1 // <forward_list.h> -*- C++ -*-
3 // Copyright (C) 2008-2018 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;
57 _Fwd_list_node_base(_Fwd_list_node_base
&& __x
) noexcept
58 : _M_next(__x
._M_next
)
59 { __x
._M_next
= nullptr; }
61 _Fwd_list_node_base(const _Fwd_list_node_base
&) = delete;
62 _Fwd_list_node_base
& operator=(const _Fwd_list_node_base
&) = delete;
65 operator=(_Fwd_list_node_base
&& __x
) noexcept
67 _M_next
= __x
._M_next
;
68 __x
._M_next
= nullptr;
72 _Fwd_list_node_base
* _M_next
= nullptr;
75 _M_transfer_after(_Fwd_list_node_base
* __begin
,
76 _Fwd_list_node_base
* __end
) noexcept
78 _Fwd_list_node_base
* __keep
= __begin
->_M_next
;
81 __begin
->_M_next
= __end
->_M_next
;
82 __end
->_M_next
= _M_next
;
85 __begin
->_M_next
= nullptr;
91 _M_reverse_after() noexcept
93 _Fwd_list_node_base
* __tail
= _M_next
;
96 while (_Fwd_list_node_base
* __temp
= __tail
->_M_next
)
98 _Fwd_list_node_base
* __keep
= _M_next
;
100 __tail
->_M_next
= __temp
->_M_next
;
101 _M_next
->_M_next
= __keep
;
107 * @brief A helper node class for %forward_list.
108 * This is just a linked list with uninitialized storage for a
109 * data value in each node.
110 * There is a sorting utility method.
112 template<typename _Tp
>
113 struct _Fwd_list_node
114 : public _Fwd_list_node_base
116 _Fwd_list_node() = default;
118 __gnu_cxx::__aligned_buffer
<_Tp
> _M_storage
;
122 { return _M_storage
._M_ptr(); }
125 _M_valptr() const noexcept
126 { return _M_storage
._M_ptr(); }
130 * @brief A forward_list::iterator.
132 * All the functions are op overloads.
134 template<typename _Tp
>
135 struct _Fwd_list_iterator
137 typedef _Fwd_list_iterator
<_Tp
> _Self
;
138 typedef _Fwd_list_node
<_Tp
> _Node
;
140 typedef _Tp value_type
;
141 typedef _Tp
* pointer
;
142 typedef _Tp
& reference
;
143 typedef ptrdiff_t difference_type
;
144 typedef std::forward_iterator_tag iterator_category
;
146 _Fwd_list_iterator() noexcept
150 _Fwd_list_iterator(_Fwd_list_node_base
* __n
) noexcept
154 operator*() const noexcept
155 { return *static_cast<_Node
*>(this->_M_node
)->_M_valptr(); }
158 operator->() const noexcept
159 { return static_cast<_Node
*>(this->_M_node
)->_M_valptr(); }
162 operator++() noexcept
164 _M_node
= _M_node
->_M_next
;
169 operator++(int) noexcept
172 _M_node
= _M_node
->_M_next
;
177 operator==(const _Self
& __x
) const noexcept
178 { return _M_node
== __x
._M_node
; }
181 operator!=(const _Self
& __x
) const noexcept
182 { return _M_node
!= __x
._M_node
; }
185 _M_next() const noexcept
188 return _Fwd_list_iterator(_M_node
->_M_next
);
190 return _Fwd_list_iterator(nullptr);
193 _Fwd_list_node_base
* _M_node
;
197 * @brief A forward_list::const_iterator.
199 * All the functions are op overloads.
