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
66namespace 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 */
2284