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>
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 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>
106  struct _Deque_iterator
107  {
108 #if __cplusplus < 201103L
109  typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator;
110  typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
111  typedef _Tp* _Elt_pointer;
112  typedef _Tp** _Map_pointer;
113 #else
114  private:
115  template<typename _Up>
116  using __ptr_to = typename pointer_traits<_Ptr>::template rebind<_Up>;
117  template<typename _CvTp>
118  using __iter = _Deque_iterator<_Tp, _CvTp&, __ptr_to<_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 
129  typedef std::random_access_iterator_tag iterator_category;
130  typedef _Tp value_type;
131  typedef _Ptr pointer;
132  typedef _Ref reference;
133  typedef size_t size_type;
134  typedef ptrdiff_t difference_type;
135  typedef _Deque_iterator _Self;
136 
137  _Elt_pointer _M_cur;
138  _Elt_pointer _M_first;
139  _Elt_pointer _M_last;
140  _Map_pointer _M_node;
141 
142  _Deque_iterator(_Elt_pointer __x, _Map_pointer __y) _GLIBCXX_NOEXCEPT
143  : _M_cur(__x), _M_first(*__y),
144  _M_last(*__y + _S_buffer_size()), _M_node(__y) { }
145 
146  _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>
458  class _Deque_base
459  {
460  protected:
461  typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
462  rebind<_Tp>::other _Tp_alloc_type;
463  typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Alloc_traits;
464 
465 #if __cplusplus < 201103L
466  typedef _Tp* _Ptr;
467  typedef const _Tp* _Ptr_const;
468 #else
469  typedef typename _Alloc_traits::pointer _Ptr;
470  typedef typename _Alloc_traits::const_pointer _Ptr_const;
471 #endif
472 
473  typedef typename _Alloc_traits::template rebind<_Ptr>::other
474  _Map_alloc_type;
475  typedef __gnu_cxx::__alloc_traits<_Map_alloc_type> _Map_alloc_traits;
476 
477  public:
478  typedef _Alloc allocator_type;
479  typedef typename _Alloc_traits::size_type size_type;
480 
481  allocator_type
482  get_allocator() const _GLIBCXX_NOEXCEPT
483  { return allocator_type(_M_get_Tp_allocator()); }
484 
485  typedef _Deque_iterator<_Tp, _Tp&, _Ptr> iterator;
486  typedef _Deque_iterator<_Tp, const _Tp&, _Ptr_const> const_iterator;
487 
488  _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  {
512  _M_initialize_map(0);
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  {
529  _M_initialize_map(0);
530  this->_M_impl._M_swap_data(__x._M_impl);
531  }
532  }
533  else
534  {
535  _M_initialize_map(__n);
536  }
537  }
538 #endif
539 
540  ~_Deque_base() _GLIBCXX_NOEXCEPT;
541 
542  protected:
543  typedef typename iterator::_Map_pointer _Map_pointer;
544 
545  //This struct encapsulates the implementation of the std::deque
546  //standard container and at the same time makes use of the EBO
547  //for empty allocators.
548  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  {
600  typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
601  return _Traits::allocate(_M_impl, __deque_buf_size(sizeof(_Tp)));
602  }
603 
604  void
605  _M_deallocate_node(_Ptr __p) _GLIBCXX_NOEXCEPT
606  {
607  typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
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  __empty._M_initialize_map(0);
649  // Now safe to modify current allocator and perform non-throwing swaps.
650  _Deque_impl __ret{std::move(_M_get_Tp_allocator())};
651  _M_impl._M_swap_data(__ret);
652  _M_impl._M_swap_data(__empty._M_impl);
653  return __ret;
654  }
655 #endif
656  };
657 
658  template<typename _Tp, typename _Alloc>
659  _Deque_base<_Tp, _Alloc>::
660  ~_Deque_base() _GLIBCXX_NOEXCEPT
661  {
662  if (this->_M_impl._M_map)
663  {
664  _M_destroy_nodes(this->_M_impl._M_start._M_node,
665  this->_M_impl._M_finish._M_node + 1);
666  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
667  }
668  }
669 
670  /**
671  * @brief Layout storage.
672  * @param __num_elements The count of T's for which to allocate space
673  * at first.
674  * @return Nothing.
675  *
676  * The initial underlying memory layout is a bit complicated...
677  */
678  template<typename _Tp, typename _Alloc>
679  void
680  _Deque_base<_Tp, _Alloc>::
681  _M_initialize_map(size_t __num_elements)
682  {
683  const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
684  + 1);
685 
686  this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
687  size_t(__num_nodes + 2));
688  this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
689 
690  // For "small" maps (needing less than _M_map_size nodes), allocation
691  // starts in the middle elements and grows outwards. So nstart may be
692  // the beginning of _M_map, but for small maps it may be as far in as
693  // _M_map+3.
694 
695  _Map_pointer __nstart = (this->_M_impl._M_map
696  + (this->_M_impl._M_map_size - __num_nodes) / 2);
697  _Map_pointer __nfinish = __nstart + __num_nodes;
698 
699  __try
700  { _M_create_nodes(__nstart, __nfinish); }
701  __catch(...)
702  {
703  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
704  this->_M_impl._M_map = _Map_pointer();
705  this->_M_impl._M_map_size = 0;
706  __throw_exception_again;
707  }
708 
709  this->_M_impl._M_start._M_set_node(__nstart);
710  this->_M_impl._M_finish._M_set_node(__nfinish - 1);
711  this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
712  this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
713  + __num_elements
714  % __deque_buf_size(sizeof(_Tp)));
715  }
716 
717  template<typename _Tp, typename _Alloc>
718  void
719  _Deque_base<_Tp, _Alloc>::
720  _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish)
721  {
722  _Map_pointer __cur;
723  __try
724  {
725  for (__cur = __nstart; __cur < __nfinish; ++__cur)
726  *__cur = this->_M_allocate_node();
727  }
728  __catch(...)
729  {
730  _M_destroy_nodes(__nstart, __cur);
731  __throw_exception_again;
732  }
733  }
734 
735  template<typename _Tp, typename _Alloc>
736  void
737  _Deque_base<_Tp, _Alloc>::
738  _M_destroy_nodes(_Map_pointer __nstart,
739  _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT
740  {
741  for (_Map_pointer __n = __nstart; __n < __nfinish; ++__n)
742  _M_deallocate_node(*__n);
743  }
744 
745  /**
746  * @brief A standard container using fixed-size memory allocation and
747  * constant-time manipulation of elements at either end.
748  *
749  * @ingroup sequences
750  *
751  * @tparam _Tp Type of element.
752  * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
753  *
754  * Meets the requirements of a <a href="tables.html#65">container</a>, a
755  * <a href="tables.html#66">reversible container</a>, and a
756  * <a href="tables.html#67">sequence</a>, including the
757  * <a href="tables.html#68">optional sequence requirements</a>.
758  *
759  * In previous HP/SGI versions of deque, there was an extra template
760  * parameter so users could control the node size. This extension turned
761  * out to violate the C++ standard (it can be detected using template
762  * template parameters), and it was removed.
763  *
764  * Here's how a deque<Tp> manages memory. Each deque has 4 members:
765  *
766  * - Tp** _M_map
767  * - size_t _M_map_size
768  * - iterator _M_start, _M_finish
769  *
770  * map_size is at least 8. %map is an array of map_size
771  * pointers-to-@a nodes. (The name %map has nothing to do with the
772  * std::map class, and @b nodes should not be confused with
773  * std::list's usage of @a node.)
774  *
775  * A @a node has no specific type name as such, but it is referred
776  * to as @a node in this file. It is a simple array-of-Tp. If Tp
777  * is very large, there will be one Tp element per node (i.e., an
778  * @a array of one). For non-huge Tp's, node size is inversely
779  * related to Tp size: the larger the Tp, the fewer Tp's will fit
780  * in a node. The goal here is to keep the total size of a node
781  * relatively small and constant over different Tp's, to improve
782  * allocator efficiency.
783  *
784  * Not every pointer in the %map array will point to a node. If
785  * the initial number of elements in the deque is small, the
786  * /middle/ %map pointers will be valid, and the ones at the edges
787  * will be unused. This same situation will arise as the %map
788  * grows: available %map pointers, if any, will be on the ends. As
789  * new nodes are created, only a subset of the %map's pointers need
790  * to be copied @a outward.
791  *
792  * Class invariants:
793  * - For any nonsingular iterator i:
794  * - i.node points to a member of the %map array. (Yes, you read that
795  * correctly: i.node does not actually point to a node.) The member of
796  * the %map array is what actually points to the node.