201 template<typename _Tp
>
202 struct _Fwd_list_const_iterator
204 typedef _Fwd_list_const_iterator
<_Tp
> _Self
;
205 typedef const _Fwd_list_node
<_Tp
> _Node
;
206 typedef _Fwd_list_iterator
<_Tp
> iterator
;
208 typedef _Tp value_type
;
209 typedef const _Tp
* pointer
;
210 typedef const _Tp
& reference
;
211 typedef ptrdiff_t difference_type
;
212 typedef std::forward_iterator_tag iterator_category
;
214 _Fwd_list_const_iterator() noexcept
218 _Fwd_list_const_iterator(const _Fwd_list_node_base
* __n
) noexcept
221 _Fwd_list_const_iterator(const iterator
& __iter
) noexcept
222 : _M_node(__iter
._M_node
) { }
225 operator*() const noexcept
226 { return *static_cast<_Node
*>(this->_M_node
)->_M_valptr(); }
229 operator->() const noexcept
230 { return static_cast<_Node
*>(this->_M_node
)->_M_valptr(); }
233 operator++() noexcept
235 _M_node
= _M_node
->_M_next
;
240 operator++(int) noexcept
243 _M_node
= _M_node
->_M_next
;
248 operator==(const _Self
& __x
) const noexcept
249 { return _M_node
== __x
._M_node
; }
252 operator!=(const _Self
& __x
) const noexcept
253 { return _M_node
!= __x
._M_node
; }
256 _M_next() const noexcept
259 return _Fwd_list_const_iterator(_M_node
->_M_next
);
261 return _Fwd_list_const_iterator(nullptr);
264 const _Fwd_list_node_base
* _M_node
;
268 * @brief Forward list iterator equality comparison.
270 template<typename _Tp
>
272 operator==(const _Fwd_list_iterator
<_Tp
>& __x
,
273 const _Fwd_list_const_iterator
<_Tp
>& __y
) noexcept
274 { return __x
._M_node
== __y
._M_node
; }
277 * @brief Forward list iterator inequality comparison.
279 template<typename _Tp
>
281 operator!=(const _Fwd_list_iterator
<_Tp
>& __x
,
282 const _Fwd_list_const_iterator
<_Tp
>& __y
) noexcept
283 { return __x
._M_node
!= __y
._M_node
; }
286 * @brief Base class for %forward_list.
288 template<typename _Tp
, typename _Alloc
>
289 struct _Fwd_list_base
292 typedef __alloc_rebind
<_Alloc
, _Fwd_list_node
<_Tp
>> _Node_alloc_type
;
293 typedef __gnu_cxx::__alloc_traits
<_Node_alloc_type
> _Node_alloc_traits
;
295 struct _Fwd_list_impl
296 : public _Node_alloc_type
298 _Fwd_list_node_base _M_head
;
301 noexcept( noexcept(_Node_alloc_type()) )
302 : _Node_alloc_type(), _M_head()
305 _Fwd_list_impl(_Fwd_list_impl
&&) = default;
307 _Fwd_list_impl(_Fwd_list_impl
&& __fl
, _Node_alloc_type
&& __a
)
308 : _Node_alloc_type(std::move(__a
)), _M_head(std::move(__fl
._M_head
))
311 _Fwd_list_impl(_Node_alloc_type
&& __a
)
312 : _Node_alloc_type(std::move(__a
)), _M_head()
316 _Fwd_list_impl _M_impl
;
319 typedef _Fwd_list_iterator
<_Tp
> iterator
;
320 typedef _Fwd_list_const_iterator
<_Tp
> const_iterator
;
321 typedef _Fwd_list_node
<_Tp
> _Node
;
324 _M_get_Node_allocator() noexcept
325 { return this->_M_impl
; }
327 const _Node_alloc_type
&
328 _M_get_Node_allocator() const noexcept
329 { return this->_M_impl
; }
331 _Fwd_list_base() = default;
333 _Fwd_list_base(_Node_alloc_type
&& __a
)
334 : _M_impl(std::move(__a
)) { }
336 // When allocators are always equal.
337 _Fwd_list_base(_Fwd_list_base
&& __lst
, _Node_alloc_type
&& __a
,
339 : _M_impl(std::move(__lst
._M_impl
), std::move(__a
))
342 // When allocators are not always equal.
343 _Fwd_list_base(_Fwd_list_base
&& __lst
, _Node_alloc_type
&& __a
);
345 _Fwd_list_base(_Fwd_list_base
&&) = default;
348 { _M_erase_after(&_M_impl
._M_head
, nullptr); }
354 auto __ptr
= _Node_alloc_traits::allocate(_M_get_Node_allocator(), 1);
355 return std::__to_address(__ptr
);
358 template<typename
... _Args
>
360 _M_create_node(_Args
&&... __args
)
362 _Node
* __node
= this->_M_get_node();
365 ::new ((void*)__node
) _Node
;
366 _Node_alloc_traits::construct(_M_get_Node_allocator(),
368 std::forward
<_Args
>(__args
)...);
372 this->_M_put_node(__node
);
373 __throw_exception_again
;
378 template<typename
... _Args
>
380 _M_insert_after(const_iterator __pos
, _Args
&&... __args
);
383 _M_put_node(_Node
* __p
)
385 typedef typename
_Node_alloc_traits::pointer _Ptr
;
386 auto __ptr
= std::pointer_traits
<_Ptr
>::pointer_to(*__p
);
387 _Node_alloc_traits::deallocate(_M_get_Node_allocator(), __ptr
, 1);
391 _M_erase_after(_Fwd_list_node_base
* __pos
);
394 _M_erase_after(_Fwd_list_node_base
* __pos
,
395 _Fwd_list_node_base
* __last
);
399 * @brief A standard container with linear time access to elements,
400 * and fixed time insertion/deletion at any point in the sequence.
