1// Deque implementation -*- C++ -*-
2
3// Copyright (C) 2001-2017 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation. Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose. It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1997
40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
45 * that both that copyright notice and this permission notice appear
46 * in supporting documentation. Silicon Graphics makes no
47 * representations about the suitability of this software for any
48 * purpose. It is provided "as is" without express or implied warranty.
49 */
50
51/** @file bits/stl_deque.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{deque}
54 */
55
56#ifndef _STL_DEQUE_H
57#define _STL_DEQUE_H 1
58
59#include <bits/concept_check.h>
60#include <bits/stl_iterator_base_types.h>
61#include <bits/stl_iterator_base_funcs.h>
62#if __cplusplus >= 201103L
63#include <initializer_list>
64#endif
65
66#include <debug/assertions.h>
67
68namespace std _GLIBCXX_VISIBILITY(default)
69{
70_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
71
72 /**
73 * @brief This function controls the size of memory nodes.
74 * @param __size The size of an element.
75 * @return The number (not byte size) of elements per node.
76 *
77 * This function started off as a compiler kludge from SGI, but
78 * seems to be a useful wrapper around a repeated constant
79 * expression. The @b 512 is tunable (and no other code needs to
80 * change), but no investigation has been done since inheriting the
81 * SGI code. Touch _GLIBCXX_DEQUE_BUF_SIZE only if you know what
82 * you are doing, however: changing it breaks the binary
83 * compatibility!!
84 */
85
86#ifndef _GLIBCXX_DEQUE_BUF_SIZE
87#define _GLIBCXX_DEQUE_BUF_SIZE 512
88#endif
89
90 _GLIBCXX_CONSTEXPR inline size_t
91 __deque_buf_size(size_t __size)
92 { return (__size < _GLIBCXX_DEQUE_BUF_SIZE
93 ? size_t(_GLIBCXX_DEQUE_BUF_SIZE / __size) : size_t(1)); }
94
95
96 /**
97 * @brief A deque::iterator.
98 *
99 * Quite a bit of intelligence here. Much of the functionality of
100 * deque is actually passed off to this class. A deque holds two
101 * of these internally, marking its valid range. Access to
102 * elements is done as offsets of either of those two, relying on
103 * operator overloading in this class.
104 *
105 * All the functions are op overloads except for _M_set_node.
106 */
107 template<typename _Tp, typename _Ref, typename _Ptr>
108 struct _Deque_iterator
109 {
110#if __cplusplus < 201103L
111 typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator;
112 typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
113 typedef _Tp* _Elt_pointer;
114 typedef _Tp** _Map_pointer;
115#else
116 private:
117 template<typename _Up>
118 using __ptr_to = typename pointer_traits<_Ptr>::template rebind<_Up>;
119 template<typename _CvTp>
120 using __iter = _Deque_iterator<_Tp, _CvTp&, __ptr_to<_CvTp>>;
121 public:
122 typedef __iter<_Tp> iterator;
123 typedef __iter<const _Tp> const_iterator;
124 typedef __ptr_to<_Tp> _Elt_pointer;
125 typedef __ptr_to<_Elt_pointer> _Map_pointer;
126#endif
127
128 static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
129 { return __deque_buf_size(sizeof(_Tp)); }
130
131 typedef std::random_access_iterator_tag iterator_category;
132 typedef _Tp value_type;
133 typedef _Ptr pointer;
134 typedef _Ref reference;
135 typedef size_t size_type;
136 typedef ptrdiff_t difference_type;
137 typedef _Deque_iterator _Self;
138
139 _Elt_pointer _M_cur;
140 _Elt_pointer _M_first;
141 _Elt_pointer _M_last;
142 _Map_pointer _M_node;
143
144 _Deque_iterator(_Elt_pointer __x, _Map_pointer __y) _GLIBCXX_NOEXCEPT
145 : _M_cur(__x), _M_first(*__y),
146 _M_last(*__y + _S_buffer_size()), _M_node(__y) { }
147
148 _Deque_iterator() _GLIBCXX_NOEXCEPT
149 : _M_cur(), _M_first(), _M_last(), _M_node() { }
150
151 _Deque_iterator(const iterator& __x) _GLIBCXX_NOEXCEPT
152 : _M_cur(__x._M_cur), _M_first(__x._M_first),
153 _M_last(__x._M_last), _M_node(__x._M_node) { }
154
155 iterator
156 _M_const_cast() const _GLIBCXX_NOEXCEPT
157 { return iterator(_M_cur, _M_node); }
158
159 reference
160 operator*() const _GLIBCXX_NOEXCEPT
161 { return *_M_cur; }
162
163 pointer
164 operator->() const _GLIBCXX_NOEXCEPT
165 { return _M_cur; }
166
167 _Self&
168 operator++() _GLIBCXX_NOEXCEPT
169 {
170 ++_M_cur;
171 if (_M_cur == _M_last)
172 {
173 _M_set_node(_M_node + 1);
174 _M_cur = _M_first;
175 }
176 return *this;
177 }
178
179 _Self
180 operator++(int) _GLIBCXX_NOEXCEPT
181 {
182 _Self __tmp = *this;
183 ++*this;
184 return __tmp;
185 }
186
187 _Self&
188 operator--() _GLIBCXX_NOEXCEPT
189 {
190 if (_M_cur == _M_first)
191 {
192 _M_set_node(_M_node - 1);
193 _M_cur = _M_last;
194 }
195 --_M_cur;
196 return *this;
197 }
198
199 _Self
200 operator--(int) _GLIBCXX_NOEXCEPT
201 {
202 _Self __tmp = *this;
203 --*this;
204 return __tmp;
205 }
206
207 _Self&
208 operator+=(difference_type __n) _GLIBCXX_NOEXCEPT
209 {
210 const difference_type __offset = __n + (_M_cur - _M_first);
211 if (__offset >= 0 && __offset < difference_type(_S_buffer_size()))
212 _M_cur += __n;
213 else
214 {
215 const difference_type __node_offset =
216 __offset > 0 ? __offset / difference_type(_S_buffer_size())
217 : -difference_type((-__offset - 1)
218 / _S_buffer_size()) - 1;
219 _M_set_node(_M_node + __node_offset);
220 _M_cur = _M_first + (__offset - __node_offset
221 * difference_type(_S_buffer_size()));
222 }
223 return *this;
224 }
225
226 _Self
227 operator+(difference_type __n) const _GLIBCXX_NOEXCEPT
228 {
229 _Self __tmp = *this;
230 return __tmp += __n;
231 }
232
233 _Self&
234 operator-=(difference_type __n) _GLIBCXX_NOEXCEPT
235 { return *this += -__n; }
236
237 _Self
238 operator-(difference_type __n) const _GLIBCXX_NOEXCEPT
239 {
240 _Self __tmp = *this;
241 return __tmp -= __n;
242 }
243
244 reference
245 operator[](difference_type __n) const _GLIBCXX_NOEXCEPT
246 { return *(*this + __n); }
247
248 /**
249 * Prepares to traverse new_node. Sets everything except
250 * _M_cur, which should therefore be set by the caller
251 * immediately afterwards, based on _M_first and _M_last.
252 */
253 void
254 _M_set_node(_Map_pointer __new_node) _GLIBCXX_NOEXCEPT
255 {
256 _M_node = __new_node;
257 _M_first = *__new_node;
258 _M_last = _M_first + difference_type(_S_buffer_size());
259 }
260 };
261
262 // Note: we also provide overloads whose operands are of the same type in
263 // order to avoid ambiguous overload resolution when std::rel_ops operators
264 // are in scope (for additional details, see libstdc++/3628)
265 template<typename _Tp, typename _Ref, typename _Ptr>
266 inline bool
267 operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
268 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
269 { return __x._M_cur == __y._M_cur; }
270
271 template<typename _Tp, typename _RefL, typename _PtrL,
272 typename _RefR, typename _PtrR>
273 inline bool
274 operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
275 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
276 { return __x._M_cur == __y._M_cur; }
277
278 template<typename _Tp, typename _Ref, typename _Ptr>
279 inline bool
280 operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
281 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
282 { return !(__x == __y); }
283
284 template<typename _Tp, typename _RefL, typename _PtrL,
285 typename _RefR, typename _PtrR>
286 inline bool
287 operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
288 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
289 { return !(__x == __y); }
290
291 template<typename _Tp, typename _Ref, typename _Ptr>
292 inline bool
293 operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
294 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
295 { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
296 : (__x._M_node < __y._M_node); }
297
298 template<typename _Tp, typename _RefL, typename _PtrL,
299 typename _RefR, typename _PtrR>
300 inline bool
301 operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
302 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
303 { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
304 : (__x._M_node < __y._M_node); }
305
306 template<typename _Tp, typename _Ref, typename _Ptr>
307 inline bool
308 operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
309 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
310 { return __y < __x; }
311
312 template<typename _Tp, typename _RefL, typename _PtrL,
313 typename _RefR, typename _PtrR>
314 inline bool
315 operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
316 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
317 { return __y < __x; }
318
319 template<typename _Tp, typename _Ref, typename _Ptr>
320 inline bool
321 operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
322 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
323 { return !(__y < __x); }
324
325 template<typename _Tp, typename _RefL, typename _PtrL,
326 typename _RefR, typename _PtrR>
327 inline bool
328 operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
329 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
330 { return !(__y < __x); }
331
332 template<typename _Tp, typename _Ref, typename _Ptr>
333 inline bool
334 operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
335 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
336 { return !(__x < __y); }
337
338 template<typename _Tp, typename _RefL, typename _PtrL,
339 typename _RefR, typename _PtrR>
340 inline bool
341 operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
342 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
343 { return !(__x < __y); }
344
345 // _GLIBCXX_RESOLVE_LIB_DEFECTS
346 // According to the resolution of DR179 not only the various comparison
347 // operators but also operator- must accept mixed iterator/const_iterator
348 // parameters.
