number of elements to be inserted.
1710  * @param __x Data to be inserted.
1711  *
1712  * This function will insert a specified number of copies of the given
1713  * data before the location specified by @a __position.
1714  */
1715  void
1716  insert(iterator __position, size_type __n, const value_type& __x)
1717  { _M_fill_insert(__position, __n, __x); }
1718 #endif
1719 
1720 #if __cplusplus >= 201103L
1721  /**
1722  * @brief Inserts a range into the %deque.
1723  * @param __position A const_iterator into the %deque.
1724  * @param __first An input iterator.
1725  * @param __last An input iterator.
1726  * @return An iterator that points to the inserted data.
1727  *
1728  * This function will insert copies of the data in the range
1729  * [__first,__last) into the %deque before the location specified
1730  * by @a __position. This is known as <em>range insert</em>.
1731  */
1732  template<typename _InputIterator,
1733  typename = std::_RequireInputIter<_InputIterator>>
1734  iterator
1735  insert(const_iterator __position, _InputIterator __first,
1736  _InputIterator __last)
1737  {
1738  difference_type __offset = __position - cbegin();
1739  _M_insert_dispatch(__position._M_const_cast(),
1740  __first, __last, __false_type());
1741  return begin() + __offset;
1742  }
1743 #else
1744  /**
1745  * @brief Inserts a range into the %deque.
1746  * @param __position An iterator into the %deque.
1747  * @param __first An input iterator.
1748  * @param __last An input iterator.
1749  *
1750  * This function will insert copies of the data in the range
1751  * [__first,__last) into the %deque before the location specified
1752  * by @a __position. This is known as <em>range insert</em>.
1753  */
1754  template<typename _InputIterator>
1755  void
1756  insert(iterator __position, _InputIterator __first,
1757  _InputIterator __last)
1758  {
1759  // Check whether it's an integral type. If so, it's not an iterator.
1760  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1761  _M_insert_dispatch(__position, __first, __last, _Integral());
1762  }
1763 #endif
1764 
1765  /**
1766  * @brief Remove element at given position.
1767  * @param __position Iterator pointing to element to be erased.
1768  * @return An iterator pointing to the next element (or end()).
1769  *
1770  * This function will erase the element at the given position and thus
1771  * shorten the %deque by one.
1772  *
1773  * The user is cautioned that
1774  * this function only erases the element, and that if the element is
1775  * itself a pointer, the pointed-to memory is not touched in any way.
1776  * Managing the pointer is the user's responsibility.
1777  */
1778  iterator
1779 #if __cplusplus >= 201103L
1780  erase(const_iterator __position)
1781 #else
1782  erase(iterator __position)
1783 #endif
1784  { return _M_erase(__position._M_const_cast()); }
1785 
1786  /**
1787  * @brief Remove a range of elements.
1788  * @param __first Iterator pointing to the first element to be erased.
1789  * @param __last Iterator pointing to one past the last element to be
1790  * erased.
1791  * @return An iterator pointing to the element pointed to by @a last
1792  * prior to erasing (or end()).
1793  *
1794  * This function will erase the elements in the range
1795  * [__first,__last) and shorten the %deque accordingly.
1796  *
1797  * The user is cautioned that
1798  * this function only erases the elements, and that if the elements
1799  * themselves are pointers, the pointed-to memory is not touched in any
1800  * way. Managing the pointer is the user's responsibility.
1801  */
1802  iterator
1803 #if __cplusplus >= 201103L
1804  erase(const_iterator __first, const_iterator __last)
1805 #else
1806  erase(iterator __first, iterator __last)
1807 #endif
1808  { return _M_erase(__first._M_const_cast(), __last._M_const_cast()); }
1809 
1810  /**
1811  * @brief Swaps data with another %deque.
1812  * @param __x A %deque of the same element and allocator types.
1813  *
1814  * This exchanges the elements between two deques in constant time.
1815  * (Four pointers, so it should be quite fast.)
1816  * Note that the global std::swap() function is specialized such that
1817  * std::swap(d1,d2) will feed to this function.