404 * @tparam _Tp Type of element.
405 * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
407 * Meets the requirements of a <a href="tables.html#65">container</a>, a
408 * <a href="tables.html#67">sequence</a>, including the
409 * <a href="tables.html#68">optional sequence requirements</a> with the
410 * %exception of @c at and @c operator[].
412 * This is a @e singly @e linked %list. Traversal up the
413 * %list requires linear time, but adding and removing elements (or
414 * @e nodes) is done in constant time, regardless of where the
415 * change takes place. Unlike std::vector and std::deque,
416 * random-access iterators are not provided, so subscripting ( @c
417 * [] ) access is not allowed. For algorithms which only need
418 * sequential access, this lack makes no difference.
420 * Also unlike the other standard containers, std::forward_list provides
421 * specialized algorithms %unique to linked lists, such as
422 * splicing, sorting, and in-place reversal.
424 template<typename _Tp
, typename _Alloc
= allocator
<_Tp
>>
425 class forward_list
: private _Fwd_list_base
<_Tp
, _Alloc
>
427 static_assert(is_same
<typename remove_cv
<_Tp
>::type
, _Tp
>::value
,
428 "std::forward_list must have a non-const, non-volatile value_type");
429 #ifdef __STRICT_ANSI__
430 static_assert(is_same
<typename
_Alloc::value_type
, _Tp
>::value
,
431 "std::forward_list must have the same value_type as its allocator");
435 typedef _Fwd_list_base
<_Tp
, _Alloc
> _Base
;
436 typedef _Fwd_list_node
<_Tp
> _Node
;
437 typedef _Fwd_list_node_base _Node_base
;
438 typedef typename
_Base::_Node_alloc_type _Node_alloc_type
;
439 typedef typename
_Base::_Node_alloc_traits _Node_alloc_traits
;
440 typedef allocator_traits
<__alloc_rebind
<_Alloc
, _Tp
>> _Alloc_traits
;
444 typedef _Tp value_type
;
445 typedef typename
_Alloc_traits::pointer pointer
;
446 typedef typename
_Alloc_traits::const_pointer const_pointer
;
447 typedef value_type
& reference
;
448 typedef const value_type
& const_reference
;
450 typedef _Fwd_list_iterator
<_Tp
> iterator
;
451 typedef _Fwd_list_const_iterator
<_Tp
> const_iterator
;
452 typedef std::size_t size_type
;
453 typedef std::ptrdiff_t difference_type
;
454 typedef _Alloc allocator_type
;
456 // 23.3.4.2 construct/copy/destroy:
459 * @brief Creates a %forward_list with no elements.
461 forward_list() = default;
464 * @brief Creates a %forward_list with no elements.
465 * @param __al An allocator object.
468 forward_list(const _Alloc
& __al
) noexcept
469 : _Base(_Node_alloc_type(__al
))
473 * @brief Copy constructor with allocator argument.
474 * @param __list Input list to copy.
475 * @param __al An allocator object.
477 forward_list(const forward_list
& __list
, const _Alloc
& __al
)
478 : _Base(_Node_alloc_type(__al
))
479 { _M_range_initialize(__list
.begin(), __list
.end()); }
482 forward_list(forward_list
&& __list
, _Node_alloc_type
&& __al
,
484 : _Base(std::move(__list
), std::move(__al
))
486 // If __list is not empty it means its allocator is not equal to __a,
487 // so we need to move from each element individually.