349 template<typename _Tp, typename _Ref, typename _Ptr>
350 inline typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
351 operator-(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
352 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
353 {
354 return typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
355 (_Deque_iterator<_Tp, _Ref, _Ptr>::_S_buffer_size())
356 * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
357 + (__y._M_last - __y._M_cur);
358 }
359
360 template<typename _Tp, typename _RefL, typename _PtrL,
361 typename _RefR, typename _PtrR>
362 inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
363 operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
364 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
365 {
366 return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
367 (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size())
368 * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
369 + (__y._M_last - __y._M_cur);
370 }
371
372 template<typename _Tp, typename _Ref, typename _Ptr>
373 inline _Deque_iterator<_Tp, _Ref, _Ptr>
374 operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x)
375 _GLIBCXX_NOEXCEPT
376 { return __x + __n; }
377
378 template<typename _Tp>
379 void
380 fill(const _Deque_iterator<_Tp, _Tp&, _Tp*>&,
381 const _Deque_iterator<_Tp, _Tp&, _Tp*>&, const _Tp&);
382
383 template<typename _Tp>
384 _Deque_iterator<_Tp, _Tp&, _Tp*>
385 copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
386 _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
387 _Deque_iterator<_Tp, _Tp&, _Tp*>);
388
389 template<typename _Tp>
390 inline _Deque_iterator<_Tp, _Tp&, _Tp*>
391 copy(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
392 _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
393 _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
394 { return std::copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first),
395 _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last),
396 __result); }
397
398 template<typename _Tp>
399 _Deque_iterator<_Tp, _Tp&, _Tp*>
400 copy_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
401 _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
402 _Deque_iterator<_Tp, _Tp&, _Tp*>);
403
404 template<typename _Tp>
405 inline _Deque_iterator<_Tp, _Tp&, _Tp*>
406 copy_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
407 _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
408 _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
409 { return std::copy_backward(_Deque_iterator<_Tp,
410 const _Tp&, const _Tp*>(__first),
411 _Deque_iterator<_Tp,
412 const _Tp&, const _Tp*>(__last),
413 __result); }
414
415#if __cplusplus >= 201103L
416 template<typename _Tp>
417 _Deque_iterator<_Tp, _Tp&, _Tp*>
418 move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
419 _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
420 _Deque_iterator<_Tp, _Tp&, _Tp*>);
421
422 template<typename _Tp>
423 inline _Deque_iterator<_Tp, _Tp&, _Tp*>
424 move(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
425 _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
426 _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
427 { return std::move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first),
428 _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last),
429 __result); }
430
431 template<typename _Tp>
432 _Deque_iterator<_Tp, _Tp&, _Tp*>
433 move_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
434 _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
435 _Deque_iterator<_Tp, _Tp&, _Tp*>);
436
437 template<typename _Tp>
438 inline _Deque_iterator<_Tp, _Tp&, _Tp*>
439 move_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
440 _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
441 _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
442 { return std::move_backward(_Deque_iterator<_Tp,
443 const _Tp&, const _Tp*>(__first),
444 _Deque_iterator<_Tp,
445 const _Tp&, const _Tp*>(__last),
446 __result); }
447#endif
448
449 /**
450 * Deque base class. This class provides the unified face for %deque's
451 * allocation. This class's constructor and destructor allocate and
452 * deallocate (but do not initialize) storage. This makes %exception
453 * safety easier.
454 *
455 * Nothing in this class ever constructs or destroys an actual Tp element.
456 * (Deque handles that itself.) Only/All memory management is performed
457 * here.
458 */
459 template<typename _Tp, typename _Alloc>
460 class _Deque_base
461 {
462 protected:
463 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
464 rebind<_Tp>::other _Tp_alloc_type;
465 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Alloc_traits;
466
467#if __cplusplus < 201103L
468 typedef _Tp* _Ptr;
469 typedef const _Tp* _Ptr_const;
470#else
471 typedef typename _Alloc_traits::pointer _Ptr;
472 typedef typename _Alloc_traits::const_pointer _Ptr_const;
473#endif
474
475 typedef typename _Alloc_traits::template rebind<_Ptr>::other
476 _Map_alloc_type;
477 typedef __gnu_cxx::__alloc_traits<_Map_alloc_type> _Map_alloc_traits;
478
479 public:
480 typedef _Alloc allocator_type;
481 typedef typename _Alloc_traits::size_type size_type;
482
483 allocator_type
484 get_allocator() const _GLIBCXX_NOEXCEPT
485 { return allocator_type(_M_get_Tp_allocator()); }
486
487 typedef _Deque_iterator<_Tp, _Tp&, _Ptr> iterator;
488 typedef _Deque_iterator<_Tp, const _Tp&, _Ptr_const> const_iterator;
489
490 _Deque_base()
491 : _M_impl()
492 { _M_initialize_map(0); }
493
494 _Deque_base(size_t __num_elements)
495 : _M_impl()
496 { _M_initialize_map(__num_elements); }
497
498 _Deque_base(const allocator_type& __a, size_t __num_elements)
499 : _M_impl(__a)
500 { _M_initialize_map(__num_elements); }
501
502 _Deque_base(const allocator_type& __a)
503 : _M_impl(__a)
504 { /* Caller must initialize map. */ }
505
506#if __cplusplus >= 201103L
507 _Deque_base(_Deque_base&& __x, false_type)
508 : _M_impl(__x._M_move_impl())
509 { }
510
511 _Deque_base(_Deque_base&& __x, true_type)
512 : _M_impl(std::move(__x._M_get_Tp_allocator()))
513 {
514 _M_initialize_map(0);
515 if (__x._M_impl._M_map)
516 this->_M_impl._M_swap_data(__x._M_impl);
517 }
518
519 _Deque_base(_Deque_base&& __x)
520 : _Deque_base(std::move(__x), typename _Alloc_traits::is_always_equal{})
521 { }
522
523 _Deque_base(_Deque_base&& __x, const allocator_type& __a, size_type __n)
524 : _M_impl(__a)
525 {
526 if (__x.get_allocator() == __a)
527 {
528 if (__x._M_impl._M_map)
529 {
530 _M_initialize_map(0);
531 this->_M_impl._M_swap_data(__x._M_impl);
532 }
533 }
534 else
535 {
536 _M_initialize_map(__n);
537 }
538 }
539#endif
540
541 ~_Deque_base() _GLIBCXX_NOEXCEPT;
542
543 protected:
544 typedef typename iterator::_Map_pointer _Map_pointer;
545
546 //This struct encapsulates the implementation of the std::deque
547 //standard container and at the same time makes use of the EBO
548 //for empty allocators.
549 struct _Deque_impl
550 : public _Tp_alloc_type
551 {
552 _Map_pointer _M_map;
553 size_t _M_map_size;
554 iterator _M_start;
555 iterator _M_finish;
556
557 _Deque_impl()
558 : _Tp_alloc_type(), _M_map(), _M_map_size(0),
559 _M_start(), _M_finish()
560 { }
561
562 _Deque_impl(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT
563 : _Tp_alloc_type(__a), _M_map(), _M_map_size(0),
564 _M_start(), _M_finish()
565 { }
566
567#if __cplusplus >= 201103L
568 _Deque_impl(_Deque_impl&&) = default;
569
570 _Deque_impl(_Tp_alloc_type&& __a) noexcept
571 : _Tp_alloc_type(std::move(__a)), _M_map(), _M_map_size(0),
572 _M_start(), _M_finish()
573 { }
574#endif
575
576 void _M_swap_data(_Deque_impl& __x) _GLIBCXX_NOEXCEPT
577 {
578 using std::swap;
579 swap(this->_M_start, __x._M_start);
580 swap(this->_M_finish, __x._M_finish);
581 swap(this->_M_map, __x._M_map);
582 swap(this->_M_map_size, __x._M_map_size);
583 }
584 };
585
586 _Tp_alloc_type&
587 _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT
588 { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); }
589
590 const _Tp_alloc_type&
591 _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT
592 { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); }
593
594 _Map_alloc_type
595 _M_get_map_allocator() const _GLIBCXX_NOEXCEPT
596 { return _Map_alloc_type(_M_get_Tp_allocator()); }
597
598 _Ptr
599 _M_allocate_node()
600 {
601 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
602 return _Traits::allocate(_M_impl, __deque_buf_size(sizeof(_Tp)));
603 }
604
605 void
606 _M_deallocate_node(_Ptr __p) _GLIBCXX_NOEXCEPT
607 {
608 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
609 _Traits::deallocate(_M_impl, __p, __deque_buf_size(sizeof(_Tp)));
610 }
611
612 _Map_pointer
613 _M_allocate_map(size_t __n)
614 {
615 _Map_alloc_type __map_alloc = _M_get_map_allocator();
616 return _Map_alloc_traits::allocate(__map_alloc, __n);
617 }
618
619 void
620 _M_deallocate_map(_Map_pointer __p, size_t __n) _GLIBCXX_NOEXCEPT
621 {
622 _Map_alloc_type __map_alloc = _M_get_map_allocator();
623 _Map_alloc_traits::deallocate(__map_alloc, __p, __n);
624 }
625
626 protected:
627 void _M_initialize_map(size_t);
628 void _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish);
629 void _M_destroy_nodes(_Map_pointer __nstart,
630 _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT;
631 enum { _S_initial_map_size = 8 };
632
633 _Deque_impl _M_impl;
634
635#if __cplusplus >= 201103L
636 private:
637 _Deque_impl
638 _M_move_impl()
639 {
640 if (!_M_impl._M_map)
641 return std::move(_M_impl);
642
643 // Create a copy of the current allocator.
