1// List implementation -*- C++ -*-
2
3// Copyright (C) 2001-2018 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) 1996,1997
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_list.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{list}
54 */
55
56#ifndef _STL_LIST_H
57#define _STL_LIST_H 1
58
59#include <bits/concept_check.h>
60#include <ext/alloc_traits.h>
61#if __cplusplus >= 201103L
62#include <initializer_list>
63#include <bits/allocated_ptr.h>
64#include <ext/aligned_buffer.h>
65#endif
66
67namespace std _GLIBCXX_VISIBILITY(default)
68{
69_GLIBCXX_BEGIN_NAMESPACE_VERSION
70
71 namespace __detail
72 {
73 // Supporting structures are split into common and templated
74 // types; the latter publicly inherits from the former in an
75 // effort to reduce code duplication. This results in some
76 // "needless" static_cast'ing later on, but it's all safe
77 // downcasting.
78
79 /// Common part of a node in the %list.
80 struct _List_node_base
81 {
82 _List_node_base* _M_next;
83 _List_node_base* _M_prev;
84
85 static void
86 swap(_List_node_base& __x, _List_node_base& __y) _GLIBCXX_USE_NOEXCEPT;
87
88 void
89 _M_transfer(_List_node_base* const __first,
90 _List_node_base* const __last) _GLIBCXX_USE_NOEXCEPT;
91
92 void
93 _M_reverse() _GLIBCXX_USE_NOEXCEPT;
94
95 void
96 _M_hook(_List_node_base* const __position) _GLIBCXX_USE_NOEXCEPT;
97
98 void
99 _M_unhook() _GLIBCXX_USE_NOEXCEPT;
100 };
101
102 /// The %list node header.
103 struct _List_node_header : public _List_node_base
104 {
105#if _GLIBCXX_USE_CXX11_ABI
106 std::size_t _M_size;
107#endif
108
109 _List_node_header() _GLIBCXX_NOEXCEPT
110 { _M_init(); }
111
112#if __cplusplus >= 201103L
113 _List_node_header(_List_node_header&& __x) noexcept
114 : _List_node_base{ __x._M_next, __x._M_prev }
115# if _GLIBCXX_USE_CXX11_ABI
116 , _M_size(__x._M_size)
117# endif
118 {
119 if (__x._M_base()->_M_next == __x._M_base())
120 this->_M_next = this->_M_prev = this;
121 else
122 {
123 this->_M_next->_M_prev = this->_M_prev->_M_next = this->_M_base();
124 __x._M_init();
125 }
126 }
127
128 void
129 _M_move_nodes(_List_node_header&& __x)
130 {
131 _List_node_base* const __xnode = __x._M_base();
132 if (__xnode->_M_next == __xnode)
133 _M_init();
134 else
135 {
136 _List_node_base* const __node = this->_M_base();
137 __node->_M_next = __xnode->_M_next;
138 __node->_M_prev = __xnode->_M_prev;
139 __node->_M_next->_M_prev = __node->_M_prev->_M_next = __node;
140# if _GLIBCXX_USE_CXX11_ABI
141 _M_size = __x._M_size;
142# endif
143 __x._M_init();
144 }
145 }
146#endif
147
148 void
149 _M_init() _GLIBCXX_NOEXCEPT
150 {
151 this->_M_next = this->_M_prev = this;
152#if _GLIBCXX_USE_CXX11_ABI
153 this->_M_size = 0;
154#endif
155 }
156
157 private:
158 _List_node_base* _M_base() { return this; }
159 };
160 } // namespace detail
161
162_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
163
164 /// An actual node in the %list.
165 template<typename _Tp>
166 struct _List_node : public __detail::_List_node_base
167 {
168#if __cplusplus >= 201103L
169 __gnu_cxx::__aligned_membuf<_Tp> _M_storage;
170 _Tp* _M_valptr() { return _M_storage._M_ptr(); }
171 _Tp const* _M_valptr() const { return _M_storage._M_ptr(); }
172#else
173 _Tp _M_data;
174 _Tp* _M_valptr() { return std::__addressof(_M_data); }
175 _Tp const* _M_valptr() const { return std::__addressof(_M_data); }
176#endif
177 };
178
179 /**
180 * @brief A list::iterator.
181 *
182 * All the functions are op overloads.
183 */
184 template<typename _Tp>
185 struct _List_iterator
186 {
187 typedef _List_iterator<_Tp> _Self;
188 typedef _List_node<_Tp> _Node;
189
190 typedef ptrdiff_t difference_type;
191 typedef std::bidirectional_iterator_tag iterator_category;
192 typedef _Tp value_type;
193 typedef _Tp* pointer;
194 typedef _Tp& reference;
195
196 _List_iterator() _GLIBCXX_NOEXCEPT
197 : _M_node() { }
198
199 explicit
200 _List_iterator(__detail::_List_node_base* __x) _GLIBCXX_NOEXCEPT
201 : _M_node(__x) { }
202
203 _Self
204 _M_const_cast() const _GLIBCXX_NOEXCEPT
205 { return *this; }
206
207 // Must downcast from _List_node_base to _List_node to get to value.
208 reference
209 operator*() const _GLIBCXX_NOEXCEPT
210 { return *static_cast<_Node*>(_M_node)->_M_valptr(); }
211
212 pointer
213 operator->() const _GLIBCXX_NOEXCEPT
214 { return static_cast<_Node*>(_M_node)->_M_valptr(); }
215
216 _Self&
217 operator++() _GLIBCXX_NOEXCEPT
218 {
219 _M_node = _M_node->_M_next;
220 return *this;
221 }
222
223 _Self
224 operator++(int) _GLIBCXX_NOEXCEPT
225 {
226 _Self __tmp = *this;
227 _M_node = _M_node->_M_next;
228 return __tmp;
229 }
230
231 _Self&
232 operator--() _GLIBCXX_NOEXCEPT
233 {
234 _M_node = _M_node->_M_prev;
235 return *this;
236 }
237
238 _Self
239 operator--(int) _GLIBCXX_NOEXCEPT
240 {
241 _Self __tmp = *this;
242 _M_node = _M_node->_M_prev;
243 return __tmp;
244 }
245
246 bool
247 operator==(const _Self& __x) const _GLIBCXX_NOEXCEPT
248 { return _M_node == __x._M_node; }
249
250 bool
251 operator!=(const _Self& __x) const _GLIBCXX_NOEXCEPT
252 { return _M_node != __x._M_node; }
253
254 // The only member points to the %list element.
255 __detail::_List_node_base* _M_node;
256 };
257
258 /**
259 * @brief A list::const_iterator.
260 *
261 * All the functions are op overloads.
262 */
263 template<typename _Tp>
264 struct _List_const_iterator
265 {
266 typedef _List_const_iterator<_Tp> _Self;
267 typedef const _List_node<_Tp> _Node;
268 typedef _List_iterator<_Tp> iterator;
269
270 typedef ptrdiff_t difference_type;
271 typedef std::bidirectional_iterator_tag iterator_category;
272 typedef _Tp value_type;
273 typedef const _Tp* pointer;
274 typedef const _Tp& reference;
275
276 _List_const_iterator() _GLIBCXX_NOEXCEPT
277 : _M_node() { }
278
279 explicit
280 _List_const_iterator(const __detail::_List_node_base* __x)
281 _GLIBCXX_NOEXCEPT
282 : _M_node(__x) { }
283
284 _List_const_iterator(const iterator& __x) _GLIBCXX_NOEXCEPT
285 : _M_node(__x._M_node) { }
286
287 iterator
288 _M_const_cast() const _GLIBCXX_NOEXCEPT
289 { return iterator(const_cast<__detail::_List_node_base*>(_M_node)); }
290
291 // Must downcast from List_node_base to _List_node to get to value.
292 reference
293 operator*() const _GLIBCXX_NOEXCEPT
294 { return *static_cast<_Node*>(_M_node)->_M_valptr(); }
295
296 pointer
297 operator->() const _GLIBCXX_NOEXCEPT
298 { return static_cast<_Node*>(_M_node)->_M_valptr(); }
299
300 _Self&
301 operator++() _GLIBCXX_NOEXCEPT
302 {
303 _M_node = _M_node->_M_next;
304 return *this;
305 }
306
307 _Self
308 operator++(int) _GLIBCXX_NOEXCEPT
309 {
310 _Self __tmp = *this;
311 _M_node = _M_node->_M_next;
312 return __tmp;
313 }
314
315 _Self&
316 operator--() _GLIBCXX_NOEXCEPT
317 {
318 _M_node = _M_node->_M_prev;
319 return *this;
320 }
321
322 _Self
323 operator--(int) _GLIBCXX_NOEXCEPT
324 {
325 _Self __tmp = *this;
326 _M_node = _M_node->_M_prev;
327 return __tmp;
328 }
329
330 bool
331 operator==(const _Self& __x) const _GLIBCXX_NOEXCEPT
332 { return _M_node == __x._M_node; }
333
334 bool
335 operator!=(const _Self& __x) const _GLIBCXX_NOEXCEPT
336 { return _M_node != __x._M_node; }
337
338 // The only member points to the %list element.