488 insert_after(cbefore_begin(),
489 std::__make_move_if_noexcept_iterator(__list
.begin()),
490 std::__make_move_if_noexcept_iterator(__list
.end()));
493 forward_list(forward_list
&& __list
, _Node_alloc_type
&& __al
,
496 : _Base(std::move(__list
), _Node_alloc_type(__al
), true_type
{})
501 * @brief Move constructor with allocator argument.
502 * @param __list Input list to move.
503 * @param __al An allocator object.
505 forward_list(forward_list
&& __list
, const _Alloc
& __al
)
506 noexcept(_Node_alloc_traits::_S_always_equal())
507 : forward_list(std::move(__list
), _Node_alloc_type(__al
),
508 typename
_Node_alloc_traits::is_always_equal
{})
512 * @brief Creates a %forward_list with default constructed elements.
513 * @param __n The number of elements to initially create.
514 * @param __al An allocator object.
516 * This constructor creates the %forward_list with @a __n default
517 * constructed elements.
520 forward_list(size_type __n
, const _Alloc
& __al
= _Alloc())
521 : _Base(_Node_alloc_type(__al
))
522 { _M_default_initialize(__n
); }
525 * @brief Creates a %forward_list with copies of an exemplar element.
526 * @param __n The number of elements to initially create.
527 * @param __value An element to copy.
528 * @param __al An allocator object.
530 * This constructor fills the %forward_list with @a __n copies of
533 forward_list(size_type __n
, const _Tp
& __value
,
534 const _Alloc
& __al
= _Alloc())
535 : _Base(_Node_alloc_type(__al
))
536 { _M_fill_initialize(__n
, __value
); }
539 * @brief Builds a %forward_list from a range.
540 * @param __first An input iterator.
541 * @param __last An input iterator.
542 * @param __al An allocator object.
544 * Create a %forward_list consisting of copies of the elements from
545 * [@a __first,@a __last). This is linear in N (where N is
546 * distance(@a __first,@a __last)).
548 template<typename _InputIterator
,
549 typename
= std::_RequireInputIter
<_InputIterator
>>
550 forward_list(_InputIterator __first
, _InputIterator __last
,
551 const _Alloc
& __al
= _Alloc())
552 : _Base(_Node_alloc_type(__al
))
553 { _M_range_initialize(__first
, __last
); }
556 * @brief The %forward_list copy constructor.
557 * @param __list A %forward_list of identical element and allocator
560 forward_list(const forward_list
& __list
)
561 : _Base(_Node_alloc_traits::_S_select_on_copy(
562 __list
._M_get_Node_allocator()))
563 { _M_range_initialize(__list
.begin(), __list
.end()); }
566 * @brief The %forward_list move constructor.
567 * @param __list A %forward_list of identical element and allocator
570 * The newly-created %forward_list contains the exact contents of the
571 * moved instance. The contents of the moved instance are a valid, but
572 * unspecified %forward_list.
574 forward_list(forward_list
&&) = default;
577 * @brief Builds a %forward_list from an initializer_list
578 * @param __il An initializer_list of value_type.
579 * @param __al An allocator object.
581 * Create a %forward_list consisting of copies of the elements
582 * in the initializer_list @a __il. This is linear in __il.size().
584 forward_list(std::initializer_list
<_Tp
> __il
,
585 const _Alloc
& __al
= _Alloc())
586 : _Base(_Node_alloc_type(__al
))
587 { _M_range_initialize(__il
.begin(), __il
.end()); }
590 * @brief The forward_list dtor.
592 ~forward_list() noexcept
596 * @brief The %forward_list assignment operator.
597 * @param __list A %forward_list of identical element and allocator
600 * All the elements of @a __list are copied.
602 * Whether the allocator is copied depends on the allocator traits.
605 operator=(const forward_list
& __list
);
608 * @brief The %forward_list move assignment operator.
609 * @param __list A %forward_list of identical element and allocator
612 * The contents of @a __list are moved into this %forward_list
613 * (without copying, if the allocators permit it).
615 * Afterwards @a __list is a valid, but unspecified %forward_list
617 * Whether the allocator is moved depends on the allocator traits.
620 operator=(forward_list
&& __list
)
621 noexcept(_Node_alloc_traits::_S_nothrow_move())
623 constexpr bool __move_storage
=
624 _Node_alloc_traits::_S_propagate_on_move_assign()
625 || _Node_alloc_traits::_S_always_equal();
626 _M_move_assign(std::move(__list
), __bool_constant
<__move_storage
>());
631 * @brief The %forward_list initializer list assignment operator.
