libstdc++
stl_deque.h
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1 // Deque implementation -*- C++ -*-
2 
3 // Copyright (C) 2001-2016 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), typename _Alloc_traits::is_always_equal{})
519  { }
520 
521  _Deque_base(_Deque_base&& __x, const allocator_type& __a, size_type __n)
522  : _M_impl(__a)
523  {
524  if (__x.get_allocator() == __a)
525  {
526  if (__x._M_impl._M_map)
527  {
528  _M_initialize_map(0);
529  this->_M_impl._M_swap_data(__x._M_impl);
530  }
531  }
532  else
533  {
534  _M_initialize_map(__n);
535  }
536  }
537 #endif
538 
539  ~_Deque_base() _GLIBCXX_NOEXCEPT;
540 
541  protected:
542  typedef typename iterator::_Map_pointer _Map_pointer;
543 
544  //This struct encapsulates the implementation of the std::deque
545  //standard container and at the same time makes use of the EBO
546  //for empty allocators.
547  struct _Deque_impl
548  : public _Tp_alloc_type
549  {
550  _Map_pointer _M_map;
551  size_t _M_map_size;
552  iterator _M_start;
553  iterator _M_finish;
554 
555  _Deque_impl()
556  : _Tp_alloc_type(), _M_map(), _M_map_size(0),
557  _M_start(), _M_finish()
558  { }
559 
560  _Deque_impl(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT
561  : _Tp_alloc_type(__a), _M_map(), _M_map_size(0),
562  _M_start(), _M_finish()
563  { }
564 
565 #if __cplusplus >= 201103L
566  _Deque_impl(_Deque_impl&&) = default;
567 
568  _Deque_impl(_Tp_alloc_type&& __a) noexcept
569  : _Tp_alloc_type(std::move(__a)), _M_map(), _M_map_size(0),
570  _M_start(), _M_finish()
571  { }
572 #endif
573 
574  void _M_swap_data(_Deque_impl& __x) _GLIBCXX_NOEXCEPT
575  {
576  using std::swap;
577  swap(this->_M_start, __x._M_start);
578  swap(this->_M_finish, __x._M_finish);
579  swap(this->_M_map, __x._M_map);
580  swap(this->_M_map_size, __x._M_map_size);
581  }
582  };
583 
584  _Tp_alloc_type&
585  _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT
586  { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); }
587 
588  const _Tp_alloc_type&
589  _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT
590  { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); }
591 
592  _Map_alloc_type
593  _M_get_map_allocator() const _GLIBCXX_NOEXCEPT
594  { return _Map_alloc_type(_M_get_Tp_allocator()); }
595 
596  _Ptr
597  _M_allocate_node()
598  {
599  typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
600  return _Traits::allocate(_M_impl, __deque_buf_size(sizeof(_Tp)));
601  }
602 
603  void
604  _M_deallocate_node(_Ptr __p) _GLIBCXX_NOEXCEPT
605  {
606  typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
607  _Traits::deallocate(_M_impl, __p, __deque_buf_size(sizeof(_Tp)));
608  }
609 
610  _Map_pointer
611  _M_allocate_map(size_t __n)
612  {
613  _Map_alloc_type __map_alloc = _M_get_map_allocator();
614  return _Map_alloc_traits::allocate(__map_alloc, __n);
615  }
616 
617  void
618  _M_deallocate_map(_Map_pointer __p, size_t __n) _GLIBCXX_NOEXCEPT
619  {
620  _Map_alloc_type __map_alloc = _M_get_map_allocator();
621  _Map_alloc_traits::deallocate(__map_alloc, __p, __n);
622  }
623 
624  protected:
625  void _M_initialize_map(size_t);
626  void _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish);
627  void _M_destroy_nodes(_Map_pointer __nstart,
628  _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT;
629  enum { _S_initial_map_size = 8 };
630 
631  _Deque_impl _M_impl;
632 
633 #if __cplusplus >= 201103L
634  private:
635  _Deque_impl
636  _M_move_impl()
637  {
638  if (!_M_impl._M_map)
639  return std::move(_M_impl);
640 
641  // Create a copy of the current allocator.
642  _Tp_alloc_type __alloc{_M_get_Tp_allocator()};
643  // Put that copy in a moved-from state.
644  _Tp_alloc_type __sink __attribute((__unused__)) {std::move(__alloc)};
645  // Create an empty map that allocates using the moved-from allocator.
646  _Deque_base __empty{__alloc};
647  __empty._M_initialize_map(0);
648  // Now safe to modify current allocator and perform non-throwing swaps.
649  _Deque_impl __ret{std::move(_M_get_Tp_allocator())};
650  _M_impl._M_swap_data(__ret);
651  _M_impl._M_swap_data(__empty._M_impl);
652  return __ret;
653  }
654 #endif
655  };
656 
657  template<typename _Tp, typename _Alloc>
658  _Deque_base<_Tp, _Alloc>::
659  ~_Deque_base() _GLIBCXX_NOEXCEPT
660  {
661  if (this->_M_impl._M_map)
662  {
663  _M_destroy_nodes(this->_M_impl._M_start._M_node,
664  this->_M_impl._M_finish._M_node + 1);
665  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
666  }
667  }
668 
669  /**
670  * @brief Layout storage.
671  * @param __num_elements The count of T's for which to allocate space
672  * at first.
673  * @return Nothing.
674  *
675  * The initial underlying memory layout is a bit complicated...
676  */
677  template<typename _Tp, typename _Alloc>
678  void
679  _Deque_base<_Tp, _Alloc>::
680  _M_initialize_map(size_t __num_elements)
681  {
682  const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
683  + 1);
684 
685  this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
686  size_t(__num_nodes + 2));
687  this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
688 
689  // For "small" maps (needing less than _M_map_size nodes), allocation
690  // starts in the middle elements and grows outwards. So nstart may be
691  // the beginning of _M_map, but for small maps it may be as far in as
692  // _M_map+3.
693 
694  _Map_pointer __nstart = (this->_M_impl._M_map
695  + (this->_M_impl._M_map_size - __num_nodes) / 2);
696  _Map_pointer __nfinish = __nstart + __num_nodes;
697 
698  __try
699  { _M_create_nodes(__nstart, __nfinish); }
700  __catch(...)
701  {
702  _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
703  this->_M_impl._M_map = _Map_pointer();
704  this->_M_impl._M_map_size = 0;
705  __throw_exception_again;
706  }
707 
708  this->_M_impl._M_start._M_set_node(__nstart);
709  this->_M_impl._M_finish._M_set_node(__nfinish - 1);
710  this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
711  this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
712  + __num_elements
713  % __deque_buf_size(sizeof(_Tp)));
714  }
715 
716  template<typename _Tp, typename _Alloc>
717  void
718  _Deque_base<_Tp, _Alloc>::
719  _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish)
720  {
721  _Map_pointer __cur;
722  __try
723  {
724  for (__cur = __nstart; __cur < __nfinish; ++__cur)
725  *__cur = this->_M_allocate_node();
726  }
727  __catch(...)
728  {
729  _M_destroy_nodes(__nstart, __cur);
730  __throw_exception_again;
731  }
732  }
733 
734  template<typename _Tp, typename _Alloc>
735  void
736  _Deque_base<_Tp, _Alloc>::
737  _M_destroy_nodes(_Map_pointer __nstart,
738  _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT
739  {
740  for (_Map_pointer __n = __nstart; __n < __nfinish; ++__n)
741  _M_deallocate_node(*__n);
742  }
743 
744  /**
745  * @brief A standard container using fixed-size memory allocation and
746  * constant-time manipulation of elements at either end.
747  *
748  * @ingroup sequences
749  *
750  * @tparam _Tp Type of element.
751  * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
752  *
753  * Meets the requirements of a <a href="tables.html#65">container</a>, a
754  * <a href="tables.html#66">reversible container</a>, and a
755  * <a href="tables.html#67">sequence</a>, including the
756  * <a href="tables.html#68">optional sequence requirements</a>.
757  *
758  * In previous HP/SGI versions of deque, there was an extra template
759  * parameter so users could control the node size. This extension turned
760  * out to violate the C++ standard (it can be detected using template
761  * template parameters), and it was removed.