644 _Tp_alloc_type __alloc{_M_get_Tp_allocator()};
645 // Put that copy in a moved-from state.
646 _Tp_alloc_type __sink __attribute((__unused__)) {std::move(__alloc)};
647 // Create an empty map that allocates using the moved-from allocator.
648 _Deque_base __empty{__alloc};
649 __empty._M_initialize_map(0);
650 // Now safe to modify current allocator and perform non-throwing swaps.
651 _Deque_impl __ret{std::move(_M_get_Tp_allocator())};
652 _M_impl._M_swap_data(__ret);
653 _M_impl._M_swap_data(__empty._M_impl);
654 return __ret;
655 }
656#endif
657 };
658
659 template<typename _Tp, typename _Alloc>
660 _Deque_base<_Tp, _Alloc>::
661 ~_Deque_base() _GLIBCXX_NOEXCEPT
662 {
663 if (this->_M_impl._M_map)
664 {
665 _M_destroy_nodes(this->_M_impl._M_start._M_node,
666 this->_M_impl._M_finish._M_node + 1);
667 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
668 }
669 }
670
671 /**
672 * @brief Layout storage.
673 * @param __num_elements The count of T's for which to allocate space
674 * at first.
675 * @return Nothing.
676 *
677 * The initial underlying memory layout is a bit complicated...
678 */
679 template<typename _Tp, typename _Alloc>
680 void
681 _Deque_base<_Tp, _Alloc>::
682 _M_initialize_map(size_t __num_elements)
683 {
684 const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
685 + 1);
686
687 this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
688 size_t(__num_nodes + 2));
689 this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
690
691 // For "small" maps (needing less than _M_map_size nodes), allocation
692 // starts in the middle elements and grows outwards. So nstart may be
693 // the beginning of _M_map, but for small maps it may be as far in as
694 // _M_map+3.
695
696 _Map_pointer __nstart = (this->_M_impl._M_map
697 + (this->_M_impl._M_map_size - __num_nodes) / 2);
698 _Map_pointer __nfinish = __nstart + __num_nodes;
699
700 __try
701 { _M_create_nodes(__nstart, __nfinish); }
702 __catch(...)
703 {
704 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
705 this->_M_impl._M_map = _Map_pointer();
706 this->_M_impl._M_map_size = 0;
707 __throw_exception_again;
708 }
709
710 this->_M_impl._M_start._M_set_node(__nstart);
711 this->_M_impl._M_finish._M_set_node(__nfinish - 1);
712 this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
713 this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
714 + __num_elements
715 % __deque_buf_size(sizeof(_Tp)));
716 }
717
718 template<typename _Tp, typename _Alloc>
719 void
720 _Deque_base<_Tp, _Alloc>::
721 _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish)
722 {
723 _Map_pointer __cur;
724 __try
725 {
726 for (__cur = __nstart; __cur < __nfinish; ++__cur)
727 *__cur = this->_M_allocate_node();
728 }
729 __catch(...)
730 {
731 _M_destroy_nodes(__nstart, __cur);
732 __throw_exception_again;
733 }
734 }
735
736 template<typename _Tp, typename _Alloc>
737 void
738 _Deque_base<_Tp, _Alloc>::
739 _M_destroy_nodes(_Map_pointer __nstart,
740 _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT
741 {
742 for (_Map_pointer __n = __nstart; __n < __nfinish; ++__n)
743 _M_deallocate_node(*__n);
744 }
745
746 /**
747 * @brief A standard container using fixed-size memory allocation and
748 * constant-time manipulation of elements at either end.
749 *
750 * @ingroup sequences
751 *
752 * @tparam _Tp Type of element.
753 * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
754 *
755 * Meets the requirements of a <a href="tables.html#65">container</a>, a
756 * <a href="tables.html#66">reversible container</a>, and a
757 * <a href="tables.html#67">sequence</a>, including the
758 * <a href="tables.html#68">optional sequence requirements</a>.
759 *
760 * In previous HP/SGI versions of deque, there was an extra template
761 * parameter so users could control the node size. This extension turned
762 * out to violate the C++ standard (it can be detected using template
763 * template parameters), and it was removed.
764 *
765 * Here's how a deque<Tp> manages memory. Each deque has 4 members:
766 *
767 * - Tp** _M_map
768 * - size_t _M_map_size
769 * - iterator _M_start, _M_finish
770 *
771 * map_size is at least 8. %map is an array of map_size
772 * pointers-to-@a nodes. (The name %map has nothing to do with the
773 * std::map class, and @b nodes should not be confused with
774 * std::list's usage of @a node.)
775 *
776 * A @a node has no specific type name as such, but it is referred
777 * to as @a node in this file. It is a simple array-of-Tp. If Tp
778 * is very large, there will be one Tp element per node (i.e., an
779 * @a array of one). For non-huge Tp's, node size is inversely
780 * related to Tp size: the larger the Tp, the fewer Tp's will fit
781 * in a node. The goal here is to keep the total size of a node
782 * relatively small and constant over different Tp's, to improve
783 * allocator efficiency.
784 *
785 * Not every pointer in the %map array will point to a node. If
786 * the initial number of elements in the deque is small, the
787 * /middle/ %map pointers will be valid, and the ones at the edges
788 * will be unused. This same situation will arise as the %map
789 * grows: available %map pointers, if any, will be on the ends. As
790 * new nodes are created, only a subset of the %map's pointers need
791 * to be copied @a outward.
792 *
793 * Class invariants:
794 * - For any nonsingular iterator i:
795 * - i.node points to a member of the %map array. (Yes, you read that
796 * correctly: i.node does not actually point to a node.) The member of
797 * the %map array is what actually points to the node.
798 * - i.first == *(i.node) (This points to the node (first Tp element).)
799 * - i.last == i.first + node_size
800 * - i.cur is a pointer in the range [i.first, i.last). NOTE:
801 * the implication of this is that i.cur is always a dereferenceable
802 * pointer, even if i is a past-the-end iterator.
803 * - Start and Finish are always nonsingular iterators. NOTE: this
804 * means that an empty deque must have one node, a deque with <N
805 * elements (where N is the node buffer size) must have one node, a
806 * deque with N through (2N-1) elements must have two nodes, etc.
807 * - For every node other than start.node and finish.node, every
808 * element in the node is an initialized object. If start.node ==
809 * finish.node, then [start.cur, finish.cur) are initialized
810 * objects, and the elements outside that range are uninitialized
811 * storage. Otherwise, [start.cur, start.last) and [finish.first,
812 * finish.cur) are initialized objects, and [start.first, start.cur)
813 * and [finish.cur, finish.last) are uninitialized storage.
814 * - [%map, %map + map_size) is a valid, non-empty range.
815 * - [start.node, finish.node] is a valid range contained within
816 * [%map, %map + map_size).
817 * - A pointer in the range [%map, %map + map_size) points to an allocated
818 * node if and only if the pointer is in the range
819 * [start.node, finish.node].
820 *
821 * Here's the magic: nothing in deque is @b aware of the discontiguous
822 * storage!
823 *
824 * The memory setup and layout occurs in the parent, _Base, and the iterator
825 * class is entirely responsible for @a leaping from one node to the next.
826 * All the implementation routines for deque itself work only through the
827 * start and finish iterators. This keeps the routines simple and sane,
828 * and we can use other standard algorithms as well.
829 */
830 template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
831 class deque : protected _Deque_base<_Tp, _Alloc>
832 {
833#ifdef _GLIBCXX_CONCEPT_CHECKS
834 // concept requirements
835 typedef typename _Alloc::value_type _Alloc_value_type;
836# if __cplusplus < 201103L
837 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
838# endif
839 __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
840#endif
841
842 typedef _Deque_base<_Tp, _Alloc> _Base;
843 typedef typename _Base::_Tp_alloc_type _Tp_alloc_type;
844 typedef typename _Base::_Alloc_traits _Alloc_traits;
845 typedef typename _Base::_Map_pointer _Map_pointer;
846
847 public:
848 typedef _Tp value_type;
849 typedef typename _Alloc_traits::pointer pointer;
850 typedef typename _Alloc_traits::const_pointer const_pointer;
851 typedef typename _Alloc_traits::reference reference;
852 typedef typename _Alloc_traits::const_reference const_reference;
853 typedef typename _Base::iterator iterator;
854 typedef typename _Base::const_iterator const_iterator;
855 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
856 typedef std::reverse_iterator<iterator> reverse_iterator;
857 typedef size_t size_type;
858 typedef ptrdiff_t difference_type;
859 typedef _Alloc allocator_type;
860
861 protected:
862 static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
863 { return __deque_buf_size(sizeof(_Tp)); }
864
865 // Functions controlling memory layout, and nothing else.
866 using _Base::_M_initialize_map;
867 using _Base::_M_create_nodes;
868 using _Base::_M_destroy_nodes;
869 using _Base::_M_allocate_node;
870 using _Base::_M_deallocate_node;
871 using _Base::_M_allocate_map;
872 using _Base::_M_deallocate_map;
873 using _Base::_M_get_Tp_allocator;
874
875 /**
876 * A total of four data members accumulated down the hierarchy.
877 * May be accessed via _M_impl.*
878 */
879 using _Base::_M_impl;
880
881 public:
882 // [23.2.1.1] construct/copy/destroy
883 // (assign() and get_allocator() are also listed in this section)
884
885 /**
886 * @brief Creates a %deque with no elements.
887 */
888 deque() : _Base() { }
889
890 /**
891 * @brief Creates a %deque with no elements.
892 * @param __a An allocator object.
893 */
894 explicit
895 deque(const allocator_type& __a)
896 : _Base(__a, 0) { }
897
898#if __cplusplus >= 201103L
899 /**
900 * @brief Creates a %deque with default constructed elements.