632 * @param __il An initializer_list of value_type.
634 * Replace the contents of the %forward_list with copies of the
635 * elements in the initializer_list @a __il. This is linear in
639 operator=(std::initializer_list
<_Tp
> __il
)
646 * @brief Assigns a range to a %forward_list.
647 * @param __first An input iterator.
648 * @param __last An input iterator.
650 * This function fills a %forward_list with copies of the elements
651 * in the range [@a __first,@a __last).
653 * Note that the assignment completely changes the %forward_list and
654 * that the number of elements of the resulting %forward_list is the
655 * same as the number of elements assigned.
657 template<typename _InputIterator
,
658 typename
= std::_RequireInputIter
<_InputIterator
>>
660 assign(_InputIterator __first
, _InputIterator __last
)
662 typedef is_assignable
<_Tp
, decltype(*__first
)> __assignable
;
663 _M_assign(__first
, __last
, __assignable());
667 * @brief Assigns a given value to a %forward_list.
668 * @param __n Number of elements to be assigned.
669 * @param __val Value to be assigned.
671 * This function fills a %forward_list with @a __n copies of the
672 * given value. Note that the assignment completely changes the
673 * %forward_list, and that the resulting %forward_list has __n
677 assign(size_type __n
, const _Tp
& __val
)
678 { _M_assign_n(__n
, __val
, is_copy_assignable
<_Tp
>()); }
681 * @brief Assigns an initializer_list to a %forward_list.
682 * @param __il An initializer_list of value_type.
684 * Replace the contents of the %forward_list with copies of the
685 * elements in the initializer_list @a __il. This is linear in
689 assign(std::initializer_list
<_Tp
> __il
)
690 { assign(__il
.begin(), __il
.end()); }
692 /// Get a copy of the memory allocation object.
694 get_allocator() const noexcept
695 { return allocator_type(this->_M_get_Node_allocator()); }
697 // 23.3.4.3 iterators:
700 * Returns a read/write iterator that points before the first element
701 * in the %forward_list. Iteration is done in ordinary element order.
704 before_begin() noexcept
705 { return iterator(&this->_M_impl
._M_head
); }
708 * Returns a read-only (constant) iterator that points before the
709 * first element in the %forward_list. Iteration is done in ordinary
713 before_begin() const noexcept
714 { return const_iterator(&this->_M_impl
._M_head
); }
717 * Returns a read/write iterator that points to the first element
718 * in the %forward_list. Iteration is done in ordinary element order.
722 { return iterator(this->_M_impl
._M_head
._M_next
); }
725 * Returns a read-only (constant) iterator that points to the first
726 * element in the %forward_list. Iteration is done in ordinary
730 begin() const noexcept
731 { return const_iterator(this->_M_impl
._M_head
._M_next
); }
734 * Returns a read/write iterator that points one past the last
735 * element in the %forward_list. Iteration is done in ordinary
740 { return iterator(nullptr); }
743 * Returns a read-only iterator that points one past the last
744 * element in the %forward_list. Iteration is done in ordinary
749 { return const_iterator(nullptr); }
752 * Returns a read-only (constant) iterator that points to the
753 * first element in the %forward_list. Iteration is done in ordinary
757 cbegin() const noexcept
758 { return const_iterator(this->_M_impl
._M_head
._M_next
); }
761 * Returns a read-only (constant) iterator that points before the
762 * first element in the %forward_list. Iteration is done in ordinary
766 cbefore_begin() const noexcept
767 { return const_iterator(&this->_M_impl
._M_head
); }
770 * Returns a read-only (constant) iterator that points one past
771 * the last element in the %forward_list. Iteration is done in
772 * ordinary element order.
775 cend() const noexcept
776 { return const_iterator(nullptr); }
779 * Returns true if the %forward_list is empty. (Thus begin() would
783 empty() const noexcept
784 { return this->_M_impl
._M_head
._M_next
== nullptr; }
787 * Returns the largest possible number of elements of %forward_list.
790 max_size() const noexcept
791 { return _Node_alloc_traits::max_size(this->_M_get_Node_allocator()); }
793 // 23.3.4.4 element access:
796 * Returns a read/write reference to the data at the first
797 * element of the %forward_list.
