1 // <forward_list.h> -*- C++ -*-
3 // Copyright (C) 2008-2017 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file bits/forward_list.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{forward_list}
30 #ifndef _FORWARD_LIST_H
31 #define _FORWARD_LIST_H 1
33 #pragma GCC system_header
35 #include <initializer_list>
36 #include <bits/stl_iterator_base_types.h>
37 #include <bits/stl_iterator.h>
38 #include <bits/stl_algobase.h>
39 #include <bits/stl_function.h>
40 #include <bits/allocator.h>
41 #include <ext/alloc_traits.h>
42 #include <ext/aligned_buffer.h>
44 namespace std
_GLIBCXX_VISIBILITY(default)
46 _GLIBCXX_BEGIN_NAMESPACE_VERSION
47 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
50 * @brief A helper basic node class for %forward_list.
51 * This is just a linked list with nothing inside it.
52 * There are purely list shuffling utility methods here.
54 struct _Fwd_list_node_base
56 _Fwd_list_node_base() = default;
58 _Fwd_list_node_base
* _M_next
= nullptr;
61 _M_transfer_after(_Fwd_list_node_base
* __begin
,
62 _Fwd_list_node_base
* __end
) noexcept
64 _Fwd_list_node_base
* __keep
= __begin
->_M_next
;
67 __begin
->_M_next
= __end
->_M_next
;
68 __end
->_M_next
= _M_next
;
77 _M_reverse_after() noexcept
79 _Fwd_list_node_base
* __tail
= _M_next
;
82 while (_Fwd_list_node_base
* __temp
= __tail
->_M_next
)
84 _Fwd_list_node_base
* __keep
= _M_next
;
86 __tail
->_M_next
= __temp
->_M_next
;
87 _M_next
->_M_next
= __keep
;
93 * @brief A helper node class for %forward_list.
94 * This is just a linked list with uninitialized storage for a
95 * data value in each node.
96 * There is a sorting utility method.
98 template<typename _Tp
>
100 : public _Fwd_list_node_base
102 _Fwd_list_node() = default;
104 __gnu_cxx::__aligned_buffer
<_Tp
> _M_storage
;
108 { return _M_storage
._M_ptr(); }
111 _M_valptr() const noexcept
112 { return _M_storage
._M_ptr(); }
116 * @brief A forward_list::iterator.
118 * All the functions are op overloads.
120 template<typename _Tp
>
121 struct _Fwd_list_iterator
123 typedef _Fwd_list_iterator
<_Tp
> _Self
;
124 typedef _Fwd_list_node
<_Tp
> _Node
;
126 typedef _Tp value_type
;
127 typedef _Tp
* pointer
;
128 typedef _Tp
& reference
;
129 typedef ptrdiff_t difference_type
;
130 typedef std::forward_iterator_tag iterator_category
;
132 _Fwd_list_iterator() noexcept
136 _Fwd_list_iterator(_Fwd_list_node_base
* __n
) noexcept
140 operator*() const noexcept
141 { return *static_cast<_Node
*>(this->_M_node
)->_M_valptr(); }
144 operator->() const noexcept
145 { return static_cast<_Node
*>(this->_M_node
)->_M_valptr(); }
148 operator++() noexcept
150 _M_node
= _M_node
->_M_next
;
155 operator++(int) noexcept
158 _M_node
= _M_node
->_M_next
;
163 operator==(const _Self
& __x
) const noexcept
164 { return _M_node
== __x
._M_node
; }
167 operator!=(const _Self
& __x
) const noexcept
168 { return _M_node
!= __x
._M_node
; }
171 _M_next() const noexcept
174 return _Fwd_list_iterator(_M_node
->_M_next
);
176 return _Fwd_list_iterator(0);
179 _Fwd_list_node_base
* _M_node
;
183 * @brief A forward_list::const_iterator.
185 * All the functions are op overloads.
187 template<typename _Tp
>
188 struct _Fwd_list_const_iterator
190 typedef _Fwd_list_const_iterator
<_Tp
> _Self
;
191 typedef const _Fwd_list_node
<_Tp
> _Node
;
192 typedef _Fwd_list_iterator
<_Tp
> iterator
;
194 typedef _Tp value_type
;
195 typedef const _Tp
* pointer
;
196 typedef const _Tp
& reference
;
197 typedef ptrdiff_t difference_type
;
198 typedef std::forward_iterator_tag iterator_category
;
200 _Fwd_list_const_iterator() noexcept
204 _Fwd_list_const_iterator(const _Fwd_list_node_base
* __n
) noexcept
207 _Fwd_list_const_iterator(const iterator
& __iter
) noexcept
208 : _M_node(__iter
._M_node
) { }
211 operator*() const noexcept
212 { return *static_cast<_Node
*>(this->_M_node
)->_M_valptr(); }
215 operator->() const noexcept
216 { return static_cast<_Node
*>(this->_M_node
)->_M_valptr(); }
219 operator++() noexcept
221 _M_node
= _M_node
->_M_next
;
226 operator++(int) noexcept
229 _M_node
= _M_node
->_M_next
;
234 operator==(const _Self
& __x
) const noexcept
235 { return _M_node
== __x
._M_node
; }
238 operator!=(const _Self
& __x
) const noexcept
239 { return _M_node
!= __x
._M_node
; }
242 _M_next() const noexcept
245 return _Fwd_list_const_iterator(_M_node
->_M_next
);
247 return _Fwd_list_const_iterator(0);
250 const _Fwd_list_node_base
* _M_node
;
254 * @brief Forward list iterator equality comparison.
