1// Deque implementation -*- C++ -*-
2
3// Copyright (C) 2001-2019 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#include <bits/stl_uninitialized.h> // for __is_bitwise_relocatable
65#endif
66
67#include <debug/assertions.h>
68
69namespace std _GLIBCXX_VISIBILITY(default)
70{
71_GLIBCXX_BEGIN_NAMESPACE_VERSION
72_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
73
74 /**
75 * @brief This function controls the size of memory nodes.
76 * @param __size The size of an element.
77 * @return The number (not byte size) of elements per node.
78 *
79 * This function started off as a compiler kludge from SGI, but
80 * seems to be a useful wrapper around a repeated constant
81 * expression. The @b 512 is tunable (and no other code needs to
82 * change), but no investigation has been done since inheriting the
83 * SGI code. Touch _GLIBCXX_DEQUE_BUF_SIZE only if you know what
84 * you are doing, however: changing it breaks the binary
85 * compatibility!!
86 */
87
88#ifndef _GLIBCXX_DEQUE_BUF_SIZE
89#define _GLIBCXX_DEQUE_BUF_SIZE 512
90#endif
91
92 _GLIBCXX_CONSTEXPR inline size_t
93 __deque_buf_size(size_t __size)
94 { return (__size < _GLIBCXX_DEQUE_BUF_SIZE
95 ? size_t(_GLIBCXX_DEQUE_BUF_SIZE / __size) : size_t(1)); }
96
97
98 /**
99 * @brief A deque::iterator.
100 *
101 * Quite a bit of intelligence here. Much of the functionality of
102 * deque is actually passed off to this class. A deque holds two
103 * of these internally, marking its valid range. Access to
104 * elements is done as offsets of either of those two, relying on
105 * operator overloading in this class.
106 *
107 * All the functions are op overloads except for _M_set_node.
108 */
109 template<typename _Tp, typename _Ref, typename _Ptr>
110 struct _Deque_iterator
111 {
112#if __cplusplus < 201103L
113 typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator;
114 typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
115 typedef _Tp* _Elt_pointer;
116 typedef _Tp** _Map_pointer;
117#else
118 private:
119 template<typename _Up>
120 using __ptr_to = typename pointer_traits<_Ptr>::template rebind<_Up>;
121 template<typename _CvTp>
122 using __iter = _Deque_iterator<_Tp, _CvTp&, __ptr_to<_CvTp>>;
123 public:
124 typedef __iter<_Tp> iterator;
125 typedef __iter<const _Tp> const_iterator;
126 typedef __ptr_to<_Tp> _Elt_pointer;
127 typedef __ptr_to<_Elt_pointer> _Map_pointer;
128#endif
129
130 static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
131 { return __deque_buf_size(sizeof(_Tp)); }
132
133 typedef std::random_access_iterator_tag iterator_category;
134 typedef _Tp value_type;
135 typedef _Ptr pointer;
136 typedef _Ref reference;
137 typedef size_t size_type;
138 typedef ptrdiff_t difference_type;
139 typedef _Deque_iterator _Self;
140
141 _Elt_pointer _M_cur;
142 _Elt_pointer _M_first;
143 _Elt_pointer _M_last;
144 _Map_pointer _M_node;
145
146 _Deque_iterator(_Elt_pointer __x, _Map_pointer __y) _GLIBCXX_NOEXCEPT
147 : _M_cur(__x), _M_first(*__y),
148 _M_last(*__y + _S_buffer_size()), _M_node(__y) { }
149
150 _Deque_iterator() _GLIBCXX_NOEXCEPT
151 : _M_cur(), _M_first(), _M_last(), _M_node() { }
152
153#if __cplusplus < 201103L
154 // Conversion from iterator to const_iterator.
155 _Deque_iterator(const iterator& __x) _GLIBCXX_NOEXCEPT
156 : _M_cur(__x._M_cur), _M_first(__x._M_first),
157 _M_last(__x._M_last), _M_node(__x._M_node) { }
158#else
159 // Conversion from iterator to const_iterator.
160 template<typename _Iter,
161 typename = _Require<is_same<_Self, const_iterator>,
162 is_same<_Iter, iterator>>>
163 _Deque_iterator(const _Iter& __x) noexcept
164 : _M_cur(__x._M_cur), _M_first(__x._M_first),
165 _M_last(__x._M_last), _M_node(__x._M_node) { }
166
167 _Deque_iterator(const _Deque_iterator& __x) noexcept
168 : _M_cur(__x._M_cur), _M_first(__x._M_first),
169 _M_last(__x._M_last), _M_node(__x._M_node) { }
170
171 _Deque_iterator& operator=(const _Deque_iterator&) = default;
172#endif
173
174 iterator
175 _M_const_cast() const _GLIBCXX_NOEXCEPT
176 { return iterator(_M_cur, _M_node); }
177
178 reference
179 operator*() const _GLIBCXX_NOEXCEPT
180 { return *_M_cur; }
181
182 pointer
183 operator->() const _GLIBCXX_NOEXCEPT
184 { return _M_cur; }
185
186 _Self&
187 operator++() _GLIBCXX_NOEXCEPT
188 {
189 ++_M_cur;
190 if (_M_cur == _M_last)
191 {
192 _M_set_node(_M_node + 1);
193 _M_cur = _M_first;
194 }
195 return *this;
196 }
197
198 _Self
199 operator++(int) _GLIBCXX_NOEXCEPT
200 {
201 _Self __tmp = *this;
202 ++*this;
203 return __tmp;
204 }
205
206 _Self&
207 operator--() _GLIBCXX_NOEXCEPT
208 {
209 if (_M_cur == _M_first)
210 {
211 _M_set_node(_M_node - 1);
212 _M_cur = _M_last;
213 }
214 --_M_cur;
215 return *this;
216 }
217
218 _Self
219 operator--(int) _GLIBCXX_NOEXCEPT
220 {
221 _Self __tmp = *this;
222 --*this;
223 return __tmp;
224 }
225
226 _Self&
227 operator+=(difference_type __n) _GLIBCXX_NOEXCEPT
228 {
229 const difference_type __offset = __n + (_M_cur - _M_first);
230 if (__offset >= 0 && __offset < difference_type(_S_buffer_size()))
231 _M_cur += __n;
232 else
233 {
234 const difference_type __node_offset =
235 __offset > 0 ? __offset / difference_type(_S_buffer_size())
236 : -difference_type((-__offset - 1)
237 / _S_buffer_size()) - 1;
238 _M_set_node(_M_node + __node_offset);
239 _M_cur = _M_first + (__offset - __node_offset
240 * difference_type(_S_buffer_size()));
241 }
242 return *this;
243 }
244
245 _Self
246 operator+(difference_type __n) const _GLIBCXX_NOEXCEPT
247 {
248 _Self __tmp = *this;
249 return __tmp += __n;
250 }
251
252 _Self&
253 operator-=(difference_type __n) _GLIBCXX_NOEXCEPT
254 { return *this += -__n; }
255
256 _Self
257 operator-(difference_type __n) const _GLIBCXX_NOEXCEPT
258 {
259 _Self __tmp = *this;
260 return __tmp -= __n;
261 }
262
263 reference
264 operator[](difference_type __n) const _GLIBCXX_NOEXCEPT
265 { return *(*this + __n); }
266
267 /**
268 * Prepares to traverse new_node. Sets everything except
269 * _M_cur, which should therefore be set by the caller
270 * immediately afterwards, based on _M_first and _M_last.
271 */
272 void
273 _M_set_node(_Map_pointer __new_node) _GLIBCXX_NOEXCEPT
274 {
275 _M_node = __new_node;
276 _M_first = *__new_node;
277 _M_last = _M_first + difference_type(_S_buffer_size());
278 }
279 };
280
281 // Note: we also provide overloads whose operands are of the same type in
282 // order to avoid ambiguous overload resolution when std::rel_ops operators
283 // are in scope (for additional details, see libstdc++/3628)
284 template<typename _Tp, typename _Ref, typename _Ptr>
285 inline bool
286 operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
287 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
288 { return __x._M_cur == __y._M_cur; }
289
290 template<typename _Tp, typename _RefL, typename _PtrL,
291 typename _RefR, typename _PtrR>
292 inline bool
293 operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
294 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
295 { return __x._M_cur == __y._M_cur; }
296
297 template<typename _Tp, typename _Ref, typename _Ptr>
298 inline bool
299 operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
300 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
301 { return !(__x == __y); }
302
303 template<typename _Tp, typename _RefL, typename _PtrL,
304 typename _RefR, typename _PtrR>
305 inline bool
306 operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
307 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
308 { return !(__x == __y); }
309
310 template<typename _Tp, typename _Ref, typename _Ptr>
311 inline bool
312 operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
313 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
314 { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
315 : (__x._M_node < __y._M_node); }
316
317 template<typename _Tp, typename _RefL, typename _PtrL,
318 typename _RefR, typename _PtrR>
319 inline bool
320 operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
321 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
322 { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
323 : (__x._M_node < __y._M_node); }
324
325 template<typename _Tp, typename _Ref, typename _Ptr>
326 inline bool
327 operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
328 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
329 { return __y < __x; }
330
331 template<typename _Tp, typename _RefL, typename _PtrL,
332 typename _RefR, typename _PtrR>
333 inline bool
334 operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
335 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
336 { return __y < __x; }
337
338 template<typename _Tp, typename _Ref, typename _Ptr>
339 inline bool
340 operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
341 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
342 { return !(__y < __x); }
343
344 template<typename _Tp, typename _RefL, typename _PtrL,
345 typename _RefR, typename _PtrR>
346 inline bool
347 operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
348 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
349 { return !(__y < __x); }
350
351 template<typename _Tp, typename _Ref, typename _Ptr>
352 inline bool
353 operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
354 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
355 { return !(__x < __y); }
356
357 template<typename _Tp, typename _RefL, typename _PtrL,
358 typename _RefR, typename _PtrR>
359 inline bool
360 operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
361 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
362 { return !(__x < __y); }
363
364 // _GLIBCXX_RESOLVE_LIB_DEFECTS
365 // According to the resolution of DR179 not only the various comparison
366 // operators but also operator- must accept mixed iterator/const_iterator
367 // parameters.