339 const __detail::_List_node_base* _M_node;
340 };
341
342 template<typename _Val>
343 inline bool
344 operator==(const _List_iterator<_Val>& __x,
345 const _List_const_iterator<_Val>& __y) _GLIBCXX_NOEXCEPT
346 { return __x._M_node == __y._M_node; }
347
348 template<typename _Val>
349 inline bool
350 operator!=(const _List_iterator<_Val>& __x,
351 const _List_const_iterator<_Val>& __y) _GLIBCXX_NOEXCEPT
352 { return __x._M_node != __y._M_node; }
353
354_GLIBCXX_BEGIN_NAMESPACE_CXX11
355 /// See bits/stl_deque.h's _Deque_base for an explanation.
356 template<typename _Tp, typename _Alloc>
357 class _List_base
358 {
359 protected:
360 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
361 rebind<_Tp>::other _Tp_alloc_type;
362 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Tp_alloc_traits;
363 typedef typename _Tp_alloc_traits::template
364 rebind<_List_node<_Tp> >::other _Node_alloc_type;
365 typedef __gnu_cxx::__alloc_traits<_Node_alloc_type> _Node_alloc_traits;
366
367#if !_GLIBCXX_INLINE_VERSION
368 static size_t
369 _S_distance(const __detail::_List_node_base* __first,
370 const __detail::_List_node_base* __last)
371 {
372 size_t __n = 0;
373 while (__first != __last)
374 {
375 __first = __first->_M_next;
376 ++__n;
377 }
378 return __n;
379 }
380#endif
381
382 struct _List_impl
383 : public _Node_alloc_type
384 {
385 __detail::_List_node_header _M_node;
386
387 _List_impl() _GLIBCXX_NOEXCEPT_IF( noexcept(_Node_alloc_type()) )
388 : _Node_alloc_type()
389 { }
390
391 _List_impl(const _Node_alloc_type& __a) _GLIBCXX_NOEXCEPT
392 : _Node_alloc_type(__a)
393 { }
394
395#if __cplusplus >= 201103L
396 _List_impl(_List_impl&&) = default;
397
398 _List_impl(_Node_alloc_type&& __a, _List_impl&& __x)
399 : _Node_alloc_type(std::move(__a)), _M_node(std::move(__x._M_node))
400 { }
401
402 _List_impl(_Node_alloc_type&& __a) noexcept
403 : _Node_alloc_type(std::move(__a))
404 { }
405#endif
406 };
407
408 _List_impl _M_impl;
409
410#if _GLIBCXX_USE_CXX11_ABI
411 size_t _M_get_size() const { return _M_impl._M_node._M_size; }
412
413 void _M_set_size(size_t __n) { _M_impl._M_node._M_size = __n; }
414
415 void _M_inc_size(size_t __n) { _M_impl._M_node._M_size += __n; }
416
417 void _M_dec_size(size_t __n) { _M_impl._M_node._M_size -= __n; }
418
419# if !_GLIBCXX_INLINE_VERSION
420 size_t
421 _M_distance(const __detail::_List_node_base* __first,
422 const __detail::_List_node_base* __last) const
423 { return _S_distance(__first, __last); }
424
425 // return the stored size
426 size_t _M_node_count() const { return _M_get_size(); }
427# endif
428#else
429 // dummy implementations used when the size is not stored
430 size_t _M_get_size() const { return 0; }
431 void _M_set_size(size_t) { }
432 void _M_inc_size(size_t) { }
433 void _M_dec_size(size_t) { }
434
435# if !_GLIBCXX_INLINE_VERSION
436 size_t _M_distance(const void*, const void*) const { return 0; }
437
438 // count the number of nodes
439 size_t _M_node_count() const
440 {
441 return _S_distance(_M_impl._M_node._M_next,
442 std::__addressof(_M_impl._M_node));
443 }
444# endif
445#endif
446
447 typename _Node_alloc_traits::pointer
448 _M_get_node()
449 { return _Node_alloc_traits::allocate(_M_impl, 1); }
450
451 void
452 _M_put_node(typename _Node_alloc_traits::pointer __p) _GLIBCXX_NOEXCEPT
453 { _Node_alloc_traits::deallocate(_M_impl, __p, 1); }
454
455 public:
456 typedef _Alloc allocator_type;
457
458 _Node_alloc_type&
459 _M_get_Node_allocator() _GLIBCXX_NOEXCEPT
460 { return _M_impl; }
461
462 const _Node_alloc_type&
463 _M_get_Node_allocator() const _GLIBCXX_NOEXCEPT
464 { return _M_impl; }
465
466#if __cplusplus >= 201103L
467 _List_base() = default;
468#else
469 _List_base() { }
470#endif
471
472 _List_base(const _Node_alloc_type& __a) _GLIBCXX_NOEXCEPT
473 : _M_impl(__a)
474 { }
475
476#if __cplusplus >= 201103L
477 _List_base(_List_base&&) = default;
478
479# if !_GLIBCXX_INLINE_VERSION
480 _List_base(_List_base&& __x, _Node_alloc_type&& __a)
481 : _M_impl(std::move(__a))
482 {
483 if (__x._M_get_Node_allocator() == _M_get_Node_allocator())
484 _M_move_nodes(std::move(__x));
485 // else caller must move individual elements.
486 }
487# endif
488
489 // Used when allocator is_always_equal.
490 _List_base(_Node_alloc_type&& __a, _List_base&& __x)
491 : _M_impl(std::move(__a), std::move(__x._M_impl))
492 { }
493
494 // Used when allocator !is_always_equal.
495 _List_base(_Node_alloc_type&& __a)
496 : _M_impl(std::move(__a))
497 { }
498
499 void
500 _M_move_nodes(_List_base&& __x)
501 { _M_impl._M_node._M_move_nodes(std::move(__x._M_impl._M_node)); }
502#endif
503
504 // This is what actually destroys the list.
505 ~_List_base() _GLIBCXX_NOEXCEPT
506 { _M_clear(); }
507
508 void
509 _M_clear() _GLIBCXX_NOEXCEPT;
510
511 void
512 _M_init() _GLIBCXX_NOEXCEPT
513 { this->_M_impl._M_node._M_init(); }
514 };
515
516 /**
517 * @brief A standard container with linear time access to elements,
518 * and fixed time insertion/deletion at any point in the sequence.
519 *
520 * @ingroup sequences
521 *
522 * @tparam _Tp Type of element.
523 * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
524 *
525 * Meets the requirements of a <a href="tables.html#65">container</a>, a
526 * <a href="tables.html#66">reversible container</a>, and a
527 * <a href="tables.html#67">sequence</a>, including the
528 * <a href="tables.html#68">optional sequence requirements</a> with the
529 * %exception of @c at and @c operator[].
530 *
531 * This is a @e doubly @e linked %list. Traversal up and down the
532 * %list requires linear time, but adding and removing elements (or
533 * @e nodes) is done in constant time, regardless of where the
534 * change takes place. Unlike std::vector and std::deque,
535 * random-access iterators are not provided, so subscripting ( @c
536 * [] ) access is not allowed. For algorithms which only need
537 * sequential access, this lack makes no difference.
538 *
539 * Also unlike the other standard containers, std::list provides
540 * specialized algorithms %unique to linked lists, such as
541 * splicing, sorting, and in-place reversal.
542 *
543 * A couple points on memory allocation for list<Tp>:
544 *
545 * First, we never actually allocate a Tp, we allocate
546 * List_node<Tp>'s and trust [20.1.5]/4 to DTRT. This is to ensure
547 * that after elements from %list<X,Alloc1> are spliced into
548 * %list<X,Alloc2>, destroying the memory of the second %list is a
549 * valid operation, i.e., Alloc1 giveth and Alloc2 taketh away.
550 *
551 * Second, a %list conceptually represented as
552 * @code
553 * A <---> B <---> C <---> D
554 * @endcode
555 * is actually circular; a link exists between A and D. The %list
556 * class holds (as its only data member) a private list::iterator
557 * pointing to @e D, not to @e A! To get to the head of the %list,
558 * we start at the tail and move forward by one. When this member
559 * iterator's next/previous pointers refer to itself, the %list is
560 * %empty.