256 template<typename _Tp
>
258 operator==(const _Fwd_list_iterator
<_Tp
>& __x
,
259 const _Fwd_list_const_iterator
<_Tp
>& __y
) noexcept
260 { return __x
._M_node
== __y
._M_node
; }
263 * @brief Forward list iterator inequality comparison.
265 template<typename _Tp
>
267 operator!=(const _Fwd_list_iterator
<_Tp
>& __x
,
268 const _Fwd_list_const_iterator
<_Tp
>& __y
) noexcept
269 { return __x
._M_node
!= __y
._M_node
; }
272 * @brief Base class for %forward_list.
274 template<typename _Tp
, typename _Alloc
>
275 struct _Fwd_list_base
278 typedef __alloc_rebind
<_Alloc
, _Tp
> _Tp_alloc_type
;
279 typedef __alloc_rebind
<_Alloc
, _Fwd_list_node
<_Tp
>> _Node_alloc_type
;
280 typedef __gnu_cxx::__alloc_traits
<_Node_alloc_type
> _Node_alloc_traits
;
282 struct _Fwd_list_impl
283 : public _Node_alloc_type
285 _Fwd_list_node_base _M_head
;
288 : _Node_alloc_type(), _M_head()
291 _Fwd_list_impl(const _Node_alloc_type
& __a
)
292 : _Node_alloc_type(__a
), _M_head()
295 _Fwd_list_impl(_Node_alloc_type
&& __a
)
296 : _Node_alloc_type(std::move(__a
)), _M_head()
300 _Fwd_list_impl _M_impl
;
303 typedef _Fwd_list_iterator
<_Tp
> iterator
;
304 typedef _Fwd_list_const_iterator
<_Tp
> const_iterator
;
305 typedef _Fwd_list_node
<_Tp
> _Node
;
308 _M_get_Node_allocator() noexcept
309 { return this->_M_impl
; }
311 const _Node_alloc_type
&
312 _M_get_Node_allocator() const noexcept
313 { return this->_M_impl
; }
318 _Fwd_list_base(_Node_alloc_type
&& __a
)
319 : _M_impl(std::move(__a
)) { }
321 _Fwd_list_base(_Fwd_list_base
&& __lst
, _Node_alloc_type
&& __a
);
323 _Fwd_list_base(_Fwd_list_base
&& __lst
)
324 : _M_impl(std::move(__lst
._M_get_Node_allocator()))
326 this->_M_impl
._M_head
._M_next
= __lst
._M_impl
._M_head
._M_next
;
327 __lst
._M_impl
._M_head
._M_next
= 0;
331 { _M_erase_after(&_M_impl
._M_head
, 0); }
338 auto __ptr
= _Node_alloc_traits::allocate(_M_get_Node_allocator(), 1);
339 return std::__to_address(__ptr
);
342 template<typename
... _Args
>
344 _M_create_node(_Args
&&... __args
)
346 _Node
* __node
= this->_M_get_node();
349 _Tp_alloc_type
__a(_M_get_Node_allocator());
350 typedef allocator_traits
<_Tp_alloc_type
> _Alloc_traits
;
351 ::new ((void*)__node
) _Node
;
352 _Alloc_traits::construct(__a
, __node
->_M_valptr(),
353 std::forward
<_Args
>(__args
)...);
357 this->_M_put_node(__node
);
358 __throw_exception_again
;
363 template<typename
... _Args
>
365 _M_insert_after(const_iterator __pos
, _Args
&&... __args
);
368 _M_put_node(_Node
* __p
)
370 typedef typename
_Node_alloc_traits::pointer _Ptr
;
371 auto __ptr
= std::pointer_traits
<_Ptr
>::pointer_to(*__p
);
372 _Node_alloc_traits::deallocate(_M_get_Node_allocator(), __ptr
, 1);
376 _M_erase_after(_Fwd_list_node_base
* __pos
);
379 _M_erase_after(_Fwd_list_node_base
* __pos
,
380 _Fwd_list_node_base
* __last
);
384 * @brief A standard container with linear time access to elements,
385 * and fixed time insertion/deletion at any point in the sequence.
389 * @tparam _Tp Type of element.
390 * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
392 * Meets the requirements of a <a href="tables.html#65">container</a>, a
393 * <a href="tables.html#67">sequence</a>, including the
394 * <a href="tables.html#68">optional sequence requirements</a> with the
395 * %exception of @c at and @c operator[].
397 * This is a @e singly @e linked %list. Traversal up the
398 * %list requires linear time, but adding and removing elements (or
399 * @e nodes) is done in constant time, regardless of where the
400 * change takes place. Unlike std::vector and std::deque,
401 * random-access iterators are not provided, so subscripting ( @c
402 * [] ) access is not allowed. For algorithms which only need
403 * sequential access, this lack makes no difference.
405 * Also unlike the other standard containers, std::forward_list provides
406 * specialized algorithms %unique to linked lists, such as
407 * splicing, sorting, and in-place reversal.