368 template<typename _Tp, typename _Ref, typename _Ptr>
369 inline typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
370 operator-(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
371 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
372 {
373 return typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
374 (_Deque_iterator<_Tp, _Ref, _Ptr>::_S_buffer_size())
375 * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
376 + (__y._M_last - __y._M_cur);
377 }
378
379 template<typename _Tp, typename _RefL, typename _PtrL,
380 typename _RefR, typename _PtrR>
381 inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
382 operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
383 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
384 {
385 return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
386 (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size())
387 * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
388 + (__y._M_last - __y._M_cur);
389 }
390
391 template<typename _Tp, typename _Ref, typename _Ptr>
392 inline _Deque_iterator<_Tp, _Ref, _Ptr>
393 operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x)
394 _GLIBCXX_NOEXCEPT
395 { return __x + __n; }
396
397 template<typename _Tp>
398 void
399 fill(const _Deque_iterator<_Tp, _Tp&, _Tp*>&,
400 const _Deque_iterator<_Tp, _Tp&, _Tp*>&, const _Tp&);
401
402 template<typename _Tp>
403 _Deque_iterator<_Tp, _Tp&, _Tp*>
404 copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
405 _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
406 _Deque_iterator<_Tp, _Tp&, _Tp*>);
407
408 template<typename _Tp>
409 inline _Deque_iterator<_Tp, _Tp&, _Tp*>
410 copy(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
411 _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
412 _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
413 { return std::copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first),
414 _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last),
415 __result); }
416
417 template<typename _Tp>
418 _Deque_iterator<_Tp, _Tp&, _Tp*>
419 copy_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
420 _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
421 _Deque_iterator<_Tp, _Tp&, _Tp*>);
422
423 template<typename _Tp>
424 inline _Deque_iterator<_Tp, _Tp&, _Tp*>
425 copy_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
426 _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
427 _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
428 { return std::copy_backward(_Deque_iterator<_Tp,
429 const _Tp&, const _Tp*>(__first),
430 _Deque_iterator<_Tp,
431 const _Tp&, const _Tp*>(__last),
432 __result); }
433
434#if __cplusplus >= 201103L
435 template<typename _Tp>
436 _Deque_iterator<_Tp, _Tp&, _Tp*>
437 move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
438 _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
439 _Deque_iterator<_Tp, _Tp&, _Tp*>);
440
441 template<typename _Tp>
442 inline _Deque_iterator<_Tp, _Tp&, _Tp*>
443 move(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
444 _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
445 _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
446 { return std::move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first),
447 _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last),
448 __result); }
449
450 template<typename _Tp>
451 _Deque_iterator<_Tp, _Tp&, _Tp*>
452 move_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
453 _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
454 _Deque_iterator<_Tp, _Tp&, _Tp*>);
455
456 template<typename _Tp>
457 inline _Deque_iterator<_Tp, _Tp&, _Tp*>
458 move_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
459 _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
460 _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
461 { return std::move_backward(_Deque_iterator<_Tp,
462 const _Tp&, const _Tp*>(__first),
463 _Deque_iterator<_Tp,
464 const _Tp&, const _Tp*>(__last),
465 __result); }
466#endif
467
468 /**
469 * Deque base class. This class provides the unified face for %deque's
470 * allocation. This class's constructor and destructor allocate and
471 * deallocate (but do not initialize) storage. This makes %exception
472 * safety easier.
473 *
474 * Nothing in this class ever constructs or destroys an actual Tp element.
475 * (Deque handles that itself.) Only/All memory management is performed
476 * here.
477 */
478 template<typename _Tp, typename _Alloc>
479 class _Deque_base
480 {
481 protected:
482 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
483 rebind<_Tp>::other _Tp_alloc_type;
484 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Alloc_traits;
485
486#if __cplusplus < 201103L
487 typedef _Tp* _Ptr;
488 typedef const _Tp* _Ptr_const;
489#else
490 typedef typename _Alloc_traits::pointer _Ptr;
491 typedef typename _Alloc_traits::const_pointer _Ptr_const;
492#endif
493
494 typedef typename _Alloc_traits::template rebind<_Ptr>::other
495 _Map_alloc_type;
496 typedef __gnu_cxx::__alloc_traits<_Map_alloc_type> _Map_alloc_traits;
497
498 public:
499 typedef _Alloc allocator_type;
500
501 allocator_type
502 get_allocator() const _GLIBCXX_NOEXCEPT
503 { return allocator_type(_M_get_Tp_allocator()); }
504
505 typedef _Deque_iterator<_Tp, _Tp&, _Ptr> iterator;
506 typedef _Deque_iterator<_Tp, const _Tp&, _Ptr_const> const_iterator;
507
508 _Deque_base()
509 : _M_impl()
510 { _M_initialize_map(0); }
511
512 _Deque_base(size_t __num_elements)
513 : _M_impl()
514 { _M_initialize_map(__num_elements); }
515
516 _Deque_base(const allocator_type& __a, size_t __num_elements)
517 : _M_impl(__a)
518 { _M_initialize_map(__num_elements); }
519
520 _Deque_base(const allocator_type& __a)
521 : _M_impl(__a)
522 { /* Caller must initialize map. */ }
523
524#if __cplusplus >= 201103L
525 _Deque_base(_Deque_base&& __x, false_type)
526 : _M_impl(__x._M_move_impl())
527 { }
528
529 _Deque_base(_Deque_base&& __x, true_type)
530 : _M_impl(std::move(__x._M_get_Tp_allocator()))
531 {
532 _M_initialize_map(0);
533 if (__x._M_impl._M_map)
534 this->_M_impl._M_swap_data(__x._M_impl);
535 }
536
537 _Deque_base(_Deque_base&& __x)
538 : _Deque_base(std::move(__x), typename _Alloc_traits::is_always_equal{})
539 { }
540
541 _Deque_base(_Deque_base&& __x, const allocator_type& __a, size_t __n)
542 : _M_impl(__a)
543 {
544 if (__x.get_allocator() == __a)
545 {
546 if (__x._M_impl._M_map)
547 {
548 _M_initialize_map(0);
549 this->_M_impl._M_swap_data(__x._M_impl);
550 }
551 }
552 else
553 {
554 _M_initialize_map(__n);
555 }
556 }
557#endif
558
559 ~_Deque_base() _GLIBCXX_NOEXCEPT;
560
561 protected:
562 typedef typename iterator::_Map_pointer _Map_pointer;
563
564 //This struct encapsulates the implementation of the std::deque
565 //standard container and at the same time makes use of the EBO
566 //for empty allocators.
567 struct _Deque_impl
568 : public _Tp_alloc_type
569 {
570 _Map_pointer _M_map;
571 size_t _M_map_size;
572 iterator _M_start;
573 iterator _M_finish;
574
575 _Deque_impl()
576 : _Tp_alloc_type(), _M_map(), _M_map_size(0),
577 _M_start(), _M_finish()
578 { }
579
580 _Deque_impl(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT
581 : _Tp_alloc_type(__a), _M_map(), _M_map_size(0),
582 _M_start(), _M_finish()
583 { }
584
585#if __cplusplus >= 201103L
586 _Deque_impl(_Deque_impl&&) = default;
587
588 _Deque_impl(_Tp_alloc_type&& __a) noexcept
589 : _Tp_alloc_type(std::move(__a)), _M_map(), _M_map_size(0),
590 _M_start(), _M_finish()
591 { }
592#endif
593
594 void _M_swap_data(_Deque_impl& __x) _GLIBCXX_NOEXCEPT
595 {
596 using std::swap;
597 swap(this->_M_start, __x._M_start);
598 swap(this->_M_finish, __x._M_finish);
599 swap(this->_M_map, __x._M_map);
600 swap(this->_M_map_size, __x._M_map_size);
601 }
602 };
603
604 _Tp_alloc_type&
605 _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT
606 { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); }
607
608 const _Tp_alloc_type&
609 _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT
610 { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); }
611
612 _Map_alloc_type
613 _M_get_map_allocator() const _GLIBCXX_NOEXCEPT
614 { return _Map_alloc_type(_M_get_Tp_allocator()); }
615
616 _Ptr
617 _M_allocate_node()
618 {
619 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
620 return _Traits::allocate(_M_impl, __deque_buf_size(sizeof(_Tp)));
621 }
622
623 void
624 _M_deallocate_node(_Ptr __p) _GLIBCXX_NOEXCEPT
625 {
626 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
627 _Traits::deallocate(_M_impl, __p, __deque_buf_size(sizeof(_Tp)));
628 }
629
630 _Map_pointer
631 _M_allocate_map(size_t __n)
632 {
633 _Map_alloc_type __map_alloc = _M_get_map_allocator();
634 return _Map_alloc_traits::allocate(__map_alloc, __n);
635 }
636
637 void
638 _M_deallocate_map(_Map_pointer __p, size_t __n) _GLIBCXX_NOEXCEPT
639 {
640 _Map_alloc_type __map_alloc = _M_get_map_allocator();
641 _Map_alloc_traits::deallocate(__map_alloc, __p, __n);
642 }
643
644 protected:
645 void _M_initialize_map(size_t);
646 void _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish);
647 void _M_destroy_nodes(_Map_pointer __nstart,
648 _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT;
649 enum { _S_initial_map_size = 8 };
650
651 _Deque_impl _M_impl;
652
653#if __cplusplus >= 201103L
654 private:
655 _Deque_impl
656 _M_move_impl()
657 {
658 if (!_M_impl._M_map)
659 return std::move(_M_impl);
660
661 // Create a copy of the current allocator.
662 _Tp_alloc_type __alloc{_M_get_Tp_allocator()};
663 // Put that copy in a moved-from state.
664 _Tp_alloc_type __sink __attribute((__unused__)) {std::move(__alloc)};
665 // Create an empty map that allocates using the moved-from allocator.