901 * @param __n The number of elements to initially create.
902 * @param __a An allocator.
903 *
904 * This constructor fills the %deque with @a n default
905 * constructed elements.
906 */
907 explicit
908 deque(size_type __n, const allocator_type& __a = allocator_type())
909 : _Base(__a, __n)
910 { _M_default_initialize(); }
911
912 /**
913 * @brief Creates a %deque with copies of an exemplar element.
914 * @param __n The number of elements to initially create.
915 * @param __value An element to copy.
916 * @param __a An allocator.
917 *
918 * This constructor fills the %deque with @a __n copies of @a __value.
919 */
920 deque(size_type __n, const value_type& __value,
921 const allocator_type& __a = allocator_type())
922 : _Base(__a, __n)
923 { _M_fill_initialize(__value); }
924#else
925 /**
926 * @brief Creates a %deque with copies of an exemplar element.
927 * @param __n The number of elements to initially create.
928 * @param __value An element to copy.
929 * @param __a An allocator.
930 *
931 * This constructor fills the %deque with @a __n copies of @a __value.
932 */
933 explicit
934 deque(size_type __n, const value_type& __value = value_type(),
935 const allocator_type& __a = allocator_type())
936 : _Base(__a, __n)
937 { _M_fill_initialize(__value); }
938#endif
939
940 /**
941 * @brief %Deque copy constructor.
942 * @param __x A %deque of identical element and allocator types.
943 *
944 * The newly-created %deque uses a copy of the allocator object used
945 * by @a __x (unless the allocator traits dictate a different object).
946 */
947 deque(const deque& __x)
948 : _Base(_Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()),
949 __x.size())
950 { std::__uninitialized_copy_a(__x.begin(), __x.end(),
951 this->_M_impl._M_start,
952 _M_get_Tp_allocator()); }
953
954#if __cplusplus >= 201103L
955 /**
956 * @brief %Deque move constructor.
957 * @param __x A %deque of identical element and allocator types.
958 *
959 * The newly-created %deque contains the exact contents of @a __x.
960 * The contents of @a __x are a valid, but unspecified %deque.
961 */
962 deque(deque&& __x)
963 : _Base(std::move(__x)) { }
964
965 /// Copy constructor with alternative allocator
966 deque(const deque& __x, const allocator_type& __a)
967 : _Base(__a, __x.size())
968 { std::__uninitialized_copy_a(__x.begin(), __x.end(),
969 this->_M_impl._M_start,
970 _M_get_Tp_allocator()); }
971
972 /// Move constructor with alternative allocator
973 deque(deque&& __x, const allocator_type& __a)
974 : _Base(std::move(__x), __a, __x.size())
975 {
976 if (__x.get_allocator() != __a)
977 {
978 std::__uninitialized_move_a(__x.begin(), __x.end(),
979 this->_M_impl._M_start,
980 _M_get_Tp_allocator());
981 __x.clear();
982 }
983 }
984
985 /**
986 * @brief Builds a %deque from an initializer list.
987 * @param __l An initializer_list.
988 * @param __a An allocator object.
989 *
990 * Create a %deque consisting of copies of the elements in the
991 * initializer_list @a __l.
992 *
993 * This will call the element type's copy constructor N times
994 * (where N is __l.size()) and do no memory reallocation.
995 */
996 deque(initializer_list<value_type> __l,
997 const allocator_type& __a = allocator_type())
998 : _Base(__a)
999 {
1000 _M_range_initialize(__l.begin(), __l.end(),
1001 random_access_iterator_tag());
1002 }
1003#endif
1004
1005 /**
1006 * @brief Builds a %deque from a range.
1007 * @param __first An input iterator.
1008 * @param __last An input iterator.
1009 * @param __a An allocator object.
1010 *
1011 * Create a %deque consisting of copies of the elements from [__first,
1012 * __last).
1013 *
1014 * If the iterators are forward, bidirectional, or random-access, then
1015 * this will call the elements' copy constructor N times (where N is
1016 * distance(__first,__last)) and do no memory reallocation. But if only
1017 * input iterators are used, then this will do at most 2N calls to the
1018 * copy constructor, and logN memory reallocations.
1019 */
1020#if __cplusplus >= 201103L
1021 template<typename _InputIterator,
1022 typename = std::_RequireInputIter<_InputIterator>>
1023 deque(_InputIterator __first, _InputIterator __last,
1024 const allocator_type& __a = allocator_type())
1025 : _Base(__a)
1026 { _M_initialize_dispatch(__first, __last, __false_type()); }
1027#else
1028 template<typename _InputIterator>
1029 deque(_InputIterator __first, _InputIterator __last,
1030 const allocator_type& __a = allocator_type())
1031 : _Base(__a)
1032 {
1033 // Check whether it's an integral type. If so, it's not an iterator.
1034 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1035 _M_initialize_dispatch(__first, __last, _Integral());
1036 }
1037#endif
1038
1039 /**
1040 * The dtor only erases the elements, and note that if the elements
1041 * themselves are pointers, the pointed-to memory is not touched in any
1042 * way. Managing the pointer is the user's responsibility.
1043 */
1044 ~deque()
1045 { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); }
1046
1047 /**
1048 * @brief %Deque assignment operator.
1049 * @param __x A %deque of identical element and allocator types.
1050 *
1051 * All the elements of @a x are copied.
1052 *
1053 * The newly-created %deque uses a copy of the allocator object used
1054 * by @a __x (unless the allocator traits dictate a different object).
1055 */
1056 deque&
1057 operator=(const deque& __x);
1058
1059#if __cplusplus >= 201103L
1060 /**
1061 * @brief %Deque move assignment operator.
1062 * @param __x A %deque of identical element and allocator types.
1063 *
1064 * The contents of @a __x are moved into this deque (without copying,
1065 * if the allocators permit it).
1066 * @a __x is a valid, but unspecified %deque.
1067 */
1068 deque&
1069 operator=(deque&& __x) noexcept(_Alloc_traits::_S_always_equal())
1070 {
1071 using __always_equal = typename _Alloc_traits::is_always_equal;
1072 _M_move_assign1(std::move(__x), __always_equal{});
1073 return *this;
1074 }
1075
1076 /**
1077 * @brief Assigns an initializer list to a %deque.
1078 * @param __l An initializer_list.
1079 *
1080 * This function fills a %deque with copies of the elements in the
1081 * initializer_list @a __l.
1082 *
1083 * Note that the assignment completely changes the %deque and that the
1084 * resulting %deque's size is the same as the number of elements
1085 * assigned.
1086 */
1087 deque&
1088 operator=(initializer_list<value_type> __l)
1089 {
1090 _M_assign_aux(__l.begin(), __l.end(),
1091 random_access_iterator_tag());
1092 return *this;
1093 }
1094#endif
1095
1096 /**
1097 * @brief Assigns a given value to a %deque.
1098 * @param __n Number of elements to be assigned.
1099 * @param __val Value to be assigned.
1100 *
1101 * This function fills a %deque with @a n copies of the given
1102 * value. Note that the assignment completely changes the
1103 * %deque and that the resulting %deque's size is the same as
1104 * the number of elements assigned.
1105 */
1106 void
1107 assign(size_type __n, const value_type& __val)
1108 { _M_fill_assign(__n, __val); }
1109
1110 /**
1111 * @brief Assigns a range to a %deque.
1112 * @param __first An input iterator.
1113 * @param __last An input iterator.
1114 *
1115 * This function fills a %deque with copies of the elements in the
1116 * range [__first,__last).
1117 *
1118 * Note that the assignment completely changes the %deque and that the
1119 * resulting %deque's size is the same as the number of elements
1120 * assigned.
1121 */
1122#if __cplusplus >= 201103L
1123 template<typename _InputIterator,
1124 typename = std::_RequireInputIter<_InputIterator>>
1125 void
1126 assign(_InputIterator __first, _InputIterator __last)
1127 { _M_assign_dispatch(__first, __last, __false_type()); }
1128#else
1129 template<typename _InputIterator>
1130 void
1131 assign(_InputIterator __first, _InputIterator __last)
1132 {
1133 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1134 _M_assign_dispatch(__first, __last, _Integral());
1135 }
1136#endif
1137
1138#if __cplusplus >= 201103L
1139 /**
1140 * @brief Assigns an initializer list to a %deque.
1141 * @param __l An initializer_list.
1142 *
1143 * This function fills a %deque with copies of the elements in the
1144 * initializer_list @a __l.
1145 *
1146 * Note that the assignment completely changes the %deque and that the
1147 * resulting %deque's size is the same as the number of elements
1148 * assigned.
1149 */
1150 void
1151 assign(initializer_list<value_type> __l)
1152 { _M_assign_aux(__l.begin(), __l.end(), random_access_iterator_tag()); }
1153#endif
1154
1155 /// Get a copy of the memory allocation object.
1156 allocator_type
1157 get_allocator() const _GLIBCXX_NOEXCEPT
1158 { return _Base::get_allocator(); }
1159
1160 // iterators
1161 /**
1162 * Returns a read/write iterator that points to the first element in the
1163 * %deque. Iteration is done in ordinary element order.
1164 */
1165 iterator
1166 begin() _GLIBCXX_NOEXCEPT
1167 { return this->_M_impl._M_start; }
1168
1169 /**
1170 * Returns a read-only (constant) iterator that points to the first
1171 * element in the %deque. Iteration is done in ordinary element order.
1172 */
1173 const_iterator
1174 begin() const _GLIBCXX_NOEXCEPT
1175 { return this->_M_impl._M_start; }
1176
1177 /**
1178 * Returns a read/write iterator that points one past the last
1179 * element in the %deque. Iteration is done in ordinary
1180 * element order.