409 template<typename _Tp
, typename _Alloc
= allocator
<_Tp
>>
410 class forward_list
: private _Fwd_list_base
<_Tp
, _Alloc
>
412 static_assert(is_same
<typename remove_cv
<_Tp
>::type
, _Tp
>::value
,
413 "std::forward_list must have a non-const, non-volatile value_type");
414 #ifdef __STRICT_ANSI__
415 static_assert(is_same
<typename
_Alloc::value_type
, _Tp
>::value
,
416 "std::forward_list must have the same value_type as its allocator");
420 typedef _Fwd_list_base
<_Tp
, _Alloc
> _Base
;
421 typedef _Fwd_list_node
<_Tp
> _Node
;
422 typedef _Fwd_list_node_base _Node_base
;
423 typedef typename
_Base::_Tp_alloc_type _Tp_alloc_type
;
424 typedef typename
_Base::_Node_alloc_type _Node_alloc_type
;
425 typedef typename
_Base::_Node_alloc_traits _Node_alloc_traits
;
426 typedef __gnu_cxx::__alloc_traits
<_Tp_alloc_type
> _Alloc_traits
;
430 typedef _Tp value_type
;
431 typedef typename
_Alloc_traits::pointer pointer
;
432 typedef typename
_Alloc_traits::const_pointer const_pointer
;
433 typedef value_type
& reference
;
434 typedef const value_type
& const_reference
;
436 typedef _Fwd_list_iterator
<_Tp
> iterator
;
437 typedef _Fwd_list_const_iterator
<_Tp
> const_iterator
;
438 typedef std::size_t size_type
;
439 typedef std::ptrdiff_t difference_type
;
440 typedef _Alloc allocator_type
;
442 // 23.3.4.2 construct/copy/destroy:
445 * @brief Creates a %forward_list with no elements.
448 noexcept(is_nothrow_default_constructible
<_Node_alloc_type
>::value
)
453 * @brief Creates a %forward_list with no elements.
454 * @param __al An allocator object.
457 forward_list(const _Alloc
& __al
) noexcept
458 : _Base(_Node_alloc_type(__al
))
463 * @brief Copy constructor with allocator argument.
464 * @param __list Input list to copy.
465 * @param __al An allocator object.
467 forward_list(const forward_list
& __list
, const _Alloc
& __al
)
468 : _Base(_Node_alloc_type(__al
))
469 { _M_range_initialize(__list
.begin(), __list
.end()); }
472 * @brief Move constructor with allocator argument.
473 * @param __list Input list to move.
474 * @param __al An allocator object.
476 forward_list(forward_list
&& __list
, const _Alloc
& __al
)
477 noexcept(_Node_alloc_traits::_S_always_equal())
478 : _Base(std::move(__list
), _Node_alloc_type(__al
))
480 // If __list is not empty it means its allocator is not equal to __a,
481 // so we need to move from each element individually.
482 insert_after(cbefore_begin(),
483 std::__make_move_if_noexcept_iterator(__list
.begin()),
484 std::__make_move_if_noexcept_iterator(__list
.end()));
488 * @brief Creates a %forward_list with default constructed elements.
489 * @param __n The number of elements to initially create.
490 * @param __al An allocator object.
492 * This constructor creates the %forward_list with @a __n default
493 * constructed elements.
496 forward_list(size_type __n
, const _Alloc
& __al
= _Alloc())
497 : _Base(_Node_alloc_type(__al
))
498 { _M_default_initialize(__n
); }
501 * @brief Creates a %forward_list with copies of an exemplar element.
502 * @param __n The number of elements to initially create.
503 * @param __value An element to copy.
504 * @param __al An allocator object.
506 * This constructor fills the %forward_list with @a __n copies of
509 forward_list(size_type __n
, const _Tp
& __value
,
510 const _Alloc
& __al
= _Alloc())
511 : _Base(_Node_alloc_type(__al
))
512 { _M_fill_initialize(__n
, __value
); }
515 * @brief Builds a %forward_list from a range.
516 * @param __first An input iterator.
517 * @param __last An input iterator.
518 * @param __al An allocator object.
520 * Create a %forward_list consisting of copies of the elements from
521 * [@a __first,@a __last). This is linear in N (where N is
522 * distance(@a __first,@a __last)).
524 template<typename _InputIterator
,
525 typename
= std::_RequireInputIter
<_InputIterator
>>
526 forward_list(_InputIterator __first
, _InputIterator __last
,
527 const _Alloc
& __al
= _Alloc())
528 : _Base(_Node_alloc_type(__al
))
529 { _M_range_initialize(__first
, __last
); }
532 * @brief The %forward_list copy constructor.
533 * @param __list A %forward_list of identical element and allocator
536 forward_list(const forward_list
& __list
)
537 : _Base(_Node_alloc_traits::_S_select_on_copy(
538 __list
._M_get_Node_allocator()))
539 { _M_range_initialize(__list
.begin(), __list
.end()); }
542 * @brief The %forward_list move constructor.
543 * @param __list A %forward_list of identical element and allocator
546 * The newly-created %forward_list contains the exact contents of @a
547 * __list. The contents of @a __list are a valid, but unspecified
550 forward_list(forward_list
&& __list
) noexcept
551 : _Base(std::move(__list
)) { }
554 * @brief Builds a %forward_list from an initializer_list
555 * @param __il An initializer_list of value_type.
556 * @param __al An allocator object.
558 * Create a %forward_list consisting of copies of the elements
559 * in the initializer_list @a __il. This is linear in __il.size().