666 _Deque_base __empty{__alloc};
667 __empty._M_initialize_map(0);
668 // Now safe to modify current allocator and perform non-throwing swaps.
669 _Deque_impl __ret{std::move(_M_get_Tp_allocator())};
670 _M_impl._M_swap_data(__ret);
671 _M_impl._M_swap_data(__empty._M_impl);
672 return __ret;
673 }
674#endif
675 };
676
677 template<typename _Tp, typename _Alloc>
678 _Deque_base<_Tp, _Alloc>::
679 ~_Deque_base() _GLIBCXX_NOEXCEPT
680 {
681 if (this->_M_impl._M_map)
682 {
683 _M_destroy_nodes(this->_M_impl._M_start._M_node,
684 this->_M_impl._M_finish._M_node + 1);
685 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
686 }
687 }
688
689 /**
690 * @brief Layout storage.
691 * @param __num_elements The count of T's for which to allocate space
692 * at first.
693 * @return Nothing.
694 *
695 * The initial underlying memory layout is a bit complicated...
696 */
697 template<typename _Tp, typename _Alloc>
698 void
699 _Deque_base<_Tp, _Alloc>::
700 _M_initialize_map(size_t __num_elements)
701 {
702 const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
703 + 1);
704
705 this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
706 size_t(__num_nodes + 2));
707 this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
708
709 // For "small" maps (needing less than _M_map_size nodes), allocation
710 // starts in the middle elements and grows outwards. So nstart may be
711 // the beginning of _M_map, but for small maps it may be as far in as
712 // _M_map+3.
713
714 _Map_pointer __nstart = (this->_M_impl._M_map
715 + (this->_M_impl._M_map_size - __num_nodes) / 2);
716 _Map_pointer __nfinish = __nstart + __num_nodes;
717
718 __try
719 { _M_create_nodes(__nstart, __nfinish); }
720 __catch(...)
721 {
722 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
723 this->_M_impl._M_map = _Map_pointer();
724 this->_M_impl._M_map_size = 0;
725 __throw_exception_again;
726 }
727
728 this->_M_impl._M_start._M_set_node(__nstart);
729 this->_M_impl._M_finish._M_set_node(__nfinish - 1);
730 this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
731 this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
732 + __num_elements
733 % __deque_buf_size(sizeof(_Tp)));
734 }
735
736 template<typename _Tp, typename _Alloc>
737 void
738 _Deque_base<_Tp, _Alloc>::
739 _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish)
740 {
741 _Map_pointer __cur;
742 __try
743 {
744 for (__cur = __nstart; __cur < __nfinish; ++__cur)
745 *__cur = this->_M_allocate_node();
746 }
747 __catch(...)
748 {
749 _M_destroy_nodes(__nstart, __cur);
750 __throw_exception_again;
751 }
752 }
753
754 template<typename _Tp, typename _Alloc>
755 void
756 _Deque_base<_Tp, _Alloc>::
757 _M_destroy_nodes(_Map_pointer __nstart,
758 _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT
759 {
760 for (_Map_pointer __n = __nstart; __n < __nfinish; ++__n)
761 _M_deallocate_node(*__n);
762 }
763
764 /**
765 * @brief A standard container using fixed-size memory allocation and
766 * constant-time manipulation of elements at either end.
767 *
768 * @ingroup sequences
769 *
770 * @tparam _Tp Type of element.
771 * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
772 *
773 * Meets the requirements of a <a href="tables.html#65">container</a>, a
774 * <a href="tables.html#66">reversible container</a>, and a
775 * <a href="tables.html#67">sequence</a>, including the
776 * <a href="tables.html#68">optional sequence requirements</a>.
777 *
778 * In previous HP/SGI versions of deque, there was an extra template
779 * parameter so users could control the node size. This extension turned
780 * out to violate the C++ standard (it can be detected using template
781 * template parameters), and it was removed.
782 *
783 * Here's how a deque<Tp> manages memory. Each deque has 4 members:
784 *
785 * - Tp** _M_map
786 * - size_t _M_map_size
787 * - iterator _M_start, _M_finish
788 *
789 * map_size is at least 8. %map is an array of map_size
790 * pointers-to-@a nodes. (The name %map has nothing to do with the
791 * std::map class, and @b nodes should not be confused with
792 * std::list's usage of @a node.)
793 *
794 * A @a node has no specific type name as such, but it is referred
795 * to as @a node in this file. It is a simple array-of-Tp. If Tp
796 * is very large, there will be one Tp element per node (i.e., an
797 * @a array of one). For non-huge Tp's, node size is inversely
798 * related to Tp size: the larger the Tp, the fewer Tp's will fit
799 * in a node. The goal here is to keep the total size of a node
800 * relatively small and constant over different Tp's, to improve
801 * allocator efficiency.
802 *
803 * Not every pointer in the %map array will point to a node. If
804 * the initial number of elements in the deque is small, the
805 * /middle/ %map pointers will be valid, and the ones at the edges
806 * will be unused. This same situation will arise as the %map
807 * grows: available %map pointers, if any, will be on the ends. As
808 * new nodes are created, only a subset of the %map's pointers need
809 * to be copied @a outward.
810 *
811 * Class invariants:
812 * - For any nonsingular iterator i:
813 * - i.node points to a member of the %map array. (Yes, you read that
814 * correctly: i.node does not actually point to a node.) The member of
815 * the %map array is what actually points to the node.
816 * - i.first == *(i.node) (This points to the node (first Tp element).)
817 * - i.last == i.first + node_size
818 * - i.cur is a pointer in the range [i.first, i.last). NOTE:
819 * the implication of this is that i.cur is always a dereferenceable
820 * pointer, even if i is a past-the-end iterator.
821 * - Start and Finish are always nonsingular iterators. NOTE: this
822 * means that an empty deque must have one node, a deque with <N
823 * elements (where N is the node buffer size) must have one node, a
824 * deque with N through (2N-1) elements must have two nodes, etc.
825 * - For every node other than start.node and finish.node, every
826 * element in the node is an initialized object. If start.node ==
827 * finish.node, then [start.cur, finish.cur) are initialized
828 * objects, and the elements outside that range are uninitialized
829 * storage. Otherwise, [start.cur, start.last) and [finish.first,
830 * finish.cur) are initialized objects, and [start.first, start.cur)
831 * and [finish.cur, finish.last) are uninitialized storage.
832 * - [%map, %map + map_size) is a valid, non-empty range.
833 * - [start.node, finish.node] is a valid range contained within
834 * [%map, %map + map_size).
835 * - A pointer in the range [%map, %map + map_size) points to an allocated
836 * node if and only if the pointer is in the range
837 * [start.node, finish.node].
838 *
839 * Here's the magic: nothing in deque is @b aware of the discontiguous
840 * storage!
841 *
842 * The memory setup and layout occurs in the parent, _Base, and the iterator
843 * class is entirely responsible for @a leaping from one node to the next.
844 * All the implementation routines for deque itself work only through the
845 * start and finish iterators. This keeps the routines simple and sane,
846 * and we can use other standard algorithms as well.
847 */
848 template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
849 class deque : protected _Deque_base<_Tp, _Alloc>
850 {
851#ifdef _GLIBCXX_CONCEPT_CHECKS
852 // concept requirements
853 typedef typename _Alloc::value_type _Alloc_value_type;
854# if __cplusplus < 201103L
855 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
856# endif
857 __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
858#endif
859
860#if __cplusplus >= 201103L
861 static_assert(is_same<typename remove_cv<_Tp>::type, _Tp>::value,
862 "std::deque must have a non-const, non-volatile value_type");
863# ifdef __STRICT_ANSI__
864 static_assert(is_same<typename _Alloc::value_type, _Tp>::value,
865 "std::deque must have the same value_type as its allocator");
866# endif
867#endif
868
869 typedef _Deque_base<_Tp, _Alloc> _Base;
870 typedef typename _Base::_Tp_alloc_type _Tp_alloc_type;
871 typedef typename _Base::_Alloc_traits _Alloc_traits;
872 typedef typename _Base::_Map_pointer _Map_pointer;
873
874 public:
875 typedef _Tp value_type;
876 typedef typename _Alloc_traits::pointer pointer;
877 typedef typename _Alloc_traits::const_pointer const_pointer;
878 typedef typename _Alloc_traits::reference reference;
879 typedef typename _Alloc_traits::const_reference const_reference;
880 typedef typename _Base::iterator iterator;
881 typedef typename _Base::const_iterator const_iterator;
882 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
883 typedef std::reverse_iterator<iterator> reverse_iterator;
884 typedef size_t size_type;
885 typedef ptrdiff_t difference_type;
886 typedef _Alloc allocator_type;
887
888 protected:
889 static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
890 { return __deque_buf_size(sizeof(_Tp)); }
891
892 // Functions controlling memory layout, and nothing else.
893 using _Base::_M_initialize_map;
894 using _Base::_M_create_nodes;
895 using _Base::_M_destroy_nodes;
896 using _Base::_M_allocate_node;
897 using _Base::_M_deallocate_node;
898 using _Base::_M_allocate_map;
899 using _Base::_M_deallocate_map;
900 using _Base::_M_get_Tp_allocator;
901
902 /**
903 * A total of four data members accumulated down the hierarchy.
904 * May be accessed via _M_impl.*
905 */
906 using _Base::_M_impl;
907
908 public:
909 // [23.2.1.1] construct/copy/destroy
910 // (assign() and get_allocator() are also listed in this section)
911
912 /**
913 * @brief Creates a %deque with no elements.
914 */
915 deque() : _Base() { }
916
917 /**
918 * @brief Creates a %deque with no elements.
919 * @param __a An allocator object.
920 */
921 explicit
922 deque(const allocator_type& __a)
923 : _Base(__a, 0) { }
924
925#if __cplusplus >= 201103L
926 /**
927 * @brief Creates a %deque with default constructed elements.
928 * @param __n The number of elements to initially create.
929 * @param __a An allocator.
930 *
931 * This constructor fills the %deque with @a n default
932 * constructed elements.