561 */
562 template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
563 class list : protected _List_base<_Tp, _Alloc>
564 {
565#ifdef _GLIBCXX_CONCEPT_CHECKS
566 // concept requirements
567 typedef typename _Alloc::value_type _Alloc_value_type;
568# if __cplusplus < 201103L
569 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
570# endif
571 __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
572#endif
573
574#if __cplusplus >= 201103L
575 static_assert(is_same<typename remove_cv<_Tp>::type, _Tp>::value,
576 "std::list must have a non-const, non-volatile value_type");
577# ifdef __STRICT_ANSI__
578 static_assert(is_same<typename _Alloc::value_type, _Tp>::value,
579 "std::list must have the same value_type as its allocator");
580# endif
581#endif
582
583 typedef _List_base<_Tp, _Alloc> _Base;
584 typedef typename _Base::_Tp_alloc_type _Tp_alloc_type;
585 typedef typename _Base::_Tp_alloc_traits _Tp_alloc_traits;
586 typedef typename _Base::_Node_alloc_type _Node_alloc_type;
587 typedef typename _Base::_Node_alloc_traits _Node_alloc_traits;
588
589 public:
590 typedef _Tp value_type;
591 typedef typename _Tp_alloc_traits::pointer pointer;
592 typedef typename _Tp_alloc_traits::const_pointer const_pointer;
593 typedef typename _Tp_alloc_traits::reference reference;
594 typedef typename _Tp_alloc_traits::const_reference const_reference;
595 typedef _List_iterator<_Tp> iterator;
596 typedef _List_const_iterator<_Tp> const_iterator;
597 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
598 typedef std::reverse_iterator<iterator> reverse_iterator;
599 typedef size_t size_type;
600 typedef ptrdiff_t difference_type;
601 typedef _Alloc allocator_type;
602
603 protected:
604 // Note that pointers-to-_Node's can be ctor-converted to
605 // iterator types.
606 typedef _List_node<_Tp> _Node;
607
608 using _Base::_M_impl;
609 using _Base::_M_put_node;
610 using _Base::_M_get_node;
611 using _Base::_M_get_Node_allocator;
612
613 /**
614 * @param __args An instance of user data.
615 *
616 * Allocates space for a new node and constructs a copy of
617 * @a __args in it.
618 */
619#if __cplusplus < 201103L
620 _Node*
621 _M_create_node(const value_type& __x)
622 {
623 _Node* __p = this->_M_get_node();
624 __try
625 {
626 _Tp_alloc_type __alloc(_M_get_Node_allocator());
627 __alloc.construct(__p->_M_valptr(), __x);
628 }
629 __catch(...)
630 {
631 _M_put_node(__p);
632 __throw_exception_again;
633 }
634 return __p;
635 }
636#else
637 template<typename... _Args>
638 _Node*
639 _M_create_node(_Args&&... __args)
640 {
641 auto __p = this->_M_get_node();
642 auto& __alloc = _M_get_Node_allocator();
643 __allocated_ptr<_Node_alloc_type> __guard{__alloc, __p};
644 _Node_alloc_traits::construct(__alloc, __p->_M_valptr(),
645 std::forward<_Args>(__args)...);
646 __guard = nullptr;
647 return __p;
648 }
649#endif
650
651#if _GLIBCXX_USE_CXX11_ABI
652 static size_t
653 _S_distance(const_iterator __first, const_iterator __last)
654 { return std::distance(__first, __last); }
655
656 // return the stored size
657 size_t
658 _M_node_count() const
659 { return this->_M_get_size(); }
660#else
661 // dummy implementations used when the size is not stored
662 static size_t
663 _S_distance(const_iterator, const_iterator)
664 { return 0; }
665
666 // count the number of nodes
667 size_t
668 _M_node_count() const
669 { return std::distance(begin(), end()); }
670#endif
671
672 public:
673 // [23.2.2.1] construct/copy/destroy
674 // (assign() and get_allocator() are also listed in this section)
675
676 /**
677 * @brief Creates a %list with no elements.
678 */
679#if __cplusplus >= 201103L
680 list() = default;
681#else
682 list() { }
683#endif
684
685 /**
686 * @brief Creates a %list with no elements.
687 * @param __a An allocator object.
688 */
689 explicit
690 list(const allocator_type& __a) _GLIBCXX_NOEXCEPT
691 : _Base(_Node_alloc_type(__a)) { }
692
693#if __cplusplus >= 201103L
694 /**
695 * @brief Creates a %list with default constructed elements.
696 * @param __n The number of elements to initially create.
697 * @param __a An allocator object.
698 *
699 * This constructor fills the %list with @a __n default
700 * constructed elements.
701 */
702 explicit
703 list(size_type __n, const allocator_type& __a = allocator_type())
704 : _Base(_Node_alloc_type(__a))
705 { _M_default_initialize(__n); }
706
707 /**
708 * @brief Creates a %list with copies of an exemplar element.
709 * @param __n The number of elements to initially create.
710 * @param __value An element to copy.
711 * @param __a An allocator object.
712 *
713 * This constructor fills the %list with @a __n copies of @a __value.
714 */
715 list(size_type __n, const value_type& __value,
716 const allocator_type& __a = allocator_type())
717 : _Base(_Node_alloc_type(__a))
718 { _M_fill_initialize(__n, __value); }
719#else
720 /**
721 * @brief Creates a %list with copies of an exemplar element.
722 * @param __n The number of elements to initially create.
723 * @param __value An element to copy.
724 * @param __a An allocator object.
725 *
726 * This constructor fills the %list with @a __n copies of @a __value.
727 */
728 explicit
729 list(size_type __n, const value_type& __value = value_type(),
730 const allocator_type& __a = allocator_type())
731 : _Base(_Node_alloc_type(__a))
732 { _M_fill_initialize(__n, __value); }
733#endif
734
735 /**
736 * @brief %List copy constructor.
737 * @param __x A %list of identical element and allocator types.
738 *
739 * The newly-created %list uses a copy of the allocation object used
740 * by @a __x (unless the allocator traits dictate a different object).
741 */
742 list(const list& __x)
743 : _Base(_Node_alloc_traits::
744 _S_select_on_copy(__x._M_get_Node_allocator()))
745 { _M_initialize_dispatch(__x.begin(), __x.end(), __false_type()); }
746
747#if __cplusplus >= 201103L
748 /**
749 * @brief %List move constructor.
750 *
751 * The newly-created %list contains the exact contents of the moved
752 * instance. The contents of the moved instance are a valid, but
753 * unspecified %list.
754 */
755 list(list&&) = default;
756
757 /**
758 * @brief Builds a %list from an initializer_list
759 * @param __l An initializer_list of value_type.
760 * @param __a An allocator object.
761 *
762 * Create a %list consisting of copies of the elements in the
763 * initializer_list @a __l. This is linear in __l.size().
764 */
765 list(initializer_list<value_type> __l,
766 const allocator_type& __a = allocator_type())
767 : _Base(_Node_alloc_type(__a))
768 { _M_initialize_dispatch(__l.begin(), __l.end(), __false_type()); }
769
770 list(const list& __x, const allocator_type& __a)
771 : _Base(_Node_alloc_type(__a))
772 { _M_initialize_dispatch(__x.begin(), __x.end(), __false_type()); }
773
774 private:
775 list(list&& __x, const allocator_type& __a, true_type) noexcept
776 : _Base(_Node_alloc_type(__a), std::move(__x))
777 { }
778
779 list(list&& __x, const allocator_type& __a, false_type)
780 : _Base(_Node_alloc_type(__a))
781 {
782 if (__x._M_get_Node_allocator() == this->_M_get_Node_allocator())
783 this->_M_move_nodes(std::move(__x));
784 else
785 insert(begin(), std::__make_move_if_noexcept_iterator(__x.begin()),
786 std::__make_move_if_noexcept_iterator(__x.end()));
787 }
788
789 public:
790 list(list&& __x, const allocator_type& __a)
791 noexcept(_Node_alloc_traits::_S_always_equal())
792 : list(std::move(__x), __a,
793 typename _Node_alloc_traits::is_always_equal{})
794 { }
795#endif
796
797 /**
798 * @brief Builds a %list from a range.
799 * @param __first An input iterator.
800 * @param __last An input iterator.
801 * @param __a An allocator object.
802 *
803 * Create a %list consisting of copies of the elements from
804 * [@a __first,@a __last). This is linear in N (where N is
805 * distance(@a __first,@a __last)).