561 forward_list(std::initializer_list
<_Tp
> __il
,
562 const _Alloc
& __al
= _Alloc())
563 : _Base(_Node_alloc_type(__al
))
564 { _M_range_initialize(__il
.begin(), __il
.end()); }
567 * @brief The forward_list dtor.
569 ~forward_list() noexcept
573 * @brief The %forward_list assignment operator.
574 * @param __list A %forward_list of identical element and allocator
577 * All the elements of @a __list are copied.
579 * Whether the allocator is copied depends on the allocator traits.
582 operator=(const forward_list
& __list
);
585 * @brief The %forward_list move assignment operator.
586 * @param __list A %forward_list of identical element and allocator
589 * The contents of @a __list are moved into this %forward_list
590 * (without copying, if the allocators permit it).
592 * Afterwards @a __list is a valid, but unspecified %forward_list
594 * Whether the allocator is moved depends on the allocator traits.
597 operator=(forward_list
&& __list
)
598 noexcept(_Node_alloc_traits::_S_nothrow_move())
600 constexpr bool __move_storage
=
601 _Node_alloc_traits::_S_propagate_on_move_assign()
602 || _Node_alloc_traits::_S_always_equal();
603 _M_move_assign(std::move(__list
), __bool_constant
<__move_storage
>());
608 * @brief The %forward_list initializer list assignment operator.
609 * @param __il An initializer_list of value_type.
611 * Replace the contents of the %forward_list with copies of the
612 * elements in the initializer_list @a __il. This is linear in
616 operator=(std::initializer_list
<_Tp
> __il
)
623 * @brief Assigns a range to a %forward_list.
624 * @param __first An input iterator.
625 * @param __last An input iterator.
627 * This function fills a %forward_list with copies of the elements
628 * in the range [@a __first,@a __last).
630 * Note that the assignment completely changes the %forward_list and
631 * that the number of elements of the resulting %forward_list is the
632 * same as the number of elements assigned.
634 template<typename _InputIterator
,
635 typename
= std::_RequireInputIter
<_InputIterator
>>
637 assign(_InputIterator __first
, _InputIterator __last
)
639 typedef is_assignable
<_Tp
, decltype(*__first
)> __assignable
;
640 _M_assign(__first
, __last
, __assignable());
644 * @brief Assigns a given value to a %forward_list.
645 * @param __n Number of elements to be assigned.
646 * @param __val Value to be assigned.
648 * This function fills a %forward_list with @a __n copies of the
649 * given value. Note that the assignment completely changes the
650 * %forward_list, and that the resulting %forward_list has __n
654 assign(size_type __n
, const _Tp
& __val
)
655 { _M_assign_n(__n
, __val
, is_copy_assignable
<_Tp
>()); }
658 * @brief Assigns an initializer_list to a %forward_list.
659 * @param __il An initializer_list of value_type.
661 * Replace the contents of the %forward_list with copies of the
662 * elements in the initializer_list @a __il. This is linear in
666 assign(std::initializer_list
<_Tp
> __il
)
667 { assign(__il
.begin(), __il
.end()); }
669 /// Get a copy of the memory allocation object.
671 get_allocator() const noexcept
672 { return allocator_type(this->_M_get_Node_allocator()); }
674 // 23.3.4.3 iterators:
677 * Returns a read/write iterator that points before the first element
678 * in the %forward_list. Iteration is done in ordinary element order.
681 before_begin() noexcept
682 { return iterator(&this->_M_impl
._M_head
); }
685 * Returns a read-only (constant) iterator that points before the
686 * first element in the %forward_list. Iteration is done in ordinary
690 before_begin() const noexcept
691 { return const_iterator(&this->_M_impl
._M_head
); }
694 * Returns a read/write iterator that points to the first element
695 * in the %forward_list. Iteration is done in ordinary element order.
699 { return iterator(this->_M_impl
._M_head
._M_next
); }
702 * Returns a read-only (constant) iterator that points to the first
703 * element in the %forward_list. Iteration is done in ordinary
707 begin() const noexcept
708 { return const_iterator(this->_M_impl
._M_head
._M_next
); }
711 * Returns a read/write iterator that points one past the last
712 * element in the %forward_list. Iteration is done in ordinary
717 { return iterator(0); }
720 * Returns a read-only iterator that points one past the last
721 * element in the %forward_list. Iteration is done in ordinary
726 { return const_iterator(0); }
729 * Returns a read-only (constant) iterator that points to the
730 * first element in the %forward_list. Iteration is done in ordinary
734 cbegin() const noexcept
735 { return const_iterator(this->_M_impl
._M_head
._M_next
); }
738 * Returns a read-only (constant) iterator that points before the
739 * first element in the %forward_list. Iteration is done in ordinary
743 cbefore_begin() const noexcept
744 { return const_iterator(&this->_M_impl
._M_head
); }
747 * Returns a read-only (constant) iterator that points one past
748 * the last element in the %forward_list. Iteration is done in
749 * ordinary element order.
752 cend() const noexcept
753 { return const_iterator(0); }
756 * Returns true if the %forward_list is empty. (Thus begin() would
760 empty() const noexcept
761 { return this->_M_impl
._M_head
._M_next
== 0; }
764 * Returns the largest possible number of elements of %forward_list.
767 max_size() const noexcept
768 { return _Node_alloc_traits::max_size(this->_M_get_Node_allocator()); }
770 // 23.3.4.4 element access:
773 * Returns a read/write reference to the data at the first
774 * element of the %forward_list.