933 */
934 explicit
935 deque(size_type __n, const allocator_type& __a = allocator_type())
936 : _Base(__a, _S_check_init_len(__n, __a))
937 { _M_default_initialize(); }
938
939 /**
940 * @brief Creates a %deque with copies of an exemplar element.
941 * @param __n The number of elements to initially create.
942 * @param __value An element to copy.
943 * @param __a An allocator.
944 *
945 * This constructor fills the %deque with @a __n copies of @a __value.
946 */
947 deque(size_type __n, const value_type& __value,
948 const allocator_type& __a = allocator_type())
949 : _Base(__a, _S_check_init_len(__n, __a))
950 { _M_fill_initialize(__value); }
951#else
952 /**
953 * @brief Creates a %deque with copies of an exemplar element.
954 * @param __n The number of elements to initially create.
955 * @param __value An element to copy.
956 * @param __a An allocator.
957 *
958 * This constructor fills the %deque with @a __n copies of @a __value.
959 */
960 explicit
961 deque(size_type __n, const value_type& __value = value_type(),
962 const allocator_type& __a = allocator_type())
963 : _Base(__a, _S_check_init_len(__n, __a))
964 { _M_fill_initialize(__value); }
965#endif
966
967 /**
968 * @brief %Deque copy constructor.
969 * @param __x A %deque of identical element and allocator types.
970 *
971 * The newly-created %deque uses a copy of the allocator object used
972 * by @a __x (unless the allocator traits dictate a different object).
973 */
974 deque(const deque& __x)
975 : _Base(_Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()),
976 __x.size())
977 { std::__uninitialized_copy_a(__x.begin(), __x.end(),
978 this->_M_impl._M_start,
979 _M_get_Tp_allocator()); }
980
981#if __cplusplus >= 201103L
982 /**
983 * @brief %Deque move constructor.
984 * @param __x A %deque of identical element and allocator types.
985 *
986 * The newly-created %deque contains the exact contents of @a __x.
987 * The contents of @a __x are a valid, but unspecified %deque.
988 */
989 deque(deque&& __x)
990 : _Base(std::move(__x)) { }
991
992 /// Copy constructor with alternative allocator
993 deque(const deque& __x, const allocator_type& __a)
994 : _Base(__a, __x.size())
995 { std::__uninitialized_copy_a(__x.begin(), __x.end(),
996 this->_M_impl._M_start,
997 _M_get_Tp_allocator()); }
998
999 /// Move constructor with alternative allocator
1000 deque(deque&& __x, const allocator_type& __a)
1001 : _Base(std::move(__x), __a, __x.size())
1002 {
1003 if (__x.get_allocator() != __a)
1004 {
1005 std::__uninitialized_move_a(__x.begin(), __x.end(),
1006 this->_M_impl._M_start,
1007 _M_get_Tp_allocator());
1008 __x.clear();
1009 }
1010 }
1011
1012 /**
1013 * @brief Builds a %deque from an initializer list.
1014 * @param __l An initializer_list.
1015 * @param __a An allocator object.
1016 *
1017 * Create a %deque consisting of copies of the elements in the
1018 * initializer_list @a __l.
1019 *
1020 * This will call the element type's copy constructor N times
1021 * (where N is __l.size()) and do no memory reallocation.
1022 */
1023 deque(initializer_list<value_type> __l,
1024 const allocator_type& __a = allocator_type())
1025 : _Base(__a)
1026 {
1027 _M_range_initialize(__l.begin(), __l.end(),
1028 random_access_iterator_tag());
1029 }
1030#endif
1031
1032 /**
1033 * @brief Builds a %deque from a range.
1034 * @param __first An input iterator.
1035 * @param __last An input iterator.
1036 * @param __a An allocator object.
1037 *
1038 * Create a %deque consisting of copies of the elements from [__first,
1039 * __last).
1040 *
1041 * If the iterators are forward, bidirectional, or random-access, then
1042 * this will call the elements' copy constructor N times (where N is
1043 * distance(__first,__last)) and do no memory reallocation. But if only
1044 * input iterators are used, then this will do at most 2N calls to the
1045 * copy constructor, and logN memory reallocations.
1046 */
1047#if __cplusplus >= 201103L
1048 template<typename _InputIterator,
1049 typename = std::_RequireInputIter<_InputIterator>>
1050 deque(_InputIterator __first, _InputIterator __last,
1051 const allocator_type& __a = allocator_type())
1052 : _Base(__a)
1053 { _M_initialize_dispatch(__first, __last, __false_type()); }
1054#else
1055 template<typename _InputIterator>
1056 deque(_InputIterator __first, _InputIterator __last,
1057 const allocator_type& __a = allocator_type())
1058 : _Base(__a)
1059 {
1060 // Check whether it's an integral type. If so, it's not an iterator.
1061 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1062 _M_initialize_dispatch(__first, __last, _Integral());
1063 }
1064#endif
1065
1066 /**
1067 * The dtor only erases the elements, and note that if the elements
1068 * themselves are pointers, the pointed-to memory is not touched in any
1069 * way. Managing the pointer is the user's responsibility.
1070 */
1071 ~deque()
1072 { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); }
1073
1074 /**
1075 * @brief %Deque assignment operator.
1076 * @param __x A %deque of identical element and allocator types.
1077 *
1078 * All the elements of @a x are copied.
1079 *
1080 * The newly-created %deque uses a copy of the allocator object used
1081 * by @a __x (unless the allocator traits dictate a different object).
1082 */
1083 deque&
1084 operator=(const deque& __x);
1085
1086#if __cplusplus >= 201103L
1087 /**
1088 * @brief %Deque move assignment operator.
1089 * @param __x A %deque of identical element and allocator types.
1090 *
1091 * The contents of @a __x are moved into this deque (without copying,
1092 * if the allocators permit it).
1093 * @a __x is a valid, but unspecified %deque.
1094 */
1095 deque&
1096 operator=(deque&& __x) noexcept(_Alloc_traits::_S_always_equal())
1097 {
1098 using __always_equal = typename _Alloc_traits::is_always_equal;
1099 _M_move_assign1(std::move(__x), __always_equal{});
1100 return *this;
1101 }
1102
1103 /**
1104 * @brief Assigns an initializer list to a %deque.
1105 * @param __l An initializer_list.
1106 *
1107 * This function fills a %deque with copies of the elements in the
1108 * initializer_list @a __l.
1109 *
1110 * Note that the assignment completely changes the %deque and that the
1111 * resulting %deque's size is the same as the number of elements
1112 * assigned.
1113 */
1114 deque&
1115 operator=(initializer_list<value_type> __l)
1116 {
1117 _M_assign_aux(__l.begin(), __l.end(),
1118 random_access_iterator_tag());
1119 return *this;
1120 }
1121#endif
1122
1123 /**
1124 * @brief Assigns a given value to a %deque.
1125 * @param __n Number of elements to be assigned.
1126 * @param __val Value to be assigned.
1127 *
1128 * This function fills a %deque with @a n copies of the given
1129 * value. Note that the assignment completely changes the
1130 * %deque and that the resulting %deque's size is the same as
1131 * the number of elements assigned.
1132 */
1133 void
1134 assign(size_type __n, const value_type& __val)
1135 { _M_fill_assign(__n, __val); }
1136
1137 /**
1138 * @brief Assigns a range to a %deque.
1139 * @param __first An input iterator.
1140 * @param __last An input iterator.
1141 *
1142 * This function fills a %deque with copies of the elements in the
1143 * range [__first,__last).
1144 *
1145 * Note that the assignment completely changes the %deque and that the
1146 * resulting %deque's size is the same as the number of elements
1147 * assigned.
1148 */
1149#if __cplusplus >= 201103L
1150 template<typename _InputIterator,
1151 typename = std::_RequireInputIter<_InputIterator>>
1152 void
1153 assign(_InputIterator __first, _InputIterator __last)
1154 { _M_assign_dispatch(__first, __last, __false_type()); }
1155#else
1156 template<typename _InputIterator>
1157 void
1158 assign(_InputIterator __first, _InputIterator __last)
1159 {
1160 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1161 _M_assign_dispatch(__first, __last, _Integral());
1162 }
1163#endif
1164
1165#if __cplusplus >= 201103L
1166 /**
1167 * @brief Assigns an initializer list to a %deque.
1168 * @param __l An initializer_list.
1169 *
1170 * This function fills a %deque with copies of the elements in the
1171 * initializer_list @a __l.
1172 *
1173 * Note that the assignment completely changes the %deque and that the
1174 * resulting %deque's size is the same as the number of elements
1175 * assigned.
1176 */
1177 void
1178 assign(initializer_list<value_type> __l)
1179 { _M_assign_aux(__l.begin(), __l.end(), random_access_iterator_tag()); }
1180#endif
1181
1182 /// Get a copy of the memory allocation object.
1183 allocator_type
1184 get_allocator() const _GLIBCXX_NOEXCEPT
1185 { return _Base::get_allocator(); }
1186
1187 // iterators
1188 /**
1189 * Returns a read/write iterator that points to the first element in the
1190 * %deque. Iteration is done in ordinary element order.
1191 */
1192 iterator
1193 begin() _GLIBCXX_NOEXCEPT
1194 { return this->_M_impl._M_start; }
1195
1196 /**
1197 * Returns a read-only (constant) iterator that points to the first
1198 * element in the %deque. Iteration is done in ordinary element order.
1199 */
1200 const_iterator
1201 begin() const _GLIBCXX_NOEXCEPT
1202 { return this->_M_impl._M_start; }
1203
1204 /**
1205 * Returns a read/write iterator that points one past the last
1206 * element in the %deque. Iteration is done in ordinary
1207 * element order.
1208 */
1209 iterator
1210 end() _GLIBCXX_NOEXCEPT
1211 { return this->_M_impl._M_finish; }
1212
1213 /**
1214 * Returns a read-only (constant) iterator that points one past
1215 * the last element in the %deque. Iteration is done in
1216 * ordinary element order.