797  * - i.first == *(i.node) (This points to the node (first Tp element).)
798  * - i.last == i.first + node_size
799  * - i.cur is a pointer in the range [i.first, i.last). NOTE:
800  * the implication of this is that i.cur is always a dereferenceable
801  * pointer, even if i is a past-the-end iterator.
802  * - Start and Finish are always nonsingular iterators. NOTE: this
803  * means that an empty deque must have one node, a deque with <N
804  * elements (where N is the node buffer size) must have one node, a
805  * deque with N through (2N-1) elements must have two nodes, etc.
806  * - For every node other than start.node and finish.node, every
807  * element in the node is an initialized object. If start.node ==
808  * finish.node, then [start.cur, finish.cur) are initialized
809  * objects, and the elements outside that range are uninitialized
810  * storage. Otherwise, [start.cur, start.last) and [finish.first,
811  * finish.cur) are initialized objects, and [start.first, start.cur)
812  * and [finish.cur, finish.last) are uninitialized storage.
813  * - [%map, %map + map_size) is a valid, non-empty range.
814  * - [start.node, finish.node] is a valid range contained within
815  * [%map, %map + map_size).
816  * - A pointer in the range [%map, %map + map_size) points to an allocated
817  * node if and only if the pointer is in the range
818  * [start.node, finish.node].
819  *
820  * Here's the magic: nothing in deque is @b aware of the discontiguous
821  * storage!
822  *
823  * The memory setup and layout occurs in the parent, _Base, and the iterator
824  * class is entirely responsible for @a leaping from one node to the next.
825  * All the implementation routines for deque itself work only through the
826  * start and finish iterators. This keeps the routines simple and sane,
827  * and we can use other standard algorithms as well.
828  */
829  template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
830  class deque : protected _Deque_base<_Tp, _Alloc>
831  {
832  // concept requirements
833  typedef typename _Alloc::value_type _Alloc_value_type;
834  __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
835  __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
836 
837  typedef _Deque_base<_Tp, _Alloc> _Base;
838  typedef typename _Base::_Tp_alloc_type _Tp_alloc_type;
839  typedef typename _Base::_Alloc_traits _Alloc_traits;
840  typedef typename _Base::_Map_pointer _Map_pointer;
841 
842  public:
843  typedef _Tp value_type;
844  typedef typename _Alloc_traits::pointer pointer;
845  typedef typename _Alloc_traits::const_pointer const_pointer;
846  typedef typename _Alloc_traits::reference reference;
847  typedef typename _Alloc_traits::const_reference const_reference;
848  typedef typename _Base::iterator iterator;
849  typedef typename _Base::const_iterator const_iterator;
850  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
851  typedef std::reverse_iterator<iterator> reverse_iterator;
852  typedef size_t size_type;
853  typedef ptrdiff_t difference_type;
854  typedef _Alloc allocator_type;
855 
856  protected:
857  static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
858  { return __deque_buf_size(sizeof(_Tp)); }
859 
860  // Functions controlling memory layout, and nothing else.
861  using _Base::_M_initialize_map;
862  using _Base::_M_create_nodes;
863  using _Base::_M_destroy_nodes;
864  using _Base::_M_allocate_node;
865  using _Base::_M_deallocate_node;
866  using _Base::_M_allocate_map;
867  using _Base::_M_deallocate_map;
868  using _Base::_M_get_Tp_allocator;
869 
870  /**
871  * A total of four data members accumulated down the hierarchy.
872  * May be accessed via _M_impl.*
873  */
874  using _Base::_M_impl;
875 
876  public:
877  // [23.2.1.1] construct/copy/destroy
878  // (assign() and get_allocator() are also listed in this section)
879 
880  /**
881  * @brief Creates a %deque with no elements.
882  */
883  deque() : _Base() { }
884 
885  /**
886  * @brief Creates a %deque with no elements.
887  * @param __a An allocator object.
888  */
889  explicit
890  deque(const allocator_type& __a)
891  : _Base(__a, 0) { }
892 
893 #if __cplusplus >= 201103L
894  /**
895  * @brief Creates a %deque with default constructed elements.
896  * @param __n The number of elements to initially create.
897  *
898  * This constructor fills the %deque with @a n default
899  * constructed elements.
900  */
901  explicit
902  deque(size_type __n, const allocator_type& __a = allocator_type())
903  : _Base(__a, __n)
904  { _M_default_initialize(); }
905 
906  /**
907  * @brief Creates a %deque with copies of an exemplar element.
908  * @param __n The number of elements to initially create.
909  * @param __value An element to copy.
910  * @param __a An allocator.
911  *
912  * This constructor fills the %deque with @a __n copies of @a __value.
913  */
914  deque(size_type __n, const value_type& __value,
915  const allocator_type& __a = allocator_type())
916  : _Base(__a, __n)
917  { _M_fill_initialize(__value); }
918 #else
919  /**
920  * @brief Creates a %deque with copies of an exemplar element.
921  * @param __n The number of elements to initially create.
922  * @param __value An element to copy.
923  * @param __a An allocator.
924  *
925  * This constructor fills the %deque with @a __n copies of @a __value.
926  */
927  explicit
928  deque(size_type __n, const value_type& __value = value_type(),
929  const allocator_type& __a = allocator_type())
930  : _Base(__a, __n)
931  { _M_fill_initialize(__value); }
932 #endif
933 
934  /**
935  * @brief %Deque copy constructor.
936  * @param __x A %deque of identical element and allocator types.
937  *
938  * The newly-created %deque uses a copy of the allocation object used
939  * by @a __x.
940  */
941  deque(const deque& __x)
942  : _Base(_Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()),
943  __x.size())
944  { std::__uninitialized_copy_a(__x.begin(), __x.end(),
945  this->_M_impl._M_start,
946  _M_get_Tp_allocator()); }
947 
948 #if __cplusplus >= 201103L
949  /**
950  * @brief %Deque move constructor.
951  * @param __x A %deque of identical element and allocator types.
952  *
953  * The newly-created %deque contains the exact contents of @a __x.
954  * The contents of @a __x are a valid, but unspecified %deque.
955  */
956  deque(deque&& __x)
957  : _Base(std::move(__x)) { }
958 
959  /// Copy constructor with alternative allocator
960  deque(const deque& __x, const allocator_type& __a)
961  : _Base(__a, __x.size())
962  { std::__uninitialized_copy_a(__x.begin(), __x.end(),
963  this->_M_impl._M_start,
964  _M_get_Tp_allocator()); }
965 
966  /// Move constructor with alternative allocator
967  deque(deque&& __x, const allocator_type& __a)
968  : _Base(std::move(__x), __a, __x.size())
969  {
970  if (__x.get_allocator() != __a)
971  {
972  std::__uninitialized_move_a(__x.begin(), __x.end(),
973  this->_M_impl._M_start,
974  _M_get_Tp_allocator());
975  __x.clear();
976  }
977  }
978 
979  /**
980  * @brief Builds a %deque from an initializer list.
981  * @param __l An initializer_list.
982  * @param __a An allocator object.
983  *
984  * Create a %deque consisting of copies of the elements in the
985  * initializer_list @a __l.
986  *
987  * This will call the element type's copy constructor N times
988  * (where N is __l.size()) and do no memory reallocation.
989  */
990  deque(initializer_list<value_type> __l,
991  const allocator_type& __a = allocator_type())
992  : _Base(__a)
993  {
994  _M_range_initialize(__l.begin(), __l.end(),
995  random_access_iterator_tag());
996  }
997 #endif
998 
999  /**
1000  * @brief Builds a %deque from a range.
1001  * @param __first An input iterator.
1002  * @param __last An input iterator.
1003  * @param __a An allocator object.
1004  *
1005  * Create a %deque consisting of copies of the elements from [__first,
1006  * __last).
1007  *
1008  * If the iterators are forward, bidirectional, or random-access, then
1009  * this will call the elements' copy constructor N times (where N is
1010  * distance(__first,__last)) and do no memory reallocation. But if only
1011  * input iterators are used, then this will do at most 2N calls to the
1012  * copy constructor, and logN memory reallocations.
1013  */
1014 #if __cplusplus >= 201103L
1015  template<typename _InputIterator,
1016  typename = std::_RequireInputIter<_InputIterator>>
1017  deque(_InputIterator __first, _InputIterator __last,
1018  const allocator_type& __a = allocator_type())
1019  : _Base(__a)
1020  { _M_initialize_dispatch(__first, __last, __false_type()); }
1021 #else
1022  template<typename _InputIterator>
1023  deque(_InputIterator __first, _InputIterator __last,
1024  const allocator_type& __a = allocator_type())
1025  : _Base(__a)
1026  {
1027  // Check whether it's an integral type. If so, it's not an iterator.