779 _Node
* __front
= static_cast<_Node
*>(this->_M_impl
._M_head
._M_next
);
780 return *__front
->_M_valptr();
784 * Returns a read-only (constant) reference to the data at the first
785 * element of the %forward_list.
790 _Node
* __front
= static_cast<_Node
*>(this->_M_impl
._M_head
._M_next
);
791 return *__front
->_M_valptr();
794 // 23.3.4.5 modifiers:
797 * @brief Constructs object in %forward_list at the front of the
799 * @param __args Arguments.
801 * This function will insert an object of type Tp constructed
802 * with Tp(std::forward<Args>(args)...) at the front of the list
803 * Due to the nature of a %forward_list this operation can
804 * be done in constant time, and does not invalidate iterators
807 template<typename
... _Args
>
808 #if __cplusplus > 201402L
813 emplace_front(_Args
&&... __args
)
815 this->_M_insert_after(cbefore_begin(),
816 std::forward
<_Args
>(__args
)...);
817 #if __cplusplus > 201402L
823 * @brief Add data to the front of the %forward_list.
824 * @param __val Data to be added.
826 * This is a typical stack operation. The function creates an
827 * element at the front of the %forward_list and assigns the given
828 * data to it. Due to the nature of a %forward_list this operation
829 * can be done in constant time, and does not invalidate iterators
833 push_front(const _Tp
& __val
)
834 { this->_M_insert_after(cbefore_begin(), __val
); }
840 push_front(_Tp
&& __val
)
841 { this->_M_insert_after(cbefore_begin(), std::move(__val
)); }
844 * @brief Removes first element.
846 * This is a typical stack operation. It shrinks the %forward_list
847 * by one. Due to the nature of a %forward_list this operation can
848 * be done in constant time, and only invalidates iterators/references
849 * to the element being removed.
851 * Note that no data is returned, and if the first element's data
852 * is needed, it should be retrieved before pop_front() is
857 { this->_M_erase_after(&this->_M_impl
._M_head
); }
860 * @brief Constructs object in %forward_list after the specified
862 * @param __pos A const_iterator into the %forward_list.
863 * @param __args Arguments.
864 * @return An iterator that points to the inserted data.
866 * This function will insert an object of type T constructed
867 * with T(std::forward<Args>(args)...) after the specified
868 * location. Due to the nature of a %forward_list this operation can
869 * be done in constant time, and does not invalidate iterators
872 template<typename
... _Args
>
874 emplace_after(const_iterator __pos
, _Args
&&... __args
)
875 { return iterator(this->_M_insert_after(__pos
,
876 std::forward
<_Args
>(__args
)...)); }
879 * @brief Inserts given value into %forward_list after specified
881 * @param __pos An iterator into the %forward_list.
882 * @param __val Data to be inserted.
883 * @return An iterator that points to the inserted data.
885 * This function will insert a copy of the given value after
886 * the specified location. Due to the nature of a %forward_list this
887 * operation can be done in constant time, and does not
888 * invalidate iterators and references.
891 insert_after(const_iterator __pos
, const _Tp
& __val
)
892 { return iterator(this->_M_insert_after(__pos
, __val
)); }
898 insert_after(const_iterator __pos
, _Tp
&& __val
)
899 { return iterator(this->_M_insert_after(__pos
, std::move(__val
))); }
902 * @brief Inserts a number of copies of given data into the
904 * @param __pos An iterator into the %forward_list.
905 * @param __n Number of elements to be inserted.
906 * @param __val Data to be inserted.
907 * @return An iterator pointing to the last inserted copy of
908 * @a val or @a pos if @a n == 0.
910 * This function will insert a specified number of copies of the
911 * given data after the location specified by @a pos.
913 * This operation is linear in the number of elements inserted and
914 * does not invalidate iterators and references.
917 insert_after(const_iterator __pos
, size_type __n
, const _Tp
& __val
);
920 * @brief Inserts a range into the %forward_list.
921 * @param __pos An iterator into the %forward_list.
922 * @param __first An input iterator.
923 * @param __last An input iterator.
924 * @return An iterator pointing to the last inserted element or
925 * @a __pos if @a __first == @a __last.
927 * This function will insert copies of the data in the range
928 * [@a __first,@a __last) into the %forward_list after the
929 * location specified by @a __pos.
931 * This operation is linear in the number of elements inserted and
932 * does not invalidate iterators and references.
934 template<typename _InputIterator
,
935 typename
= std::_RequireInputIter
<_InputIterator
>>
937 insert_after(const_iterator __pos
,
938 _InputIterator __first
, _InputIterator __last
);
941 * @brief Inserts the contents of an initializer_list into
942 * %forward_list after the specified iterator.
943 * @param __pos An iterator into the %forward_list.
944 * @param __il An initializer_list of value_type.
945 * @return An iterator pointing to the last inserted element
946 * or @a __pos if @a __il is empty.
948 * This function will insert copies of the data in the
949 * initializer_list @a __il into the %forward_list before the location
950 * specified by @a __pos.
952 * This operation is linear in the number of elements inserted and
953 * does not invalidate iterators and references.
956 insert_after(const_iterator __pos
, std::initializer_list
<_Tp
> __il
)
957 { return insert_after(__pos
, __il
.begin(), __il
.end()); }
960 * @brief Removes the element pointed to by the iterator following
962 * @param __pos Iterator pointing before element to be erased.