1217 */
1218 const_iterator
1219 end() const _GLIBCXX_NOEXCEPT
1220 { return this->_M_impl._M_finish; }
1221
1222 /**
1223 * Returns a read/write reverse iterator that points to the
1224 * last element in the %deque. Iteration is done in reverse
1225 * element order.
1226 */
1227 reverse_iterator
1228 rbegin() _GLIBCXX_NOEXCEPT
1229 { return reverse_iterator(this->_M_impl._M_finish); }
1230
1231 /**
1232 * Returns a read-only (constant) reverse iterator that points
1233 * to the last element in the %deque. Iteration is done in
1234 * reverse element order.
1235 */
1236 const_reverse_iterator
1237 rbegin() const _GLIBCXX_NOEXCEPT
1238 { return const_reverse_iterator(this->_M_impl._M_finish); }
1239
1240 /**
1241 * Returns a read/write reverse iterator that points to one
1242 * before the first element in the %deque. Iteration is done
1243 * in reverse element order.
1244 */
1245 reverse_iterator
1246 rend() _GLIBCXX_NOEXCEPT
1247 { return reverse_iterator(this->_M_impl._M_start); }
1248
1249 /**
1250 * Returns a read-only (constant) reverse iterator that points
1251 * to one before the first element in the %deque. Iteration is
1252 * done in reverse element order.
1253 */
1254 const_reverse_iterator
1255 rend() const _GLIBCXX_NOEXCEPT
1256 { return const_reverse_iterator(this->_M_impl._M_start); }
1257
1258#if __cplusplus >= 201103L
1259 /**
1260 * Returns a read-only (constant) iterator that points to the first
1261 * element in the %deque. Iteration is done in ordinary element order.
1262 */
1263 const_iterator
1264 cbegin() const noexcept
1265 { return this->_M_impl._M_start; }
1266
1267 /**
1268 * Returns a read-only (constant) iterator that points one past
1269 * the last element in the %deque. Iteration is done in
1270 * ordinary element order.
1271 */
1272 const_iterator
1273 cend() const noexcept
1274 { return this->_M_impl._M_finish; }
1275
1276 /**
1277 * Returns a read-only (constant) reverse iterator that points
1278 * to the last element in the %deque. Iteration is done in
1279 * reverse element order.
1280 */
1281 const_reverse_iterator
1282 crbegin() const noexcept
1283 { return const_reverse_iterator(this->_M_impl._M_finish); }
1284
1285 /**
1286 * Returns a read-only (constant) reverse iterator that points
1287 * to one before the first element in the %deque. Iteration is
1288 * done in reverse element order.
1289 */
1290 const_reverse_iterator
1291 crend() const noexcept
1292 { return const_reverse_iterator(this->_M_impl._M_start); }
1293#endif
1294
1295 // [23.2.1.2] capacity
1296 /** Returns the number of elements in the %deque. */
1297 size_type
1298 size() const _GLIBCXX_NOEXCEPT
1299 { return this->_M_impl._M_finish - this->_M_impl._M_start; }
1300
1301 /** Returns the size() of the largest possible %deque. */
1302 size_type
1303 max_size() const _GLIBCXX_NOEXCEPT
1304 { return _S_max_size(_M_get_Tp_allocator()); }
1305
1306#if __cplusplus >= 201103L
1307 /**
1308 * @brief Resizes the %deque to the specified number of elements.
1309 * @param __new_size Number of elements the %deque should contain.
1310 *
1311 * This function will %resize the %deque to the specified
1312 * number of elements. If the number is smaller than the
1313 * %deque's current size the %deque is truncated, otherwise
1314 * default constructed elements are appended.
1315 */
1316 void
1317 resize(size_type __new_size)
1318 {
1319 const size_type __len = size();
1320 if (__new_size > __len)
1321 _M_default_append(__new_size - __len);
1322 else if (__new_size < __len)
1323 _M_erase_at_end(this->_M_impl._M_start
1324 + difference_type(__new_size));
1325 }
1326
1327 /**
1328 * @brief Resizes the %deque to the specified number of elements.
1329 * @param __new_size Number of elements the %deque should contain.
1330 * @param __x Data with which new elements should be populated.
1331 *
1332 * This function will %resize the %deque to the specified
1333 * number of elements. If the number is smaller than the
1334 * %deque's current size the %deque is truncated, otherwise the
1335 * %deque is extended and new elements are populated with given
1336 * data.
1337 */
1338 void
1339 resize(size_type __new_size, const value_type& __x)
1340 {
1341 const size_type __len = size();
1342 if (__new_size > __len)
1343 _M_fill_insert(this->_M_impl._M_finish, __new_size - __len, __x);
1344 else if (__new_size < __len)
1345 _M_erase_at_end(this->_M_impl._M_start
1346 + difference_type(__new_size));
1347 }
1348#else
1349 /**
1350 * @brief Resizes the %deque to the specified number of elements.
1351 * @param __new_size Number of elements the %deque should contain.
1352 * @param __x Data with which new elements should be populated.
1353 *
1354 * This function will %resize the %deque to the specified
1355 * number of elements. If the number is smaller than the
1356 * %deque's current size the %deque is truncated, otherwise the
1357 * %deque is extended and new elements are populated with given
1358 * data.
1359 */
1360 void
1361 resize(size_type __new_size, value_type __x = value_type())
1362 {
1363 const size_type __len = size();
1364 if (__new_size > __len)
1365 _M_fill_insert(this->_M_impl._M_finish, __new_size - __len, __x);
1366 else if (__new_size < __len)
1367 _M_erase_at_end(this->_M_impl._M_start
1368 + difference_type(__new_size));
1369 }
1370#endif
1371
1372#if __cplusplus >= 201103L
1373 /** A non-binding request to reduce memory use. */
1374 void
1375 shrink_to_fit() noexcept
1376 { _M_shrink_to_fit(); }
1377#endif
1378
1379 /**
1380 * Returns true if the %deque is empty. (Thus begin() would
1381 * equal end().)
1382 */
1383 _GLIBCXX_NODISCARD bool
1384 empty() const _GLIBCXX_NOEXCEPT
1385 { return this->_M_impl._M_finish == this->_M_impl._M_start; }
1386
1387 // element access
1388 /**
1389 * @brief Subscript access to the data contained in the %deque.
1390 * @param __n The index of the element for which data should be
1391 * accessed.
1392 * @return Read/write reference to data.
1393 *
1394 * This operator allows for easy, array-style, data access.
1395 * Note that data access with this operator is unchecked and
1396 * out_of_range lookups are not defined. (For checked lookups
1397 * see at().)
1398 */
1399 reference
1400 operator[](size_type __n) _GLIBCXX_NOEXCEPT
1401 {
1402 __glibcxx_requires_subscript(__n);
1403 return this->_M_impl._M_start[difference_type(__n)];
1404 }
1405
1406 /**
1407 * @brief Subscript access to the data contained in the %deque.
1408 * @param __n The index of the element for which data should be
1409 * accessed.
1410 * @return Read-only (constant) reference to data.
1411 *
1412 * This operator allows for easy, array-style, data access.
1413 * Note that data access with this operator is unchecked and
1414 * out_of_range lookups are not defined. (For checked lookups
1415 * see at().)
1416 */
1417 const_reference
1418 operator[](size_type __n) const _GLIBCXX_NOEXCEPT
1419 {
1420 __glibcxx_requires_subscript(__n);
1421 return this->_M_impl._M_start[difference_type(__n)];
1422 }
1423
1424 protected:
1425 /// Safety check used only from at().
1426 void
1427 _M_range_check(size_type __n) const
1428 {
1429 if (__n >= this->size())
1430 __throw_out_of_range_fmt(__N("deque::_M_range_check: __n "
1431 "(which is %zu)>= this->size() "
1432 "(which is %zu)"),
1433 __n, this->size());
1434 }
1435
1436 public:
1437 /**
1438 * @brief Provides access to the data contained in the %deque.
1439 * @param __n The index of the element for which data should be
1440 * accessed.
1441 * @return Read/write reference to data.
1442 * @throw std::out_of_range If @a __n is an invalid index.
1443 *
1444 * This function provides for safer data access. The parameter
1445 * is first checked that it is in the range of the deque. The
1446 * function throws out_of_range if the check fails.
1447 */
1448 reference
1449 at(size_type __n)
1450 {
1451 _M_range_check(__n);
1452 return (*this)[__n];
1453 }
1454
1455 /**
1456 * @brief Provides access to the data contained in the %deque.
1457 * @param __n The index of the element for which data should be
1458 * accessed.
1459 * @return Read-only (constant) reference to data.
1460 * @throw std::out_of_range If @a __n is an invalid index.
1461 *
1462 * This function provides for safer data access. The parameter is first
1463 * checked that it is in the range of the deque. The function throws
1464 * out_of_range if the check fails.
1465 */
1466 const_reference
1467 at(size_type __n) const
1468 {
1469 _M_range_check(__n);
1470 return (*this)[__n];
1471 }
1472
1473 /**
1474 * Returns a read/write reference to the data at the first
1475 * element of the %deque.
1476 */
1477 reference
1478 front() _GLIBCXX_NOEXCEPT
1479 {
1480 __glibcxx_requires_nonempty();
1481 return *begin();
1482 }
1483
1484 /**
1485 * Returns a read-only (constant) reference to the data at the first
1486 * element of the %deque.
1487 */
1488 const_reference
1489 front() const _GLIBCXX_NOEXCEPT
1490 {
1491 __glibcxx_requires_nonempty();
1492 return *begin();
1493 }
1494
1495 /**
1496 * Returns a read/write reference to the data at the last element of the
1497 * %deque.
1498 */
1499 reference
1500 back() _GLIBCXX_NOEXCEPT
1501 {
1502 __glibcxx_requires_nonempty();
1503 iterator __tmp = end();
1504 --__tmp;
1505 return *__tmp;
1506 }
1507
1508 /**
1509 * Returns a read-only (constant) reference to the data at the last
1510 * element of the %deque.