1818  *
1819  * Whether the allocators are swapped depends on the allocator traits.
1820  */
1821  void
1822  swap(deque& __x) _GLIBCXX_NOEXCEPT
1823  {
1824 #if __cplusplus >= 201103L
1825  __glibcxx_assert(_Alloc_traits::propagate_on_container_swap::value
1826  || _M_get_Tp_allocator() == __x._M_get_Tp_allocator());
1827 #endif
1828  _M_impl._M_swap_data(__x._M_impl);
1829  _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(),
1830  __x._M_get_Tp_allocator());
1831  }
1832 
1833  /**
1834  * Erases all the elements. Note that this function only erases the
1835  * elements, and that if the elements themselves are pointers, the
1836  * pointed-to memory is not touched in any way. Managing the pointer is
1837  * the user's responsibility.
1838  */
1839  void
1840  clear() _GLIBCXX_NOEXCEPT
1841  { _M_erase_at_end(begin()); }
1842 
1843  protected:
1844  // Internal constructor functions follow.
1845 
1846  // called by the range constructor to implement [23.1.1]/9
1847 
1848  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1849  // 438. Ambiguity in the "do the right thing" clause
1850  template<typename _Integer>
1851  void
1852  _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
1853  {
1854  _M_initialize_map(static_cast<size_type>(__n));
1855  _M_fill_initialize(__x);
1856  }
1857 
1858  // called by the range constructor to implement [23.1.1]/9
1859  template<typename _InputIterator>
1860  void
1861  _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
1862  __false_type)
1863  {
1864  _M_range_initialize(__first, __last,
1865  std::__iterator_category(__first));
1866  }
1867 
1868  // called by the second initialize_dispatch above
1869  //@{
1870  /**
1871  * @brief Fills the deque with whatever is in [first,last).
1872  * @param __first An input iterator.
1873  * @param __last An input iterator.
1874  * @return Nothing.
1875  *
1876  * If the iterators are actually forward iterators (or better), then the
1877  * memory layout can be done all at once. Else we move forward using
1878  * push_back on each value from the iterator.
1879  */
1880  template<typename _InputIterator>
1881  void
1882  _M_range_initialize(_InputIterator __first, _InputIterator __last,
1883  std::input_iterator_tag);
1884 
1885  // called by the second initialize_dispatch above
1886  template<typename _ForwardIterator>
1887  void
1888  _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
1889  std::forward_iterator_tag);
1890  //@}
1891 
1892  /**
1893  * @brief Fills the %deque with copies of value.
1894  * @param __value Initial value.
1895  * @return Nothing.
1896  * @pre _M_start and _M_finish have already been initialized,
1897  * but none of the %deque's elements have yet been constructed.
1898  *
1899  * This function is called only when the user provides an explicit size
1900  * (with or without an explicit exemplar value).
1901  */
1902  void
1903  _M_fill_initialize(const value_type& __value);
1904 
1905 #if __cplusplus >= 201103L
1906  // called by deque(n).
1907  void
1908  _M_default_initialize();
1909 #endif
1910 
1911  // Internal assign functions follow. The *_aux functions do the actual
1912  // assignment work for the range versions.
1913 
1914  // called by the range assign to implement [23.1.1]/9
1915 
1916  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1917  // 438. Ambiguity in the "do the right thing" clause
1918  template<typename _Integer>
1919  void
1920  _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
1921  { _M_fill_assign(__n, __val); }
1922 
1923  // called by the range assign to implement [23.1.1]/9
1924  template<typename _InputIterator>
1925  void
1926  _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
1927  __false_type)
1928  { _M_assign_aux(__first, __last, std::__iterator_category(__first)); }
1929 
1930  // called by the second assign_dispatch above
1931  template<typename _InputIterator>
1932  void
1933  _M_assign_aux(_InputIterator __first, _InputIterator __last,
1934  std::input_iterator_tag);
1935 
1936  // called by the second assign_dispatch above
1937  template<typename _ForwardIterator>
1938  void
1939  _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
1940  std::forward_iterator_tag)
1941  {
1942  const size_type __len = std::distance(__first, __last);
1943  if (__len > size())
1944  {
1945  _ForwardIterator __mid = __first;
1946  std::advance(__mid, size());
1947  std::copy(__first, __mid, begin());
1948  _M_range_insert_aux(end(), __mid, __last,
1949  std::__iterator_category(__first));
1950  }
1951  else
1952  _M_erase_at_end(std::copy(__first, __last, begin()));
1953  }
1954 
1955  // Called by assign(n,t), and the range assign when it turns out
1956  // to be the same thing.