806 */
807#if __cplusplus >= 201103L
808 template<typename _InputIterator,
809 typename = std::_RequireInputIter<_InputIterator>>
810 list(_InputIterator __first, _InputIterator __last,
811 const allocator_type& __a = allocator_type())
812 : _Base(_Node_alloc_type(__a))
813 { _M_initialize_dispatch(__first, __last, __false_type()); }
814#else
815 template<typename _InputIterator>
816 list(_InputIterator __first, _InputIterator __last,
817 const allocator_type& __a = allocator_type())
818 : _Base(_Node_alloc_type(__a))
819 {
820 // Check whether it's an integral type. If so, it's not an iterator.
821 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
822 _M_initialize_dispatch(__first, __last, _Integral());
823 }
824#endif
825
826#if __cplusplus >= 201103L
827 /**
828 * No explicit dtor needed as the _Base dtor takes care of
829 * things. The _Base dtor only erases the elements, and note
830 * that if the elements themselves are pointers, the pointed-to
831 * memory is not touched in any way. Managing the pointer is
832 * the user's responsibility.
833 */
834 ~list() = default;
835#endif
836
837 /**
838 * @brief %List assignment operator.
839 * @param __x A %list of identical element and allocator types.
840 *
841 * All the elements of @a __x are copied.
842 *
843 * Whether the allocator is copied depends on the allocator traits.
844 */
845 list&
846 operator=(const list& __x);
847
848#if __cplusplus >= 201103L
849 /**
850 * @brief %List move assignment operator.
851 * @param __x A %list of identical element and allocator types.
852 *
853 * The contents of @a __x are moved into this %list (without copying).
854 *
855 * Afterwards @a __x is a valid, but unspecified %list
856 *
857 * Whether the allocator is moved depends on the allocator traits.
858 */
859 list&
860 operator=(list&& __x)
861 noexcept(_Node_alloc_traits::_S_nothrow_move())
862 {
863 constexpr bool __move_storage =
864 _Node_alloc_traits::_S_propagate_on_move_assign()
865 || _Node_alloc_traits::_S_always_equal();
866 _M_move_assign(std::move(__x), __bool_constant<__move_storage>());
867 return *this;
868 }
869
870 /**
871 * @brief %List initializer list assignment operator.
872 * @param __l An initializer_list of value_type.
873 *
874 * Replace the contents of the %list with copies of the elements
875 * in the initializer_list @a __l. This is linear in l.size().
876 */
877 list&
878 operator=(initializer_list<value_type> __l)
879 {
880 this->assign(__l.begin(), __l.end());
881 return *this;
882 }
883#endif
884
885 /**
886 * @brief Assigns a given value to a %list.
887 * @param __n Number of elements to be assigned.
888 * @param __val Value to be assigned.
889 *
890 * This function fills a %list with @a __n copies of the given
891 * value. Note that the assignment completely changes the %list
892 * and that the resulting %list's size is the same as the number
893 * of elements assigned.
894 */
895 void
896 assign(size_type __n, const value_type& __val)
897 { _M_fill_assign(__n, __val); }
898
899 /**
900 * @brief Assigns a range to a %list.
901 * @param __first An input iterator.
902 * @param __last An input iterator.
903 *
904 * This function fills a %list with copies of the elements in the
905 * range [@a __first,@a __last).
906 *
907 * Note that the assignment completely changes the %list and
908 * that the resulting %list's size is the same as the number of
909 * elements assigned.
910 */
911#if __cplusplus >= 201103L
912 template<typename _InputIterator,
913 typename = std::_RequireInputIter<_InputIterator>>
914 void
915 assign(_InputIterator __first, _InputIterator __last)
916 { _M_assign_dispatch(__first, __last, __false_type()); }
917#else
918 template<typename _InputIterator>
919 void
920 assign(_InputIterator __first, _InputIterator __last)
921 {
922 // Check whether it's an integral type. If so, it's not an iterator.
923 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
924 _M_assign_dispatch(__first, __last, _Integral());
925 }
926#endif
927
928#if __cplusplus >= 201103L
929 /**
930 * @brief Assigns an initializer_list to a %list.
931 * @param __l An initializer_list of value_type.
932 *
933 * Replace the contents of the %list with copies of the elements
934 * in the initializer_list @a __l. This is linear in __l.size().
935 */
936 void
937 assign(initializer_list<value_type> __l)
938 { this->_M_assign_dispatch(__l.begin(), __l.end(), __false_type()); }
939#endif
940
941 /// Get a copy of the memory allocation object.
942 allocator_type
943 get_allocator() const _GLIBCXX_NOEXCEPT
944 { return allocator_type(_Base::_M_get_Node_allocator()); }
945
946 // iterators
947 /**
948 * Returns a read/write iterator that points to the first element in the
949 * %list. Iteration is done in ordinary element order.
950 */
951 iterator
952 begin() _GLIBCXX_NOEXCEPT
953 { return iterator(this->_M_impl._M_node._M_next); }
954
955 /**
956 * Returns a read-only (constant) iterator that points to the
957 * first element in the %list. Iteration is done in ordinary
958 * element order.
959 */
960 const_iterator
961 begin() const _GLIBCXX_NOEXCEPT
962 { return const_iterator(this->_M_impl._M_node._M_next); }
963
964 /**
965 * Returns a read/write iterator that points one past the last
966 * element in the %list. Iteration is done in ordinary element
967 * order.
968 */
969 iterator
970 end() _GLIBCXX_NOEXCEPT
971 { return iterator(&this->_M_impl._M_node); }
972
973 /**
974 * Returns a read-only (constant) iterator that points one past
975 * the last element in the %list. Iteration is done in ordinary
976 * element order.
977 */
978 const_iterator
979 end() const _GLIBCXX_NOEXCEPT
980 { return const_iterator(&this->_M_impl._M_node); }
981
982 /**
983 * Returns a read/write reverse iterator that points to the last
984 * element in the %list. Iteration is done in reverse element
985 * order.
986 */
987 reverse_iterator
988 rbegin() _GLIBCXX_NOEXCEPT
989 { return reverse_iterator(end()); }
990
991 /**
992 * Returns a read-only (constant) reverse iterator that points to
993 * the last element in the %list. Iteration is done in reverse
994 * element order.
995 */
996 const_reverse_iterator
997 rbegin() const _GLIBCXX_NOEXCEPT
998 { return const_reverse_iterator(end()); }
999
1000 /**
1001 * Returns a read/write reverse iterator that points to one
1002 * before the first element in the %list. Iteration is done in
1003 * reverse element order.
1004 */
1005 reverse_iterator
1006 rend() _GLIBCXX_NOEXCEPT
1007 { return reverse_iterator(begin()); }
1008
1009 /**
1010 * Returns a read-only (constant) reverse iterator that points to one
1011 * before the first element in the %list. Iteration is done in reverse
1012 * element order.
1013 */
1014 const_reverse_iterator
1015 rend() const _GLIBCXX_NOEXCEPT
1016 { return const_reverse_iterator(begin()); }
1017
1018#if __cplusplus >= 201103L
1019 /**
1020 * Returns a read-only (constant) iterator that points to the
1021 * first element in the %list. Iteration is done in ordinary
1022 * element order.
1023 */
1024 const_iterator
1025 cbegin() const noexcept
1026 { return const_iterator(this->_M_impl._M_node._M_next); }
1027
1028 /**
1029 * Returns a read-only (constant) iterator that points one past
1030 * the last element in the %list. Iteration is done in ordinary
1031 * element order.
1032 */
1033 const_iterator
1034 cend() const noexcept
1035 { return const_iterator(&this->_M_impl._M_node); }
1036
1037 /**
1038 * Returns a read-only (constant) reverse iterator that points to
1039 * the last element in the %list. Iteration is done in reverse
1040 * element order.
1041 */
1042 const_reverse_iterator
1043 crbegin() const noexcept
1044 { return const_reverse_iterator(end()); }
1045
1046 /**
1047 * Returns a read-only (constant) reverse iterator that points to one
1048 * before the first element in the %list. Iteration is done in reverse
1049 * element order.
1050 */
1051 const_reverse_iterator
1052 crend() const noexcept
1053 { return const_reverse_iterator(begin()); }
1054#endif
1055
1056 // [23.2.2.2] capacity
1057 /**
1058 * Returns true if the %list is empty. (Thus begin() would equal
1059 * end().)
1060 */
1061 bool
1062 empty() const _GLIBCXX_NOEXCEPT
1063 { return this->_M_impl._M_node._M_next == &this->_M_impl._M_node; }
1064
1065 /** Returns the number of elements in the %list. */
1066 size_type
1067 size() const _GLIBCXX_NOEXCEPT
1068 { return _M_node_count(); }
1069
1070 /** Returns the size() of the largest possible %list. */
1071 size_type
1072 max_size() const _GLIBCXX_NOEXCEPT
1073 { return _Node_alloc_traits::max_size(_M_get_Node_allocator()); }
1074
1075#if __cplusplus >= 201103L
1076 /**
1077 * @brief Resizes the %list to the specified number of elements.