1511 */
1512 const_reference
1513 back() const _GLIBCXX_NOEXCEPT
1514 {
1515 __glibcxx_requires_nonempty();
1516 const_iterator __tmp = end();
1517 --__tmp;
1518 return *__tmp;
1519 }
1520
1521 // [23.2.1.2] modifiers
1522 /**
1523 * @brief Add data to the front of the %deque.
1524 * @param __x Data to be added.
1525 *
1526 * This is a typical stack operation. The function creates an
1527 * element at the front of the %deque and assigns the given
1528 * data to it. Due to the nature of a %deque this operation
1529 * can be done in constant time.
1530 */
1531 void
1532 push_front(const value_type& __x)
1533 {
1534 if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
1535 {
1536 _Alloc_traits::construct(this->_M_impl,
1537 this->_M_impl._M_start._M_cur - 1,
1538 __x);
1539 --this->_M_impl._M_start._M_cur;
1540 }
1541 else
1542 _M_push_front_aux(__x);
1543 }
1544
1545#if __cplusplus >= 201103L
1546 void
1547 push_front(value_type&& __x)
1548 { emplace_front(std::move(__x)); }
1549
1550 template<typename... _Args>
1551#if __cplusplus > 201402L
1552 reference
1553#else
1554 void
1555#endif
1556 emplace_front(_Args&&... __args);
1557#endif
1558
1559 /**
1560 * @brief Add data to the end of the %deque.
1561 * @param __x Data to be added.
1562 *
1563 * This is a typical stack operation. The function creates an
1564 * element at the end of the %deque and assigns the given data
1565 * to it. Due to the nature of a %deque this operation can be
1566 * done in constant time.
1567 */
1568 void
1569 push_back(const value_type& __x)
1570 {
1571 if (this->_M_impl._M_finish._M_cur
1572 != this->_M_impl._M_finish._M_last - 1)
1573 {
1574 _Alloc_traits::construct(this->_M_impl,
1575 this->_M_impl._M_finish._M_cur, __x);
1576 ++this->_M_impl._M_finish._M_cur;
1577 }
1578 else
1579 _M_push_back_aux(__x);
1580 }
1581
1582#if __cplusplus >= 201103L
1583 void
1584 push_back(value_type&& __x)
1585 { emplace_back(std::move(__x)); }
1586
1587 template<typename... _Args>
1588#if __cplusplus > 201402L
1589 reference
1590#else
1591 void
1592#endif
1593 emplace_back(_Args&&... __args);
1594#endif
1595
1596 /**
1597 * @brief Removes first element.
1598 *
1599 * This is a typical stack operation. It shrinks the %deque by one.
1600 *
1601 * Note that no data is returned, and if the first element's data is
1602 * needed, it should be retrieved before pop_front() is called.
1603 */
1604 void
1605 pop_front() _GLIBCXX_NOEXCEPT
1606 {
1607 __glibcxx_requires_nonempty();
1608 if (this->_M_impl._M_start._M_cur
1609 != this->_M_impl._M_start._M_last - 1)
1610 {
1611 _Alloc_traits::destroy(this->_M_impl,
1612 this->_M_impl._M_start._M_cur);
1613 ++this->_M_impl._M_start._M_cur;
1614 }
1615 else
1616 _M_pop_front_aux();
1617 }
1618
1619 /**
1620 * @brief Removes last element.
1621 *
1622 * This is a typical stack operation. It shrinks the %deque by one.
1623 *
1624 * Note that no data is returned, and if the last element's data is
1625 * needed, it should be retrieved before pop_back() is called.
1626 */
1627 void
1628 pop_back() _GLIBCXX_NOEXCEPT
1629 {
1630 __glibcxx_requires_nonempty();
1631 if (this->_M_impl._M_finish._M_cur
1632 != this->_M_impl._M_finish._M_first)
1633 {
1634 --this->_M_impl._M_finish._M_cur;
1635 _Alloc_traits::destroy(this->_M_impl,
1636 this->_M_impl._M_finish._M_cur);
1637 }
1638 else
1639 _M_pop_back_aux();
1640 }
1641
1642#if __cplusplus >= 201103L
1643 /**
1644 * @brief Inserts an object in %deque before specified iterator.
1645 * @param __position A const_iterator into the %deque.
1646 * @param __args Arguments.
1647 * @return An iterator that points to the inserted data.
1648 *
1649 * This function will insert an object of type T constructed
1650 * with T(std::forward<Args>(args)...) before the specified location.
1651 */
1652 template<typename... _Args>
1653 iterator
1654 emplace(const_iterator __position, _Args&&... __args);
1655
1656 /**
1657 * @brief Inserts given value into %deque before specified iterator.
1658 * @param __position A const_iterator into the %deque.
1659 * @param __x Data to be inserted.
1660 * @return An iterator that points to the inserted data.
1661 *
1662 * This function will insert a copy of the given value before the
1663 * specified location.
1664 */
1665 iterator
1666 insert(const_iterator __position, const value_type& __x);
1667#else
1668 /**
1669 * @brief Inserts given value into %deque before specified iterator.
1670 * @param __position An iterator into the %deque.
1671 * @param __x Data to be inserted.
1672 * @return An iterator that points to the inserted data.
1673 *
1674 * This function will insert a copy of the given value before the
1675 * specified location.
1676 */
1677 iterator
1678 insert(iterator __position, const value_type& __x);
1679#endif
1680
1681#if __cplusplus >= 201103L
1682 /**
1683 * @brief Inserts given rvalue into %deque before specified iterator.
1684 * @param __position A const_iterator into the %deque.
1685 * @param __x Data to be inserted.
1686 * @return An iterator that points to the inserted data.
1687 *
1688 * This function will insert a copy of the given rvalue before the
1689 * specified location.
1690 */
1691 iterator
1692 insert(const_iterator __position, value_type&& __x)
1693 { return emplace(__position, std::move(__x)); }
1694
1695 /**
1696 * @brief Inserts an initializer list into the %deque.
1697 * @param __p An iterator into the %deque.
1698 * @param __l An initializer_list.
1699 *
1700 * This function will insert copies of the data in the
1701 * initializer_list @a __l into the %deque before the location
1702 * specified by @a __p. This is known as <em>list insert</em>.
1703 */
1704 iterator
1705 insert(const_iterator __p, initializer_list<value_type> __l)
1706 {
1707 auto __offset = __p - cbegin();
1708 _M_range_insert_aux(__p._M_const_cast(), __l.begin(), __l.end(),
1709 std::random_access_iterator_tag());
1710 return begin() + __offset;
1711 }
1712#endif
1713
1714#if __cplusplus >= 201103L
1715 /**
1716 * @brief Inserts a number of copies of given data into the %deque.
1717 * @param __position A const_iterator into the %deque.
1718 * @param __n Number of elements to be inserted.
1719 * @param __x Data to be inserted.
1720 * @return An iterator that points to the inserted data.
1721 *
1722 * This function will insert a specified number of copies of the given
1723 * data before the location specified by @a __position.
1724 */
1725 iterator
1726 insert(const_iterator __position, size_type __n, const value_type& __x)
1727 {
1728 difference_type __offset = __position - cbegin();
1729 _M_fill_insert(__position._M_const_cast(), __n, __x);
1730 return begin() + __offset;
1731 }
1732#else
1733 /**
1734 * @brief Inserts a number of copies of given data into the %deque.
1735 * @param __position An iterator into the %deque.
1736 * @param __n Number of elements to be inserted.
1737 * @param __x Data to be inserted.
1738 *
1739 * This function will insert a specified number of copies of the given
1740 * data before the location specified by @a __position.
1741 */
1742 void
1743 insert(iterator __position, size_type __n, const value_type& __x)
1744 { _M_fill_insert(__position, __n, __x); }
1745#endif
1746
1747#if __cplusplus >= 201103L
1748 /**
1749 * @brief Inserts a range into the %deque.
1750 * @param __position A const_iterator into the %deque.
1751 * @param __first An input iterator.
1752 * @param __last An input iterator.
1753 * @return An iterator that points to the inserted data.
1754 *
1755 * This function will insert copies of the data in the range
1756 * [__first,__last) into the %deque before the location specified
1757 * by @a __position. This is known as <em>range insert</em>.
1758 */
1759 template<typename _InputIterator,
1760 typename = std::_RequireInputIter<_InputIterator>>
1761 iterator
1762 insert(const_iterator __position, _InputIterator __first,
1763 _InputIterator __last)
1764 {
1765 difference_type __offset = __position - cbegin();
1766 _M_insert_dispatch(__position._M_const_cast(),
1767 __first, __last, __false_type());
1768 return begin() + __offset;
1769 }
1770#else
1771 /**
1772 * @brief Inserts a range into the %deque.
1773 * @param __position An iterator into the %deque.
1774 * @param __first An input iterator.
1775 * @param __last An input iterator.
1776 *
1777 * This function will insert copies of the data in the range
1778 * [__first,__last) into the %deque before the location specified
1779 * by @a __position. This is known as <em>range insert</em>.
1780 */
1781 template<typename _InputIterator>
1782 void
1783 insert(iterator __position, _InputIterator __first,
1784 _InputIterator __last)
1785 {
1786 // Check whether it's an integral type. If so, it's not an iterator.
1787 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1788 _M_insert_dispatch(__position, __first, __last, _Integral());
1789 }
1790#endif
1791
1792 /**
1793 * @brief Remove element at given position.
1794 * @param __position Iterator pointing to element to be erased.
1795 * @return An iterator pointing to the next element (or end()).
1796 *
1797 * This function will erase the element at the given position and thus
1798 * shorten the %deque by one.
1799 *
1800 * The user is cautioned that
1801 * this function only erases the element, and that if the element is
1802 * itself a pointer, the pointed-to memory is not touched in any way.
1803 * Managing the pointer is the user's responsibility.
1804 */
1805 iterator
1806#if __cplusplus >= 201103L
1807 erase(const_iterator __position)
1808#else
1809 erase(iterator __position)
1810#endif
1811 { return _M_erase(__position._M_const_cast()); }
1812
1813 /**
1814 * @brief Remove a range of elements.