1028  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1029  _M_initialize_dispatch(__first, __last, _Integral());
1030  }
1031 #endif
1032 
1033  /**
1034  * The dtor only erases the elements, and note that if the elements
1035  * themselves are pointers, the pointed-to memory is not touched in any
1036  * way. Managing the pointer is the user's responsibility.
1037  */
1038  ~deque()
1039  { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); }
1040 
1041  /**
1042  * @brief %Deque assignment operator.
1043  * @param __x A %deque of identical element and allocator types.
1044  *
1045  * All the elements of @a x are copied, but unlike the copy constructor,
1046  * the allocator object is not copied.
1047  */
1048  deque&
1049  operator=(const deque& __x);
1050 
1051 #if __cplusplus >= 201103L
1052  /**
1053  * @brief %Deque move assignment operator.
1054  * @param __x A %deque of identical element and allocator types.
1055  *
1056  * The contents of @a __x are moved into this deque (without copying,
1057  * if the allocators permit it).
1058  * @a __x is a valid, but unspecified %deque.
1059  */
1060  deque&
1061  operator=(deque&& __x) noexcept(_Alloc_traits::_S_always_equal())
1062  {
1063  constexpr bool __always_equal = _Alloc_traits::_S_always_equal();
1064  _M_move_assign1(std::move(__x),
1065  integral_constant<bool, __always_equal>());
1066  return *this;
1067  }
1068 
1069  /**
1070  * @brief Assigns an initializer list to a %deque.
1071  * @param __l An initializer_list.
1072  *
1073  * This function fills a %deque with copies of the elements in the
1074  * initializer_list @a __l.
1075  *
1076  * Note that the assignment completely changes the %deque and that the
1077  * resulting %deque's size is the same as the number of elements
1078  * assigned. Old data may be lost.
1079  */
1080  deque&
1081  operator=(initializer_list<value_type> __l)
1082  {
1083  this->assign(__l.begin(), __l.end());
1084  return *this;
1085  }
1086 #endif
1087 
1088  /**
1089  * @brief Assigns a given value to a %deque.
1090  * @param __n Number of elements to be assigned.
1091  * @param __val Value to be assigned.
1092  *
1093  * This function fills a %deque with @a n copies of the given
1094  * value. Note that the assignment completely changes the
1095  * %deque and that the resulting %deque's size is the same as
1096  * the number of elements assigned. Old data may be lost.
1097  */
1098  void
1099  assign(size_type __n, const value_type& __val)
1100  { _M_fill_assign(__n, __val); }
1101 
1102  /**
1103  * @brief Assigns a range to a %deque.
1104  * @param __first An input iterator.
1105  * @param __last An input iterator.
1106  *
1107  * This function fills a %deque with copies of the elements in the
1108  * range [__first,__last).
1109  *
1110  * Note that the assignment completely changes the %deque and that the
1111  * resulting %deque's size is the same as the number of elements
1112  * assigned. Old data may be lost.
1113  */
1114 #if __cplusplus >= 201103L
1115  template<typename _InputIterator,
1116  typename = std::_RequireInputIter<_InputIterator>>
1117  void
1118  assign(_InputIterator __first, _InputIterator __last)
1119  { _M_assign_dispatch(__first, __last, __false_type()); }
1120 #else
1121  template<typename _InputIterator>
1122  void
1123  assign(_InputIterator __first, _InputIterator __last)
1124  {
1125  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1126  _M_assign_dispatch(__first, __last, _Integral());
1127  }
1128 #endif
1129 
1130 #if __cplusplus >= 201103L
1131  /**
1132  * @brief Assigns an initializer list to a %deque.
1133  * @param __l An initializer_list.
1134  *
1135  * This function fills a %deque with copies of the elements in the
1136  * initializer_list @a __l.
1137  *
1138  * Note that the assignment completely changes the %deque and that the
1139  * resulting %deque's size is the same as the number of elements
1140  * assigned. Old data may be lost.
1141  */
1142  void
1143  assign(initializer_list<value_type> __l)
1144  { this->assign(__l.begin(), __l.end()); }
1145 #endif
1146 
1147  /// Get a copy of the memory allocation object.
1148  allocator_type
1149  get_allocator() const _GLIBCXX_NOEXCEPT
1150  { return _Base::get_allocator(); }
1151 
1152  // iterators
1153  /**
1154  * Returns a read/write iterator that points to the first element in the
1155  * %deque. Iteration is done in ordinary element order.
1156  */
1157  iterator
1158  begin() _GLIBCXX_NOEXCEPT
1159  { return this->_M_impl._M_start; }
1160 
1161  /**
1162  * Returns a read-only (constant) iterator that points to the first
1163  * element in the %deque. Iteration is done in ordinary element order.
1164  */
1165  const_iterator
1166  begin() const _GLIBCXX_NOEXCEPT
1167  { return this->_M_impl._M_start; }
1168 
1169  /**
1170  * Returns a read/write iterator that points one past the last
1171  * element in the %deque. Iteration is done in ordinary
1172  * element order.
1173  */
1174  iterator
1175  end() _GLIBCXX_NOEXCEPT
1176  { return this->_M_impl._M_finish; }
1177 
1178  /**
1179  * Returns a read-only (constant) iterator that points one past
1180  * the last element in the %deque. Iteration is done in
1181  * ordinary element order.
1182  */
1183  const_iterator
1184  end() const _GLIBCXX_NOEXCEPT
1185  { return this->_M_impl._M_finish; }
1186 
1187  /**
1188  * Returns a read/write reverse iterator that points to the
1189  * last element in the %deque. Iteration is done in reverse
1190  * element order.
1191  */
1192  reverse_iterator
1193  rbegin() _GLIBCXX_NOEXCEPT
1194  { return reverse_iterator(this->_M_impl._M_finish); }
1195 
1196  /**
1197  * Returns a read-only (constant) reverse iterator that points
1198  * to the last element in the %deque. Iteration is done in
1199  * reverse element order.
1200  */
1201  const_reverse_iterator
1202  rbegin() const _GLIBCXX_NOEXCEPT
1203  { return const_reverse_iterator(this->_M_impl._M_finish); }
1204 
1205  /**
1206  * Returns a read/write reverse iterator that points to one
1207  * before the first element in the %deque. Iteration is done
1208  * in reverse element order.
1209  */
1210  reverse_iterator
1211  rend() _GLIBCXX_NOEXCEPT
1212  { return reverse_iterator(this->_M_impl._M_start); }
1213 
1214  /**
1215  * Returns a read-only (constant) reverse iterator that points
1216  * to one before the first element in the %deque. Iteration is
1217  * done in reverse element order.
1218  */
1219  const_reverse_iterator
1220  rend() const _GLIBCXX_NOEXCEPT
1221  { return const_reverse_iterator(this->_M_impl._M_start); }
1222 
1223 #if __cplusplus >= 201103L
1224  /**
1225  * Returns a read-only (constant) iterator that points to the first
1226  * element in the %deque. Iteration is done in ordinary element order.
1227  */
1228  const_iterator
1229  cbegin() const noexcept
1230  { return this->_M_impl._M_start; }
1231 
1232  /**
1233  * Returns a read-only (constant) iterator that points one past
1234  * the last element in the %deque. Iteration is done in
1235  * ordinary element order.
1236  */
1237  const_iterator
1238  cend() const noexcept
1239  { return this->_M_impl._M_finish; }
1240 
1241  /**
1242  * Returns a read-only (constant) reverse iterator that points
1243  * to the last element in the %deque. Iteration is done in
1244  * reverse element order.
1245  */
1246  const_reverse_iterator
1247  crbegin() const noexcept
1248  { return const_reverse_iterator(this->_M_impl._M_finish); }
1249 
1250  /**
1251  * Returns a read-only (constant) reverse iterator that points
1252  * to one before the first element in the %deque. Iteration is
1253  * done in reverse element order.
1254  */
1255  const_reverse_iterator
1256  crend() const noexcept
1257  { return const_reverse_iterator(this->_M_impl._M_start); }
1258 #endif
1259 
1260  // [23.2.1.2] capacity
1261  /** Returns the number of elements in the %deque. */
1262  size_type
1263  size() const _GLIBCXX_NOEXCEPT
1264  { return this->_M_impl._M_finish - this->_M_impl._M_start; }
1265 
1266  /** Returns the size() of the largest possible %deque. */
1267  size_type
1268  max_size() const _GLIBCXX_NOEXCEPT
1269  { return _Alloc_traits::max_size(_M_get_Tp_allocator()); }
1270 
1271 #if __cplusplus >= 201103L
1272  /**
1273  * @brief Resizes the %deque to the specified number of elements.