762  *
763  * Here's how a deque<Tp> manages memory. Each deque has 4 members:
764  *
765  * - Tp** _M_map
766  * - size_t _M_map_size
767  * - iterator _M_start, _M_finish
768  *
769  * map_size is at least 8. %map is an array of map_size
770  * pointers-to-@a nodes. (The name %map has nothing to do with the
771  * std::map class, and @b nodes should not be confused with
772  * std::list's usage of @a node.)
773  *
774  * A @a node has no specific type name as such, but it is referred
775  * to as @a node in this file. It is a simple array-of-Tp. If Tp
776  * is very large, there will be one Tp element per node (i.e., an
777  * @a array of one). For non-huge Tp's, node size is inversely
778  * related to Tp size: the larger the Tp, the fewer Tp's will fit
779  * in a node. The goal here is to keep the total size of a node
780  * relatively small and constant over different Tp's, to improve
781  * allocator efficiency.
782  *
783  * Not every pointer in the %map array will point to a node. If
784  * the initial number of elements in the deque is small, the
785  * /middle/ %map pointers will be valid, and the ones at the edges
786  * will be unused. This same situation will arise as the %map
787  * grows: available %map pointers, if any, will be on the ends. As
788  * new nodes are created, only a subset of the %map's pointers need
789  * to be copied @a outward.
790  *
791  * Class invariants:
792  * - For any nonsingular iterator i:
793  * - i.node points to a member of the %map array. (Yes, you read that
794  * correctly: i.node does not actually point to a node.) The member of
795  * the %map array is what actually points to the node.
796  * - i.first == *(i.node) (This points to the node (first Tp element).)
797  * - i.last == i.first + node_size
798  * - i.cur is a pointer in the range [i.first, i.last). NOTE:
799  * the implication of this is that i.cur is always a dereferenceable
800  * pointer, even if i is a past-the-end iterator.
801  * - Start and Finish are always nonsingular iterators. NOTE: this
802  * means that an empty deque must have one node, a deque with <N
803  * elements (where N is the node buffer size) must have one node, a
804  * deque with N through (2N-1) elements must have two nodes, etc.
805  * - For every node other than start.node and finish.node, every
806  * element in the node is an initialized object. If start.node ==
807  * finish.node, then [start.cur, finish.cur) are initialized
808  * objects, and the elements outside that range are uninitialized
809  * storage. Otherwise, [start.cur, start.last) and [finish.first,
810  * finish.cur) are initialized objects, and [start.first, start.cur)
811  * and [finish.cur, finish.last) are uninitialized storage.
812  * - [%map, %map + map_size) is a valid, non-empty range.
813  * - [start.node, finish.node] is a valid range contained within
814  * [%map, %map + map_size).
815  * - A pointer in the range [%map, %map + map_size) points to an allocated
816  * node if and only if the pointer is in the range
817  * [start.node, finish.node].
818  *
819  * Here's the magic: nothing in deque is @b aware of the discontiguous
820  * storage!
821  *
822  * The memory setup and layout occurs in the parent, _Base, and the iterator
823  * class is entirely responsible for @a leaping from one node to the next.
824  * All the implementation routines for deque itself work only through the
825  * start and finish iterators. This keeps the routines simple and sane,
826  * and we can use other standard algorithms as well.
827  */
828  template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
829  class deque : protected _Deque_base<_Tp, _Alloc>
830  {
831  // concept requirements
832  typedef typename _Alloc::value_type _Alloc_value_type;
833 #if __cplusplus < 201103L
834  __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
835 #endif
836  __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
837 
838  typedef _Deque_base<_Tp, _Alloc> _Base;
839  typedef typename _Base::_Tp_alloc_type _Tp_alloc_type;
840  typedef typename _Base::_Alloc_traits _Alloc_traits;
841  typedef typename _Base::_Map_pointer _Map_pointer;
842 
843  public:
844  typedef _Tp value_type;
845  typedef typename _Alloc_traits::pointer pointer;
846  typedef typename _Alloc_traits::const_pointer const_pointer;
847  typedef typename _Alloc_traits::reference reference;
848  typedef typename _Alloc_traits::const_reference const_reference;
849  typedef typename _Base::iterator iterator;
850  typedef typename _Base::const_iterator const_iterator;
851  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
852  typedef std::reverse_iterator<iterator> reverse_iterator;
853  typedef size_t size_type;
854  typedef ptrdiff_t difference_type;
855  typedef _Alloc allocator_type;
856 
857  protected:
858  static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
859  { return __deque_buf_size(sizeof(_Tp)); }
860 
861  // Functions controlling memory layout, and nothing else.
862  using _Base::_M_initialize_map;
863  using _Base::_M_create_nodes;
864  using _Base::_M_destroy_nodes;
865  using _Base::_M_allocate_node;
866  using _Base::_M_deallocate_node;
867  using _Base::_M_allocate_map;
868  using _Base::_M_deallocate_map;
869  using _Base::_M_get_Tp_allocator;
870 
871  /**
872  * A total of four data members accumulated down the hierarchy.
873  * May be accessed via _M_impl.*
874  */
875  using _Base::_M_impl;
876 
877  public:
878  // [23.2.1.1] construct/copy/destroy
879  // (assign() and get_allocator() are also listed in this section)
880 
881  /**
882  * @brief Creates a %deque with no elements.
883  */
884  deque() : _Base() { }
885 
886  /**
887  * @brief Creates a %deque with no elements.
888  * @param __a An allocator object.
889  */
890  explicit
891  deque(const allocator_type& __a)
892  : _Base(__a, 0) { }
893 
894 #if __cplusplus >= 201103L
895  /**
896  * @brief Creates a %deque with default constructed elements.
897  * @param __n The number of elements to initially create.
898  * @param __a An allocator.
899  *
900  * This constructor fills the %deque with @a n default
901  * constructed elements.
902  */
903  explicit
904  deque(size_type __n, const allocator_type& __a = allocator_type())
905  : _Base(__a, __n)
906  { _M_default_initialize(); }
907 
908  /**
909  * @brief Creates a %deque with copies of an exemplar element.
910  * @param __n The number of elements to initially create.
911  * @param __value An element to copy.
912  * @param __a An allocator.
913  *
914  * This constructor fills the %deque with @a __n copies of @a __value.
915  */
916  deque(size_type __n, const value_type& __value,
917  const allocator_type& __a = allocator_type())
918  : _Base(__a, __n)
919  { _M_fill_initialize(__value); }
920 #else
921  /**
922  * @brief Creates a %deque with copies of an exemplar element.
923  * @param __n The number of elements to initially create.
924  * @param __value An element to copy.
925  * @param __a An allocator.
926  *
927  * This constructor fills the %deque with @a __n copies of @a __value.
928  */
929  explicit
930  deque(size_type __n, const value_type& __value = value_type(),
931  const allocator_type& __a = allocator_type())
932  : _Base(__a, __n)
933  { _M_fill_initialize(__value); }
934 #endif
935 
936  /**
937  * @brief %Deque copy constructor.
938  * @param __x A %deque of identical element and allocator types.
939  *
940  * The newly-created %deque uses a copy of the allocation object used
941  * by @a __x.
942  */
943  deque(const deque& __x)
944  : _Base(_Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()),
945  __x.size())
946  { std::__uninitialized_copy_a(__x.begin(), __x.end(),
947  this->_M_impl._M_start,
948  _M_get_Tp_allocator()); }
949 
950 #if __cplusplus >= 201103L
951  /**
952  * @brief %Deque move constructor.
953  * @param __x A %deque of identical element and allocator types.
954  *
955  * The newly-created %deque contains the exact contents of @a __x.
956  * The contents of @a __x are a valid, but unspecified %deque.