1957  void
1958  _M_fill_assign(size_type __n, const value_type& __val)
1959  {
1960  if (__n > size())
1961  {
1962  std::fill(begin(), end(), __val);
1963  _M_fill_insert(end(), __n - size(), __val);
1964  }
1965  else
1966  {
1967  _M_erase_at_end(begin() + difference_type(__n));
1968  std::fill(begin(), end(), __val);
1969  }
1970  }
1971 
1972  //@{
1973  /// Helper functions for push_* and pop_*.
1974 #if __cplusplus < 201103L
1975  void _M_push_back_aux(const value_type&);
1976 
1977  void _M_push_front_aux(const value_type&);
1978 #else
1979  template<typename... _Args>
1980  void _M_push_back_aux(_Args&&... __args);
1981 
1982  template<typename... _Args>
1983  void _M_push_front_aux(_Args&&... __args);
1984 #endif
1985 
1986  void _M_pop_back_aux();
1987 
1988  void _M_pop_front_aux();
1989  //@}
1990 
1991  // Internal insert functions follow. The *_aux functions do the actual
1992  // insertion work when all shortcuts fail.
1993 
1994  // called by the range insert to implement [23.1.1]/9
1995 
1996  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1997  // 438. Ambiguity in the "do the right thing" clause
1998  template<typename _Integer>
1999  void
2000  _M_insert_dispatch(iterator __pos,
2001  _Integer __n, _Integer __x, __true_type)
2002  { _M_fill_insert(__pos, __n, __x); }
2003 
2004  // called by the range insert to implement [23.1.1]/9
2005  template<typename _InputIterator>
2006  void
2007  _M_insert_dispatch(iterator __pos,
2008  _InputIterator __first, _InputIterator __last,
2009  __false_type)
2010  {
2011  _M_range_insert_aux(__pos, __first, __last,
2012  std::__iterator_category(__first));
2013  }
2014 
2015  // called by the second insert_dispatch above
2016  template<typename _InputIterator>
2017  void
2018  _M_range_insert_aux(iterator __pos, _InputIterator __first,
2019  _InputIterator __last, std::input_iterator_tag);
2020 
2021  // called by the second insert_dispatch above
2022  template<typename _ForwardIterator>
2023  void
2024  _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
2025  _ForwardIterator __last, std::forward_iterator_tag);
2026 
2027  // Called by insert(p,n,x), and the range insert when it turns out to be
2028  // the same thing. Can use fill functions in optimal situations,
2029  // otherwise passes off to insert_aux(p,n,x).
2030  void
2031  _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
2032 
2033  // called by insert(p,x)
2034 #if __cplusplus < 201103L
2035  iterator
2036  _M_insert_aux(iterator __pos, const value_type& __x);
2037 #else
2038  template<typename... _Args>
2039  iterator
2040  _M_insert_aux(iterator __pos, _Args&&... __args);
2041 #endif
2042 
2043  // called by insert(p,n,x) via fill_insert
2044  void
2045  _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
2046 
2047  // called by range_insert_aux for forward iterators
2048  template<typename _ForwardIterator>
2049  void
2050  _M_insert_aux(iterator __pos,
2051  _ForwardIterator __first, _ForwardIterator __last,
2052  size_type __n);
2053 
2054 
2055  // Internal erase functions follow.
2056 
2057  void
2058  _M_destroy_data_aux(iterator __first, iterator __last);
2059 
2060  // Called by ~deque().
2061  // NB: Doesn't deallocate the nodes.