1181 */
1182 iterator
1183 end() _GLIBCXX_NOEXCEPT
1184 { return this->_M_impl._M_finish; }
1185
1186 /**
1187 * Returns a read-only (constant) iterator that points one past
1188 * the last element in the %deque. Iteration is done in
1189 * ordinary element order.
1190 */
1191 const_iterator
1192 end() const _GLIBCXX_NOEXCEPT
1193 { return this->_M_impl._M_finish; }
1194
1195 /**
1196 * Returns a read/write reverse iterator that points to the
1197 * last element in the %deque. Iteration is done in reverse
1198 * element order.
1199 */
1200 reverse_iterator
1201 rbegin() _GLIBCXX_NOEXCEPT
1202 { return reverse_iterator(this->_M_impl._M_finish); }
1203
1204 /**
1205 * Returns a read-only (constant) reverse iterator that points
1206 * to the last element in the %deque. Iteration is done in
1207 * reverse element order.
1208 */
1209 const_reverse_iterator
1210 rbegin() const _GLIBCXX_NOEXCEPT
1211 { return const_reverse_iterator(this->_M_impl._M_finish); }
1212
1213 /**
1214 * Returns a read/write reverse iterator that points to one
1215 * before the first element in the %deque. Iteration is done
1216 * in reverse element order.
1217 */
1218 reverse_iterator
1219 rend() _GLIBCXX_NOEXCEPT
1220 { return reverse_iterator(this->_M_impl._M_start); }
1221
1222 /**
1223 * Returns a read-only (constant) reverse iterator that points
1224 * to one before the first element in the %deque. Iteration is
1225 * done in reverse element order.
1226 */
1227 const_reverse_iterator
1228 rend() const _GLIBCXX_NOEXCEPT
1229 { return const_reverse_iterator(this->_M_impl._M_start); }
1230
1231#if __cplusplus >= 201103L
1232 /**
1233 * Returns a read-only (constant) iterator that points to the first
1234 * element in the %deque. Iteration is done in ordinary element order.
1235 */
1236 const_iterator
1237 cbegin() const noexcept
1238 { return this->_M_impl._M_start; }
1239
1240 /**
1241 * Returns a read-only (constant) iterator that points one past
1242 * the last element in the %deque. Iteration is done in
1243 * ordinary element order.
1244 */
1245 const_iterator
1246 cend() const noexcept
1247 { return this->_M_impl._M_finish; }
1248
1249 /**
1250 * Returns a read-only (constant) reverse iterator that points
1251 * to the last element in the %deque. Iteration is done in
1252 * reverse element order.
1253 */
1254 const_reverse_iterator
1255 crbegin() const noexcept
1256 { return const_reverse_iterator(this->_M_impl._M_finish); }
1257
1258 /**
1259 * Returns a read-only (constant) reverse iterator that points
1260 * to one before the first element in the %deque. Iteration is
1261 * done in reverse element order.
1262 */
1263 const_reverse_iterator
1264 crend() const noexcept
1265 { return const_reverse_iterator(this->_M_impl._M_start); }
1266#endif
1267
1268 // [23.2.1.2] capacity
1269 /** Returns the number of elements in the %deque. */
1270 size_type
1271 size() const _GLIBCXX_NOEXCEPT
1272 { return this->_M_impl._M_finish - this->_M_impl._M_start; }
1273
1274 /** Returns the size() of the largest possible %deque. */
1275 size_type
1276 max_size() const _GLIBCXX_NOEXCEPT
1277 { return _Alloc_traits::max_size(_M_get_Tp_allocator()); }
1278
1279#if __cplusplus >= 201103L
1280 /**
1281 * @brief Resizes the %deque to the specified number of elements.
1282 * @param __new_size Number of elements the %deque should contain.
1283 *
1284 * This function will %resize the %deque to the specified
1285 * number of elements. If the number is smaller than the
1286 * %deque's current size the %deque is truncated, otherwise
1287 * default constructed elements are appended.
1288 */
1289 void
1290 resize(size_type __new_size)
1291 {
1292 const size_type __len = size();
1293 if (__new_size > __len)
1294 _M_default_append(__new_size - __len);
1295 else if (__new_size < __len)
1296 _M_erase_at_end(this->_M_impl._M_start
1297 + difference_type(__new_size));
1298 }
1299
1300 /**
1301 * @brief Resizes the %deque to the specified number of elements.
1302 * @param __new_size Number of elements the %deque should contain.
1303 * @param __x Data with which new elements should be populated.
1304 *
1305 * This function will %resize the %deque to the specified
1306 * number of elements. If the number is smaller than the
1307 * %deque's current size the %deque is truncated, otherwise the
1308 * %deque is extended and new elements are populated with given
1309 * data.
1310 */
1311 void
1312 resize(size_type __new_size, const value_type& __x)
1313 {
1314 const size_type __len = size();
1315 if (__new_size > __len)
1316 _M_fill_insert(this->_M_impl._M_finish, __new_size - __len, __x);
1317 else if (__new_size < __len)
1318 _M_erase_at_end(this->_M_impl._M_start
1319 + difference_type(__new_size));
1320 }
1321#else
1322 /**
1323 * @brief Resizes the %deque to the specified number of elements.
1324 * @param __new_size Number of elements the %deque should contain.
1325 * @param __x Data with which new elements should be populated.
1326 *
1327 * This function will %resize the %deque to the specified
1328 * number of elements. If the number is smaller than the
1329 * %deque's current size the %deque is truncated, otherwise the
1330 * %deque is extended and new elements are populated with given
1331 * data.
1332 */
1333 void
1334 resize(size_type __new_size, value_type __x = value_type())
1335 {
1336 const size_type __len = size();
1337 if (__new_size > __len)
1338 _M_fill_insert(this->_M_impl._M_finish, __new_size - __len, __x);
1339 else if (__new_size < __len)
1340 _M_erase_at_end(this->_M_impl._M_start
1341 + difference_type(__new_size));
1342 }
1343#endif
1344
1345#if __cplusplus >= 201103L
1346 /** A non-binding request to reduce memory use. */
1347 void
1348 shrink_to_fit() noexcept
1349 { _M_shrink_to_fit(); }
1350#endif
1351
1352 /**
1353 * Returns true if the %deque is empty. (Thus begin() would
1354 * equal end().)
1355 */
1356 bool
1357 empty() const _GLIBCXX_NOEXCEPT
1358 { return this->_M_impl._M_finish == this->_M_impl._M_start; }
1359
1360 // element access
1361 /**
1362 * @brief Subscript access to the data contained in the %deque.
1363 * @param __n The index of the element for which data should be
1364 * accessed.
1365 * @return Read/write reference to data.
1366 *
1367 * This operator allows for easy, array-style, data access.
1368 * Note that data access with this operator is unchecked and
1369 * out_of_range lookups are not defined. (For checked lookups
1370 * see at().)
1371 */
1372 reference
1373 operator[](size_type __n) _GLIBCXX_NOEXCEPT
1374 {
1375 __glibcxx_requires_subscript(__n);
1376 return this->_M_impl._M_start[difference_type(__n)];
1377 }
1378
1379 /**
1380 * @brief Subscript access to the data contained in the %deque.
1381 * @param __n The index of the element for which data should be
1382 * accessed.
1383 * @return Read-only (constant) reference to data.
1384 *
1385 * This operator allows for easy, array-style, data access.
1386 * Note that data access with this operator is unchecked and
1387 * out_of_range lookups are not defined. (For checked lookups
1388 * see at().)
1389 */
1390 const_reference
1391 operator[](size_type __n) const _GLIBCXX_NOEXCEPT
1392 {
1393 __glibcxx_requires_subscript(__n);
1394 return this->_M_impl._M_start[difference_type(__n)];
1395 }
1396
1397 protected:
1398 /// Safety check used only from at().
1399 void
1400 _M_range_check(size_type __n) const
1401 {
1402 if (__n >= this->size())
1403 __throw_out_of_range_fmt(__N("deque::_M_range_check: __n "
1404 "(which is %zu)>= this->size() "
1405 "(which is %zu)"),
1406 __n, this->size());
1407 }
1408
1409 public:
1410 /**
1411 * @brief Provides access to the data contained in the %deque.
1412 * @param __n The index of the element for which data should be
1413 * accessed.
1414 * @return Read/write reference to data.
1415 * @throw std::out_of_range If @a __n is an invalid index.
1416 *
1417 * This function provides for safer data access. The parameter
1418 * is first checked that it is in the range of the deque. The
1419 * function throws out_of_range if the check fails.
1420 */
1421 reference
1422 at(size_type __n)
1423 {
1424 _M_range_check(__n);
1425 return (*this)[__n];
1426 }
1427
1428 /**
1429 * @brief Provides access to the data contained in the %deque.
1430 * @param __n The index of the element for which data should be
1431 * accessed.
1432 * @return Read-only (constant) reference to data.
1433 * @throw std::out_of_range If @a __n is an invalid index.
1434 *
1435 * This function provides for safer data access. The parameter is first
1436 * checked that it is in the range of the deque. The function throws
1437 * out_of_range if the check fails.
1438 */
1439 const_reference
1440 at(size_type __n) const
1441 {
1442 _M_range_check(__n);
1443 return (*this)[__n];
1444 }
1445
1446 /**
1447 * Returns a read/write reference to the data at the first
1448 * element of the %deque.
1449 */
1450 reference
1451 front() _GLIBCXX_NOEXCEPT
1452 {
1453 __glibcxx_requires_nonempty();
1454 return *begin();
1455 }
1456
1457 /**
1458 * Returns a read-only (constant) reference to the data at the first
1459 * element of the %deque.
1460 */
1461 const_reference
1462 front() const _GLIBCXX_NOEXCEPT
1463 {
1464 __glibcxx_requires_nonempty();
1465 return *begin();
1466 }
1467
1468 /**
1469 * Returns a read/write reference to the data at the last element of the
1470 * %deque.