1274  * @param __new_size Number of elements the %deque should contain.
1275  *
1276  * This function will %resize the %deque to the specified
1277  * number of elements. If the number is smaller than the
1278  * %deque's current size the %deque is truncated, otherwise
1279  * default constructed elements are appended.
1280  */
1281  void
1282  resize(size_type __new_size)
1283  {
1284  const size_type __len = size();
1285  if (__new_size > __len)
1286  _M_default_append(__new_size - __len);
1287  else if (__new_size < __len)
1288  _M_erase_at_end(this->_M_impl._M_start
1289  + difference_type(__new_size));
1290  }
1291 
1292  /**
1293  * @brief Resizes the %deque to the specified number of elements.
1294  * @param __new_size Number of elements the %deque should contain.
1295  * @param __x Data with which new elements should be populated.
1296  *
1297  * This function will %resize the %deque to the specified
1298  * number of elements. If the number is smaller than the
1299  * %deque's current size the %deque is truncated, otherwise the
1300  * %deque is extended and new elements are populated with given
1301  * data.
1302  */
1303  void
1304  resize(size_type __new_size, const value_type& __x)
1305  {
1306  const size_type __len = size();
1307  if (__new_size > __len)
1308  insert(this->_M_impl._M_finish, __new_size - __len, __x);
1309  else if (__new_size < __len)
1310  _M_erase_at_end(this->_M_impl._M_start
1311  + difference_type(__new_size));
1312  }
1313 #else
1314  /**
1315  * @brief Resizes the %deque to the specified number of elements.
1316  * @param __new_size Number of elements the %deque should contain.
1317  * @param __x Data with which new elements should be populated.
1318  *
1319  * This function will %resize the %deque to the specified
1320  * number of elements. If the number is smaller than the
1321  * %deque's current size the %deque is truncated, otherwise the
1322  * %deque is extended and new elements are populated with given
1323  * data.
1324  */
1325  void
1326  resize(size_type __new_size, value_type __x = value_type())
1327  {
1328  const size_type __len = size();
1329  if (__new_size > __len)
1330  insert(this->_M_impl._M_finish, __new_size - __len, __x);
1331  else if (__new_size < __len)
1332  _M_erase_at_end(this->_M_impl._M_start
1333  + difference_type(__new_size));
1334  }
1335 #endif
1336 
1337 #if __cplusplus >= 201103L
1338  /** A non-binding request to reduce memory use. */
1339  void
1340  shrink_to_fit() noexcept
1341  { _M_shrink_to_fit(); }
1342 #endif
1343 
1344  /**
1345  * Returns true if the %deque is empty. (Thus begin() would
1346  * equal end().)
1347  */
1348  bool
1349  empty() const _GLIBCXX_NOEXCEPT
1350  { return this->_M_impl._M_finish == this->_M_impl._M_start; }
1351 
1352  // element access
1353  /**
1354  * @brief Subscript access to the data contained in the %deque.
1355  * @param __n The index of the element for which data should be
1356  * accessed.
1357  * @return Read/write reference to data.
1358  *
1359  * This operator allows for easy, array-style, data access.
1360  * Note that data access with this operator is unchecked and
1361  * out_of_range lookups are not defined. (For checked lookups
1362  * see at().)
1363  */
1364  reference
1365  operator[](size_type __n) _GLIBCXX_NOEXCEPT
1366  { return this->_M_impl._M_start[difference_type(__n)]; }
1367 
1368  /**
1369  * @brief Subscript access to the data contained in the %deque.
1370  * @param __n The index of the element for which data should be
1371  * accessed.
1372  * @return Read-only (constant) reference to data.
1373  *
1374  * This operator allows for easy, array-style, data access.
1375  * Note that data access with this operator is unchecked and
1376  * out_of_range lookups are not defined. (For checked lookups
1377  * see at().)
1378  */
1379  const_reference
1380  operator[](size_type __n) const _GLIBCXX_NOEXCEPT
1381  { return this->_M_impl._M_start[difference_type(__n)]; }
1382 
1383  protected:
1384  /// Safety check used only from at().
1385  void
1386  _M_range_check(size_type __n) const
1387  {
1388  if (__n >= this->size())
1389  __throw_out_of_range_fmt(__N("deque::_M_range_check: __n "
1390  "(which is %zu)>= this->size() "
1391  "(which is %zu)"),
1392  __n, this->size());
1393  }
1394 
1395  public:
1396  /**
1397  * @brief Provides access to the data contained in the %deque.
1398  * @param __n The index of the element for which data should be
1399  * accessed.
1400  * @return Read/write reference to data.
1401  * @throw std::out_of_range If @a __n is an invalid index.
1402  *
1403  * This function provides for safer data access. The parameter
1404  * is first checked that it is in the range of the deque. The
1405  * function throws out_of_range if the check fails.
1406  */
1407  reference
1408  at(size_type __n)
1409  {
1410  _M_range_check(__n);
1411  return (*this)[__n];
1412  }
1413 
1414  /**
1415  * @brief Provides access to the data contained in the %deque.
1416  * @param __n The index of the element for which data should be
1417  * accessed.
1418  * @return Read-only (constant) reference to data.
1419  * @throw std::out_of_range If @a __n is an invalid index.
1420  *
1421  * This function provides for safer data access. The parameter is first
1422  * checked that it is in the range of the deque. The function throws
1423  * out_of_range if the check fails.
1424  */
1425  const_reference
1426  at(size_type __n) const
1427  {
1428  _M_range_check(__n);
1429  return (*this)[__n];
1430  }
1431 
1432  /**
1433  * Returns a read/write reference to the data at the first
1434  * element of the %deque.
1435  */
1436  reference
1437  front() _GLIBCXX_NOEXCEPT
1438  { return *begin(); }
1439 
1440  /**
1441  * Returns a read-only (constant) reference to the data at the first
1442  * element of the %deque.
1443  */
1444  const_reference
1445  front() const _GLIBCXX_NOEXCEPT
1446  { return *begin(); }
1447 
1448  /**
1449  * Returns a read/write reference to the data at the last element of the
1450  * %deque.
1451  */
1452  reference
1453  back() _GLIBCXX_NOEXCEPT
1454  {
1455  iterator __tmp = end();
1456  --__tmp;
1457  return *__tmp;
1458  }
1459 
1460  /**
1461  * Returns a read-only (constant) reference to the data at the last
1462  * element of the %deque.
1463  */
1464  const_reference
1465  back() const _GLIBCXX_NOEXCEPT
1466  {
1467  const_iterator __tmp = end();
1468  --__tmp;
1469  return *__tmp;
1470  }
1471 
1472  // [23.2.1.2] modifiers
1473  /**
1474  * @brief Add data to the front of the %deque.
1475  * @param __x Data to be added.
1476  *
1477  * This is a typical stack operation. The function creates an
1478  * element at the front of the %deque and assigns the given
1479  * data to it. Due to the nature of a %deque this operation
1480  * can be done in constant time.
1481  */
1482  void
1483  push_front(const value_type& __x)
1484  {
1485  if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
1486  {
1487  _Alloc_traits::construct(this->_M_impl,
1488  this->_M_impl._M_start._M_cur - 1,
1489  __x);
1490  --this->_M_impl._M_start._M_cur;
1491  }
1492  else
1493  _M_push_front_aux(__x);
1494  }
1495 
1496 #if __cplusplus >= 201103L
1497  void
1498  push_front(value_type&& __x)
1499  { emplace_front(std::move(__x)); }
1500 
1501  template<typename... _Args>
1502  void
1503  emplace_front(_Args&&... __args);
1504 #endif
1505 
1506  /**
1507  * @brief Add data to the end of the %deque.
1508  * @param __x Data to be added.
1509  *
1510  * This is a typical stack operation. The function creates an
1511  * element at the end of the %deque and assigns the given data
1512  * to it. Due to the nature of a %deque this operation can be
1513  * done in constant time.