963 * @return An iterator pointing to the element following the one
964 * that was erased, or end() if no such element exists.
966 * This function will erase the element at the given position and
967 * thus shorten the %forward_list by one.
969 * Due to the nature of a %forward_list this operation can be done
970 * in constant time, and only invalidates iterators/references to
971 * the element being removed. The user is also cautioned that
972 * this function only erases the element, and that if the element
973 * is itself a pointer, the pointed-to memory is not touched in
974 * any way. Managing the pointer is the user's responsibility.
977 erase_after(const_iterator __pos
)
978 { return iterator(this->_M_erase_after(const_cast<_Node_base
*>
982 * @brief Remove a range of elements.
983 * @param __pos Iterator pointing before the first element to be
985 * @param __last Iterator pointing to one past the last element to be
989 * This function will erase the elements in the range
990 * @a (__pos,__last) and shorten the %forward_list accordingly.
992 * This operation is linear time in the size of the range and only
993 * invalidates iterators/references to the element being removed.
994 * The user is also cautioned that this function only erases the
995 * elements, and that if the elements themselves are pointers, the
996 * pointed-to memory is not touched in any way. Managing the pointer
997 * is the user's responsibility.
1000 erase_after(const_iterator __pos
, const_iterator __last
)
1001 { return iterator(this->_M_erase_after(const_cast<_Node_base
*>
1003 const_cast<_Node_base
*>
1004 (__last
._M_node
))); }
1007 * @brief Swaps data with another %forward_list.
1008 * @param __list A %forward_list of the same element and allocator
1011 * This exchanges the elements between two lists in constant
1012 * time. Note that the global std::swap() function is
1013 * specialized such that std::swap(l1,l2) will feed to this
1016 * Whether the allocators are swapped depends on the allocator traits.
1019 swap(forward_list
& __list
) noexcept
1021 std::swap(this->_M_impl
._M_head
._M_next
,
1022 __list
._M_impl
._M_head
._M_next
);
1023 _Node_alloc_traits::_S_on_swap(this->_M_get_Node_allocator(),
1024 __list
._M_get_Node_allocator());
1028 * @brief Resizes the %forward_list to the specified number of
1030 * @param __sz Number of elements the %forward_list should contain.
1032 * This function will %resize the %forward_list to the specified
1033 * number of elements. If the number is smaller than the
1034 * %forward_list's current number of elements the %forward_list
1035 * is truncated, otherwise the %forward_list is extended and the
1036 * new elements are default constructed.
1039 resize(size_type __sz
);
1042 * @brief Resizes the %forward_list to the specified number of
1044 * @param __sz Number of elements the %forward_list should contain.
1045 * @param __val Data with which new elements should be populated.
1047 * This function will %resize the %forward_list to the specified
1048 * number of elements. If the number is smaller than the
1049 * %forward_list's current number of elements the %forward_list
1050 * is truncated, otherwise the %forward_list is extended and new
1051 * elements are populated with given data.
1054 resize(size_type __sz
, const value_type
& __val
);
1057 * @brief Erases all the elements.
1059 * Note that this function only erases
1060 * the elements, and that if the elements themselves are
1061 * pointers, the pointed-to memory is not touched in any way.
1062 * Managing the pointer is the user's responsibility.
1066 { this->_M_erase_after(&this->_M_impl
._M_head
, 0); }
1068 // 23.3.4.6 forward_list operations:
1071 * @brief Insert contents of another %forward_list.
1072 * @param __pos Iterator referencing the element to insert after.
1073 * @param __list Source list.
1075 * The elements of @a list are inserted in constant time after
1076 * the element referenced by @a pos. @a list becomes an empty
1079 * Requires this != @a x.
1082 splice_after(const_iterator __pos
, forward_list
&& __list
) noexcept
1084 if (!__list
.empty())
1085 _M_splice_after(__pos
, __list
.before_begin(), __list
.end());
1089 splice_after(const_iterator __pos
, forward_list
& __list
) noexcept
1090 { splice_after(__pos
, std::move(__list
)); }
1093 * @brief Insert element from another %forward_list.
1094 * @param __pos Iterator referencing the element to insert after.
1095 * @param __list Source list.
1096 * @param __i Iterator referencing the element before the element
1099 * Removes the element in list @a list referenced by @a i and
1100 * inserts it into the current list after @a pos.
1103 splice_after(const_iterator __pos
, forward_list
&& __list
,
1104 const_iterator __i
) noexcept
;
1107 splice_after(const_iterator __pos
, forward_list
& __list
,
1108 const_iterator __i
) noexcept
1109 { splice_after(__pos
, std::move(__list
), __i
); }
1112 * @brief Insert range from another %forward_list.
1113 * @param __pos Iterator referencing the element to insert after.
1114 * @param __list Source list.
1115 * @param __before Iterator referencing before the start of range
1117 * @param __last Iterator referencing the end of range in list.
1119 * Removes elements in the range (__before,__last) and inserts them
1120 * after @a __pos in constant time.
1122 * Undefined if @a __pos is in (__before,__last).