2062  template<typename _Alloc1>
2063  void
2064  _M_destroy_data(iterator __first, iterator __last, const _Alloc1&)
2065  { _M_destroy_data_aux(__first, __last); }
2066 
2067  void
2068  _M_destroy_data(iterator __first, iterator __last,
2069  const std::allocator<_Tp>&)
2070  {
2071  if (!__has_trivial_destructor(value_type))
2072  _M_destroy_data_aux(__first, __last);
2073  }
2074 
2075  // Called by erase(q1, q2).
2076  void
2077  _M_erase_at_begin(iterator __pos)
2078  {
2079  _M_destroy_data(begin(), __pos, _M_get_Tp_allocator());
2080  _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node);
2081  this->_M_impl._M_start = __pos;
2082  }
2083 
2084  // Called by erase(q1, q2), resize(), clear(), _M_assign_aux,
2085  // _M_fill_assign, operator=.
2086  void
2087  _M_erase_at_end(iterator __pos)
2088  {
2089  _M_destroy_data(__pos, end(), _M_get_Tp_allocator());
2090  _M_destroy_nodes(__pos._M_node + 1,
2091  this->_M_impl._M_finish._M_node + 1);
2092  this->_M_impl._M_finish = __pos;
2093  }
2094 
2095  iterator
2096  _M_erase(iterator __pos);
2097 
2098  iterator
2099  _M_erase(iterator __first, iterator __last);
2100 
2101 #if __cplusplus >= 201103L
2102  // Called by resize(sz).
2103  void
2104  _M_default_append(size_type __n);
2105 
2106  bool
2107  _M_shrink_to_fit();
2108 #endif
2109 
2110  //@{
2111  /// Memory-handling helpers for the previous internal insert functions.
2112  iterator
2113  _M_reserve_elements_at_front(size_type __n)
2114  {
2115  const size_type __vacancies = this->_M_impl._M_start._M_cur
2116  - this->_M_impl._M_start._M_first;
2117  if (__n > __vacancies)
2118  _M_new_elements_at_front(__n - __vacancies);
2119  return this->_M_impl._M_start - difference_type(__n);
2120  }
2121 
2122  iterator
2123  _M_reserve_elements_at_back(size_type __n)
2124  {
2125  const size_type __vacancies = (this->_M_impl._M_finish._M_last
2126  - this->_M_impl._M_finish._M_cur) - 1;
2127  if (__n > __vacancies)
2128  _M_new_elements_at_back(__n - __vacancies);
2129  return this->_M_impl._M_finish + difference_type(__n);
2130  }
2131 
2132  void
2133  _M_new_elements_at_front(size_type __new_elements);
2134 
2135  void
2136  _M_new_elements_at_back(size_type __new_elements);
2137  //@}
2138 
2139 
2140  //@{
2141  /**
2142  * @brief Memory-handling helpers for the major %map.
2143  *
2144  * Makes sure the _M_map has space for new nodes. Does not
2145  * actually add the nodes. Can invalidate _M_map pointers.
2146  * (And consequently, %deque iterators.)
2147  */
2148  void
2149  _M_reserve_map_at_back(size_type __nodes_to_add = 1)
2150  {
2151  if (__nodes_to_add + 1 > this->_M_impl._M_map_size
2152  - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
2153  _M_reallocate_map(__nodes_to_add, false);
2154  }
2155 
2156  void
2157  _M_reserve_map_at_front(size_type __nodes_to_add = 1)
2158  {
2159  if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
2160  - this->_M_impl._M_map))
2161  _M_reallocate_map(__nodes_to_add, true);
2162  }
2163 
2164  void
2165  _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
2166  //@}
2167 
2168 #if __cplusplus >= 201103L
2169  // Constant-time, nothrow move assignment when source object's memory
2170  // can be moved because the allocators are equal.
2171  void
2172  _M_move_assign1(deque&& __x, /* always equal: */ true_type) noexcept
2173  {
2174  this->_M_impl._M_swap_data(__x._M_impl);
2175  __x.clear();
2176  std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator());
2177  }
2178 
2179  // When the allocators are not equal the operation could throw, because
2180  // we might need to allocate a new map for __x after moving from it
2181  // or we might need to allocate new elements for *this.