957  */
958  deque(deque&& __x)
959  : _Base(std::move(__x)) { }
960 
961  /// Copy constructor with alternative allocator
962  deque(const deque& __x, const allocator_type& __a)
963  : _Base(__a, __x.size())
964  { std::__uninitialized_copy_a(__x.begin(), __x.end(),
965  this->_M_impl._M_start,
966  _M_get_Tp_allocator()); }
967 
968  /// Move constructor with alternative allocator
969  deque(deque&& __x, const allocator_type& __a)
970  : _Base(std::move(__x), __a, __x.size())
971  {
972  if (__x.get_allocator() != __a)
973  {
974  std::__uninitialized_move_a(__x.begin(), __x.end(),
975  this->_M_impl._M_start,
976  _M_get_Tp_allocator());
977  __x.clear();
978  }
979  }
980 
981  /**
982  * @brief Builds a %deque from an initializer list.
983  * @param __l An initializer_list.
984  * @param __a An allocator object.
985  *
986  * Create a %deque consisting of copies of the elements in the
987  * initializer_list @a __l.
988  *
989  * This will call the element type's copy constructor N times
990  * (where N is __l.size()) and do no memory reallocation.
991  */
992  deque(initializer_list<value_type> __l,
993  const allocator_type& __a = allocator_type())
994  : _Base(__a)
995  {
996  _M_range_initialize(__l.begin(), __l.end(),
997  random_access_iterator_tag());
998  }
999 #endif
1000 
1001  /**
1002  * @brief Builds a %deque from a range.
1003  * @param __first An input iterator.
1004  * @param __last An input iterator.
1005  * @param __a An allocator object.
1006  *
1007  * Create a %deque consisting of copies of the elements from [__first,
1008  * __last).
1009  *
1010  * If the iterators are forward, bidirectional, or random-access, then
1011  * this will call the elements' copy constructor N times (where N is
1012  * distance(__first,__last)) and do no memory reallocation. But if only
1013  * input iterators are used, then this will do at most 2N calls to the
1014  * copy constructor, and logN memory reallocations.
1015  */
1016 #if __cplusplus >= 201103L
1017  template<typename _InputIterator,
1018  typename = std::_RequireInputIter<_InputIterator>>
1019  deque(_InputIterator __first, _InputIterator __last,
1020  const allocator_type& __a = allocator_type())
1021  : _Base(__a)
1022  { _M_initialize_dispatch(__first, __last, __false_type()); }
1023 #else
1024  template<typename _InputIterator>
1025  deque(_InputIterator __first, _InputIterator __last,
1026  const allocator_type& __a = allocator_type())
1027  : _Base(__a)
1028  {
1029  // Check whether it's an integral type. If so, it's not an iterator.
1030  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1031  _M_initialize_dispatch(__first, __last, _Integral());
1032  }
1033 #endif
1034 
1035  /**
1036  * The dtor only erases the elements, and note that if the elements
1037  * themselves are pointers, the pointed-to memory is not touched in any
1038  * way. Managing the pointer is the user's responsibility.
1039  */
1040  ~deque()
1041  { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); }
1042 
1043  /**
1044  * @brief %Deque assignment operator.
1045  * @param __x A %deque of identical element and allocator types.
1046  *
1047  * All the elements of @a x are copied, but unlike the copy constructor,
1048  * the allocator object is not copied.
1049  */
1050  deque&
1051  operator=(const deque& __x);
1052 
1053 #if __cplusplus >= 201103L
1054  /**
1055  * @brief %Deque move assignment operator.
1056  * @param __x A %deque of identical element and allocator types.
1057  *
1058  * The contents of @a __x are moved into this deque (without copying,
1059  * if the allocators permit it).
1060  * @a __x is a valid, but unspecified %deque.
1061  */
1062  deque&
1063  operator=(deque&& __x) noexcept(_Alloc_traits::_S_always_equal())
1064  {
1065  using __always_equal = typename _Alloc_traits::is_always_equal;
1066  _M_move_assign1(std::move(__x), __always_equal{});
1067  return *this;
1068  }
1069 
1070  /**
1071  * @brief Assigns an initializer list to a %deque.
1072  * @param __l An initializer_list.
1073  *
1074  * This function fills a %deque with copies of the elements in the
1075  * initializer_list @a __l.
1076  *
1077  * Note that the assignment completely changes the %deque and that the
1078  * resulting %deque's size is the same as the number of elements
1079  * assigned. Old data may be lost.
1080  */
1081  deque&
1082  operator=(initializer_list<value_type> __l)
1083  {
1084  this->assign(__l.begin(), __l.end());
1085  return *this;
1086  }
1087 #endif
1088 
1089  /**
1090  * @brief Assigns a given value to a %deque.
1091  * @param __n Number of elements to be assigned.
1092  * @param __val Value to be assigned.
1093  *
1094  * This function fills a %deque with @a n copies of the given
1095  * value. Note that the assignment completely changes the
1096  * %deque and that the resulting %deque's size is the same as
1097  * the number of elements assigned. Old data may be lost.
1098  */
1099  void
1100  assign(size_type __n, const value_type& __val)
1101  { _M_fill_assign(__n, __val); }
1102 
1103  /**
1104  * @brief Assigns a range to a %deque.
1105  * @param __first An input iterator.
1106  * @param __last An input iterator.
1107  *
1108  * This function fills a %deque with copies of the elements in the
1109  * range [__first,__last).
1110  *
1111  * Note that the assignment completely changes the %deque and that the
1112  * resulting %deque's size is the same as the number of elements
1113  * assigned. Old data may be lost.
1114  */
1115 #if __cplusplus >= 201103L
1116  template<typename _InputIterator,
1117  typename = std::_RequireInputIter<_InputIterator>>
1118  void
1119  assign(_InputIterator __first, _InputIterator __last)
1120  { _M_assign_dispatch(__first, __last, __false_type()); }
1121 #else
1122  template<typename _InputIterator>
1123  void
1124  assign(_InputIterator __first, _InputIterator __last)
1125  {
1126  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1127  _M_assign_dispatch(__first, __last, _Integral());
1128  }
1129 #endif
1130 
1131 #if __cplusplus >= 201103L
1132  /**
1133  * @brief Assigns an initializer list to a %deque.
1134  * @param __l An initializer_list.
1135  *
1136  * This function fills a %deque with copies of the elements in the
1137  * initializer_list @a __l.
1138  *
1139  * Note that the assignment completely changes the %deque and that the
1140  * resulting %deque's size is the same as the number of elements
1141  * assigned. Old data may be lost.
1142  */
1143  void
1144  assign(initializer_list<value_type> __l)
1145  { this->assign(__l.begin(), __l.end()); }
1146 #endif
1147 
1148  /// Get a copy of the memory allocation object.
1149  allocator_type
1150  get_allocator() const _GLIBCXX_NOEXCEPT
1151  { return _Base::get_allocator(); }
1152 
1153  // iterators
1154  /**
1155  * Returns a read/write iterator that points to the first element in the
1156  * %deque. Iteration is done in ordinary element order.
1157  */
1158  iterator
1159  begin() _GLIBCXX_NOEXCEPT
1160  { return this->_M_impl._M_start; }
1161 
1162  /**
1163  * Returns a read-only (constant) iterator that points to the first
1164  * element in the %deque. Iteration is done in ordinary element order.
1165  */
1166  const_iterator
1167  begin() const _GLIBCXX_NOEXCEPT
1168  { return this->_M_impl._M_start; }
1169 
1170  /**
1171  * Returns a read/write iterator that points one past the last
1172  * element in the %deque. Iteration is done in ordinary
1173  * element order.
1174  */
1175  iterator
1176  end() _GLIBCXX_NOEXCEPT
1177  { return this->_M_impl._M_finish; }
1178 
1179  /**
1180  * Returns a read-only (constant) iterator that points one past
1181  * the last element in the %deque. Iteration is done in
1182  * ordinary element order.
1183  */
1184  const_iterator
1185  end() const _GLIBCXX_NOEXCEPT
1186  { return this->_M_impl._M_finish; }
1187 
1188  /**
1189  * Returns a read/write reverse iterator that points to the
1190  * last element in the %deque. Iteration is done in reverse
1191  * element order.
1192  */
1193  reverse_iterator
1194  rbegin() _GLIBCXX_NOEXCEPT
1195  { return reverse_iterator(this->_M_impl._M_finish); }
1196 
1197  /**
1198  * Returns a read-only (constant) reverse iterator that points
1199  * to the last element in the %deque. Iteration is done in
1200  * reverse element order.