1471 */
1472 reference
1473 back() _GLIBCXX_NOEXCEPT
1474 {
1475 __glibcxx_requires_nonempty();
1476 iterator __tmp = end();
1477 --__tmp;
1478 return *__tmp;
1479 }
1480
1481 /**
1482 * Returns a read-only (constant) reference to the data at the last
1483 * element of the %deque.
1484 */
1485 const_reference
1486 back() const _GLIBCXX_NOEXCEPT
1487 {
1488 __glibcxx_requires_nonempty();
1489 const_iterator __tmp = end();
1490 --__tmp;
1491 return *__tmp;
1492 }
1493
1494 // [23.2.1.2] modifiers
1495 /**
1496 * @brief Add data to the front of the %deque.
1497 * @param __x Data to be added.
1498 *
1499 * This is a typical stack operation. The function creates an
1500 * element at the front of the %deque and assigns the given
1501 * data to it. Due to the nature of a %deque this operation
1502 * can be done in constant time.
1503 */
1504 void
1505 push_front(const value_type& __x)
1506 {
1507 if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
1508 {
1509 _Alloc_traits::construct(this->_M_impl,
1510 this->_M_impl._M_start._M_cur - 1,
1511 __x);
1512 --this->_M_impl._M_start._M_cur;
1513 }
1514 else
1515 _M_push_front_aux(__x);
1516 }
1517
1518#if __cplusplus >= 201103L
1519 void
1520 push_front(value_type&& __x)
1521 { emplace_front(std::move(__x)); }
1522
1523 template<typename... _Args>
1524#if __cplusplus > 201402L
1525 reference
1526#else
1527 void
1528#endif
1529 emplace_front(_Args&&... __args);
1530#endif
1531
1532 /**
1533 * @brief Add data to the end of the %deque.
1534 * @param __x Data to be added.
1535 *
1536 * This is a typical stack operation. The function creates an
1537 * element at the end of the %deque and assigns the given data
1538 * to it. Due to the nature of a %deque this operation can be
1539 * done in constant time.
1540 */
1541 void
1542 push_back(const value_type& __x)
1543 {
1544 if (this->_M_impl._M_finish._M_cur
1545 != this->_M_impl._M_finish._M_last - 1)
1546 {
1547 _Alloc_traits::construct(this->_M_impl,
1548 this->_M_impl._M_finish._M_cur, __x);
1549 ++this->_M_impl._M_finish._M_cur;
1550 }
1551 else
1552 _M_push_back_aux(__x);
1553 }
1554
1555#if __cplusplus >= 201103L
1556 void
1557 push_back(value_type&& __x)
1558 { emplace_back(std::move(__x)); }
1559
1560 template<typename... _Args>
1561#if __cplusplus > 201402L
1562 reference
1563#else
1564 void
1565#endif
1566 emplace_back(_Args&&... __args);
1567#endif
1568
1569 /**
1570 * @brief Removes first element.
1571 *
1572 * This is a typical stack operation. It shrinks the %deque by one.
1573 *
1574 * Note that no data is returned, and if the first element's data is
1575 * needed, it should be retrieved before pop_front() is called.
1576 */
1577 void
1578 pop_front() _GLIBCXX_NOEXCEPT
1579 {
1580 __glibcxx_requires_nonempty();
1581 if (this->_M_impl._M_start._M_cur
1582 != this->_M_impl._M_start._M_last - 1)
1583 {
1584 _Alloc_traits::destroy(this->_M_impl,
1585 this->_M_impl._M_start._M_cur);
1586 ++this->_M_impl._M_start._M_cur;
1587 }
1588 else
1589 _M_pop_front_aux();
1590 }
1591
1592 /**
1593 * @brief Removes last element.
1594 *
1595 * This is a typical stack operation. It shrinks the %deque by one.
1596 *
1597 * Note that no data is returned, and if the last element's data is
1598 * needed, it should be retrieved before pop_back() is called.
1599 */
1600 void
1601 pop_back() _GLIBCXX_NOEXCEPT
1602 {
1603 __glibcxx_requires_nonempty();
1604 if (this->_M_impl._M_finish._M_cur
1605 != this->_M_impl._M_finish._M_first)
1606 {
1607 --this->_M_impl._M_finish._M_cur;
1608 _Alloc_traits::destroy(this->_M_impl,
1609 this->_M_impl._M_finish._M_cur);
1610 }
1611 else
1612 _M_pop_back_aux();
1613 }
1614
1615#if __cplusplus >= 201103L
1616 /**
1617 * @brief Inserts an object in %deque before specified iterator.
1618 * @param __position A const_iterator into the %deque.
1619 * @param __args Arguments.
1620 * @return An iterator that points to the inserted data.
1621 *
1622 * This function will insert an object of type T constructed
1623 * with T(std::forward<Args>(args)...) before the specified location.
1624 */
1625 template<typename... _Args>
1626 iterator
1627 emplace(const_iterator __position, _Args&&... __args);
1628
1629 /**
1630 * @brief Inserts given value into %deque before specified iterator.
1631 * @param __position A const_iterator into the %deque.
1632 * @param __x Data to be inserted.
1633 * @return An iterator that points to the inserted data.
1634 *
1635 * This function will insert a copy of the given value before the
1636 * specified location.
1637 */
1638 iterator
1639 insert(const_iterator __position, const value_type& __x);
1640#else
1641 /**
1642 * @brief Inserts given value into %deque before specified iterator.
1643 * @param __position An iterator into the %deque.
1644 * @param __x Data to be inserted.
1645 * @return An iterator that points to the inserted data.
1646 *
1647 * This function will insert a copy of the given value before the
1648 * specified location.
1649 */
1650 iterator
1651 insert(iterator __position, const value_type& __x);
1652#endif
1653
1654#if __cplusplus >= 201103L
1655 /**
1656 * @brief Inserts given rvalue into %deque before specified iterator.
1657 * @param __position A const_iterator into the %deque.
1658 * @param __x Data to be inserted.
1659 * @return An iterator that points to the inserted data.
1660 *
1661 * This function will insert a copy of the given rvalue before the
1662 * specified location.
1663 */
1664 iterator
1665 insert(const_iterator __position, value_type&& __x)
1666 { return emplace(__position, std::move(__x)); }
1667
1668 /**
1669 * @brief Inserts an initializer list into the %deque.
1670 * @param __p An iterator into the %deque.
1671 * @param __l An initializer_list.
1672 *
1673 * This function will insert copies of the data in the
1674 * initializer_list @a __l into the %deque before the location
1675 * specified by @a __p. This is known as <em>list insert</em>.
1676 */
1677 iterator
1678 insert(const_iterator __p, initializer_list<value_type> __l)
1679 {
1680 auto __offset = __p - cbegin();
1681 _M_range_insert_aux(__p._M_const_cast(), __l.begin(), __l.end(),
1682 std::random_access_iterator_tag());
1683 return begin() + __offset;
1684 }
1685#endif
1686
1687#if __cplusplus >= 201103L
1688 /**
1689 * @brief Inserts a number of copies of given data into the %deque.
1690 * @param __position A const_iterator into the %deque.
1691 * @param __n Number of elements to be inserted.
1692 * @param __x Data to be inserted.
1693 * @return An iterator that points to the inserted data.
1694 *
1695 * This function will insert a specified number of copies of the given
1696 * data before the location specified by @a __position.
1697 */
1698 iterator
1699 insert(const_iterator __position, size_type __n, const value_type& __x)
1700 {
1701 difference_type __offset = __position - cbegin();
1702 _M_fill_insert(__position._M_const_cast(), __n, __x);
1703 return begin() + __offset;
1704 }
1705#else
1706 /**
1707 * @brief Inserts a number of copies of given data into the %deque.
1708 * @param __position An iterator into the %deque.
1709 * @param __n Number of elements to be inserted.
1710 * @param __x Data to be inserted.
1711 *
1712 * This function will insert a specified number of copies of the given
1713 * data before the location specified by @a __position.
1714 */
1715 void
1716 insert(iterator __position, size_type __n, const value_type& __x)
1717 { _M_fill_insert(__position, __n, __x); }
1718#endif
1719
1720#if __cplusplus >= 201103L
1721 /**
1722 * @brief Inserts a range into the %deque.
1723 * @param __position A const_iterator into the %deque.
1724 * @param __first An input iterator.
1725 * @param __last An input iterator.
1726 * @return An iterator that points to the inserted data.
1727 *
1728 * This function will insert copies of the data in the range
1729 * [__first,__last) into the %deque before the location specified
1730 * by @a __position. This is known as <em>range insert</em>.
1731 */
1732 template<typename _InputIterator,
1733 typename = std::_RequireInputIter<_InputIterator>>
1734 iterator
1735 insert(const_iterator __position, _InputIterator __first,
1736 _InputIterator __last)
1737 {
1738 difference_type __offset = __position - cbegin();
1739 _M_insert_dispatch(__position._M_const_cast(),
1740 __first, __last, __false_type());
1741 return begin() + __offset;
1742 }
1743#else
1744 /**
1745 * @brief Inserts a range into the %deque.
1746 * @param __position An iterator into the %deque.
1747 * @param __first An input iterator.
1748 * @param __last An input iterator.
1749 *
1750 * This function will insert copies of the data in the range
1751 * [__first,__last) into the %deque before the location specified
1752 * by @a __position. This is known as <em>range insert</em>.
1753 */
1754 template<typename _InputIterator>
1755 void
1756 insert(iterator __position, _InputIterator __first,
1757 _InputIterator __last)
1758 {
1759 // Check whether it's an integral type. If so, it's not an iterator.