2182  void
2183  _M_move_assign1(deque&& __x, /* always equal: */ false_type)
2184  {
2185  constexpr bool __move_storage =
2186  _Alloc_traits::_S_propagate_on_move_assign();
2187  _M_move_assign2(std::move(__x), __bool_constant<__move_storage>());
2188  }
2189 
2190  // Destroy all elements and deallocate all memory, then replace
2191  // with elements created from __args.
2192  template<typename... _Args>
2193  void
2194  _M_replace_map(_Args&&... __args)
2195  {
2196  // Create new data first, so if allocation fails there are no effects.
2197  deque __newobj(std::forward<_Args>(__args)...);
2198  // Free existing storage using existing allocator.
2199  clear();
2200  _M_deallocate_node(*begin()._M_node); // one node left after clear()
2201  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
2202  this->_M_impl._M_map = nullptr;
2203  this->_M_impl._M_map_size = 0;
2204  // Take ownership of replacement memory.
2205  this->_M_impl._M_swap_data(__newobj._M_impl);
2206  }
2207 
2208  // Do move assignment when the allocator propagates.
2209  void
2210  _M_move_assign2(deque&& __x, /* propagate: */ true_type)
2211  {
2212  // Make a copy of the original allocator state.
2213  auto __alloc = __x._M_get_Tp_allocator();
2214  // The allocator propagates so storage can be moved from __x,
2215  // leaving __x in a valid empty state with a moved-from allocator.
2216  _M_replace_map(std::move(__x));
2217  // Move the corresponding allocator state too.
2218  _M_get_Tp_allocator() = std::move(__alloc);
2219  }
2220 
2221  // Do move assignment when it may not be possible to move source
2222  // object's memory, resulting in a linear-time operation.
2223  void
2224  _M_move_assign2(deque&& __x, /* propagate: */ false_type)
2225  {
2226  if (__x._M_get_Tp_allocator() == this->_M_get_Tp_allocator())
2227  {
2228  // The allocators are equal so storage can be moved from __x,
2229  // leaving __x in a valid empty state with its current allocator.
2230  _M_replace_map(std::move(__x), __x.get_allocator());
2231  }
2232  else
2233  {
2234  // The rvalue's allocator cannot be moved and is not equal,
2235  // so we need to individually move each element.
2236  _M_assign_aux(std::__make_move_if_noexcept_iterator(__x.begin()),
2237  std::__make_move_if_noexcept_iterator(__x.end()),
2238  std::random_access_iterator_tag());
2239  __x.clear();
2240  }
2241  }
2242 #endif
2243  };
2244 
2245 
2246  /**
2247  * @brief Deque equality comparison.
2248  * @param __x A %deque.
2249  * @param __y A %deque of the same type as @a __x.
2250  * @return True iff the size and elements of the deques are equal.
2251  *
2252  * This is an equivalence relation. It is linear in the size of the
2253  * deques. Deques are considered equivalent if their sizes are equal,
2254  * and if corresponding elements compare equal.
2255  */
2256  template<typename _Tp, typename _Alloc>
2257  inline bool
2258  operator==(const deque<_Tp, _Alloc>& __x,
2259  const deque<_Tp, _Alloc>& __y)
2260  { return __x.size() == __y.size()
2261  && std::equal(__x.begin(), __x.end(), __y.begin()); }
2262 
2263  /**
2264  * @brief Deque ordering relation.
2265  * @param __x A %deque.
2266  * @param __y A %deque of the same type as @a __x.
2267  * @return True iff @a x is lexicographically less than @a __y.
2268  *
2269  * This is a total ordering relation. It is linear in the size of the
2270  * deques. The elements must be comparable with @c <.
2271  *
2272  * See std::lexicographical_compare() for how the determination is made.