1201  */
1202  const_reverse_iterator
1203  rbegin() const _GLIBCXX_NOEXCEPT
1204  { return const_reverse_iterator(this->_M_impl._M_finish); }
1205 
1206  /**
1207  * Returns a read/write reverse iterator that points to one
1208  * before the first element in the %deque. Iteration is done
1209  * in reverse element order.
1210  */
1211  reverse_iterator
1212  rend() _GLIBCXX_NOEXCEPT
1213  { return reverse_iterator(this->_M_impl._M_start); }
1214 
1215  /**
1216  * Returns a read-only (constant) reverse iterator that points
1217  * to one before the first element in the %deque. Iteration is
1218  * done in reverse element order.
1219  */
1220  const_reverse_iterator
1221  rend() const _GLIBCXX_NOEXCEPT
1222  { return const_reverse_iterator(this->_M_impl._M_start); }
1223 
1224 #if __cplusplus >= 201103L
1225  /**
1226  * Returns a read-only (constant) iterator that points to the first
1227  * element in the %deque. Iteration is done in ordinary element order.
1228  */
1229  const_iterator
1230  cbegin() const noexcept
1231  { return this->_M_impl._M_start; }
1232 
1233  /**
1234  * Returns a read-only (constant) iterator that points one past
1235  * the last element in the %deque. Iteration is done in
1236  * ordinary element order.
1237  */
1238  const_iterator
1239  cend() const noexcept
1240  { return this->_M_impl._M_finish; }
1241 
1242  /**
1243  * Returns a read-only (constant) reverse iterator that points
1244  * to the last element in the %deque. Iteration is done in
1245  * reverse element order.
1246  */
1247  const_reverse_iterator
1248  crbegin() const noexcept
1249  { return const_reverse_iterator(this->_M_impl._M_finish); }
1250 
1251  /**
1252  * Returns a read-only (constant) reverse iterator that points
1253  * to one before the first element in the %deque. Iteration is
1254  * done in reverse element order.
1255  */
1256  const_reverse_iterator
1257  crend() const noexcept
1258  { return const_reverse_iterator(this->_M_impl._M_start); }
1259 #endif
1260 
1261  // [23.2.1.2] capacity
1262  /** Returns the number of elements in the %deque. */
1263  size_type
1264  size() const _GLIBCXX_NOEXCEPT
1265  { return this->_M_impl._M_finish - this->_M_impl._M_start; }
1266 
1267  /** Returns the size() of the largest possible %deque. */
1268  size_type
1269  max_size() const _GLIBCXX_NOEXCEPT
1270  { return _Alloc_traits::max_size(_M_get_Tp_allocator()); }
1271 
1272 #if __cplusplus >= 201103L
1273  /**
1274  * @brief Resizes the %deque to the specified number of elements.
1275  * @param __new_size Number of elements the %deque should contain.
1276  *
1277  * This function will %resize the %deque to the specified
1278  * number of elements. If the number is smaller than the
1279  * %deque's current size the %deque is truncated, otherwise
1280  * default constructed elements are appended.
1281  */
1282  void
1283  resize(size_type __new_size)
1284  {
1285  const size_type __len = size();
1286  if (__new_size > __len)
1287  _M_default_append(__new_size - __len);
1288  else if (__new_size < __len)
1289  _M_erase_at_end(this->_M_impl._M_start
1290  + difference_type(__new_size));
1291  }
1292 
1293  /**
1294  * @brief Resizes the %deque to the specified number of elements.
1295  * @param __new_size Number of elements the %deque should contain.
1296  * @param __x Data with which new elements should be populated.
1297  *
1298  * This function will %resize the %deque to the specified
1299  * number of elements. If the number is smaller than the
1300  * %deque's current size the %deque is truncated, otherwise the
1301  * %deque is extended and new elements are populated with given
1302  * data.
1303  */
1304  void
1305  resize(size_type __new_size, const value_type& __x)
1306  {
1307  const size_type __len = size();
1308  if (__new_size > __len)
1309  insert(this->_M_impl._M_finish, __new_size - __len, __x);
1310  else if (__new_size < __len)
1311  _M_erase_at_end(this->_M_impl._M_start
1312  + difference_type(__new_size));
1313  }
1314 #else
1315  /**
1316  * @brief Resizes the %deque to the specified number of elements.
1317  * @param __new_size Number of elements the %deque should contain.
1318  * @param __x Data with which new elements should be populated.
1319  *
1320  * This function will %resize the %deque to the specified
1321  * number of elements. If the number is smaller than the
1322  * %deque's current size the %deque is truncated, otherwise the
1323  * %deque is extended and new elements are populated with given
1324  * data.
1325  */
1326  void
1327  resize(size_type __new_size, value_type __x = value_type())
1328  {
1329  const size_type __len = size();
1330  if (__new_size > __len)
1331  insert(this->_M_impl._M_finish, __new_size - __len, __x);
1332  else if (__new_size < __len)
1333  _M_erase_at_end(this->_M_impl._M_start
1334  + difference_type(__new_size));
1335  }
1336 #endif
1337 
1338 #if __cplusplus >= 201103L
1339  /** A non-binding request to reduce memory use. */
1340  void
1341  shrink_to_fit() noexcept
1342  { _M_shrink_to_fit(); }
1343 #endif
1344 
1345  /**
1346  * Returns true if the %deque is empty. (Thus begin() would
1347  * equal end().)
1348  */
1349  bool
1350  empty() const _GLIBCXX_NOEXCEPT
1351  { return this->_M_impl._M_finish == this->_M_impl._M_start; }
1352 
1353  // element access
1354  /**
1355  * @brief Subscript access to the data contained in the %deque.
1356  * @param __n The index of the element for which data should be
1357  * accessed.
1358  * @return Read/write reference to data.
1359  *
1360  * This operator allows for easy, array-style, data access.
1361  * Note that data access with this operator is unchecked and
1362  * out_of_range lookups are not defined. (For checked lookups
1363  * see at().)
1364  */
1365  reference
1366  operator[](size_type __n) _GLIBCXX_NOEXCEPT
1367  { return this->_M_impl._M_start[difference_type(__n)]; }
1368 
1369  /**
1370  * @brief Subscript access to the data contained in the %deque.
1371  * @param __n The index of the element for which data should be
1372  * accessed.
1373  * @return Read-only (constant) reference to data.
1374  *
1375  * This operator allows for easy, array-style, data access.
1376  * Note that data access with this operator is unchecked and
1377  * out_of_range lookups are not defined. (For checked lookups
1378  * see at().)
1379  */
1380  const_reference
1381  operator[](size_type __n) const _GLIBCXX_NOEXCEPT
1382  { return this->_M_impl._M_start[difference_type(__n)]; }
1383 
1384  protected:
1385  /// Safety check used only from at().
1386  void
1387  _M_range_check(size_type __n) const
1388  {
1389  if (__n >= this->size())
1390  __throw_out_of_range_fmt(__N("deque::_M_range_check: __n "
1391  "(which is %zu)>= this->size() "
1392  "(which is %zu)"),
1393  __n, this->size());
1394  }
1395 
1396  public:
1397  /**
1398  * @brief Provides access to the data contained in the %deque.
1399  * @param __n The index of the element for which data should be
1400  * accessed.
1401  * @return Read/write reference to data.
1402  * @throw std::out_of_range If @a __n is an invalid index.
1403  *
1404  * This function provides for safer data access. The parameter
1405  * is first checked that it is in the range of the deque. The
1406  * function throws out_of_range if the check fails.
1407  */
1408  reference
1409  at(size_type __n)
1410  {
1411  _M_range_check(__n);
1412  return (*this)[__n];
1413  }
1414 
1415  /**
1416  * @brief Provides access to the data contained in the %deque.
1417  * @param __n The index of the element for which data should be
1418  * accessed.
1419  * @return Read-only (constant) reference to data.
1420  * @throw std::out_of_range If @a __n is an invalid index.