1514  */
1515  void
1516  push_back(const value_type& __x)
1517  {
1518  if (this->_M_impl._M_finish._M_cur
1519  != this->_M_impl._M_finish._M_last - 1)
1520  {
1521  _Alloc_traits::construct(this->_M_impl,
1522  this->_M_impl._M_finish._M_cur, __x);
1523  ++this->_M_impl._M_finish._M_cur;
1524  }
1525  else
1526  _M_push_back_aux(__x);
1527  }
1528 
1529 #if __cplusplus >= 201103L
1530  void
1531  push_back(value_type&& __x)
1532  { emplace_back(std::move(__x)); }
1533 
1534  template<typename... _Args>
1535  void
1536  emplace_back(_Args&&... __args);
1537 #endif
1538 
1539  /**
1540  * @brief Removes first element.
1541  *
1542  * This is a typical stack operation. It shrinks the %deque by one.
1543  *
1544  * Note that no data is returned, and if the first element's data is
1545  * needed, it should be retrieved before pop_front() is called.
1546  */
1547  void
1548  pop_front() _GLIBCXX_NOEXCEPT
1549  {
1550  if (this->_M_impl._M_start._M_cur
1551  != this->_M_impl._M_start._M_last - 1)
1552  {
1553  _Alloc_traits::destroy(this->_M_impl,
1554  this->_M_impl._M_start._M_cur);
1555  ++this->_M_impl._M_start._M_cur;
1556  }
1557  else
1558  _M_pop_front_aux();
1559  }
1560 
1561  /**
1562  * @brief Removes last element.
1563  *
1564  * This is a typical stack operation. It shrinks the %deque by one.
1565  *
1566  * Note that no data is returned, and if the last element's data is
1567  * needed, it should be retrieved before pop_back() is called.
1568  */
1569  void
1570  pop_back() _GLIBCXX_NOEXCEPT
1571  {
1572  if (this->_M_impl._M_finish._M_cur
1573  != this->_M_impl._M_finish._M_first)
1574  {
1575  --this->_M_impl._M_finish._M_cur;
1576  _Alloc_traits::destroy(this->_M_impl,
1577  this->_M_impl._M_finish._M_cur);
1578  }
1579  else
1580  _M_pop_back_aux();
1581  }
1582 
1583 #if __cplusplus >= 201103L
1584  /**
1585  * @brief Inserts an object in %deque before specified iterator.
1586  * @param __position A const_iterator into the %deque.
1587  * @param __args Arguments.
1588  * @return An iterator that points to the inserted data.
1589  *
1590  * This function will insert an object of type T constructed
1591  * with T(std::forward<Args>(args)...) before the specified location.
1592  */
1593  template<typename... _Args>
1594  iterator
1595  emplace(const_iterator __position, _Args&&... __args);
1596 
1597  /**
1598  * @brief Inserts given value into %deque before specified iterator.
1599  * @param __position A const_iterator into the %deque.
1600  * @param __x Data to be inserted.
1601  * @return An iterator that points to the inserted data.
1602  *
1603  * This function will insert a copy of the given value before the
1604  * specified location.
1605  */
1606  iterator
1607  insert(const_iterator __position, const value_type& __x);
1608 #else
1609  /**
1610  * @brief Inserts given value into %deque before specified iterator.
1611  * @param __position An iterator into the %deque.
1612  * @param __x Data to be inserted.
1613  * @return An iterator that points to the inserted data.
1614  *
1615  * This function will insert a copy of the given value before the
1616  * specified location.
1617  */
1618  iterator
1619  insert(iterator __position, const value_type& __x);
1620 #endif
1621 
1622 #if __cplusplus >= 201103L
1623  /**
1624  * @brief Inserts given rvalue into %deque before specified iterator.
1625  * @param __position A const_iterator into the %deque.
1626  * @param __x Data to be inserted.
1627  * @return An iterator that points to the inserted data.
1628  *
1629  * This function will insert a copy of the given rvalue before the
1630  * specified location.
1631  */
1632  iterator
1633  insert(const_iterator __position, value_type&& __x)
1634  { return emplace(__position, std::move(__x)); }
1635 
1636  /**
1637  * @brief Inserts an initializer list into the %deque.
1638  * @param __p An iterator into the %deque.
1639  * @param __l An initializer_list.
1640  *
1641  * This function will insert copies of the data in the
1642  * initializer_list @a __l into the %deque before the location
1643  * specified by @a __p. This is known as <em>list insert</em>.
1644  */
1645  iterator
1646  insert(const_iterator __p, initializer_list<value_type> __l)
1647  { return this->insert(__p, __l.begin(), __l.end()); }
1648 #endif
1649 
1650 #if __cplusplus >= 201103L
1651  /**
1652  * @brief Inserts a number of copies of given data into the %deque.
1653  * @param __position A const_iterator into the %deque.
1654  * @param __n Number of elements to be inserted.
1655  * @param __x Data to be inserted.
1656  * @return An iterator that points to the inserted data.
1657  *
1658  * This function will insert a specified number of copies of the given
1659  * data before the location specified by @a __position.
1660  */
1661  iterator
1662  insert(const_iterator __position, size_type __n, const value_type& __x)
1663  {
1664  difference_type __offset = __position - cbegin();
1665  _M_fill_insert(__position._M_const_cast(), __n, __x);
1666  return begin() + __offset;
1667  }
1668 #else
1669  /**
1670  * @brief Inserts a number of copies of given data into the %deque.
1671  * @param __position An iterator into the %deque.
1672  * @param __n Number of elements to be inserted.
1673  * @param __x Data to be inserted.
1674  *
1675  * This function will insert a specified number of copies of the given
1676  * data before the location specified by @a __position.
1677  */
1678  void
1679  insert(iterator __position, size_type __n, const value_type& __x)
1680  { _M_fill_insert(__position, __n, __x); }
1681 #endif
1682 
1683 #if __cplusplus >= 201103L
1684  /**
1685  * @brief Inserts a range into the %deque.
1686  * @param __position A const_iterator into the %deque.
1687  * @param __first An input iterator.
1688  * @param __last An input iterator.
1689  * @return An iterator that points to the inserted data.
1690  *
1691  * This function will insert copies of the data in the range
1692  * [__first,__last) into the %deque before the location specified
1693  * by @a __position. This is known as <em>range insert</em>.
1694  */
1695  template<typename _InputIterator,
1696  typename = std::_RequireInputIter<_InputIterator>>
1697  iterator
1698  insert(const_iterator __position, _InputIterator __first,
1699  _InputIterator __last)
1700  {
1701  difference_type __offset = __position - cbegin();
1702  _M_insert_dispatch(__position._M_const_cast(),
1703  __first, __last, __false_type());
1704  return begin() + __offset;
1705  }
1706 #else
1707  /**
1708  * @brief Inserts a range into the %deque.
1709  * @param __position An iterator into the %deque.
1710  * @param __first An input iterator.
1711  * @param __last An input iterator.
1712  *
1713  * This function will insert copies of the data in the range
1714  * [__first,__last) into the %deque before the location specified
1715  * by @a __position. This is known as <em>range insert</em>.
1716  */
1717  template<typename _InputIterator>
1718  void
1719  insert(iterator __position, _InputIterator __first,
1720  _InputIterator __last)
1721  {
1722  // Check whether it's an integral type. If so, it's not an iterator.
1723  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1724  _M_insert_dispatch(__position, __first, __last, _Integral());
1725  }
1726 #endif
1727 
1728  /**
1729  * @brief Remove element at given position.
1730  * @param __position Iterator pointing to element to be erased.
1731  * @return An iterator pointing to the next element (or end()).
1732  *
1733  * This function will erase the element at the given position and thus
1734  * shorten the %deque by one.
1735  *
1736  * The user is cautioned that
1737  * this function only erases the element, and that if the element is
1738  * itself a pointer, the pointed-to memory is not touched in any way.
1739  * Managing the pointer is the user's responsibility.
1740  */
1741  iterator
1742 #if __cplusplus >= 201103L
1743  erase(const_iterator __position)
1744 #else
1745  erase(iterator __position)
1746 #endif
1747  { return _M_erase(__position._M_const_cast()); }
1748 
1749  /**
1750  * @brief Remove a range of elements.
1751  * @param __first Iterator pointing to the first element to be erased.
1752  * @param __last Iterator pointing to one past the last element to be
1753  * erased.
1754  * @return An iterator pointing to the element pointed to by @a last
1755  * prior to erasing (or end()).
1756  *
1757  * This function will erase the elements in the range
1758  * [__first,__last) and shorten the %deque accordingly.
1759  *
1760  * The user is cautioned that
1761  * this function only erases the elements, and that if the elements
1762  * themselves are pointers, the pointed-to memory is not touched in any
1763  * way. Managing the pointer is the user's responsibility.