1078 * @param __new_size Number of elements the %list should contain.
1079 *
1080 * This function will %resize the %list to the specified number
1081 * of elements. If the number is smaller than the %list's
1082 * current size the %list is truncated, otherwise default
1083 * constructed elements are appended.
1084 */
1085 void
1086 resize(size_type __new_size);
1087
1088 /**
1089 * @brief Resizes the %list to the specified number of elements.
1090 * @param __new_size Number of elements the %list should contain.
1091 * @param __x Data with which new elements should be populated.
1092 *
1093 * This function will %resize the %list to the specified number
1094 * of elements. If the number is smaller than the %list's
1095 * current size the %list is truncated, otherwise the %list is
1096 * extended and new elements are populated with given data.
1097 */
1098 void
1099 resize(size_type __new_size, const value_type& __x);
1100#else
1101 /**
1102 * @brief Resizes the %list to the specified number of elements.
1103 * @param __new_size Number of elements the %list should contain.
1104 * @param __x Data with which new elements should be populated.
1105 *
1106 * This function will %resize the %list to the specified number
1107 * of elements. If the number is smaller than the %list's
1108 * current size the %list is truncated, otherwise the %list is
1109 * extended and new elements are populated with given data.
1110 */
1111 void
1112 resize(size_type __new_size, value_type __x = value_type());
1113#endif
1114
1115 // element access
1116 /**
1117 * Returns a read/write reference to the data at the first
1118 * element of the %list.
1119 */
1120 reference
1121 front() _GLIBCXX_NOEXCEPT
1122 { return *begin(); }
1123
1124 /**
1125 * Returns a read-only (constant) reference to the data at the first
1126 * element of the %list.
1127 */
1128 const_reference
1129 front() const _GLIBCXX_NOEXCEPT
1130 { return *begin(); }
1131
1132 /**
1133 * Returns a read/write reference to the data at the last element
1134 * of the %list.
1135 */
1136 reference
1137 back() _GLIBCXX_NOEXCEPT
1138 {
1139 iterator __tmp = end();
1140 --__tmp;
1141 return *__tmp;
1142 }
1143
1144 /**
1145 * Returns a read-only (constant) reference to the data at the last
1146 * element of the %list.
1147 */
1148 const_reference
1149 back() const _GLIBCXX_NOEXCEPT
1150 {
1151 const_iterator __tmp = end();
1152 --__tmp;
1153 return *__tmp;
1154 }
1155
1156 // [23.2.2.3] modifiers
1157 /**
1158 * @brief Add data to the front of the %list.
1159 * @param __x Data to be added.
1160 *
1161 * This is a typical stack operation. The function creates an
1162 * element at the front of the %list and assigns the given data
1163 * to it. Due to the nature of a %list this operation can be
1164 * done in constant time, and does not invalidate iterators and
1165 * references.
1166 */
1167 void
1168 push_front(const value_type& __x)
1169 { this->_M_insert(begin(), __x); }
1170
1171#if __cplusplus >= 201103L
1172 void
1173 push_front(value_type&& __x)
1174 { this->_M_insert(begin(), std::move(__x)); }
1175
1176 template<typename... _Args>
1177#if __cplusplus > 201402L
1178 reference
1179#else
1180 void
1181#endif
1182 emplace_front(_Args&&... __args)
1183 {
1184 this->_M_insert(begin(), std::forward<_Args>(__args)...);
1185#if __cplusplus > 201402L
1186 return front();
1187#endif
1188 }
1189#endif
1190
1191 /**
1192 * @brief Removes first element.
1193 *
1194 * This is a typical stack operation. It shrinks the %list by
1195 * one. Due to the nature of a %list this operation can be done
1196 * in constant time, and only invalidates iterators/references to
1197 * the element being removed.
1198 *
1199 * Note that no data is returned, and if the first element's data
1200 * is needed, it should be retrieved before pop_front() is
1201 * called.
1202 */
1203 void
1204 pop_front() _GLIBCXX_NOEXCEPT
1205 { this->_M_erase(begin()); }
1206
1207 /**
1208 * @brief Add data to the end of the %list.
1209 * @param __x Data to be added.
1210 *
1211 * This is a typical stack operation. The function creates an
1212 * element at the end of the %list and assigns the given data to
1213 * it. Due to the nature of a %list this operation can be done
1214 * in constant time, and does not invalidate iterators and
1215 * references.
1216 */
1217 void
1218 push_back(const value_type& __x)
1219 { this->_M_insert(end(), __x); }
1220
1221#if __cplusplus >= 201103L
1222 void
1223 push_back(value_type&& __x)
1224 { this->_M_insert(end(), std::move(__x)); }
1225
1226 template<typename... _Args>
1227#if __cplusplus > 201402L
1228 reference
1229#else
1230 void
1231#endif
1232 emplace_back(_Args&&... __args)
1233 {
1234 this->_M_insert(end(), std::forward<_Args>(__args)...);
1235#if __cplusplus > 201402L
1236 return back();
1237#endif
1238 }
1239#endif
1240
1241 /**
1242 * @brief Removes last element.
1243 *
1244 * This is a typical stack operation. It shrinks the %list by
1245 * one. Due to the nature of a %list this operation can be done
1246 * in constant time, and only invalidates iterators/references to
1247 * the element being removed.
1248 *
1249 * Note that no data is returned, and if the last element's data
1250 * is needed, it should be retrieved before pop_back() is called.
1251 */
1252 void
1253 pop_back() _GLIBCXX_NOEXCEPT
1254 { this->_M_erase(iterator(this->_M_impl._M_node._M_prev)); }
1255
1256#if __cplusplus >= 201103L
1257 /**
1258 * @brief Constructs object in %list before specified iterator.
1259 * @param __position A const_iterator into the %list.
1260 * @param __args Arguments.
1261 * @return An iterator that points to the inserted data.
1262 *
1263 * This function will insert an object of type T constructed
1264 * with T(std::forward<Args>(args)...) before the specified
1265 * location. Due to the nature of a %list this operation can
1266 * be done in constant time, and does not invalidate iterators
1267 * and references.
1268 */
1269 template<typename... _Args>
1270 iterator
1271 emplace(const_iterator __position, _Args&&... __args);
1272
1273 /**
1274 * @brief Inserts given value into %list before specified iterator.
1275 * @param __position A const_iterator into the %list.
1276 * @param __x Data to be inserted.
1277 * @return An iterator that points to the inserted data.
1278 *
1279 * This function will insert a copy of the given value before
1280 * the specified location. Due to the nature of a %list this
1281 * operation can be done in constant time, and does not
1282 * invalidate iterators and references.
1283 */
1284 iterator
1285 insert(const_iterator __position, const value_type& __x);
1286#else
1287 /**
1288 * @brief Inserts given value into %list before specified iterator.
1289 * @param __position An iterator into the %list.
1290 * @param __x Data to be inserted.
1291 * @return An iterator that points to the inserted data.
1292 *
1293 * This function will insert a copy of the given value before
1294 * the specified location. Due to the nature of a %list this
1295 * operation can be done in constant time, and does not
1296 * invalidate iterators and references.
1297 */
1298 iterator
1299 insert(iterator __position, const value_type& __x);
1300#endif
1301
1302#if __cplusplus >= 201103L
1303 /**
1304 * @brief Inserts given rvalue into %list before specified iterator.
1305 * @param __position A const_iterator into the %list.
1306 * @param __x Data to be inserted.
1307 * @return An iterator that points to the inserted data.
1308 *
1309 * This function will insert a copy of the given rvalue before
1310 * the specified location. Due to the nature of a %list this
1311 * operation can be done in constant time, and does not
1312 * invalidate iterators and references.
1313 */
1314 iterator
1315 insert(const_iterator __position, value_type&& __x)
1316 { return emplace(__position, std::move(__x)); }
1317
1318 /**
1319 * @brief Inserts the contents of an initializer_list into %list
1320 * before specified const_iterator.
1321 * @param __p A const_iterator into the %list.
1322 * @param __l An initializer_list of value_type.
1323 * @return An iterator pointing to the first element inserted
1324 * (or __position).
1325 *
1326 * This function will insert copies of the data in the
1327 * initializer_list @a l into the %list before the location
1328 * specified by @a p.
1329 *
1330 * This operation is linear in the number of elements inserted and
1331 * does not invalidate iterators and references.
1332 */
1333 iterator
1334 insert(const_iterator __p, initializer_list<value_type> __l)
1335 { return this->insert(__p, __l.begin(), __l.end()); }
1336#endif
1337
1338#if __cplusplus >= 201103L
1339 /**
1340 * @brief Inserts a number of copies of given data into the %list.