1760 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1761 _M_insert_dispatch(__position, __first, __last, _Integral());
1762 }
1763#endif
1764
1765 /**
1766 * @brief Remove element at given position.
1767 * @param __position Iterator pointing to element to be erased.
1768 * @return An iterator pointing to the next element (or end()).
1769 *
1770 * This function will erase the element at the given position and thus
1771 * shorten the %deque by one.
1772 *
1773 * The user is cautioned that
1774 * this function only erases the element, and that if the element is
1775 * itself a pointer, the pointed-to memory is not touched in any way.
1776 * Managing the pointer is the user's responsibility.
1777 */
1778 iterator
1779#if __cplusplus >= 201103L
1780 erase(const_iterator __position)
1781#else
1782 erase(iterator __position)
1783#endif
1784 { return _M_erase(__position._M_const_cast()); }
1785
1786 /**
1787 * @brief Remove a range of elements.
1788 * @param __first Iterator pointing to the first element to be erased.
1789 * @param __last Iterator pointing to one past the last element to be
1790 * erased.
1791 * @return An iterator pointing to the element pointed to by @a last
1792 * prior to erasing (or end()).
1793 *
1794 * This function will erase the elements in the range
1795 * [__first,__last) and shorten the %deque accordingly.
1796 *
1797 * The user is cautioned that
1798 * this function only erases the elements, and that if the elements
1799 * themselves are pointers, the pointed-to memory is not touched in any
1800 * way. Managing the pointer is the user's responsibility.
1801 */
1802 iterator
1803#if __cplusplus >= 201103L
1804 erase(const_iterator __first, const_iterator __last)
1805#else
1806 erase(iterator __first, iterator __last)
1807#endif
1808 { return _M_erase(__first._M_const_cast(), __last._M_const_cast()); }
1809
1810 /**
1811 * @brief Swaps data with another %deque.
1812 * @param __x A %deque of the same element and allocator types.
1813 *
1814 * This exchanges the elements between two deques in constant time.
1815 * (Four pointers, so it should be quite fast.)
1816 * Note that the global std::swap() function is specialized such that
1817 * std::swap(d1,d2) will feed to this function.
1818 *
1819 * Whether the allocators are swapped depends on the allocator traits.
1820 */
1821 void
1822 swap(deque& __x) _GLIBCXX_NOEXCEPT
1823 {
1824#if __cplusplus >= 201103L
1825 __glibcxx_assert(_Alloc_traits::propagate_on_container_swap::value
1826 || _M_get_Tp_allocator() == __x._M_get_Tp_allocator());
1827#endif
1828 _M_impl._M_swap_data(__x._M_impl);
1829 _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(),
1830 __x._M_get_Tp_allocator());
1831 }
1832
1833 /**
1834 * Erases all the elements. Note that this function only erases the
1835 * elements, and that if the elements themselves are pointers, the
1836 * pointed-to memory is not touched in any way. Managing the pointer is
1837 * the user's responsibility.
1838 */
1839 void
1840 clear() _GLIBCXX_NOEXCEPT
1841 { _M_erase_at_end(begin()); }
1842
1843 protected:
1844 // Internal constructor functions follow.
1845
1846 // called by the range constructor to implement [23.1.1]/9
1847
1848 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1849 // 438. Ambiguity in the "do the right thing" clause
1850 template<typename _Integer>
1851 void
1852 _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
1853 {
1854 _M_initialize_map(static_cast<size_type>(__n));
1855 _M_fill_initialize(__x);
1856 }
1857
1858 // called by the range constructor to implement [23.1.1]/9
1859 template<typename _InputIterator>
1860 void
1861 _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
1862 __false_type)
1863 {
1864 _M_range_initialize(__first, __last,
1865 std::__iterator_category(__first));
1866 }
1867
1868 // called by the second initialize_dispatch above
1869 //@{
1870 /**
1871 * @brief Fills the deque with whatever is in [first,last).
1872 * @param __first An input iterator.
1873 * @param __last An input iterator.
1874 * @return Nothing.
1875 *
1876 * If the iterators are actually forward iterators (or better), then the
1877 * memory layout can be done all at once. Else we move forward using
1878 * push_back on each value from the iterator.
1879 */
1880 template<typename _InputIterator>
1881 void
1882 _M_range_initialize(_InputIterator __first, _InputIterator __last,
1883 std::input_iterator_tag);
1884
1885 // called by the second initialize_dispatch above
1886 template<typename _ForwardIterator>
1887 void
1888 _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
1889 std::forward_iterator_tag);
1890 //@}
1891
1892 /**
1893 * @brief Fills the %deque with copies of value.
1894 * @param __value Initial value.
1895 * @return Nothing.
1896 * @pre _M_start and _M_finish have already been initialized,
1897 * but none of the %deque's elements have yet been constructed.
1898 *
1899 * This function is called only when the user provides an explicit size
1900 * (with or without an explicit exemplar value).
1901 */
1902 void
1903 _M_fill_initialize(const value_type& __value);
1904
1905#if __cplusplus >= 201103L
1906 // called by deque(n).
1907 void
1908 _M_default_initialize();
1909#endif
1910
1911 // Internal assign functions follow. The *_aux functions do the actual
1912 // assignment work for the range versions.
1913
1914 // called by the range assign to implement [23.1.1]/9
1915
1916 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1917 // 438. Ambiguity in the "do the right thing" clause
1918 template<typename _Integer>
1919 void
1920 _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
1921 { _M_fill_assign(__n, __val); }
1922
1923 // called by the range assign to implement [23.1.1]/9
1924 template<typename _InputIterator>
1925 void
1926 _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
1927 __false_type)
1928 { _M_assign_aux(__first, __last, std::__iterator_category(__first)); }
1929
1930 // called by the second assign_dispatch above
1931 template<typename _InputIterator>
1932 void
1933 _M_assign_aux(_InputIterator __first, _InputIterator __last,
1934 std::input_iterator_tag);
1935
1936 // called by the second assign_dispatch above
1937 template<typename _ForwardIterator>
1938 void
1939 _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
1940 std::forward_iterator_tag)
1941 {
1942 const size_type __len = std::distance(__first, __last);
1943 if (__len > size())
1944 {
1945 _ForwardIterator __mid = __first;
1946 std::advance(__mid, size());
1947 std::copy(__first, __mid, begin());
1948 _M_range_insert_aux(end(), __mid, __last,
1949 std::__iterator_category(__first));
1950 }
1951 else
1952 _M_erase_at_end(std::copy(__first, __last, begin()));
1953 }
1954
1955 // Called by assign(n,t), and the range assign when it turns out
1956 // to be the same thing.
1957 void
1958 _M_fill_assign(size_type __n, const value_type& __val)
1959 {
1960 if (__n > size())
1961 {
1962 std::fill(begin(), end(), __val);
1963 _M_fill_insert(end(), __n - size(), __val);
1964 }
1965 else
1966 {
1967 _M_erase_at_end(begin() + difference_type(__n));
1968 std::fill(begin(), end(), __val);
1969 }
1970 }
1971
1972 //@{
1973 /// Helper functions for push_* and pop_*.
1974#if __cplusplus < 201103L
1975 void _M_push_back_aux(const value_type&);
1976
1977 void _M_push_front_aux(const value_type&);
1978#else
1979 template<typename... _Args>
1980 void _M_push_back_aux(_Args&&... __args);
1981
1982 template<typename... _Args>
1983 void _M_push_front_aux(_Args&&... __args);
1984#endif
1985
1986 void _M_pop_back_aux();
1987
1988 void _M_pop_front_aux();
1989 //@}
1990
1991 // Internal insert functions follow. The *_aux functions do the actual
1992 // insertion work when all shortcuts fail.
1993
1994 // called by the range insert to implement [23.1.1]/9
1995
1996 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1997 // 438. Ambiguity in the "do the right thing" clause
1998 template<typename _Integer>
1999 void
2000 _M_insert_dispatch(iterator __pos,
2001 _Integer __n, _Integer __x, __true_type)
2002 { _M_fill_insert(__pos, __n, __x); }
2003
2004 // called by the range insert to implement [23.1.1]/9
2005 template<typename _InputIterator>
2006 void
2007 _M_insert_dispatch(iterator __pos,
2008 _InputIterator __first, _InputIterator __last,
2009 __false_type)
2010 {
2011 _M_range_insert_aux(__pos, __first, __last,
2012 std::__iterator_category(__first));
2013 }
2014
2015 // called by the second insert_dispatch above
2016 template<typename _InputIterator>
2017 void
2018 _M_range_insert_aux(iterator __pos, _InputIterator __first,
2019 _InputIterator __last, std::input_iterator_tag);
2020
2021 // called by the second insert_dispatch above
2022 template<typename _ForwardIterator>
2023 void
2024 _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
2025 _ForwardIterator __last, std::forward_iterator_tag);
2026
2027 // Called by insert(p,n,x), and the range insert when it turns out to be
2028 // the same thing. Can use fill functions in optimal situations,
2029 // otherwise passes off to insert_aux(p,n,x).
2030 void
2031 _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
2032
2033 // called by insert(p,x)
2034#if __cplusplus < 201103L
2035 iterator
2036 _M_insert_aux(iterator __pos, const value_type& __x);
2037#else
2038 template<typename... _Args>
2039 iterator
2040 _M_insert_aux(iterator __pos, _Args&&... __args);
2041#endif
2042
2043 // called by insert(p,n,x) via fill_insert
2044 void
2045 _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
2046
2047 // called by range_insert_aux for forward iterators
2048 template<typename _ForwardIterator>
2049 void
2050 _M_insert_aux(iterator __pos,
2051 _ForwardIterator __first, _ForwardIterator __last,
2052 size_type __n);
2053
2054
2055 // Internal erase functions follow.