1421  *
1422  * This function provides for safer data access. The parameter is first
1423  * checked that it is in the range of the deque. The function throws
1424  * out_of_range if the check fails.
1425  */
1426  const_reference
1427  at(size_type __n) const
1428  {
1429  _M_range_check(__n);
1430  return (*this)[__n];
1431  }
1432 
1433  /**
1434  * Returns a read/write reference to the data at the first
1435  * element of the %deque.
1436  */
1437  reference
1438  front() _GLIBCXX_NOEXCEPT
1439  { return *begin(); }
1440 
1441  /**
1442  * Returns a read-only (constant) reference to the data at the first
1443  * element of the %deque.
1444  */
1445  const_reference
1446  front() const _GLIBCXX_NOEXCEPT
1447  { return *begin(); }
1448 
1449  /**
1450  * Returns a read/write reference to the data at the last element of the
1451  * %deque.
1452  */
1453  reference
1454  back() _GLIBCXX_NOEXCEPT
1455  {
1456  iterator __tmp = end();
1457  --__tmp;
1458  return *__tmp;
1459  }
1460 
1461  /**
1462  * Returns a read-only (constant) reference to the data at the last
1463  * element of the %deque.
1464  */
1465  const_reference
1466  back() const _GLIBCXX_NOEXCEPT
1467  {
1468  const_iterator __tmp = end();
1469  --__tmp;
1470  return *__tmp;
1471  }
1472 
1473  // [23.2.1.2] modifiers
1474  /**
1475  * @brief Add data to the front of the %deque.
1476  * @param __x Data to be added.
1477  *
1478  * This is a typical stack operation. The function creates an
1479  * element at the front of the %deque and assigns the given
1480  * data to it. Due to the nature of a %deque this operation
1481  * can be done in constant time.
1482  */
1483  void
1484  push_front(const value_type& __x)
1485  {
1486  if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
1487  {
1488  _Alloc_traits::construct(this->_M_impl,
1489  this->_M_impl._M_start._M_cur - 1,
1490  __x);
1491  --this->_M_impl._M_start._M_cur;
1492  }
1493  else
1494  _M_push_front_aux(__x);
1495  }
1496 
1497 #if __cplusplus >= 201103L
1498  void
1499  push_front(value_type&& __x)
1500  { emplace_front(std::move(__x)); }
1501 
1502  template<typename... _Args>
1503  void
1504  emplace_front(_Args&&... __args);
1505 #endif
1506 
1507  /**
1508  * @brief Add data to the end of the %deque.
1509  * @param __x Data to be added.
1510  *
1511  * This is a typical stack operation. The function creates an
1512  * element at the end of the %deque and assigns the given data
1513  * to it. Due to the nature of a %deque this operation can be
1514  * done in constant time.
1515  */
1516  void
1517  push_back(const value_type& __x)
1518  {
1519  if (this->_M_impl._M_finish._M_cur
1520  != this->_M_impl._M_finish._M_last - 1)
1521  {
1522  _Alloc_traits::construct(this->_M_impl,
1523  this->_M_impl._M_finish._M_cur, __x);
1524  ++this->_M_impl._M_finish._M_cur;
1525  }
1526  else
1527  _M_push_back_aux(__x);
1528  }
1529 
1530 #if __cplusplus >= 201103L
1531  void
1532  push_back(value_type&& __x)
1533  { emplace_back(std::move(__x)); }
1534 
1535  template<typename... _Args>
1536  void
1537  emplace_back(_Args&&... __args);
1538 #endif
1539 
1540  /**
1541  * @brief Removes first element.
1542  *
1543  * This is a typical stack operation. It shrinks the %deque by one.
1544  *
1545  * Note that no data is returned, and if the first element's data is
1546  * needed, it should be retrieved before pop_front() is called.
1547  */
1548  void
1549  pop_front() _GLIBCXX_NOEXCEPT
1550  {
1551  if (this->_M_impl._M_start._M_cur
1552  != this->_M_impl._M_start._M_last - 1)
1553  {
1554  _Alloc_traits::destroy(this->_M_impl,
1555  this->_M_impl._M_start._M_cur);
1556  ++this->_M_impl._M_start._M_cur;
1557  }
1558  else
1559  _M_pop_front_aux();
1560  }
1561 
1562  /**
1563  * @brief Removes last element.
1564  *
1565  * This is a typical stack operation. It shrinks the %deque by one.
1566  *
1567  * Note that no data is returned, and if the last element's data is
1568  * needed, it should be retrieved before pop_back() is called.
1569  */
1570  void
1571  pop_back() _GLIBCXX_NOEXCEPT
1572  {
1573  if (this->_M_impl._M_finish._M_cur
1574  != this->_M_impl._M_finish._M_first)
1575  {
1576  --this->_M_impl._M_finish._M_cur;
1577  _Alloc_traits::destroy(this->_M_impl,
1578  this->_M_impl._M_finish._M_cur);
1579  }
1580  else
1581  _M_pop_back_aux();
1582  }
1583 
1584 #if __cplusplus >= 201103L
1585  /**
1586  * @brief Inserts an object in %deque before specified iterator.
1587  * @param __position A const_iterator into the %deque.
1588  * @param __args Arguments.
1589  * @return An iterator that points to the inserted data.
1590  *
1591  * This function will insert an object of type T constructed
1592  * with T(std::forward<Args>(args)...) before the specified location.
1593  */
1594  template<typename... _Args>
1595  iterator
1596  emplace(const_iterator __position, _Args&&... __args);
1597 
1598  /**
1599  * @brief Inserts given value into %deque before specified iterator.
1600  * @param __position A const_iterator into the %deque.
1601  * @param __x Data to be inserted.
1602  * @return An iterator that points to the inserted data.
1603  *
1604  * This function will insert a copy of the given value before the
1605  * specified location.
1606  */
1607  iterator
1608  insert(const_iterator __position, const value_type& __x);
1609 #else
1610  /**
1611  * @brief Inserts given value into %deque before specified iterator.
1612  * @param __position An iterator into the %deque.
1613  * @param __x Data to be inserted.
1614  * @return An iterator that points to the inserted data.
1615  *
1616  * This function will insert a copy of the given value before the
1617  * specified location.
1618  */
1619  iterator
1620  insert(iterator __position, const value_type& __x);
1621 #endif
1622 
1623 #if __cplusplus >= 201103L
1624  /**
1625  * @brief Inserts given rvalue into %deque before specified iterator.
1626  * @param __position A const_iterator into the %deque.
1627  * @param __x Data to be inserted.
1628  * @return An iterator that points to the inserted data.
1629  *
1630  * This function will insert a copy of the given rvalue before the
1631  * specified location.
1632  */
1633  iterator
1634  insert(const_iterator __position, value_type&& __x)
1635  { return emplace(__position, std::move(__x)); }
1636 
1637  /**
1638  * @brief Inserts an initializer list into the %deque.
1639  * @param __p An iterator into the %deque.
1640  * @param __l An initializer_list.
1641  *
1642  * This function will insert copies of the data in the
1643  * initializer_list @a __l into the %deque before the location
1644  * specified by @a __p. This is known as <em>list insert</em>.
1645  */
1646  iterator
1647  insert(const_iterator __p, initializer_list<value_type> __l)
1648  { return this->insert(__p, __l.begin(), __l.end()); }
1649 #endif
1650 
1651 #if __cplusplus >= 201103L
1652  /**
1653  * @brief Inserts a number of copies of given data into the %deque.
1654  * @param __position A const_iterator into the %deque.
1655  * @param __n Number of elements to be inserted.
1656  * @param __x Data to be inserted.
1657  * @return An iterator that points to the inserted data.
1658  *
1659  * This function will insert a specified number of copies of the given
1660  * data before the location specified by @a __position.
1661  */
1662  iterator
1663  insert(const_iterator __position, size_type __n, const value_type& __x)
1664  {
1665  difference_type __offset = __position - cbegin();
1666  _M_fill_insert(__position._M_const_cast(), __n, __x);
1667  return begin() + __offset;
1668  }
1669 #else
1670  /**
1671  * @brief Inserts a number of copies of given data into the %deque.