1341 * @param __position A const_iterator into the %list.
1342 * @param __n Number of elements to be inserted.
1343 * @param __x Data to be inserted.
1344 * @return An iterator pointing to the first element inserted
1345 * (or __position).
1346 *
1347 * This function will insert a specified number of copies of the
1348 * given data before the location specified by @a position.
1349 *
1350 * This operation is linear in the number of elements inserted and
1351 * does not invalidate iterators and references.
1352 */
1353 iterator
1354 insert(const_iterator __position, size_type __n, const value_type& __x);
1355#else
1356 /**
1357 * @brief Inserts a number of copies of given data into the %list.
1358 * @param __position An iterator into the %list.
1359 * @param __n Number of elements to be inserted.
1360 * @param __x Data to be inserted.
1361 *
1362 * This function will insert a specified number of copies of the
1363 * given data before the location specified by @a position.
1364 *
1365 * This operation is linear in the number of elements inserted and
1366 * does not invalidate iterators and references.
1367 */
1368 void
1369 insert(iterator __position, size_type __n, const value_type& __x)
1370 {
1371 list __tmp(__n, __x, get_allocator());
1372 splice(__position, __tmp);
1373 }
1374#endif
1375
1376#if __cplusplus >= 201103L
1377 /**
1378 * @brief Inserts a range into the %list.
1379 * @param __position A const_iterator into the %list.
1380 * @param __first An input iterator.
1381 * @param __last An input iterator.
1382 * @return An iterator pointing to the first element inserted
1383 * (or __position).
1384 *
1385 * This function will insert copies of the data in the range [@a
1386 * first,@a last) into the %list before the location specified by
1387 * @a position.
1388 *
1389 * This operation is linear in the number of elements inserted and
1390 * does not invalidate iterators and references.
1391 */
1392 template<typename _InputIterator,
1393 typename = std::_RequireInputIter<_InputIterator>>
1394 iterator
1395 insert(const_iterator __position, _InputIterator __first,
1396 _InputIterator __last);
1397#else
1398 /**
1399 * @brief Inserts a range into the %list.
1400 * @param __position An iterator into the %list.
1401 * @param __first An input iterator.
1402 * @param __last An input iterator.
1403 *
1404 * This function will insert copies of the data in the range [@a
1405 * first,@a last) into the %list before the location specified by
1406 * @a position.
1407 *
1408 * This operation is linear in the number of elements inserted and
1409 * does not invalidate iterators and references.
1410 */
1411 template<typename _InputIterator>
1412 void
1413 insert(iterator __position, _InputIterator __first,
1414 _InputIterator __last)
1415 {
1416 list __tmp(__first, __last, get_allocator());
1417 splice(__position, __tmp);
1418 }
1419#endif
1420
1421 /**
1422 * @brief Remove element at given position.
1423 * @param __position Iterator pointing to element to be erased.
1424 * @return An iterator pointing to the next element (or end()).
1425 *
1426 * This function will erase the element at the given position and thus
1427 * shorten the %list by one.
1428 *
1429 * Due to the nature of a %list this operation can be done in
1430 * constant time, and only invalidates iterators/references to
1431 * the element being removed. The user is also cautioned that
1432 * this function only erases the element, and that if the element
1433 * is itself a pointer, the pointed-to memory is not touched in
1434 * any way. Managing the pointer is the user's responsibility.
1435 */
1436 iterator
1437#if __cplusplus >= 201103L
1438 erase(const_iterator __position) noexcept;
1439#else
1440 erase(iterator __position);
1441#endif
1442
1443 /**
1444 * @brief Remove a range of elements.
1445 * @param __first Iterator pointing to the first element to be erased.
1446 * @param __last Iterator pointing to one past the last element to be
1447 * erased.
1448 * @return An iterator pointing to the element pointed to by @a last
1449 * prior to erasing (or end()).
1450 *
1451 * This function will erase the elements in the range @a
1452 * [first,last) and shorten the %list accordingly.
1453 *
1454 * This operation is linear time in the size of the range and only
1455 * invalidates iterators/references to the element being removed.
1456 * The user is also cautioned that this function only erases the
1457 * elements, and that if the elements themselves are pointers, the
1458 * pointed-to memory is not touched in any way. Managing the pointer
1459 * is the user's responsibility.
1460 */
1461 iterator
1462#if __cplusplus >= 201103L
1463 erase(const_iterator __first, const_iterator __last) noexcept
1464#else
1465 erase(iterator __first, iterator __last)
1466#endif
1467 {
1468 while (__first != __last)
1469 __first = erase(__first);
1470 return __last._M_const_cast();
1471 }
1472
1473 /**
1474 * @brief Swaps data with another %list.
1475 * @param __x A %list of the same element and allocator types.
1476 *
1477 * This exchanges the elements between two lists in constant
1478 * time. Note that the global std::swap() function is
1479 * specialized such that std::swap(l1,l2) will feed to this
1480 * function.
1481 *
1482 * Whether the allocators are swapped depends on the allocator traits.
1483 */
1484 void
1485 swap(list& __x) _GLIBCXX_NOEXCEPT
1486 {
1487 __detail::_List_node_base::swap(this->_M_impl._M_node,
1488 __x._M_impl._M_node);
1489
1490 size_t __xsize = __x._M_get_size();
1491 __x._M_set_size(this->_M_get_size());
1492 this->_M_set_size(__xsize);
1493
1494 _Node_alloc_traits::_S_on_swap(this->_M_get_Node_allocator(),
1495 __x._M_get_Node_allocator());
1496 }
1497
1498 /**
1499 * Erases all the elements. Note that this function only erases
1500 * the elements, and that if the elements themselves are
1501 * pointers, the pointed-to memory is not touched in any way.
1502 * Managing the pointer is the user's responsibility.
1503 */
1504 void
1505 clear() _GLIBCXX_NOEXCEPT
1506 {
1507 _Base::_M_clear();
1508 _Base::_M_init();
1509 }
1510
1511 // [23.2.2.4] list operations
1512 /**
1513 * @brief Insert contents of another %list.
1514 * @param __position Iterator referencing the element to insert before.
1515 * @param __x Source list.
1516 *
1517 * The elements of @a __x are inserted in constant time in front of
1518 * the element referenced by @a __position. @a __x becomes an empty
1519 * list.
1520 *
1521 * Requires this != @a __x.
1522 */
1523 void
1524#if __cplusplus >= 201103L
1525 splice(const_iterator __position, list&& __x) noexcept
1526#else
1527 splice(iterator __position, list& __x)
1528#endif
1529 {
1530 if (!__x.empty())
1531 {
1532 _M_check_equal_allocators(__x);
1533
1534 this->_M_transfer(__position._M_const_cast(),
1535 __x.begin(), __x.end());
1536
1537 this->_M_inc_size(__x._M_get_size());
1538 __x._M_set_size(0);
1539 }
1540 }
1541
1542#if __cplusplus >= 201103L
1543 void
1544 splice(const_iterator __position, list& __x) noexcept
1545 { splice(__position, std::move(__x)); }
1546#endif
1547
1548#if __cplusplus >= 201103L
1549 /**
1550 * @brief Insert element from another %list.
1551 * @param __position Const_iterator referencing the element to
1552 * insert before.
1553 * @param __x Source list.
1554 * @param __i Const_iterator referencing the element to move.
1555 *
1556 * Removes the element in list @a __x referenced by @a __i and
1557 * inserts it into the current list before @a __position.
1558 */
1559 void
1560 splice(const_iterator __position, list&& __x, const_iterator __i) noexcept
1561#else
1562 /**
1563 * @brief Insert element from another %list.
1564 * @param __position Iterator referencing the element to insert before.
1565 * @param __x Source list.
1566 * @param __i Iterator referencing the element to move.
1567 *
1568 * Removes the element in list @a __x referenced by @a __i and
1569 * inserts it into the current list before @a __position.
1570 */
1571 void
1572 splice(iterator __position, list& __x, iterator __i)
1573#endif
1574 {
1575 iterator __j = __i._M_const_cast();
1576 ++__j;
1577 if (__position == __i || __position == __j)
1578 return;
1579
1580 if (this != std::__addressof(__x))
1581 _M_check_equal_allocators(__x);
1582
1583 this->_M_transfer(__position._M_const_cast(),
1584 __i._M_const_cast(), __j);
1585
1586 this->_M_inc_size(1);
1587 __x._M_dec_size(1);
1588 }
1589
1590#if __cplusplus >= 201103L
1591 /**
1592 * @brief Insert element from another %list.
1593 * @param __position Const_iterator referencing the element to
1594 * insert before.
1595 * @param __x Source list.
1596 * @param __i Const_iterator referencing the element to move.