1764  */
1765  iterator
1766 #if __cplusplus >= 201103L
1767  erase(const_iterator __first, const_iterator __last)
1768 #else
1769  erase(iterator __first, iterator __last)
1770 #endif
1771  { return _M_erase(__first._M_const_cast(), __last._M_const_cast()); }
1772 
1773  /**
1774  * @brief Swaps data with another %deque.
1775  * @param __x A %deque of the same element and allocator types.
1776  *
1777  * This exchanges the elements between two deques in constant time.
1778  * (Four pointers, so it should be quite fast.)
1779  * Note that the global std::swap() function is specialized such that
1780  * std::swap(d1,d2) will feed to this function.
1781  */
1782  void
1783  swap(deque& __x)
1784 #if __cplusplus >= 201103L
1785  noexcept(_Alloc_traits::_S_nothrow_swap())
1786 #endif
1787  {
1788  _M_impl._M_swap_data(__x._M_impl);
1789  _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(),
1790  __x._M_get_Tp_allocator());
1791  }
1792 
1793  /**
1794  * Erases all the elements. Note that this function only erases the
1795  * elements, and that if the elements themselves are pointers, the
1796  * pointed-to memory is not touched in any way. Managing the pointer is
1797  * the user's responsibility.
1798  */
1799  void
1800  clear() _GLIBCXX_NOEXCEPT
1801  { _M_erase_at_end(begin()); }
1802 
1803  protected:
1804  // Internal constructor functions follow.
1805 
1806  // called by the range constructor to implement [23.1.1]/9
1807 
1808  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1809  // 438. Ambiguity in the "do the right thing" clause
1810  template<typename _Integer>
1811  void
1812  _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
1813  {
1814  _M_initialize_map(static_cast<size_type>(__n));
1815  _M_fill_initialize(__x);
1816  }
1817 
1818  // called by the range constructor to implement [23.1.1]/9
1819  template<typename _InputIterator>
1820  void
1821  _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
1822  __false_type)
1823  {
1824  typedef typename std::iterator_traits<_InputIterator>::
1825  iterator_category _IterCategory;
1826  _M_range_initialize(__first, __last, _IterCategory());
1827  }
1828 
1829  // called by the second initialize_dispatch above
1830  //@{
1831  /**
1832  * @brief Fills the deque with whatever is in [first,last).
1833  * @param __first An input iterator.
1834  * @param __last An input iterator.
1835  * @return Nothing.
1836  *
1837  * If the iterators are actually forward iterators (or better), then the
1838  * memory layout can be done all at once. Else we move forward using
1839  * push_back on each value from the iterator.
1840  */
1841  template<typename _InputIterator>
1842  void
1843  _M_range_initialize(_InputIterator __first, _InputIterator __last,
1844  std::input_iterator_tag);
1845 
1846  // called by the second initialize_dispatch above
1847  template<typename _ForwardIterator>
1848  void
1849  _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
1850  std::forward_iterator_tag);
1851  //@}
1852 
1853  /**
1854  * @brief Fills the %deque with copies of value.
1855  * @param __value Initial value.
1856  * @return Nothing.
1857  * @pre _M_start and _M_finish have already been initialized,
1858  * but none of the %deque's elements have yet been constructed.
1859  *
1860  * This function is called only when the user provides an explicit size
1861  * (with or without an explicit exemplar value).
1862  */
1863  void
1864  _M_fill_initialize(const value_type& __value);
1865 
1866 #if __cplusplus >= 201103L
1867  // called by deque(n).
1868  void
1869  _M_default_initialize();
1870 #endif
1871 
1872  // Internal assign functions follow. The *_aux functions do the actual
1873  // assignment work for the range versions.
1874 
1875  // called by the range assign to implement [23.1.1]/9
1876 
1877  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1878  // 438. Ambiguity in the "do the right thing" clause
1879  template<typename _Integer>
1880  void
1881  _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
1882  { _M_fill_assign(__n, __val); }
1883 
1884  // called by the range assign to implement [23.1.1]/9
1885  template<typename _InputIterator>
1886  void
1887  _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
1888  __false_type)
1889  {
1890  typedef typename std::iterator_traits<_InputIterator>::
1891  iterator_category _IterCategory;
1892  _M_assign_aux(__first, __last, _IterCategory());
1893  }
1894 
1895  // called by the second assign_dispatch above
1896  template<typename _InputIterator>
1897  void
1898  _M_assign_aux(_InputIterator __first, _InputIterator __last,
1899  std::input_iterator_tag);
1900 
1901  // called by the second assign_dispatch above
1902  template<typename _ForwardIterator>
1903  void
1904  _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
1905  std::forward_iterator_tag)
1906  {
1907  const size_type __len = std::distance(__first, __last);
1908  if (__len > size())
1909  {
1910  _ForwardIterator __mid = __first;
1911  std::advance(__mid, size());
1912  std::copy(__first, __mid, begin());
1913  insert(end(), __mid, __last);
1914  }
1915  else
1916  _M_erase_at_end(std::copy(__first, __last, begin()));
1917  }
1918 
1919  // Called by assign(n,t), and the range assign when it turns out
1920  // to be the same thing.
1921  void
1922  _M_fill_assign(size_type __n, const value_type& __val)
1923  {
1924  if (__n > size())
1925  {
1926  std::fill(begin(), end(), __val);
1927  insert(end(), __n - size(), __val);
1928  }
1929  else
1930  {
1931  _M_erase_at_end(begin() + difference_type(__n));
1932  std::fill(begin(), end(), __val);
1933  }
1934  }
1935 
1936  //@{
1937  /// Helper functions for push_* and pop_*.
1938 #if __cplusplus < 201103L
1939  void _M_push_back_aux(const value_type&);
1940 
1941  void _M_push_front_aux(const value_type&);
1942 #else
1943  template<typename... _Args>
1944  void _M_push_back_aux(_Args&&... __args);
1945 
1946  template<typename... _Args>
1947  void _M_push_front_aux(_Args&&... __args);
1948 #endif
1949 
1950  void _M_pop_back_aux();
1951 
1952  void _M_pop_front_aux();
1953  //@}
1954 
1955  // Internal insert functions follow. The *_aux functions do the actual
1956  // insertion work when all shortcuts fail.
1957 
1958  // called by the range insert to implement [23.1.1]/9
1959 
1960  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1961  // 438. Ambiguity in the "do the right thing" clause
1962  template<typename _Integer>
1963  void
1964  _M_insert_dispatch(iterator __pos,
1965  _Integer __n, _Integer __x, __true_type)
1966  { _M_fill_insert(__pos, __n, __x); }
1967 
1968  // called by the range insert to implement [23.1.1]/9
1969  template<typename _InputIterator>
1970  void
1971  _M_insert_dispatch(iterator __pos,
1972  _InputIterator __first, _InputIterator __last,
1973  __false_type)
1974  {
1975  typedef typename std::iterator_traits<_InputIterator>::
1976  iterator_category _IterCategory;
1977  _M_range_insert_aux(__pos, __first, __last, _IterCategory());
1978  }
1979 
1980  // called by the second insert_dispatch above
1981  template<typename _InputIterator>
1982  void
1983  _M_range_insert_aux(iterator __pos, _InputIterator __first,
1984  _InputIterator __last, std::input_iterator_tag);
1985 
1986  // called by the second insert_dispatch above
1987  template<typename _ForwardIterator>
1988  void
1989  _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
1990  _ForwardIterator __last, std::forward_iterator_tag);
1991 
1992  // Called by insert(p,n,x), and the range insert when it turns out to be
1993  // the same thing. Can use fill functions in optimal situations,
1994  // otherwise passes off to insert_aux(p,n,x).
1995  void
1996  _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
1997 
1998  // called by insert(p,x)
1999 #if __cplusplus < 201103L
2000  iterator
2001  _M_insert_aux(iterator __pos, const value_type& __x);
2002 #else
2003  template<typename... _Args>
2004  iterator
2005  _M_insert_aux(iterator __pos, _Args&&... __args);
2006 #endif
2007 
2008  // called by insert(p,n,x) via fill_insert
2009  void
2010  _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
2011 
2012  // called by range_insert_aux for forward iterators
2013  template<typename _ForwardIterator>
2014  void
2015  _M_insert_aux(iterator __pos,
2016  _ForwardIterator __first, _ForwardIterator __last,
2017  size_type __n);
2018 
2019 
2020  // Internal erase functions follow.
2021 
2022  void
2023  _M_destroy_data_aux(iterator __first, iterator __last);
2024 
2025  // Called by ~deque().
2026  // NB: Doesn't deallocate the nodes.