2056
2057 void
2058 _M_destroy_data_aux(iterator __first, iterator __last);
2059
2060 // Called by ~deque().
2061 // NB: Doesn't deallocate the nodes.
2062 template<typename _Alloc1>
2063 void
2064 _M_destroy_data(iterator __first, iterator __last, const _Alloc1&)
2065 { _M_destroy_data_aux(__first, __last); }
2066
2067 void
2068 _M_destroy_data(iterator __first, iterator __last,
2069 const std::allocator<_Tp>&)
2070 {
2071 if (!__has_trivial_destructor(value_type))
2072 _M_destroy_data_aux(__first, __last);
2073 }
2074
2075 // Called by erase(q1, q2).
2076 void
2077 _M_erase_at_begin(iterator __pos)
2078 {
2079 _M_destroy_data(begin(), __pos, _M_get_Tp_allocator());
2080 _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node);
2081 this->_M_impl._M_start = __pos;
2082 }
2083
2084 // Called by erase(q1, q2), resize(), clear(), _M_assign_aux,
2085 // _M_fill_assign, operator=.
2086 void
2087 _M_erase_at_end(iterator __pos)
2088 {
2089 _M_destroy_data(__pos, end(), _M_get_Tp_allocator());
2090 _M_destroy_nodes(__pos._M_node + 1,
2091 this->_M_impl._M_finish._M_node + 1);
2092 this->_M_impl._M_finish = __pos;
2093 }
2094
2095 iterator
2096 _M_erase(iterator __pos);
2097
2098 iterator
2099 _M_erase(iterator __first, iterator __last);
2100
2101#if __cplusplus >= 201103L
2102 // Called by resize(sz).
2103 void
2104 _M_default_append(size_type __n);
2105
2106 bool
2107 _M_shrink_to_fit();
2108#endif
2109
2110 //@{
2111 /// Memory-handling helpers for the previous internal insert functions.
2112 iterator
2113 _M_reserve_elements_at_front(size_type __n)
2114 {
2115 const size_type __vacancies = this->_M_impl._M_start._M_cur
2116 - this->_M_impl._M_start._M_first;
2117 if (__n > __vacancies)
2118 _M_new_elements_at_front(__n - __vacancies);
2119 return this->_M_impl._M_start - difference_type(__n);
2120 }
2121
2122 iterator
2123 _M_reserve_elements_at_back(size_type __n)
2124 {
2125 const size_type __vacancies = (this->_M_impl._M_finish._M_last
2126 - this->_M_impl._M_finish._M_cur) - 1;
2127 if (__n > __vacancies)
2128 _M_new_elements_at_back(__n - __vacancies);
2129 return this->_M_impl._M_finish + difference_type(__n);
2130 }
2131
2132 void
2133 _M_new_elements_at_front(size_type __new_elements);
2134
2135 void
2136 _M_new_elements_at_back(size_type __new_elements);
2137 //@}
2138
2139
2140 //@{
2141 /**
2142 * @brief Memory-handling helpers for the major %map.
2143 *
2144 * Makes sure the _M_map has space for new nodes. Does not
2145 * actually add the nodes. Can invalidate _M_map pointers.
2146 * (And consequently, %deque iterators.)
2147 */
2148 void
2149 _M_reserve_map_at_back(size_type __nodes_to_add = 1)
2150 {
2151 if (__nodes_to_add + 1 > this->_M_impl._M_map_size
2152 - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
2153 _M_reallocate_map(__nodes_to_add, false);
2154 }
2155
2156 void
2157 _M_reserve_map_at_front(size_type __nodes_to_add = 1)
2158 {
2159 if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
2160 - this->_M_impl._M_map))
2161 _M_reallocate_map(__nodes_to_add, true);
2162 }
2163
2164 void
2165 _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
2166 //@}
2167
2168#if __cplusplus >= 201103L
2169 // Constant-time, nothrow move assignment when source object's memory
2170 // can be moved because the allocators are equal.
2171 void
2172 _M_move_assign1(deque&& __x, /* always equal: */ true_type) noexcept
2173 {
2174 this->_M_impl._M_swap_data(__x._M_impl);
2175 __x.clear();
2176 std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator());
2177 }
2178
2179 // When the allocators are not equal the operation could throw, because
2180 // we might need to allocate a new map for __x after moving from it
2181 // or we might need to allocate new elements for *this.
2182 void
2183 _M_move_assign1(deque&& __x, /* always equal: */ false_type)
2184 {
2185 constexpr bool __move_storage =
2186 _Alloc_traits::_S_propagate_on_move_assign();
2187 _M_move_assign2(std::move(__x), __bool_constant<__move_storage>());
2188 }
2189
2190 // Destroy all elements and deallocate all memory, then replace
2191 // with elements created from __args.
2192 template<typename... _Args>
2193 void
2194 _M_replace_map(_Args&&... __args)
2195 {
2196 // Create new data first, so if allocation fails there are no effects.
2197 deque __newobj(std::forward<_Args>(__args)...);
2198 // Free existing storage using existing allocator.
2199 clear();
2200 _M_deallocate_node(*begin()._M_node); // one node left after clear()
2201 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
2202 this->_M_impl._M_map = nullptr;
2203 this->_M_impl._M_map_size = 0;
2204 // Take ownership of replacement memory.
2205 this->_M_impl._M_swap_data(__newobj._M_impl);
2206 }
2207
2208 // Do move assignment when the allocator propagates.
2209 void
2210 _M_move_assign2(deque&& __x, /* propagate: */ true_type)
2211 {
2212 // Make a copy of the original allocator state.
2213 auto __alloc = __x._M_get_Tp_allocator();
2214 // The allocator propagates so storage can be moved from __x,
2215 // leaving __x in a valid empty state with a moved-from allocator.
2216 _M_replace_map(std::move(__x));
2217 // Move the corresponding allocator state too.
2218 _M_get_Tp_allocator() = std::move(__alloc);
2219 }
2220
2221 // Do move assignment when it may not be possible to move source
2222 // object's memory, resulting in a linear-time operation.
2223 void
2224 _M_move_assign2(deque&& __x, /* propagate: */ false_type)
2225 {
2226 if (__x._M_get_Tp_allocator() == this->_M_get_Tp_allocator())
2227 {
2228 // The allocators are equal so storage can be moved from __x,
2229 // leaving __x in a valid empty state with its current allocator.
2230 _M_replace_map(std::move(__x), __x.get_allocator());
2231 }
2232 else
2233 {
2234 // The rvalue's allocator cannot be moved and is not equal,
2235 // so we need to individually move each element.
2236 _M_assign_aux(std::__make_move_if_noexcept_iterator(__x.begin()),
2237 std::__make_move_if_noexcept_iterator(__x.end()),
2238 std::random_access_iterator_tag());
2239 __x.clear();
2240 }
2241 }
2242#endif
2243 };
2244
2245
2246 /**
2247 * @brief Deque equality comparison.
2248 * @param __x A %deque.
2249 * @param __y A %deque of the same type as @a __x.
2250 * @return True iff the size and elements of the deques are equal.
2251 *
2252 * This is an equivalence relation. It is linear in the size of the
2253 * deques. Deques are considered equivalent if their sizes are equal,
2254 * and if corresponding elements compare equal.
2255 */
2256 template<typename _Tp, typename _Alloc>
2257 inline bool
2258 operator==(const deque<_Tp, _Alloc>& __x,
2259 const deque<_Tp, _Alloc>& __y)
2260 { return __x.size() == __y.size()
2261 && std::equal(__x.begin(), __x.end(), __y.begin()); }
2262
2263 /**
2264 * @brief Deque ordering relation.
2265 * @param __x A %deque.
2266 * @param __y A %deque of the same type as @a __x.
2267 * @return True iff @a x is lexicographically less than @a __y.
2268 *
2269 * This is a total ordering relation. It is linear in the size of the
2270 * deques. The elements must be comparable with @c <.
2271 *
2272 * See std::lexicographical_compare() for how the determination is made.
2273 */
2274 template<typename _Tp, typename _Alloc>
2275 inline bool
2276 operator<(const deque<_Tp, _Alloc>& __x,
2277 const deque<_Tp, _Alloc>& __y)
2278 { return std::lexicographical_compare(__x.begin(), __x.end(),
2279 __y.begin(), __y.end()); }
2280
2281 /// Based on operator==
2282 template<typename _Tp, typename _Alloc>
2283 inline bool
2284 operator!=(const deque<_Tp, _Alloc>& __x,
2285 const deque<_Tp, _Alloc>& __y)
2286 { return !(__x == __y); }
2287
2288 /// Based on operator<
2289 template<typename _Tp, typename _Alloc>
2290 inline bool
2291 operator>(const deque<_Tp, _Alloc>& __x,
2292 const deque<_Tp, _Alloc>& __y)
2293 { return __y < __x; }
2294
2295 /// Based on operator<
2296 template<typename _Tp, typename _Alloc>
2297 inline bool
2298 operator<=(const deque<_Tp, _Alloc>& __x,
2299 const deque<_Tp, _Alloc>& __y)
2300 { return !(__y < __x); }
2301
2302 /// Based on operator<
2303 template<typename _Tp, typename _Alloc>
2304 inline bool
2305 operator>=(const deque<_Tp, _Alloc>& __x,
2306 const deque<_Tp, _Alloc>& __y)
2307 { return !(__x < __y); }
2308
2309 /// See std::deque::swap().
2310 template<typename _Tp, typename _Alloc>
2311 inline void
2312 swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y)
2313 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
2314 { __x.swap(__y); }
2315
2316#undef _GLIBCXX_DEQUE_BUF_SIZE
2317
2318_GLIBCXX_END_NAMESPACE_CONTAINER
2319} // namespace std
2320
2321#endif /* _STL_DEQUE_H */
2322