1815 * @param __first Iterator pointing to the first element to be erased.
1816 * @param __last Iterator pointing to one past the last element to be
1817 * erased.
1818 * @return An iterator pointing to the element pointed to by @a last
1819 * prior to erasing (or end()).
1820 *
1821 * This function will erase the elements in the range
1822 * [__first,__last) and shorten the %deque accordingly.
1823 *
1824 * The user is cautioned that
1825 * this function only erases the elements, and that if the elements
1826 * themselves are pointers, the pointed-to memory is not touched in any
1827 * way. Managing the pointer is the user's responsibility.
1828 */
1829 iterator
1830#if __cplusplus >= 201103L
1831 erase(const_iterator __first, const_iterator __last)
1832#else
1833 erase(iterator __first, iterator __last)
1834#endif
1835 { return _M_erase(__first._M_const_cast(), __last._M_const_cast()); }
1836
1837 /**
1838 * @brief Swaps data with another %deque.
1839 * @param __x A %deque of the same element and allocator types.
1840 *
1841 * This exchanges the elements between two deques in constant time.
1842 * (Four pointers, so it should be quite fast.)
1843 * Note that the global std::swap() function is specialized such that
1844 * std::swap(d1,d2) will feed to this function.
1845 *
1846 * Whether the allocators are swapped depends on the allocator traits.
1847 */
1848 void
1849 swap(deque& __x) _GLIBCXX_NOEXCEPT
1850 {
1851#if __cplusplus >= 201103L
1852 __glibcxx_assert(_Alloc_traits::propagate_on_container_swap::value
1853 || _M_get_Tp_allocator() == __x._M_get_Tp_allocator());
1854#endif
1855 _M_impl._M_swap_data(__x._M_impl);
1856 _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(),
1857 __x._M_get_Tp_allocator());
1858 }
1859
1860 /**
1861 * Erases all the elements. Note that this function only erases the
1862 * elements, and that if the elements themselves are pointers, the
1863 * pointed-to memory is not touched in any way. Managing the pointer is
1864 * the user's responsibility.
1865 */
1866 void
1867 clear() _GLIBCXX_NOEXCEPT
1868 { _M_erase_at_end(begin()); }
1869
1870 protected:
1871 // Internal constructor functions follow.
1872
1873 // called by the range constructor 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_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
1880 {
1881 _M_initialize_map(_S_check_init_len(static_cast<size_type>(__n),
1882 _M_get_Tp_allocator()));
1883 _M_fill_initialize(__x);
1884 }
1885
1886 static size_t
1887 _S_check_init_len(size_t __n, const allocator_type& __a)
1888 {
1889 if (__n > _S_max_size(__a))
1890 __throw_length_error(
1891 __N("cannot create std::deque larger than max_size()"));
1892 return __n;
1893 }
1894
1895 static size_type
1896 _S_max_size(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT
1897 {
1898 const size_t __diffmax = __gnu_cxx::__numeric_traits<ptrdiff_t>::__max;
1899 const size_t __allocmax = _Alloc_traits::max_size(__a);
1900 return (std::min)(__diffmax, __allocmax);
1901 }
1902
1903 // called by the range constructor to implement [23.1.1]/9
1904 template<typename _InputIterator>
1905 void
1906 _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
1907 __false_type)
1908 {
1909 _M_range_initialize(__first, __last,
1910 std::__iterator_category(__first));
1911 }
1912
1913 // called by the second initialize_dispatch above
1914 //@{
1915 /**
1916 * @brief Fills the deque with whatever is in [first,last).
1917 * @param __first An input iterator.
1918 * @param __last An input iterator.
1919 * @return Nothing.
1920 *
1921 * If the iterators are actually forward iterators (or better), then the
1922 * memory layout can be done all at once. Else we move forward using
1923 * push_back on each value from the iterator.
1924 */
1925 template<typename _InputIterator>
1926 void
1927 _M_range_initialize(_InputIterator __first, _InputIterator __last,
1928 std::input_iterator_tag);
1929
1930 // called by the second initialize_dispatch above
1931 template<typename _ForwardIterator>
1932 void
1933 _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
1934 std::forward_iterator_tag);
1935 //@}
1936
1937 /**
1938 * @brief Fills the %deque with copies of value.
1939 * @param __value Initial value.
1940 * @return Nothing.
1941 * @pre _M_start and _M_finish have already been initialized,
1942 * but none of the %deque's elements have yet been constructed.
1943 *
1944 * This function is called only when the user provides an explicit size
1945 * (with or without an explicit exemplar value).
1946 */
1947 void
1948 _M_fill_initialize(const value_type& __value);
1949
1950#if __cplusplus >= 201103L
1951 // called by deque(n).
1952 void
1953 _M_default_initialize();
1954#endif
1955
1956 // Internal assign functions follow. The *_aux functions do the actual
1957 // assignment work for the range versions.
1958
1959 // called by the range assign to implement [23.1.1]/9
1960
1961 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1962 // 438. Ambiguity in the "do the right thing" clause
1963 template<typename _Integer>
1964 void
1965 _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
1966 { _M_fill_assign(__n, __val); }
1967
1968 // called by the range assign to implement [23.1.1]/9
1969 template<typename _InputIterator>
1970 void
1971 _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
1972 __false_type)
1973 { _M_assign_aux(__first, __last, std::__iterator_category(__first)); }
1974
1975 // called by the second assign_dispatch above
1976 template<typename _InputIterator>
1977 void
1978 _M_assign_aux(_InputIterator __first, _InputIterator __last,
1979 std::input_iterator_tag);
1980
1981 // called by the second assign_dispatch above
1982 template<typename _ForwardIterator>
1983 void
1984 _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
1985 std::forward_iterator_tag)
1986 {
1987 const size_type __len = std::distance(__first, __last);
1988 if (__len > size())
1989 {
1990 _ForwardIterator __mid = __first;
1991 std::advance(__mid, size());
1992 std::copy(__first, __mid, begin());
1993 _M_range_insert_aux(end(), __mid, __last,
1994 std::__iterator_category(__first));
1995 }
1996 else
1997 _M_erase_at_end(std::copy(__first, __last, begin()));
1998 }
1999
2000 // Called by assign(n,t), and the range assign when it turns out
2001 // to be the same thing.
2002 void
2003 _M_fill_assign(size_type __n, const value_type& __val)
2004 {
2005 if (__n > size())
2006 {
2007 std::fill(begin(), end(), __val);
2008 _M_fill_insert(end(), __n - size(), __val);
2009 }
2010 else
2011 {
2012 _M_erase_at_end(begin() + difference_type(__n));
2013 std::fill(begin(), end(), __val);
2014 }
2015 }
2016
2017 //@{
2018 /// Helper functions for push_* and pop_*.
2019#if __cplusplus < 201103L
2020 void _M_push_back_aux(const value_type&);
2021
2022 void _M_push_front_aux(const value_type&);
2023#else
2024 template<typename... _Args>
2025 void _M_push_back_aux(_Args&&... __args);
2026
2027 template<typename... _Args>
2028 void _M_push_front_aux(_Args&&... __args);
2029#endif
2030
2031 void _M_pop_back_aux();
2032
2033 void _M_pop_front_aux();
2034 //@}
2035
2036 // Internal insert functions follow. The *_aux functions do the actual
2037 // insertion work when all shortcuts fail.
2038
2039 // called by the range insert to implement [23.1.1]/9
2040
2041 // _GLIBCXX_RESOLVE_LIB_DEFECTS
2042 // 438. Ambiguity in the "do the right thing" clause
2043 template<typename _Integer>
2044 void
2045 _M_insert_dispatch(iterator __pos,
2046 _Integer __n, _Integer __x, __true_type)
2047 { _M_fill_insert(__pos, __n, __x); }
2048
2049 // called by the range insert to implement [23.1.1]/9
2050 template<typename _InputIterator>
2051 void
2052 _M_insert_dispatch(iterator __pos,
2053 _InputIterator __first, _InputIterator __last,
2054 __false_type)
2055 {
2056 _M_range_insert_aux(__pos, __first, __last,
2057 std::__iterator_category(__first));
2058 }
2059
2060 // called by the second insert_dispatch above
2061 template<typename _InputIterator>
2062 void
2063 _M_range_insert_aux(iterator __pos, _InputIterator __first,
2064 _InputIterator __last, std::input_iterator_tag);
2065
2066 // called by the second insert_dispatch above
2067 template<typename _ForwardIterator>
2068 void
2069 _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
2070 _ForwardIterator __last, std::forward_iterator_tag);
2071
2072 // Called by insert(p,n,x), and the range insert when it turns out to be
2073 // the same thing. Can use fill functions in optimal situations,
2074 // otherwise passes off to insert_aux(p,n,x).
2075 void
2076 _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
2077
2078 // called by insert(p,x)
2079#if __cplusplus < 201103L
2080 iterator
2081 _M_insert_aux(iterator __pos, const value_type& __x);
2082#else
2083 template<typename... _Args>
2084 iterator
2085 _M_insert_aux(iterator __pos, _Args&&... __args);
2086#endif
2087
2088 // called by insert(p,n,x) via fill_insert
2089 void
2090 _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
2091
2092 // called by range_insert_aux for forward iterators
2093 template<typename _ForwardIterator>
2094 void
2095 _M_insert_aux(iterator __pos,
2096 _ForwardIterator __first, _ForwardIterator __last,
2097 size_type __n);
2098
2099
2100 // Internal erase functions follow.
2101
2102 void
2103 _M_destroy_data_aux(iterator __first, iterator __last);
2104
2105 // Called by ~deque().
2106 // NB: Doesn't deallocate the nodes.
2107 template<typename _Alloc1>
2108 void
2109 _M_destroy_data(iterator __first, iterator __last, const _Alloc1&)
2110 { _M_destroy_data_aux(__first, __last); }
2111
2112 void
2113 _M_destroy_data(iterator __first, iterator __last,
2114 const std::allocator<_Tp>&)
2115 {
2116 if (!__has_trivial_destructor(value_type))
2117 _M_destroy_data_aux(__first, __last);
2118 }
2119
2120 // Called by erase(q1, q2).