1672  * @param __position An iterator into the %deque.
1673  * @param __n Number of elements to be inserted.
1674  * @param __x Data to be inserted.
1675  *
1676  * This function will insert a specified number of copies of the given
1677  * data before the location specified by @a __position.
1678  */
1679  void
1680  insert(iterator __position, size_type __n, const value_type& __x)
1681  { _M_fill_insert(__position, __n, __x); }
1682 #endif
1683 
1684 #if __cplusplus >= 201103L
1685  /**
1686  * @brief Inserts a range into the %deque.
1687  * @param __position A const_iterator into the %deque.
1688  * @param __first An input iterator.
1689  * @param __last An input iterator.
1690  * @return An iterator that points to the inserted data.
1691  *
1692  * This function will insert copies of the data in the range
1693  * [__first,__last) into the %deque before the location specified
1694  * by @a __position. This is known as <em>range insert</em>.
1695  */
1696  template<typename _InputIterator,
1697  typename = std::_RequireInputIter<_InputIterator>>
1698  iterator
1699  insert(const_iterator __position, _InputIterator __first,
1700  _InputIterator __last)
1701  {
1702  difference_type __offset = __position - cbegin();
1703  _M_insert_dispatch(__position._M_const_cast(),
1704  __first, __last, __false_type());
1705  return begin() + __offset;
1706  }
1707 #else
1708  /**
1709  * @brief Inserts a range into the %deque.
1710  * @param __position An iterator into the %deque.
1711  * @param __first An input iterator.
1712  * @param __last An input iterator.
1713  *
1714  * This function will insert copies of the data in the range
1715  * [__first,__last) into the %deque before the location specified
1716  * by @a __position. This is known as <em>range insert</em>.
1717  */
1718  template<typename _InputIterator>
1719  void
1720  insert(iterator __position, _InputIterator __first,
1721  _InputIterator __last)
1722  {
1723  // Check whether it's an integral type. If so, it's not an iterator.
1724  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1725  _M_insert_dispatch(__position, __first, __last, _Integral());
1726  }
1727 #endif
1728 
1729  /**
1730  * @brief Remove element at given position.
1731  * @param __position Iterator pointing to element to be erased.
1732  * @return An iterator pointing to the next element (or end()).
1733  *
1734  * This function will erase the element at the given position and thus
1735  * shorten the %deque by one.
1736  *
1737  * The user is cautioned that
1738  * this function only erases the element, and that if the element is
1739  * itself a pointer, the pointed-to memory is not touched in any way.
1740  * Managing the pointer is the user's responsibility.
1741  */
1742  iterator
1743 #if __cplusplus >= 201103L
1744  erase(const_iterator __position)
1745 #else
1746  erase(iterator __position)
1747 #endif
1748  { return _M_erase(__position._M_const_cast()); }
1749 
1750  /**
1751  * @brief Remove a range of elements.
1752  * @param __first Iterator pointing to the first element to be erased.
1753  * @param __last Iterator pointing to one past the last element to be
1754  * erased.
1755  * @return An iterator pointing to the element pointed to by @a last
1756  * prior to erasing (or end()).
1757  *
1758  * This function will erase the elements in the range
1759  * [__first,__last) and shorten the %deque accordingly.
1760  *
1761  * The user is cautioned that
1762  * this function only erases the elements, and that if the elements
1763  * themselves are pointers, the pointed-to memory is not touched in any
1764  * way. Managing the pointer is the user's responsibility.
1765  */
1766  iterator
1767 #if __cplusplus >= 201103L
1768  erase(const_iterator __first, const_iterator __last)
1769 #else
1770  erase(iterator __first, iterator __last)
1771 #endif
1772  { return _M_erase(__first._M_const_cast(), __last._M_const_cast()); }
1773 
1774  /**
1775  * @brief Swaps data with another %deque.
1776  * @param __x A %deque of the same element and allocator types.
1777  *
1778  * This exchanges the elements between two deques in constant time.
1779  * (Four pointers, so it should be quite fast.)
1780  * Note that the global std::swap() function is specialized such that
1781  * std::swap(d1,d2) will feed to this function.
1782  */
1783  void
1784  swap(deque& __x) _GLIBCXX_NOEXCEPT
1785  {
1786  _M_impl._M_swap_data(__x._M_impl);
1787  _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(),
1788  __x._M_get_Tp_allocator());
1789  }
1790 
1791  /**
1792  * Erases all the elements. Note that this function only erases the
1793  * elements, and that if the elements themselves are pointers, the
1794  * pointed-to memory is not touched in any way. Managing the pointer is
1795  * the user's responsibility.
1796  */
1797  void
1798  clear() _GLIBCXX_NOEXCEPT
1799  { _M_erase_at_end(begin()); }
1800 
1801  protected:
1802  // Internal constructor functions follow.
1803 
1804  // called by the range constructor to implement [23.1.1]/9
1805 
1806  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1807  // 438. Ambiguity in the "do the right thing" clause
1808  template<typename _Integer>
1809  void
1810  _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
1811  {
1812  _M_initialize_map(static_cast<size_type>(__n));
1813  _M_fill_initialize(__x);
1814  }
1815 
1816  // called by the range constructor to implement [23.1.1]/9
1817  template<typename _InputIterator>
1818  void
1819  _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
1820  __false_type)
1821  {
1822  typedef typename std::iterator_traits<_InputIterator>::
1823  iterator_category _IterCategory;
1824  _M_range_initialize(__first, __last, _IterCategory());
1825  }
1826 
1827  // called by the second initialize_dispatch above
1828  //@{
1829  /**
1830  * @brief Fills the deque with whatever is in [first,last).
1831  * @param __first An input iterator.
1832  * @param __last An input iterator.
1833  * @return Nothing.
1834  *
1835  * If the iterators are actually forward iterators (or better), then the
1836  * memory layout can be done all at once. Else we move forward using
1837  * push_back on each value from the iterator.
1838  */
1839  template<typename _InputIterator>
1840  void
1841  _M_range_initialize(_InputIterator __first, _InputIterator __last,
1842  std::input_iterator_tag);
1843 
1844  // called by the second initialize_dispatch above
1845  template<typename _ForwardIterator>
1846  void
1847  _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
1848  std::forward_iterator_tag);
1849  //@}
1850 
1851  /**
1852  * @brief Fills the %deque with copies of value.
1853  * @param __value Initial value.
1854  * @return Nothing.
1855  * @pre _M_start and _M_finish have already been initialized,
1856  * but none of the %deque's elements have yet been constructed.
1857  *
1858  * This function is called only when the user provides an explicit size
1859  * (with or without an explicit exemplar value).
1860  */
1861  void
1862  _M_fill_initialize(const value_type& __value);
1863 
1864 #if __cplusplus >= 201103L
1865  // called by deque(n).
1866  void
1867  _M_default_initialize();
1868 #endif
1869 
1870  // Internal assign functions follow. The *_aux functions do the actual
1871  // assignment work for the range versions.
1872 
1873  // called by the range assign to implement [23.1.1]/9
1874 
1875  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1876  // 438. Ambiguity in the "do the right thing" clause
1877  template<typename _Integer>
1878  void
1879  _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
1880  { _M_fill_assign(__n, __val); }
1881 
1882  // called by the range assign to implement [23.1.1]/9
1883  template<typename _InputIterator>
1884  void
1885  _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
1886  __false_type)
1887  {
1888  typedef typename std::iterator_traits<_InputIterator>::
1889  iterator_category _IterCategory;
1890  _M_assign_aux(__first, __last, _IterCategory());
1891  }
1892 
1893  // called by the second assign_dispatch above
1894  template<typename _InputIterator>
1895  void
1896  _M_assign_aux(_InputIterator __first, _InputIterator __last,
1897  std::input_iterator_tag);
1898 
1899  // called by the second assign_dispatch above
1900  template<typename _ForwardIterator>
1901  void
1902  _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
1903  std::forward_iterator_tag)
1904  {
1905  const size_type __len = std::distance(__first, __last);
1906  if (__len > size())
1907  {
1908  _ForwardIterator __mid = __first;
1909  std::advance(__mid, size());
1910  std::copy(__first, __mid, begin());
1911  insert(end(), __mid, __last);
1912  }
1913  else
1914  _M_erase_at_end(std::copy(__first, __last, begin()));
1915  }
1916 
1917  // Called by assign(n,t), and the range assign when it turns out
1918  // to be the same thing.