2027  template<typename _Alloc1>
2028  void
2029  _M_destroy_data(iterator __first, iterator __last, const _Alloc1&)
2030  { _M_destroy_data_aux(__first, __last); }
2031 
2032  void
2033  _M_destroy_data(iterator __first, iterator __last,
2034  const std::allocator<_Tp>&)
2035  {
2036  if (!__has_trivial_destructor(value_type))
2037  _M_destroy_data_aux(__first, __last);
2038  }
2039 
2040  // Called by erase(q1, q2).
2041  void
2042  _M_erase_at_begin(iterator __pos)
2043  {
2044  _M_destroy_data(begin(), __pos, _M_get_Tp_allocator());
2045  _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node);
2046  this->_M_impl._M_start = __pos;
2047  }
2048 
2049  // Called by erase(q1, q2), resize(), clear(), _M_assign_aux,
2050  // _M_fill_assign, operator=.
2051  void
2052  _M_erase_at_end(iterator __pos)
2053  {
2054  _M_destroy_data(__pos, end(), _M_get_Tp_allocator());
2055  _M_destroy_nodes(__pos._M_node + 1,
2056  this->_M_impl._M_finish._M_node + 1);
2057  this->_M_impl._M_finish = __pos;
2058  }
2059 
2060  iterator
2061  _M_erase(iterator __pos);
2062 
2063  iterator
2064  _M_erase(iterator __first, iterator __last);
2065 
2066 #if __cplusplus >= 201103L
2067  // Called by resize(sz).
2068  void
2069  _M_default_append(size_type __n);
2070 
2071  bool
2072  _M_shrink_to_fit();
2073 #endif
2074 
2075  //@{
2076  /// Memory-handling helpers for the previous internal insert functions.
2077  iterator
2078  _M_reserve_elements_at_front(size_type __n)
2079  {
2080  const size_type __vacancies = this->_M_impl._M_start._M_cur
2081  - this->_M_impl._M_start._M_first;
2082  if (__n > __vacancies)
2083  _M_new_elements_at_front(__n - __vacancies);
2084  return this->_M_impl._M_start - difference_type(__n);
2085  }
2086 
2087  iterator
2088  _M_reserve_elements_at_back(size_type __n)
2089  {
2090  const size_type __vacancies = (this->_M_impl._M_finish._M_last
2091  - this->_M_impl._M_finish._M_cur) - 1;
2092  if (__n > __vacancies)
2093  _M_new_elements_at_back(__n - __vacancies);
2094  return this->_M_impl._M_finish + difference_type(__n);
2095  }
2096 
2097  void
2098  _M_new_elements_at_front(size_type __new_elements);
2099 
2100  void
2101  _M_new_elements_at_back(size_type __new_elements);
2102  //@}
2103 
2104 
2105  //@{
2106  /**
2107  * @brief Memory-handling helpers for the major %map.
2108  *
2109  * Makes sure the _M_map has space for new nodes. Does not
2110  * actually add the nodes. Can invalidate _M_map pointers.
2111  * (And consequently, %deque iterators.)
2112  */
2113  void
2114  _M_reserve_map_at_back(size_type __nodes_to_add = 1)
2115  {
2116  if (__nodes_to_add + 1 > this->_M_impl._M_map_size
2117  - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
2118  _M_reallocate_map(__nodes_to_add, false);
2119  }
2120 
2121  void
2122  _M_reserve_map_at_front(size_type __nodes_to_add = 1)
2123  {
2124  if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
2125  - this->_M_impl._M_map))
2126  _M_reallocate_map(__nodes_to_add, true);
2127  }
2128 
2129  void
2130  _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
2131  //@}
2132 
2133 #if __cplusplus >= 201103L
2134  // Constant-time, nothrow move assignment when source object's memory
2135  // can be moved because the allocators are equal.
2136  void
2137  _M_move_assign1(deque&& __x, /* always equal: */ true_type) noexcept
2138  {
2139  this->_M_impl._M_swap_data(__x._M_impl);
2140  __x.clear();
2141  std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator());
2142  }
2143 
2144  void
2145  _M_move_assign1(deque&& __x, /* always equal: */ false_type)
2146  {
2147  constexpr bool __move_storage =
2148  _Alloc_traits::_S_propagate_on_move_assign();
2149  _M_move_assign2(std::move(__x),
2150  integral_constant<bool, __move_storage>());
2151  }
2152 
2153  // Destroy all elements and deallocate all memory, then replace
2154  // with elements created from __args.
2155  template<typename... _Args>
2156  void
2157  _M_replace_map(_Args&&... __args)
2158  {
2159  // Create new data first, so if allocation fails there are no effects.
2160  deque __newobj(std::forward<_Args>(__args)...);
2161  // Free existing storage using existing allocator.
2162  clear();
2163  _M_deallocate_node(*begin()._M_node); // one node left after clear()
2164  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
2165  this->_M_impl._M_map = nullptr;
2166  this->_M_impl._M_map_size = 0;
2167  // Take ownership of replacement memory.
2168  this->_M_impl._M_swap_data(__newobj._M_impl);
2169  }
2170 
2171  // Do move assignment when the allocator propagates.
2172  void
2173  _M_move_assign2(deque&& __x, /* propagate: */ true_type)
2174  {
2175  // Make a copy of the original allocator state.
2176  auto __alloc = __x._M_get_Tp_allocator();
2177  // The allocator propagates so storage can be moved from __x,
2178  // leaving __x in a valid empty state with a moved-from allocator.
2179  _M_replace_map(std::move(__x));
2180  // Move the corresponding allocator state too.
2181  _M_get_Tp_allocator() = std::move(__alloc);
2182  }
2183 
2184  // Do move assignment when it may not be possible to move source
2185  // object's memory, resulting in a linear-time operation.
2186  void
2187  _M_move_assign2(deque&& __x, /* propagate: */ false_type)
2188  {
2189  if (__x._M_get_Tp_allocator() == this->_M_get_Tp_allocator())
2190  {
2191  // The allocators are equal so storage can be moved from __x,
2192  // leaving __x in a valid empty state with its current allocator.
2193  _M_replace_map(std::move(__x), __x.get_allocator());
2194  }
2195  else
2196  {
2197  // The rvalue's allocator cannot be moved and is not equal,
2198  // so we need to individually move each element.
2199  this->assign(std::__make_move_if_noexcept_iterator(__x.begin()),
2200  std::__make_move_if_noexcept_iterator(__x.end()));
2201  __x.clear();
2202  }
2203  }
2204 #endif
2205  };
2206 
2207 
2208  /**
2209  * @brief Deque equality comparison.
2210  * @param __x A %deque.
2211  * @param __y A %deque of the same type as @a __x.
2212  * @return True iff the size and elements of the deques are equal.
2213  *
2214  * This is an equivalence relation. It is linear in the size of the
2215  * deques. Deques are considered equivalent if their sizes are equal,
2216  * and if corresponding elements compare equal.
2217  */
2218  template<typename _Tp, typename _Alloc>
2219  inline bool
2220  operator==(const deque<_Tp, _Alloc>& __x,
2221  const deque<_Tp, _Alloc>& __y)
2222  { return __x.size() == __y.size()
2223  && std::equal(__x.begin(), __x.end(), __y.begin()); }
2224 
2225  /**
2226  * @brief Deque ordering relation.
2227  * @param __x A %deque.
2228  * @param __y A %deque of the same type as @a __x.
2229  * @return True iff @a x is lexicographically less than @a __y.
2230  *
2231  * This is a total ordering relation. It is linear in the size of the
2232  * deques. The elements must be comparable with @c <.
2233  *
2234  * See std::lexicographical_compare() for how the determination is made.
2235  */
2236  template<typename _Tp, typename _Alloc>
2237  inline bool
2238  operator<(const deque<_Tp, _Alloc>& __x,
2239  const deque<_Tp, _Alloc>& __y)
2240  { return std::lexicographical_compare(__x.begin(), __x.end(),
2241  __y.begin(), __y.end()); }
2242 
2243  /// Based on operator==
2244  template<typename _Tp, typename _Alloc>
2245  inline bool
2246  operator!=(const deque<_Tp, _Alloc>& __x,
2247  const deque<_Tp, _Alloc>& __y)
2248  { return !(__x == __y); }
2249 
2250  /// Based on operator<
2251  template<typename _Tp, typename _Alloc>
2252  inline bool
2253  operator>(const deque<_Tp, _Alloc>& __x,
2254  const deque<_Tp, _Alloc>& __y)
2255  { return __y < __x; }
2256 
2257  /// Based on operator<
2258  template<typename _Tp, typename _Alloc>
2259  inline bool
2260  operator<=(const deque<_Tp, _Alloc>& __x,
2261  const deque<_Tp, _Alloc>& __y)
2262  { return !(__y < __x); }
2263 
2264  /// Based on operator<
2265  template<typename _Tp, typename _Alloc>
2266  inline bool
2267  operator>=(const deque<_Tp, _Alloc>& __x,
2268  const deque<_Tp, _Alloc>& __y)
2269  { return !(__x < __y); }
2270 
2271  /// See std::deque::swap().