1126 splice_after(const_iterator __pos
, forward_list
&&,
1127 const_iterator __before
, const_iterator __last
) noexcept
1128 { _M_splice_after(__pos
, __before
, __last
); }
1131 splice_after(const_iterator __pos
, forward_list
&,
1132 const_iterator __before
, const_iterator __last
) noexcept
1133 { _M_splice_after(__pos
, __before
, __last
); }
1137 * @brief Remove all elements equal to value.
1138 * @param __val The value to remove.
1140 * Removes every element in the list equal to @a __val.
1141 * Remaining elements stay in list order. Note that this
1142 * function only erases the elements, and that if the elements
1143 * themselves are pointers, the pointed-to memory is not
1144 * touched in any way. Managing the pointer is the user's
1148 remove(const _Tp
& __val
);
1151 * @brief Remove all elements satisfying a predicate.
1152 * @param __pred Unary predicate function or object.
1154 * Removes every element in the list for which the predicate
1155 * returns true. Remaining elements stay in list order. Note
1156 * that this function only erases the elements, and that if the
1157 * elements themselves are pointers, the pointed-to memory is
1158 * not touched in any way. Managing the pointer is the user's
1161 template<typename _Pred
>
1163 remove_if(_Pred __pred
);
1166 * @brief Remove consecutive duplicate elements.
1168 * For each consecutive set of elements with the same value,
1169 * remove all but the first one. Remaining elements stay in
1170 * list order. Note that this function only erases the
1171 * elements, and that if the elements themselves are pointers,
1172 * the pointed-to memory is not touched in any way. Managing
1173 * the pointer is the user's responsibility.
1177 { unique(std::equal_to
<_Tp
>()); }
1180 * @brief Remove consecutive elements satisfying a predicate.
1181 * @param __binary_pred Binary predicate function or object.
1183 * For each consecutive set of elements [first,last) that
1184 * satisfy predicate(first,i) where i is an iterator in
1185 * [first,last), remove all but the first one. Remaining
1186 * elements stay in list order. Note that this function only
1187 * erases the elements, and that if the elements themselves are
1188 * pointers, the pointed-to memory is not touched in any way.
1189 * Managing the pointer is the user's responsibility.
1191 template<typename _BinPred
>
1193 unique(_BinPred __binary_pred
);
1196 * @brief Merge sorted lists.
1197 * @param __list Sorted list to merge.
1199 * Assumes that both @a list and this list are sorted according to
1200 * operator<(). Merges elements of @a __list into this list in
1201 * sorted order, leaving @a __list empty when complete. Elements in
1202 * this list precede elements in @a __list that are equal.
1205 merge(forward_list
&& __list
)
1206 { merge(std::move(__list
), std::less
<_Tp
>()); }
1209 merge(forward_list
& __list
)
1210 { merge(std::move(__list
)); }
1213 * @brief Merge sorted lists according to comparison function.
1214 * @param __list Sorted list to merge.
1215 * @param __comp Comparison function defining sort order.
1217 * Assumes that both @a __list and this list are sorted according to
1218 * comp. Merges elements of @a __list into this list
1219 * in sorted order, leaving @a __list empty when complete. Elements
1220 * in this list precede elements in @a __list that are equivalent
1221 * according to comp().
1223 template<typename _Comp
>
1225 merge(forward_list
&& __list
, _Comp __comp
);
1227 template<typename _Comp
>
1229 merge(forward_list
& __list
, _Comp __comp
)
1230 { merge(std::move(__list
), __comp
); }
1233 * @brief Sort the elements of the list.
1235 * Sorts the elements of this list in NlogN time. Equivalent
1236 * elements remain in list order.
1240 { sort(std::less
<_Tp
>()); }
1243 * @brief Sort the forward_list using a comparison function.
1245 * Sorts the elements of this list in NlogN time. Equivalent
1246 * elements remain in list order.
1248 template<typename _Comp
>
1253 * @brief Reverse the elements in list.
1255 * Reverse the order of elements in the list in linear time.
1259 { this->_M_impl
._M_head
._M_reverse_after(); }
1262 // Called by the range constructor to implement [23.3.4.2]/9
1263 template<typename _InputIterator
>
1265 _M_range_initialize(_InputIterator __first
, _InputIterator __last
);
1267 // Called by forward_list(n,v,a), and the range constructor when it
1268 // turns out to be the same thing.
1270 _M_fill_initialize(size_type __n
, const value_type
& __value
);
1272 // Called by splice_after and insert_after.
1274 _M_splice_after(const_iterator __pos
, const_iterator __before
,
1275 const_iterator __last
);
1277 // Called by forward_list(n).
1279 _M_default_initialize(size_type __n
);
1281 // Called by resize(sz).
1283 _M_default_insert_after(const_iterator __pos
, size_type __n
);
1285 // Called by operator=(forward_list&&)
1287 _M_move_assign(forward_list
&& __list
, std::true_type
) noexcept
1290 this->_M_impl
._M_head
._M_next
= __list
._M_impl
._M_head
._M_next
;
1291 __list
._M_impl
._M_head
._M_next
= nullptr;
1292 std::__alloc_on_move(this->_M_get_Node_allocator(),
1293 __list
._M_get_Node_allocator());
1296 // Called by operator=(forward_list&&)
1298 _M_move_assign(forward_list
&& __list
, std::false_type
)
1300 if (__list
._M_get_Node_allocator() == this->_M_get_Node_allocator())
1301 _M_move_assign(std::move(__list
), std::true_type());
1303 // The rvalue's allocator cannot be moved, or is not equal,
1304 // so we need to individually move each element.