1597 *
1598 * Removes the element in list @a __x referenced by @a __i and
1599 * inserts it into the current list before @a __position.
1600 */
1601 void
1602 splice(const_iterator __position, list& __x, const_iterator __i) noexcept
1603 { splice(__position, std::move(__x), __i); }
1604#endif
1605
1606#if __cplusplus >= 201103L
1607 /**
1608 * @brief Insert range from another %list.
1609 * @param __position Const_iterator referencing the element to
1610 * insert before.
1611 * @param __x Source list.
1612 * @param __first Const_iterator referencing the start of range in x.
1613 * @param __last Const_iterator referencing the end of range in x.
1614 *
1615 * Removes elements in the range [__first,__last) and inserts them
1616 * before @a __position in constant time.
1617 *
1618 * Undefined if @a __position is in [__first,__last).
1619 */
1620 void
1621 splice(const_iterator __position, list&& __x, const_iterator __first,
1622 const_iterator __last) noexcept
1623#else
1624 /**
1625 * @brief Insert range from another %list.
1626 * @param __position Iterator referencing the element to insert before.
1627 * @param __x Source list.
1628 * @param __first Iterator referencing the start of range in x.
1629 * @param __last Iterator referencing the end of range in x.
1630 *
1631 * Removes elements in the range [__first,__last) and inserts them
1632 * before @a __position in constant time.
1633 *
1634 * Undefined if @a __position is in [__first,__last).
1635 */
1636 void
1637 splice(iterator __position, list& __x, iterator __first,
1638 iterator __last)
1639#endif
1640 {
1641 if (__first != __last)
1642 {
1643 if (this != std::__addressof(__x))
1644 _M_check_equal_allocators(__x);
1645
1646 size_t __n = _S_distance(__first, __last);
1647 this->_M_inc_size(__n);
1648 __x._M_dec_size(__n);
1649
1650 this->_M_transfer(__position._M_const_cast(),
1651 __first._M_const_cast(),
1652 __last._M_const_cast());
1653 }
1654 }
1655
1656#if __cplusplus >= 201103L
1657 /**
1658 * @brief Insert range from another %list.
1659 * @param __position Const_iterator referencing the element to
1660 * insert before.
1661 * @param __x Source list.
1662 * @param __first Const_iterator referencing the start of range in x.
1663 * @param __last Const_iterator referencing the end of range in x.
1664 *
1665 * Removes elements in the range [__first,__last) and inserts them
1666 * before @a __position in constant time.
1667 *
1668 * Undefined if @a __position is in [__first,__last).
1669 */
1670 void
1671 splice(const_iterator __position, list& __x, const_iterator __first,
1672 const_iterator __last) noexcept
1673 { splice(__position, std::move(__x), __first, __last); }
1674#endif
1675
1676 /**
1677 * @brief Remove all elements equal to value.
1678 * @param __value The value to remove.
1679 *
1680 * Removes every element in the list equal to @a value.
1681 * Remaining elements stay in list order. Note that this
1682 * function only erases the elements, and that if the elements
1683 * themselves are pointers, the pointed-to memory is not
1684 * touched in any way. Managing the pointer is the user's
1685 * responsibility.
1686 */
1687 void
1688 remove(const _Tp& __value);
1689
1690 /**
1691 * @brief Remove all elements satisfying a predicate.
1692 * @tparam _Predicate Unary predicate function or object.
1693 *
1694 * Removes every element in the list for which the predicate
1695 * returns true. Remaining elements stay in list order. Note
1696 * that this function only erases the elements, and that if the
1697 * elements themselves are pointers, the pointed-to memory is
1698 * not touched in any way. Managing the pointer is the user's
1699 * responsibility.
1700 */
1701 template<typename _Predicate>
1702 void
1703 remove_if(_Predicate);
1704
1705 /**
1706 * @brief Remove consecutive duplicate elements.
1707 *
1708 * For each consecutive set of elements with the same value,
1709 * remove all but the first one. Remaining elements stay in
1710 * list order. Note that this function only erases the
1711 * elements, and that if the elements themselves are pointers,
1712 * the pointed-to memory is not touched in any way. Managing
1713 * the pointer is the user's responsibility.
1714 */
1715 void
1716 unique();
1717
1718 /**
1719 * @brief Remove consecutive elements satisfying a predicate.
1720 * @tparam _BinaryPredicate Binary predicate function or object.
1721 *
1722 * For each consecutive set of elements [first,last) that
1723 * satisfy predicate(first,i) where i is an iterator in
1724 * [first,last), remove all but the first one. Remaining
1725 * elements stay in list order. Note that this function only
1726 * erases the elements, and that if the elements themselves are
1727 * pointers, the pointed-to memory is not touched in any way.
1728 * Managing the pointer is the user's responsibility.
1729 */
1730 template<typename _BinaryPredicate>
1731 void
1732 unique(_BinaryPredicate);
1733
1734 /**
1735 * @brief Merge sorted lists.
1736 * @param __x Sorted list to merge.
1737 *
1738 * Assumes that both @a __x and this list are sorted according to
1739 * operator<(). Merges elements of @a __x into this list in
1740 * sorted order, leaving @a __x empty when complete. Elements in
1741 * this list precede elements in @a __x that are equal.
1742 */
1743#if __cplusplus >= 201103L
1744 void
1745 merge(list&& __x);
1746
1747 void
1748 merge(list& __x)
1749 { merge(std::move(__x)); }
1750#else
1751 void
1752 merge(list& __x);
1753#endif
1754
1755 /**
1756 * @brief Merge sorted lists according to comparison function.
1757 * @tparam _StrictWeakOrdering Comparison function defining
1758 * sort order.
1759 * @param __x Sorted list to merge.
1760 * @param __comp Comparison functor.
1761 *
1762 * Assumes that both @a __x and this list are sorted according to
1763 * StrictWeakOrdering. Merges elements of @a __x into this list
1764 * in sorted order, leaving @a __x empty when complete. Elements
1765 * in this list precede elements in @a __x that are equivalent
1766 * according to StrictWeakOrdering().
1767 */
1768#if __cplusplus >= 201103L
1769 template<typename _StrictWeakOrdering>
1770 void
1771 merge(list&& __x, _StrictWeakOrdering __comp);
1772
1773 template<typename _StrictWeakOrdering>
1774 void
1775 merge(list& __x, _StrictWeakOrdering __comp)
1776 { merge(std::move(__x), __comp); }
1777#else
1778 template<typename _StrictWeakOrdering>
1779 void
1780 merge(list& __x, _StrictWeakOrdering __comp);
1781#endif
1782
1783 /**
1784 * @brief Reverse the elements in list.
1785 *
1786 * Reverse the order of elements in the list in linear time.
1787 */
1788 void
1789 reverse() _GLIBCXX_NOEXCEPT
1790 { this->_M_impl._M_node._M_reverse(); }
1791
1792 /**
1793 * @brief Sort the elements.
1794 *
1795 * Sorts the elements of this list in NlogN time. Equivalent
1796 * elements remain in list order.
1797 */
1798 void
1799 sort();
1800
1801 /**
1802 * @brief Sort the elements according to comparison function.
1803 *
1804 * Sorts the elements of this list in NlogN time. Equivalent
1805 * elements remain in list order.
1806 */
1807 template<typename _StrictWeakOrdering>
1808 void
1809 sort(_StrictWeakOrdering);
1810
1811 protected:
1812 // Internal constructor functions follow.
1813
1814 // Called by the range constructor to implement [23.1.1]/9
1815
1816 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1817 // 438. Ambiguity in the "do the right thing" clause
1818 template<typename _Integer>
1819 void
1820 _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
1821 { _M_fill_initialize(static_cast<size_type>(__n), __x); }
1822
1823 // Called by the range constructor to implement [23.1.1]/9
1824 template<typename _InputIterator>
1825 void
1826 _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
1827 __false_type)
1828 {
1829 for (; __first != __last; ++__first)
1830#if __cplusplus >= 201103L
1831 emplace_back(*__first);
1832#else
1833 push_back(*__first);
1834#endif
1835 }
1836
1837 // Called by list(n,v,a), and the range constructor when it turns out
1838 // to be the same thing.
1839 void
1840 _M_fill_initialize(size_type __n, const value_type& __x)
1841 {
1842 for (; __n; --__n)
1843 push_back(__x);
1844 }
1845
1846#if __cplusplus >= 201103L
1847 // Called by list(n).
1848 void
1849 _M_default_initialize(size_type __n)
1850 {
1851 for (; __n; --__n)
1852 emplace_back();
1853 }
1854
1855 // Called by resize(sz).
1856 void
1857 _M_default_append(size_type __n);
1858#endif
1859
1860 // Internal assign functions follow.