1919  void
1920  _M_fill_assign(size_type __n, const value_type& __val)
1921  {
1922  if (__n > size())
1923  {
1924  std::fill(begin(), end(), __val);
1925  insert(end(), __n - size(), __val);
1926  }
1927  else
1928  {
1929  _M_erase_at_end(begin() + difference_type(__n));
1930  std::fill(begin(), end(), __val);
1931  }
1932  }
1933 
1934  //@{
1935  /// Helper functions for push_* and pop_*.
1936 #if __cplusplus < 201103L
1937  void _M_push_back_aux(const value_type&);
1938 
1939  void _M_push_front_aux(const value_type&);
1940 #else
1941  template<typename... _Args>
1942  void _M_push_back_aux(_Args&&... __args);
1943 
1944  template<typename... _Args>
1945  void _M_push_front_aux(_Args&&... __args);
1946 #endif
1947 
1948  void _M_pop_back_aux();
1949 
1950  void _M_pop_front_aux();
1951  //@}
1952 
1953  // Internal insert functions follow. The *_aux functions do the actual
1954  // insertion work when all shortcuts fail.
1955 
1956  // called by the range insert to implement [23.1.1]/9
1957 
1958  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1959  // 438. Ambiguity in the "do the right thing" clause
1960  template<typename _Integer>
1961  void
1962  _M_insert_dispatch(iterator __pos,
1963  _Integer __n, _Integer __x, __true_type)
1964  { _M_fill_insert(__pos, __n, __x); }
1965 
1966  // called by the range insert to implement [23.1.1]/9
1967  template<typename _InputIterator>
1968  void
1969  _M_insert_dispatch(iterator __pos,
1970  _InputIterator __first, _InputIterator __last,
1971  __false_type)
1972  {
1973  typedef typename std::iterator_traits<_InputIterator>::
1974  iterator_category _IterCategory;
1975  _M_range_insert_aux(__pos, __first, __last, _IterCategory());
1976  }
1977 
1978  // called by the second insert_dispatch above
1979  template<typename _InputIterator>
1980  void
1981  _M_range_insert_aux(iterator __pos, _InputIterator __first,
1982  _InputIterator __last, std::input_iterator_tag);
1983 
1984  // called by the second insert_dispatch above
1985  template<typename _ForwardIterator>
1986  void
1987  _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
1988  _ForwardIterator __last, std::forward_iterator_tag);
1989 
1990  // Called by insert(p,n,x), and the range insert when it turns out to be
1991  // the same thing. Can use fill functions in optimal situations,
1992  // otherwise passes off to insert_aux(p,n,x).
1993  void
1994  _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
1995 
1996  // called by insert(p,x)
1997 #if __cplusplus < 201103L
1998  iterator
1999  _M_insert_aux(iterator __pos, const value_type& __x);
2000 #else
2001  template<typename... _Args>
2002  iterator
2003  _M_insert_aux(iterator __pos, _Args&&... __args);
2004 #endif
2005 
2006  // called by insert(p,n,x) via fill_insert
2007  void
2008  _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
2009 
2010  // called by range_insert_aux for forward iterators
2011  template<typename _ForwardIterator>
2012  void
2013  _M_insert_aux(iterator __pos,
2014  _ForwardIterator __first, _ForwardIterator __last,
2015  size_type __n);
2016 
2017 
2018  // Internal erase functions follow.
2019 
2020  void
2021  _M_destroy_data_aux(iterator __first, iterator __last);
2022 
2023  // Called by ~deque().
2024  // NB: Doesn't deallocate the nodes.
2025  template<typename _Alloc1>
2026  void
2027  _M_destroy_data(iterator __first, iterator __last, const _Alloc1&)
2028  { _M_destroy_data_aux(__first, __last); }
2029 
2030  void
2031  _M_destroy_data(iterator __first, iterator __last,
2032  const std::allocator<_Tp>&)
2033  {
2034  if (!__has_trivial_destructor(value_type))
2035  _M_destroy_data_aux(__first, __last);
2036  }
2037 
2038  // Called by erase(q1, q2).
2039  void
2040  _M_erase_at_begin(iterator __pos)
2041  {
2042  _M_destroy_data(begin(), __pos, _M_get_Tp_allocator());
2043  _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node);
2044  this->_M_impl._M_start = __pos;
2045  }
2046 
2047  // Called by erase(q1, q2), resize(), clear(), _M_assign_aux,
2048  // _M_fill_assign, operator=.
2049  void
2050  _M_erase_at_end(iterator __pos)
2051  {
2052  _M_destroy_data(__pos, end(), _M_get_Tp_allocator());
2053  _M_destroy_nodes(__pos._M_node + 1,
2054  this->_M_impl._M_finish._M_node + 1);
2055  this->_M_impl._M_finish = __pos;
2056  }
2057 
2058  iterator
2059  _M_erase(iterator __pos);
2060 
2061  iterator
2062  _M_erase(iterator __first, iterator __last);
2063 
2064 #if __cplusplus >= 201103L
2065  // Called by resize(sz).
2066  void
2067  _M_default_append(size_type __n);
2068 
2069  bool
2070  _M_shrink_to_fit();
2071 #endif
2072 
2073  //@{
2074  /// Memory-handling helpers for the previous internal insert functions.
2075  iterator
2076  _M_reserve_elements_at_front(size_type __n)
2077  {
2078  const size_type __vacancies = this->_M_impl._M_start._M_cur
2079  - this->_M_impl._M_start._M_first;
2080  if (__n > __vacancies)
2081  _M_new_elements_at_front(__n - __vacancies);
2082  return this->_M_impl._M_start - difference_type(__n);
2083  }
2084 
2085  iterator
2086  _M_reserve_elements_at_back(size_type __n)
2087  {
2088  const size_type __vacancies = (this->_M_impl._M_finish._M_last
2089  - this->_M_impl._M_finish._M_cur) - 1;
2090  if (__n > __vacancies)
2091  _M_new_elements_at_back(__n - __vacancies);
2092  return this->_M_impl._M_finish + difference_type(__n);
2093  }
2094 
2095  void
2096  _M_new_elements_at_front(size_type __new_elements);
2097 
2098  void
2099  _M_new_elements_at_back(size_type __new_elements);
2100  //@}
2101 
2102 
2103  //@{
2104  /**
2105  * @brief Memory-handling helpers for the major %map.
2106  *
2107  * Makes sure the _M_map has space for new nodes. Does not
2108  * actually add the nodes. Can invalidate _M_map pointers.
2109  * (And consequently, %deque iterators.)
2110  */
2111  void
2112  _M_reserve_map_at_back(size_type __nodes_to_add = 1)
2113  {
2114  if (__nodes_to_add + 1 > this->_M_impl._M_map_size
2115  - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
2116  _M_reallocate_map(__nodes_to_add, false);
2117  }
2118 
2119  void
2120  _M_reserve_map_at_front(size_type __nodes_to_add = 1)
2121  {
2122  if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
2123  - this->_M_impl._M_map))
2124  _M_reallocate_map(__nodes_to_add, true);
2125  }
2126 
2127  void
2128  _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
2129  //@}
2130 
2131 #if __cplusplus >= 201103L
2132  // Constant-time, nothrow move assignment when source object's memory
2133  // can be moved because the allocators are equal.
2134  void
2135  _M_move_assign1(deque&& __x, /* always equal: */ true_type) noexcept
2136  {
2137  this->_M_impl._M_swap_data(__x._M_impl);
2138  __x.clear();
2139  std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator());
2140  }
2141 
2142  // When the allocators are not equal the operation could throw, because
2143  // we might need to allocate a new map for __x after moving from it
2144  // or we might need to allocate new elements for *this.