1305 this->assign(std::__make_move_if_noexcept_iterator(__list
.begin()),
1306 std::__make_move_if_noexcept_iterator(__list
.end()));
1309 // Called by assign(_InputIterator, _InputIterator) if _Tp is
1311 template<typename _InputIterator
>
1313 _M_assign(_InputIterator __first
, _InputIterator __last
, true_type
)
1315 auto __prev
= before_begin();
1316 auto __curr
= begin();
1318 while (__curr
!= __end
&& __first
!= __last
)
1325 if (__first
!= __last
)
1326 insert_after(__prev
, __first
, __last
);
1327 else if (__curr
!= __end
)
1328 erase_after(__prev
, __end
);
1331 // Called by assign(_InputIterator, _InputIterator) if _Tp is not
1333 template<typename _InputIterator
>
1335 _M_assign(_InputIterator __first
, _InputIterator __last
, false_type
)
1338 insert_after(cbefore_begin(), __first
, __last
);
1341 // Called by assign(size_type, const _Tp&) if Tp is CopyAssignable
1343 _M_assign_n(size_type __n
, const _Tp
& __val
, true_type
)
1345 auto __prev
= before_begin();
1346 auto __curr
= begin();
1348 while (__curr
!= __end
&& __n
> 0)
1356 insert_after(__prev
, __n
, __val
);
1357 else if (__curr
!= __end
)
1358 erase_after(__prev
, __end
);
1361 // Called by assign(size_type, const _Tp&) if Tp is non-CopyAssignable
1363 _M_assign_n(size_type __n
, const _Tp
& __val
, false_type
)
1366 insert_after(cbefore_begin(), __n
, __val
);
1370 #if __cpp_deduction_guides >= 201606
1371 template<typename _InputIterator
, typename _ValT
1372 = typename iterator_traits
<_InputIterator
>::value_type
,
1373 typename _Allocator
= allocator
<_ValT
>,
1374 typename
= _RequireInputIter
<_InputIterator
>,
1375 typename
= _RequireAllocator
<_Allocator
>>
1376 forward_list(_InputIterator
, _InputIterator
, _Allocator
= _Allocator())
1377 -> forward_list
<_ValT
, _Allocator
>;
1381 * @brief Forward list equality comparison.
1382 * @param __lx A %forward_list
1383 * @param __ly A %forward_list of the same type as @a __lx.
1384 * @return True iff the elements of the forward lists are equal.
1386 * This is an equivalence relation. It is linear in the number of
1387 * elements of the forward lists. Deques are considered equivalent
1388 * if corresponding elements compare equal.
1390 template<typename _Tp
, typename _Alloc
>
1392 operator==(const forward_list
<_Tp
, _Alloc
>& __lx
,
1393 const forward_list
<_Tp
, _Alloc
>& __ly
);
1396 * @brief Forward list ordering relation.
1397 * @param __lx A %forward_list.
1398 * @param __ly A %forward_list of the same type as @a __lx.
1399 * @return True iff @a __lx is lexicographically less than @a __ly.
1401 * This is a total ordering relation. It is linear in the number of
1402 * elements of the forward lists. The elements must be comparable
1405 * See std::lexicographical_compare() for how the determination is made.
1407 template<typename _Tp
, typename _Alloc
>
1409 operator<(const forward_list
<_Tp
, _Alloc
>& __lx
,
1410 const forward_list
<_Tp
, _Alloc
>& __ly
)
1411 { return std::lexicographical_compare(__lx
.cbegin(), __lx
.cend(),
1412 __ly
.cbegin(), __ly
.cend()); }
1414 /// Based on operator==
1415 template<typename _Tp
, typename _Alloc
>
1417 operator!=(const forward_list
<_Tp
, _Alloc
>& __lx
,
1418 const forward_list
<_Tp
, _Alloc
>& __ly
)
1419 { return !(__lx
== __ly
); }
1421 /// Based on operator<
1422 template<typename _Tp
, typename _Alloc
>
1424 operator>(const forward_list
<_Tp
, _Alloc
>& __lx
,
1425 const forward_list
<_Tp
, _Alloc
>& __ly
)
1426 { return (__ly
< __lx
); }
1428 /// Based on operator<
1429 template<typename _Tp
, typename _Alloc
>
1431 operator>=(const forward_list
<_Tp
, _Alloc
>& __lx
,
1432 const forward_list
<_Tp
, _Alloc
>& __ly
)
1433 { return !(__lx
< __ly
); }
1435 /// Based on operator<
1436 template<typename _Tp
, typename _Alloc
>
1438 operator<=(const forward_list
<_Tp
, _Alloc
>& __lx
,
1439 const forward_list
<_Tp
, _Alloc
>& __ly
)
1440 { return !(__ly
< __lx
); }
1442 /// See std::forward_list::swap().
1443 template<typename _Tp
, typename _Alloc
>
1445 swap(forward_list
<_Tp
, _Alloc
>& __lx
,
1446 forward_list
<_Tp
, _Alloc
>& __ly
)
1447 noexcept(noexcept(__lx
.swap(__ly
)))
1448 { __lx
.swap(__ly
); }
1450 _GLIBCXX_END_NAMESPACE_CONTAINER
1451 _GLIBCXX_END_NAMESPACE_VERSION
1454 #endif // _FORWARD_LIST_H