2121 void
2122 _M_erase_at_begin(iterator __pos)
2123 {
2124 _M_destroy_data(begin(), __pos, _M_get_Tp_allocator());
2125 _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node);
2126 this->_M_impl._M_start = __pos;
2127 }
2128
2129 // Called by erase(q1, q2), resize(), clear(), _M_assign_aux,
2130 // _M_fill_assign, operator=.
2131 void
2132 _M_erase_at_end(iterator __pos)
2133 {
2134 _M_destroy_data(__pos, end(), _M_get_Tp_allocator());
2135 _M_destroy_nodes(__pos._M_node + 1,
2136 this->_M_impl._M_finish._M_node + 1);
2137 this->_M_impl._M_finish = __pos;
2138 }
2139
2140 iterator
2141 _M_erase(iterator __pos);
2142
2143 iterator
2144 _M_erase(iterator __first, iterator __last);
2145
2146#if __cplusplus >= 201103L
2147 // Called by resize(sz).
2148 void
2149 _M_default_append(size_type __n);
2150
2151 bool
2152 _M_shrink_to_fit();
2153#endif
2154
2155 //@{
2156 /// Memory-handling helpers for the previous internal insert functions.
2157 iterator
2158 _M_reserve_elements_at_front(size_type __n)
2159 {
2160 const size_type __vacancies = this->_M_impl._M_start._M_cur
2161 - this->_M_impl._M_start._M_first;
2162 if (__n > __vacancies)
2163 _M_new_elements_at_front(__n - __vacancies);
2164 return this->_M_impl._M_start - difference_type(__n);
2165 }
2166
2167 iterator
2168 _M_reserve_elements_at_back(size_type __n)
2169 {
2170 const size_type __vacancies = (this->_M_impl._M_finish._M_last
2171 - this->_M_impl._M_finish._M_cur) - 1;
2172 if (__n > __vacancies)
2173 _M_new_elements_at_back(__n - __vacancies);
2174 return this->_M_impl._M_finish + difference_type(__n);
2175 }
2176
2177 void
2178 _M_new_elements_at_front(size_type __new_elements);
2179
2180 void
2181 _M_new_elements_at_back(size_type __new_elements);
2182 //@}
2183
2184
2185 //@{
2186 /**
2187 * @brief Memory-handling helpers for the major %map.
2188 *
2189 * Makes sure the _M_map has space for new nodes. Does not
2190 * actually add the nodes. Can invalidate _M_map pointers.
2191 * (And consequently, %deque iterators.)
2192 */
2193 void
2194 _M_reserve_map_at_back(size_type __nodes_to_add = 1)
2195 {
2196 if (__nodes_to_add + 1 > this->_M_impl._M_map_size
2197 - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
2198 _M_reallocate_map(__nodes_to_add, false);
2199 }
2200
2201 void
2202 _M_reserve_map_at_front(size_type __nodes_to_add = 1)
2203 {
2204 if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
2205 - this->_M_impl._M_map))
2206 _M_reallocate_map(__nodes_to_add, true);
2207 }
2208
2209 void
2210 _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
2211 //@}
2212
2213#if __cplusplus >= 201103L
2214 // Constant-time, nothrow move assignment when source object's memory
2215 // can be moved because the allocators are equal.
2216 void
2217 _M_move_assign1(deque&& __x, /* always equal: */ true_type) noexcept
2218 {
2219 this->_M_impl._M_swap_data(__x._M_impl);
2220 __x.clear();
2221 std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator());
2222 }
2223
2224 // When the allocators are not equal the operation could throw, because
2225 // we might need to allocate a new map for __x after moving from it
2226 // or we might need to allocate new elements for *this.
2227 void
2228 _M_move_assign1(deque&& __x, /* always equal: */ false_type)
2229 {
2230 constexpr bool __move_storage =
2231 _Alloc_traits::_S_propagate_on_move_assign();
2232 _M_move_assign2(std::move(__x), __bool_constant<__move_storage>());
2233 }
2234
2235 // Destroy all elements and deallocate all memory, then replace
2236 // with elements created from __args.
2237 template<typename... _Args>
2238 void
2239 _M_replace_map(_Args&&... __args)
2240 {
2241 // Create new data first, so if allocation fails there are no effects.
2242 deque __newobj(std::forward<_Args>(__args)...);
2243 // Free existing storage using existing allocator.
2244 clear();
2245 _M_deallocate_node(*begin()._M_node); // one node left after clear()
2246 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
2247 this->_M_impl._M_map = nullptr;
2248 this->_M_impl._M_map_size = 0;
2249 // Take ownership of replacement memory.
2250 this->_M_impl._M_swap_data(__newobj._M_impl);
2251 }
2252
2253 // Do move assignment when the allocator propagates.
2254 void
2255 _M_move_assign2(deque&& __x, /* propagate: */ true_type)
2256 {
2257 // Make a copy of the original allocator state.
2258 auto __alloc = __x._M_get_Tp_allocator();
2259 // The allocator propagates so storage can be moved from __x,
2260 // leaving __x in a valid empty state with a moved-from allocator.
2261 _M_replace_map(std::move(__x));
2262 // Move the corresponding allocator state too.
2263 _M_get_Tp_allocator() = std::move(__alloc);
2264 }
2265
2266 // Do move assignment when it may not be possible to move source
2267 // object's memory, resulting in a linear-time operation.
2268 void
2269 _M_move_assign2(deque&& __x, /* propagate: */ false_type)
2270 {
2271 if (__x._M_get_Tp_allocator() == this->_M_get_Tp_allocator())
2272 {
2273 // The allocators are equal so storage can be moved from __x,
2274 // leaving __x in a valid empty state with its current allocator.
2275 _M_replace_map(std::move(__x), __x.get_allocator());
2276 }
2277 else
2278 {
2279 // The rvalue's allocator cannot be moved and is not equal,
2280 // so we need to individually move each element.
2281 _M_assign_aux(std::__make_move_if_noexcept_iterator(__x.begin()),
2282 std::__make_move_if_noexcept_iterator(__x.end()),
2283 std::random_access_iterator_tag());
2284 __x.clear();
2285 }
2286 }
2287#endif
2288 };
2289
2290#if __cpp_deduction_guides >= 201606
2291 template<typename _InputIterator, typename _ValT
2292 = typename iterator_traits<_InputIterator>::value_type,
2293 typename _Allocator = allocator<_ValT>,
2294 typename = _RequireInputIter<_InputIterator>,
2295 typename = _RequireAllocator<_Allocator>>
2296 deque(_InputIterator, _InputIterator, _Allocator = _Allocator())
2297 -> deque<_ValT, _Allocator>;
2298#endif
2299
2300 /**
2301 * @brief Deque equality comparison.
2302 * @param __x A %deque.
2303 * @param __y A %deque of the same type as @a __x.
2304 * @return True iff the size and elements of the deques are equal.
2305 *
2306 * This is an equivalence relation. It is linear in the size of the
2307 * deques. Deques are considered equivalent if their sizes are equal,
2308 * and if corresponding elements compare equal.
2309 */
2310 template<typename _Tp, typename _Alloc>
2311 inline bool
2312 operator==(const deque<_Tp, _Alloc>& __x,
2313 const deque<_Tp, _Alloc>& __y)
2314 { return __x.size() == __y.size()
2315 && std::equal(__x.begin(), __x.end(), __y.begin()); }
2316
2317 /**
2318 * @brief Deque ordering relation.
2319 * @param __x A %deque.
2320 * @param __y A %deque of the same type as @a __x.
2321 * @return True iff @a x is lexicographically less than @a __y.
2322 *
2323 * This is a total ordering relation. It is linear in the size of the
2324 * deques. The elements must be comparable with @c <.
2325 *
2326 * See std::lexicographical_compare() for how the determination is made.
2327 */
2328 template<typename _Tp, typename _Alloc>
2329 inline bool
2330 operator<(const deque<_Tp, _Alloc>& __x,
2331 const deque<_Tp, _Alloc>& __y)
2332 { return std::lexicographical_compare(__x.begin(), __x.end(),
2333 __y.begin(), __y.end()); }
2334
2335 /// Based on operator==
2336 template<typename _Tp, typename _Alloc>
2337 inline bool
2338 operator!=(const deque<_Tp, _Alloc>& __x,
2339 const deque<_Tp, _Alloc>& __y)
2340 { return !(__x == __y); }
2341
2342 /// Based on operator<
2343 template<typename _Tp, typename _Alloc>
2344 inline bool
2345 operator>(const deque<_Tp, _Alloc>& __x,
2346 const deque<_Tp, _Alloc>& __y)
2347 { return __y < __x; }
2348
2349 /// Based on operator<
2350 template<typename _Tp, typename _Alloc>
2351 inline bool
2352 operator<=(const deque<_Tp, _Alloc>& __x,
2353 const deque<_Tp, _Alloc>& __y)
2354 { return !(__y < __x); }
2355
2356 /// Based on operator<
2357 template<typename _Tp, typename _Alloc>
2358 inline bool
2359 operator>=(const deque<_Tp, _Alloc>& __x,
2360 const deque<_Tp, _Alloc>& __y)
2361 { return !(__x < __y); }
2362
2363 /// See std::deque::swap().
2364 template<typename _Tp, typename _Alloc>
2365 inline void
2366 swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y)
2367 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
2368 { __x.swap(__y); }
2369
2370#undef _GLIBCXX_DEQUE_BUF_SIZE
2371
2372_GLIBCXX_END_NAMESPACE_CONTAINER
2373
2374#if __cplusplus >= 201103L
2375 // std::allocator is safe, but it is not the only allocator
2376 // for which this is valid.
2377 template<class _Tp>
2378 struct __is_bitwise_relocatable<_GLIBCXX_STD_C::deque<_Tp>>
2379 : true_type { };
2380#endif
2381
2382_GLIBCXX_END_NAMESPACE_VERSION
2383} // namespace std
2384
2385#endif /* _STL_DEQUE_H */
2386