1861
1862 // Called by the range assign to implement [23.1.1]/9
1863
1864 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1865 // 438. Ambiguity in the "do the right thing" clause
1866 template<typename _Integer>
1867 void
1868 _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
1869 { _M_fill_assign(__n, __val); }
1870
1871 // Called by the range assign to implement [23.1.1]/9
1872 template<typename _InputIterator>
1873 void
1874 _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
1875 __false_type);
1876
1877 // Called by assign(n,t), and the range assign when it turns out
1878 // to be the same thing.
1879 void
1880 _M_fill_assign(size_type __n, const value_type& __val);
1881
1882
1883 // Moves the elements from [first,last) before position.
1884 void
1885 _M_transfer(iterator __position, iterator __first, iterator __last)
1886 { __position._M_node->_M_transfer(__first._M_node, __last._M_node); }
1887
1888 // Inserts new element at position given and with value given.
1889#if __cplusplus < 201103L
1890 void
1891 _M_insert(iterator __position, const value_type& __x)
1892 {
1893 _Node* __tmp = _M_create_node(__x);
1894 __tmp->_M_hook(__position._M_node);
1895 this->_M_inc_size(1);
1896 }
1897#else
1898 template<typename... _Args>
1899 void
1900 _M_insert(iterator __position, _Args&&... __args)
1901 {
1902 _Node* __tmp = _M_create_node(std::forward<_Args>(__args)...);
1903 __tmp->_M_hook(__position._M_node);
1904 this->_M_inc_size(1);
1905 }
1906#endif
1907
1908 // Erases element at position given.
1909 void
1910 _M_erase(iterator __position) _GLIBCXX_NOEXCEPT
1911 {
1912 this->_M_dec_size(1);
1913 __position._M_node->_M_unhook();
1914 _Node* __n = static_cast<_Node*>(__position._M_node);
1915#if __cplusplus >= 201103L
1916 _Node_alloc_traits::destroy(_M_get_Node_allocator(), __n->_M_valptr());
1917#else
1918 _Tp_alloc_type(_M_get_Node_allocator()).destroy(__n->_M_valptr());
1919#endif
1920
1921 _M_put_node(__n);
1922 }
1923
1924 // To implement the splice (and merge) bits of N1599.
1925 void
1926 _M_check_equal_allocators(list& __x) _GLIBCXX_NOEXCEPT
1927 {
1928 if (std::__alloc_neq<typename _Base::_Node_alloc_type>::
1929 _S_do_it(_M_get_Node_allocator(), __x._M_get_Node_allocator()))
1930 __builtin_abort();
1931 }
1932
1933 // Used to implement resize.
1934 const_iterator
1935 _M_resize_pos(size_type& __new_size) const;
1936
1937#if __cplusplus >= 201103L
1938 void
1939 _M_move_assign(list&& __x, true_type) noexcept
1940 {
1941 this->_M_clear();
1942 this->_M_move_nodes(std::move(__x));
1943 std::__alloc_on_move(this->_M_get_Node_allocator(),
1944 __x._M_get_Node_allocator());
1945 }
1946
1947 void
1948 _M_move_assign(list&& __x, false_type)
1949 {
1950 if (__x._M_get_Node_allocator() == this->_M_get_Node_allocator())
1951 _M_move_assign(std::move(__x), true_type{});
1952 else
1953 // The rvalue's allocator cannot be moved, or is not equal,
1954 // so we need to individually move each element.
1955 _M_assign_dispatch(std::__make_move_if_noexcept_iterator(__x.begin()),
1956 std::__make_move_if_noexcept_iterator(__x.end()),
1957 __false_type{});
1958 }
1959#endif
1960 };
1961
1962#if __cpp_deduction_guides >= 201606
1963 template<typename _InputIterator, typename _ValT
1964 = typename iterator_traits<_InputIterator>::value_type,
1965 typename _Allocator = allocator<_ValT>,
1966 typename = _RequireInputIter<_InputIterator>,
1967 typename = _RequireAllocator<_Allocator>>
1968 list(_InputIterator, _InputIterator, _Allocator = _Allocator())
1969 -> list<_ValT, _Allocator>;
1970#endif
1971
1972_GLIBCXX_END_NAMESPACE_CXX11
1973
1974 /**
1975 * @brief List equality comparison.
1976 * @param __x A %list.
1977 * @param __y A %list of the same type as @a __x.
1978 * @return True iff the size and elements of the lists are equal.
1979 *
1980 * This is an equivalence relation. It is linear in the size of
1981 * the lists. Lists are considered equivalent if their sizes are
1982 * equal, and if corresponding elements compare equal.
1983 */
1984 template<typename _Tp, typename _Alloc>
1985 inline bool
1986 operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
1987 {
1988#if _GLIBCXX_USE_CXX11_ABI
1989 if (__x.size() != __y.size())
1990 return false;
1991#endif
1992
1993 typedef typename list<_Tp, _Alloc>::const_iterator const_iterator;
1994 const_iterator __end1 = __x.end();
1995 const_iterator __end2 = __y.end();
1996
1997 const_iterator __i1 = __x.begin();
1998 const_iterator __i2 = __y.begin();
1999 while (__i1 != __end1 && __i2 != __end2 && *__i1 == *__i2)
2000 {
2001 ++__i1;
2002 ++__i2;
2003 }
2004 return __i1 == __end1 && __i2 == __end2;
2005 }
2006
2007 /**
2008 * @brief List ordering relation.
2009 * @param __x A %list.
2010 * @param __y A %list of the same type as @a __x.
2011 * @return True iff @a __x is lexicographically less than @a __y.
2012 *
2013 * This is a total ordering relation. It is linear in the size of the
2014 * lists. The elements must be comparable with @c <.
2015 *
2016 * See std::lexicographical_compare() for how the determination is made.
2017 */
2018 template<typename _Tp, typename _Alloc>
2019 inline bool
2020 operator<(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
2021 { return std::lexicographical_compare(__x.begin(), __x.end(),
2022 __y.begin(), __y.end()); }
2023
2024 /// Based on operator==
2025 template<typename _Tp, typename _Alloc>
2026 inline bool
2027 operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
2028 { return !(__x == __y); }
2029
2030 /// Based on operator<
2031 template<typename _Tp, typename _Alloc>
2032 inline bool
2033 operator>(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
2034 { return __y < __x; }
2035
2036 /// Based on operator<
2037 template<typename _Tp, typename _Alloc>
2038 inline bool
2039 operator<=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
2040 { return !(__y < __x); }
2041
2042 /// Based on operator<
2043 template<typename _Tp, typename _Alloc>
2044 inline bool
2045 operator>=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
2046 { return !(__x < __y); }
2047
2048 /// See std::list::swap().
2049 template<typename _Tp, typename _Alloc>
2050 inline void
2051 swap(list<_Tp, _Alloc>& __x, list<_Tp, _Alloc>& __y)
2052 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
2053 { __x.swap(__y); }
2054
2055_GLIBCXX_END_NAMESPACE_CONTAINER
2056
2057#if _GLIBCXX_USE_CXX11_ABI
2058
2059 // Detect when distance is used to compute the size of the whole list.
2060 template<typename _Tp>
2061 inline ptrdiff_t
2062 __distance(_GLIBCXX_STD_C::_List_iterator<_Tp> __first,
2063 _GLIBCXX_STD_C::_List_iterator<_Tp> __last,
2064 input_iterator_tag __tag)
2065 {
2066 typedef _GLIBCXX_STD_C::_List_const_iterator<_Tp> _CIter;
2067 return std::__distance(_CIter(__first), _CIter(__last), __tag);
2068 }
2069
2070 template<typename _Tp>
2071 inline ptrdiff_t
2072 __distance(_GLIBCXX_STD_C::_List_const_iterator<_Tp> __first,
2073 _GLIBCXX_STD_C::_List_const_iterator<_Tp> __last,
2074 input_iterator_tag)
2075 {
2076 typedef __detail::_List_node_header _Sentinel;
2077 _GLIBCXX_STD_C::_List_const_iterator<_Tp> __beyond = __last;
2078 ++__beyond;
2079 const bool __whole = __first == __beyond;
2080 if (__builtin_constant_p (__whole) && __whole)
2081 return static_cast<const _Sentinel*>(__last._M_node)->_M_size;
2082
2083 ptrdiff_t __n = 0;
2084 while (__first != __last)
2085 {
2086 ++__first;
2087 ++__n;
2088 }
2089 return __n;
2090 }
2091#endif
2092
2093_GLIBCXX_END_NAMESPACE_VERSION
2094} // namespace std
2095
2096#endif /* _STL_LIST_H */
2097