2272  template<typename _Tp, typename _Alloc>
2273  inline void
2274  swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y)
2275  { __x.swap(__y); }
2276 
2277 #undef _GLIBCXX_DEQUE_BUF_SIZE
2278 
2279 _GLIBCXX_END_NAMESPACE_CONTAINER
2280 } // namespace std
2281 
2282 #endif /* _STL_DEQUE_H */
std::advance
void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:173
std::deque::shrink_to_fit
void shrink_to_fit() noexcept
Definition: stl_deque.h:1340
std::deque::operator=
deque & operator=(deque &&__x) noexcept(_Alloc_traits::_S_always_equal())
Deque move assignment operator.
Definition: stl_deque.h:1061
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:914
std::deque::rbegin
const_reverse_iterator rbegin() const noexcept
Definition: stl_deque.h:1202
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:1253
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:1143
std::deque::_M_range_check
void _M_range_check(size_type __n) const
Safety check used only from at().
Definition: stl_deque.h:1386
std::deque::max_size
size_type max_size() const noexcept
Definition: stl_deque.h:1268
std::deque::at
reference at(size_type __n)
Provides access to the data contained in the deque.
Definition: stl_deque.h:1408
std::deque::cend
const_iterator cend() const noexcept
Definition: stl_deque.h:1238
std::deque::insert
iterator insert(const_iterator __p, initializer_list< value_type > __l)
Inserts an initializer list into the deque.
Definition: stl_deque.h:1646
std::deque::resize
void resize(size_type __new_size)
Resizes the deque to the specified number of elements.
Definition: stl_deque.h:1282
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:2088
std::deque::pop_back
void pop_back() noexcept
Removes last element.
Definition: stl_deque.h:1570
std::deque::clear
void clear() noexcept
Definition: stl_deque.h:1800
std::deque::at
const_reference at(size_type __n) const
Provides access to the data contained in the deque.
Definition: stl_deque.h:1426
std::deque::begin
iterator begin() noexcept
Definition: stl_deque.h:1158
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:990
std::deque
A standard container using fixed-size memory allocation and constant-time manipulation of elements at...
Definition: stl_deque.h:830
std::_Deque_iterator::_M_set_node
void _M_set_node(_Map_pointer __new_node) noexcept
Definition: stl_deque.h:252
std::_Deque_base::_M_initialize_map
void _M_initialize_map(size_t)
Layout storage.
Definition: stl_deque.h:681
std::allocator
The standard allocator, as per [20.4].
Definition: allocator.h:92
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:2078
std::deque::deque
deque(size_type __n, const allocator_type &__a=allocator_type())
Creates a deque with default constructed elements.
Definition: stl_deque.h:902
std::deque::push_back
void push_back(const value_type &__x)
Add data to the end of the deque.
Definition: stl_deque.h:1516
std::distance
iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:114
std::deque::operator[]
const_reference operator[](size_type __n) const noexcept
Subscript access to the data contained in the deque.
Definition: stl_deque.h:1380
std::deque::insert
iterator insert(const_iterator __position, _InputIterator __first, _InputIterator __last)
Inserts a range into the deque.
Definition: stl_deque.h:1698
std::deque::empty
bool empty() const noexcept
Definition: stl_deque.h:1349
std::deque::deque
deque(_InputIterator __first, _InputIterator __last, const allocator_type &__a=allocator_type())
Builds a deque from a range.
Definition: stl_deque.h:1017
std::deque::begin
const_iterator begin() const noexcept
Definition: stl_deque.h:1166
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:1170
std::deque::rend
reverse_iterator rend() noexcept
Definition: stl_deque.h:1211
std::initializer_list
initializer_list
Definition: initializer_list:47
_GLIBCXX_DEQUE_BUF_SIZE
#define _GLIBCXX_DEQUE_BUF_SIZE
This function controls the size of memory nodes.
Definition: stl_deque.h:85
std::deque::back
const_reference back() const noexcept
Definition: stl_deque.h:1465
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::resize
void resize(size_type __new_size, const value_type &__x)
Resizes the deque to the specified number of elements.
Definition: stl_deque.h:1304
std::deque::rbegin
reverse_iterator rbegin() noexcept
Definition: stl_deque.h:1193
std::deque::assign
void assign(size_type __n, const value_type &__val)
Assigns a given value to a deque.
Definition: stl_deque.h:1099
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::crend
const_reverse_iterator crend() const noexcept
Definition: stl_deque.h:1256
std::deque::front
reference front() noexcept
Definition: stl_deque.h:1437
std::random_access_iterator_tag
Random-access iterators support a superset of bidirectional iterator operations.
Definition: stl_iterator_base_types.h:103
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:2122
std::deque::deque
deque(const deque &__x)
Deque copy constructor.
Definition: stl_deque.h:941
std::deque::crbegin
const_reverse_iterator crbegin() const noexcept
Definition: stl_deque.h:1247
std::deque::end
iterator end() noexcept
Definition: stl_deque.h:1175
std::deque::get_allocator
allocator_type get_allocator() const noexcept
Get a copy of the memory allocation object.
Definition: stl_deque.h:1149
std::deque::deque
deque(deque &&__x, const allocator_type &__a)
Move constructor with alternative allocator.
Definition: stl_deque.h:967
std::pointer_traits
Uniform interface to all pointer-like types.
Definition: ptr_traits.h:132
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::operator[]
reference operator[](size_type __n) noexcept
Subscript access to the data contained in the deque.
Definition: stl_deque.h:1365
std::deque::deque
deque(deque &&__x)
Deque move constructor.
Definition: stl_deque.h:956
std::deque::swap
void swap(deque &__x) noexcept(_Alloc_traits::_S_nothrow_swap())
Swaps data with another deque.
Definition: stl_deque.h:1783
std::deque::deque
deque()
Creates a deque with no elements.
Definition: stl_deque.h:883
std::deque::deque
deque(const allocator_type &__a)
Creates a deque with no elements.
Definition: stl_deque.h:890
std::integral_constant
integral_constant
Definition: type_traits:69
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:2114
std::deque::erase
iterator erase(const_iterator __first, const_iterator __last)
Remove a range of elements.
Definition: stl_deque.h:1767
std::deque::back
reference back() noexcept
Definition: stl_deque.h:1453
std::deque::deque
deque(const deque &__x, const allocator_type &__a)
Copy constructor with alternative allocator.
Definition: stl_deque.h:960
std::_Deque_iterator
A deque::iterator.
Definition: stl_deque.h:106
std::deque::rend
const_reverse_iterator rend() const noexcept
Definition: stl_deque.h:1220
std::deque::operator=
deque & operator=(initializer_list< value_type > __l)
Assigns an initializer list to a deque.
Definition: stl_deque.h:1081
std::deque::cbegin
const_iterator cbegin() const noexcept
Definition: stl_deque.h:1229
std::deque::erase
iterator erase(const_iterator __position)
Remove element at given position.
Definition: stl_deque.h:1743
std::deque::front
const_reference front() const noexcept
Definition: stl_deque.h:1445
std::deque::push_front
void push_front(const value_type &__x)
Add data to the front of the deque.
Definition: stl_deque.h:1483
std::deque::end
const_iterator end() const noexcept
Definition: stl_deque.h:1184
std::forward_iterator_tag
Forward iterators support a superset of input iterator operations.
Definition: stl_iterator_base_types.h:95
std::deque::assign
void assign(_InputIterator __first, _InputIterator __last)
Assigns a range to a deque.
Definition: stl_deque.h:1118
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:1662
std
ISO C++ entities toplevel namespace is std.
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::insert
iterator insert(const_iterator __position, value_type &&__x)
Inserts given rvalue into deque before specified iterator.
Definition: stl_deque.h:1633
std::deque::size
size_type size() const noexcept
Definition: stl_deque.h:1263
__gnu_cxx::__alloc_traits
Uniform interface to C++98 and C++0x allocators.
Definition: ext/alloc_traits.h:95
std::deque::pop_front
void pop_front() noexcept
Removes first element.
Definition: stl_deque.h:1548