2273  */
2274  template<typename _Tp, typename _Alloc>
2275  inline bool
2276  operator<(const deque<_Tp, _Alloc>& __x,
2277  const deque<_Tp, _Alloc>& __y)
2278  { return std::lexicographical_compare(__x.begin(), __x.end(),
2279  __y.begin(), __y.end()); }
2280 
2281  /// Based on operator==
2282  template<typename _Tp, typename _Alloc>
2283  inline bool
2284  operator!=(const deque<_Tp, _Alloc>& __x,
2285  const deque<_Tp, _Alloc>& __y)
2286  { return !(__x == __y); }
2287 
2288  /// Based on operator<
2289  template<typename _Tp, typename _Alloc>
2290  inline bool
2291  operator>(const deque<_Tp, _Alloc>& __x,
2292  const deque<_Tp, _Alloc>& __y)
2293  { return __y < __x; }
2294 
2295  /// Based on operator<
2296  template<typename _Tp, typename _Alloc>
2297  inline bool
2298  operator<=(const deque<_Tp, _Alloc>& __x,
2299  const deque<_Tp, _Alloc>& __y)
2300  { return !(__y < __x); }
2301 
2302  /// Based on operator<
2303  template<typename _Tp, typename _Alloc>
2304  inline bool
2305  operator>=(const deque<_Tp, _Alloc>& __x,
2306  const deque<_Tp, _Alloc>& __y)
2307  { return !(__x < __y); }
2308 
2309  /// See std::deque::swap().
2310  template<typename _Tp, typename _Alloc>
2311  inline void
2312  swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y)
2313  _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
2314  { __x.swap(__y); }
2315 
2316 #undef _GLIBCXX_DEQUE_BUF_SIZE
2317 
2318 _GLIBCXX_END_NAMESPACE_CONTAINER
2319 } // namespace std
2320 
2321 #endif /* _STL_DEQUE_H */
std::deque
A standard container using fixed-size memory allocation and constant-time manipulation of elements at...
Definition: stl_deque.h:831
__gnu_cxx::__alloc_traits
Uniform interface to C++98 and C++11 allocators.
Definition: ext/alloc_traits.h:50
std::deque::_M_reserve_map_at_front
void _M_reserve_map_at_front(size_type __nodes_to_add=1)
Memory-handling helpers for the major map.
Definition: stl_deque.h:2157
std::deque::get_allocator
allocator_type get_allocator() const noexcept
Get a copy of the memory allocation object.
Definition: stl_deque.h:1157
std::deque::resize
void resize(size_type __new_size)
Resizes the deque to the specified number of elements.
Definition: stl_deque.h:1290
std::_Deque_iterator
A deque::iterator.
Definition: stl_deque.h:108
std::__iterator_category
iterator_traits< _Iter >::iterator_category __iterator_category(const _Iter &)
Definition: stl_iterator_base_types.h:204
std::allocator
The standard allocator, as per [20.4].
Definition: allocator.h:108
std::deque::deque
deque(size_type __n, const allocator_type &__a=allocator_type())
Creates a deque with default constructed elements.
Definition: stl_deque.h:908
std::deque::end
iterator end() noexcept
Definition: stl_deque.h:1183
std::deque::_M_reserve_map_at_back
void _M_reserve_map_at_back(size_type __nodes_to_add=1)
Memory-handling helpers for the major map.
Definition: stl_deque.h:2149
_GLIBCXX_DEQUE_BUF_SIZE
#define _GLIBCXX_DEQUE_BUF_SIZE
This function controls the size of memory nodes.
Definition: stl_deque.h:87
std::deque::insert
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:1699
std::deque::back
reference back() noexcept
Definition: stl_deque.h:1473
std::end
constexpr const _Tp * end(initializer_list< _Tp > __ils) noexcept
Return an iterator pointing to one past the last element of the initializer_list. ...
Definition: initializer_list:99
std::deque::rend
reverse_iterator rend() noexcept
Definition: stl_deque.h:1219
std::integral_constant
integral_constant
Definition: type_traits:69
std::_Deque_base::_M_initialize_map
void _M_initialize_map(size_t)
Layout storage.
Definition: stl_deque.h:682
std::deque::assign
void assign(_InputIterator __first, _InputIterator __last)
Assigns a range to a deque.