2145  void
2146  _M_move_assign1(deque&& __x, /* always equal: */ false_type)
2147  {
2148  constexpr bool __move_storage =
2149  _Alloc_traits::_S_propagate_on_move_assign();
2150  _M_move_assign2(std::move(__x), __bool_constant<__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  _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
2276  { __x.swap(__y); }
2277 
2278 #undef _GLIBCXX_DEQUE_BUF_SIZE
2279 
2280 _GLIBCXX_END_NAMESPACE_CONTAINER
2281 } // namespace std
2282 
2283 #endif /* _STL_DEQUE_H */
std::deque::pop_back
void pop_back() noexcept
Removes last element.
Definition: stl_deque.h:1571
std::deque::deque
deque(const deque &__x, const allocator_type &__a)
Copy constructor with alternative allocator.
Definition: stl_deque.h:962
std::deque::rend
reverse_iterator rend() noexcept
Definition: stl_deque.h:1212
std::deque::at
const_reference at(size_type __n) const
Provides access to the data contained in the deque.
Definition: stl_deque.h:1427
std::deque
A standard container using fixed-size memory allocation and constant-time manipulation of elements at...
Definition: stl_deque.h:829
std::allocator
The standard allocator, as per [20.4].
Definition: allocator.h:108
std::deque::_M_range_check
void _M_range_check(size_type __n) const
Safety check used only from at().
Definition: stl_deque.h:1387
std::_Deque_base::_M_initialize_map
void _M_initialize_map(size_t)
Layout storage.
Definition: stl_deque.h:680
std::deque::rbegin
const_reverse_iterator rbegin() const noexcept
Definition: stl_deque.h:1203
__gnu_cxx::__alloc_traits
Uniform interface to C++98 and C++11 allocators.
Definition: ext/alloc_traits.h:50
std::deque::front
reference front() noexcept
Definition: stl_deque.h:1438
std::deque::swap
void swap(deque &__x) noexcept
Swaps data with another deque.
Definition: stl_deque.h:1784
std::deque::deque
deque(const deque &__x)
Deque copy constructor.
Definition: stl_deque.h:943
std::advance
void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:194
std::deque::rend
const_reverse_iterator rend() const noexcept
Definition: stl_deque.h:1221
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::cend
const_iterator cend() const noexcept
Definition: stl_deque.h:1239
std::deque::resize
void resize(size_type __new_size)
Resizes the deque to the specified number of elements.
Definition: stl_deque.h:1283
std::deque::deque
deque(_InputIterator __first, _InputIterator __last, const allocator_type &__a=allocator_type())
Builds a deque from a range.
Definition: stl_deque.h:1019
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::deque
deque(deque &&__x)
Deque move constructor.
Definition: stl_deque.h:958
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:916
std::deque::push_front
void push_front(const value_type &__x)
Add data to the front of the deque.
Definition: stl_deque.h:1484
std::initializer_list
initializer_list
Definition: initializer_list:47
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::begin
iterator begin() noexcept
Definition: stl_deque.h:1159
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:2086
std::integral_constant
integral_constant
Definition: type_traits:69
std::pointer_traits
Uniform interface to all pointer-like types.
Definition: ptr_traits.h:78
std::deque::get_allocator
allocator_type get_allocator() const noexcept
Get a copy of the memory allocation object.
Definition: stl_deque.h:1150
std::deque::back
const_reference back() const noexcept
Definition: stl_deque.h:1466
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:1305
std::deque::front
const_reference front() const noexcept
Definition: stl_deque.h:1446
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::rbegin
reverse_iterator rbegin() noexcept
Definition: stl_deque.h:1194
std::deque::begin
const_iterator begin() const noexcept
Definition: stl_deque.h:1167
std::deque::assign
void assign(size_type __n, const value_type &__val)
Assigns a given value to a deque.
Definition: stl_deque.h:1100
std::deque::push_back
void push_back(const value_type &__x)
Add data to the end of the deque.
Definition: stl_deque.h:1517
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:2120
std::deque::assign
void assign(_InputIterator __first, _InputIterator __last)
Assigns a range to a deque.
Definition: stl_deque.h:1119
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:180
std::deque::empty
bool empty() const noexcept
Definition: stl_deque.h:1350
_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
reference back() noexcept
Definition: stl_deque.h:1454
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:2076
std::deque::pop_front
void pop_front() noexcept
Removes first element.
Definition: stl_deque.h:1549
std::_Deque_iterator::_M_set_node
void _M_set_node(_Map_pointer __new_node) noexcept
Definition: stl_deque.h:252
std::deque::crend
const_reverse_iterator crend() const noexcept
Definition: stl_deque.h:1257
std::deque::deque
deque(deque &&__x, const allocator_type &__a)
Move constructor with alternative allocator.
Definition: stl_deque.h:969
std::deque::operator=
deque & operator=(deque &&__x) noexcept(_Alloc_traits::_S_always_equal())
Deque move assignment operator.
Definition: stl_deque.h:1063
std::deque::operator[]
reference operator[](size_type __n) noexcept
Subscript access to the data contained in the deque.
Definition: stl_deque.h:1366
std::deque::clear
void clear() noexcept
Definition: stl_deque.h:1798
std::deque::deque
deque()
Creates a deque with no elements.
Definition: stl_deque.h:884
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::deque
deque(initializer_list< value_type > __l, const allocator_type &__a=allocator_type())
Builds a deque from an initializer list.
Definition: stl_deque.h:992
std::random_access_iterator_tag
Random-access iterators support a superset of bidirectional iterator operations.
Definition: stl_iterator_base_types.h:103
std::deque::erase
iterator erase(const_iterator __position)
Remove element at given position.
Definition: stl_deque.h:1744
std::deque::max_size
size_type max_size() const noexcept
Definition: stl_deque.h:1269
std::deque::at
reference at(size_type __n)
Provides access to the data contained in the deque.
Definition: stl_deque.h:1409
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:1663
std::deque::shrink_to_fit
void shrink_to_fit() noexcept
Definition: stl_deque.h:1341
std::_Deque_iterator
A deque::iterator.
Definition: stl_deque.h:106
std::deque::insert
iterator insert(const_iterator __p, initializer_list< value_type > __l)
Inserts an initializer list into the deque.
Definition: stl_deque.h:1647
std::forward_iterator_tag
Forward iterators support a superset of input iterator operations.
Definition: stl_iterator_base_types.h:95
std::deque::insert
iterator insert(const_iterator __position, value_type &&__x)
Inserts given rvalue into deque before specified iterator.
Definition: stl_deque.h:1634
std::deque::erase
iterator erase(const_iterator __first, const_iterator __last)
Remove a range of elements.
Definition: stl_deque.h:1768
std::deque::end
const_iterator end() const noexcept
Definition: stl_deque.h:1185
std::deque::crbegin
const_reverse_iterator crbegin() const noexcept
Definition: stl_deque.h:1248
std::deque::deque
deque(const allocator_type &__a)
Creates a deque with no elements.
Definition: stl_deque.h:891
std::deque::end
iterator end() noexcept
Definition: stl_deque.h:1176
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:2112
std
ISO C++ entities toplevel namespace is std.
std::deque::deque
deque(size_type __n, const allocator_type &__a=allocator_type())
Creates a deque with default constructed elements.
Definition: stl_deque.h:904
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::operator[]
const_reference operator[](size_type __n) const noexcept
Subscript access to the data contained in the deque.
Definition: stl_deque.h:1381
std::input_iterator_tag
Marking input iterators.
Definition: stl_iterator_base_types.h:89
std::distance
iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:135
std::deque::operator=
deque & operator=(initializer_list< value_type > __l)
Assigns an initializer list to a deque.
Definition: stl_deque.h:1082
std::deque::cbegin
const_iterator cbegin() const noexcept
Definition: stl_deque.h:1230
std::deque::insert
iterator insert(const_iterator __position, _InputIterator __first, _InputIterator __last)
Inserts a range into the deque.
Definition: stl_deque.h:1699
std::deque::assign
void assign(initializer_list< value_type > __l)
Assigns an initializer list to a deque.
Definition: stl_deque.h:1144
std::deque::size
size_type size() const noexcept
Definition: stl_deque.h:1264