Definition: stl_deque.h:1126
std::deque::_M_range_check
void _M_range_check(size_type __n) const
Safety check used only from at().
Definition: stl_deque.h:1400
std::initializer_list
initializer_list
Definition: initializer_list:47
std::deque::rbegin
reverse_iterator rbegin() noexcept
Definition: stl_deque.h:1201
std::begin
constexpr const _Tp * begin(initializer_list< _Tp > __ils) noexcept
Return an iterator pointing to the first element of the initializer_list.
Definition: initializer_list:89
std::deque::push_back
void push_back(const value_type &__x)
Add data to the end of the deque.
Definition: stl_deque.h:1542
std::deque::push_front
void push_front(const value_type &__x)
Add data to the front of the deque.
Definition: stl_deque.h:1505
std
ISO C++ entities toplevel namespace is std.
std::deque::deque
deque(_InputIterator __first, _InputIterator __last, const allocator_type &__a=allocator_type())
Builds a deque from a range.
Definition: stl_deque.h:1023
std::deque::_M_reserve_elements_at_front
iterator _M_reserve_elements_at_front(size_type __n)
Memory-handling helpers for the previous internal insert functions.
Definition: stl_deque.h:2113
std::deque::size
size_type size() const noexcept
Definition: stl_deque.h:1271
std::distance
_GLIBCXX17_CONSTEXPR iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:138
std::deque::operator=
deque & operator=(initializer_list< value_type > __l)
Assigns an initializer list to a deque.
Definition: stl_deque.h:1088
std::deque::_M_reserve_elements_at_back
iterator _M_reserve_elements_at_back(size_type __n)
Memory-handling helpers for the previous internal insert functions.
Definition: stl_deque.h:2123
std::allocator_traits< _Tp_alloc_type >::is_always_equal
__detected_or_t< typename is_empty< _Tp_alloc_type >::type, __equal, _Tp_alloc_type > is_always_equal
Whether all instances of the allocator type compare equal.
Definition: bits/alloc_traits.h:203
std::lexicographical_compare
bool lexicographical_compare(_II1 __first1, _II1 __last1, _II2 __first2, _II2 __last2, _Compare __comp)
Performs dictionary comparison on ranges.
Definition: stl_algobase.h:1239
std::deque::cend
const_iterator cend() const noexcept
Definition: stl_deque.h:1246
std::deque::deque
deque(deque &&__x, const allocator_type &__a)
Move constructor with alternative allocator.
Definition: stl_deque.h:973
std::deque::crend
const_reverse_iterator crend() const noexcept
Definition: stl_deque.h:1264
std::deque::crbegin
const_reverse_iterator crbegin() const noexcept
Definition: stl_deque.h:1255
std::deque::front
reference front() noexcept
Definition: stl_deque.h:1451
std::_Deque_iterator::_M_set_node
void _M_set_node(_Map_pointer __new_node) noexcept
Definition: stl_deque.h:254
std::max
_GLIBCXX14_CONSTEXPR const _Tp & max(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:219
std::deque::deque
deque(deque &&__x)
Deque move constructor.
Definition: stl_deque.h:962
std::deque::resize
void resize(size_type __new_size, const value_type &__x)
Resizes the deque to the specified number of elements.
Definition: stl_deque.h:1312
std::deque::erase
iterator erase(const_iterator __position)
Remove element at given position.
Definition: stl_deque.h:1780
std::deque::clear
void clear() noexcept
Definition: stl_deque.h:1840
std::deque::pop_front
void pop_front() noexcept
Removes first element.
Definition: stl_deque.h:1578
std::deque::front
const_reference front() const noexcept
Definition: stl_deque.h:1462
std::input_iterator_tag
Marking input iterators.
Definition: stl_iterator_base_types.h:89
std::deque::assign
void assign(initializer_list< value_type > __l)
Assigns an initializer list to a deque.
Definition: stl_deque.h:1151
std::deque::operator=
deque & operator=(deque &&__x) noexcept(_Alloc_traits::_S_always_equal())
Deque move assignment operator.
Definition: stl_deque.h:1069
std::deque::operator[]
reference operator[](size_type __n) noexcept
Subscript access to the data contained in the deque.
Definition: stl_deque.h:1373
std::deque::shrink_to_fit
void shrink_to_fit() noexcept
Definition: stl_deque.h:1348
std::deque::at
const_reference at(size_type __n) const
Provides access to the data contained in the deque.
Definition: stl_deque.h:1440
std::deque::erase
iterator erase(const_iterator __first, const_iterator __last)
Remove a range of elements.
Definition: stl_deque.h:1804
std::advance
_GLIBCXX17_CONSTEXPR void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:197
std::deque::deque
deque()
Creates a deque with no elements.
Definition: stl_deque.h:888
std::forward_iterator_tag
Forward iterators support a superset of input iterator operations.
Definition: stl_iterator_base_types.h:95
std::deque::cbegin
const_iterator cbegin() const noexcept
Definition: stl_deque.h:1237
std::deque::deque
deque(const deque &__x, const allocator_type &__a)
Copy constructor with alternative allocator.
Definition: stl_deque.h:966
std::deque::operator[]
const_reference operator[](size_type __n) const noexcept
Subscript access to the data contained in the deque.
Definition: stl_deque.h:1391
std::deque::insert
iterator insert(const_iterator __p, initializer_list< value_type > __l)
Inserts an initializer list into the deque.
Definition: stl_deque.h:1678
std::deque::empty
bool empty() const noexcept
Definition: stl_deque.h:1357
std::pointer_traits
Uniform interface to all pointer-like types.
Definition: ptr_traits.h:78
std::deque::begin
iterator begin() noexcept
Definition: stl_deque.h:1166
std::deque::at
reference at(size_type __n)
Provides access to the data contained in the deque.
Definition: stl_deque.h:1422
std::deque::deque
deque(const allocator_type &__a)
Creates a deque with no elements.
Definition: stl_deque.h:895
std::deque::deque
deque(const deque &__x)
Deque copy constructor.
Definition: stl_deque.h:947
std::deque::insert
iterator insert(const_iterator __position, value_type &&__x)
Inserts given rvalue into deque before specified iterator.
Definition: stl_deque.h:1665
std::deque::deque
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:920
std::deque::assign
void assign(size_type __n, const value_type &__val)
Assigns a given value to a deque.
Definition: stl_deque.h:1107
std::deque::pop_back
void pop_back() noexcept
Removes last element.
Definition: stl_deque.h:1601
std::deque::end
const_iterator end() const noexcept
Definition: stl_deque.h:1192
std::deque::back
const_reference back() const noexcept
Definition: stl_deque.h:1486
std::deque::deque
deque(initializer_list< value_type > __l, const allocator_type &__a=allocator_type())
Builds a deque from an initializer list.
Definition: stl_deque.h:996
std::deque::rend
const_reverse_iterator rend() const noexcept
Definition: stl_deque.h:1228
std::deque::begin
const_iterator begin() const noexcept
Definition: stl_deque.h:1174
std::random_access_iterator_tag
Random-access iterators support a superset of bidirectional iterator operations.
Definition: stl_iterator_base_types.h:103
std::cbegin
constexpr auto cbegin(const _Container &__cont) noexcept(noexcept(std::begin(__cont))) -> decltype(std::begin(__cont))
Return an iterator pointing to the first element of the const container.
Definition: range_access.h:116
std::deque::max_size
size_type max_size() const noexcept
Definition: stl_deque.h:1276
std::deque::rbegin
const_reverse_iterator rbegin() const noexcept
Definition: stl_deque.h:1210
std::deque::insert
iterator insert(const_iterator __position, _InputIterator __first, _InputIterator __last)
Inserts a range into the deque.
Definition: stl_deque.h:1735
std::equal
bool equal(_IIter1 __first1, _IIter1 __last1, _IIter2 __first2, _IIter2 __last2, _BinaryPredicate __binary_pred)
Tests a range for element-wise equality.
Definition: stl_algobase.h:1155
std::deque::swap
void swap(deque &__x) noexcept
Swaps data with another deque.
Definition: stl_deque.h:1822