802 _Node
* __front
= static_cast<_Node
*>(this->_M_impl
._M_head
._M_next
);
803 return *__front
->_M_valptr();
807 * Returns a read-only (constant) reference to the data at the first
808 * element of the %forward_list.
813 _Node
* __front
= static_cast<_Node
*>(this->_M_impl
._M_head
._M_next
);
814 return *__front
->_M_valptr();
817 // 23.3.4.5 modifiers:
820 * @brief Constructs object in %forward_list at the front of the
822 * @param __args Arguments.
824 * This function will insert an object of type Tp constructed
825 * with Tp(std::forward<Args>(args)...) at the front of the list
826 * Due to the nature of a %forward_list this operation can
827 * be done in constant time, and does not invalidate iterators
830 template<typename
... _Args
>
831 #if __cplusplus > 201402L
836 emplace_front(_Args
&&... __args
)
838 this->_M_insert_after(cbefore_begin(),
839 std::forward
<_Args
>(__args
)...);
840 #if __cplusplus > 201402L
846 * @brief Add data to the front of the %forward_list.
847 * @param __val Data to be added.
849 * This is a typical stack operation. The function creates an
850 * element at the front of the %forward_list and assigns the given
851 * data to it. Due to the nature of a %forward_list this operation
852 * can be done in constant time, and does not invalidate iterators
856 push_front(const _Tp
& __val
)
857 { this->_M_insert_after(cbefore_begin(), __val
); }
863 push_front(_Tp
&& __val
)
864 { this->_M_insert_after(cbefore_begin(), std::move(__val
)); }
867 * @brief Removes first element.
869 * This is a typical stack operation. It shrinks the %forward_list
870 * by one. Due to the nature of a %forward_list this operation can
871 * be done in constant time, and only invalidates iterators/references
872 * to the element being removed.
874 * Note that no data is returned, and if the first element's data
875 * is needed, it should be retrieved before pop_front() is
880 { this->_M_erase_after(&this->_M_impl
._M_head
); }
883 * @brief Constructs object in %forward_list after the specified
885 * @param __pos A const_iterator into the %forward_list.
886 * @param __args Arguments.
887 * @return An iterator that points to the inserted data.
889 * This function will insert an object of type T constructed
890 * with T(std::forward<Args>(args)...) after the specified
891 * location. Due to the nature of a %forward_list this operation can
892 * be done in constant time, and does not invalidate iterators
895 template<typename
... _Args
>
897 emplace_after(const_iterator __pos
, _Args
&&... __args
)
898 { return iterator(this->_M_insert_after(__pos
,
899 std::forward
<_Args
>(__args
)...)); }
902 * @brief Inserts given value into %forward_list after specified
904 * @param __pos An iterator into the %forward_list.
905 * @param __val Data to be inserted.
906 * @return An iterator that points to the inserted data.
908 * This function will insert a copy of the given value after
909 * the specified location. Due to the nature of a %forward_list this
910 * operation can be done in constant time, and does not
911 * invalidate iterators and references.
914 insert_after(const_iterator __pos
, const _Tp
& __val
)
915 { return iterator(this->_M_insert_after(__pos
, __val
)); }
921 insert_after(const_iterator __pos
, _Tp
&& __val
)
922 { return iterator(this->_M_insert_after(__pos
, std::move(__val
))); }
925 * @brief Inserts a number of copies of given data into the
927 * @param __pos An iterator into the %forward_list.
928 * @param __n Number of elements to be inserted.
929 * @param __val Data to be inserted.
930 * @return An iterator pointing to the last inserted copy of
931 * @a val or @a pos if @a n == 0.
933 * This function will insert a specified number of copies of the
934 * given data after the location specified by @a pos.
936 * This operation is linear in the number of elements inserted and
937 * does not invalidate iterators and references.
940 insert_after(const_iterator __pos
, size_type __n
, const _Tp
& __val
);
943 * @brief Inserts a range into the %forward_list.
944 * @param __pos An iterator into the %forward_list.
945 * @param __first An input iterator.
946 * @param __last An input iterator.
947 * @return An iterator pointing to the last inserted element or
948 * @a __pos if @a __first == @a __last.
950 * This function will insert copies of the data in the range
951 * [@a __first,@a __last) into the %forward_list after the
952 * location specified by @a __pos.
954 * This operation is linear in the number of elements inserted and
955 * does not invalidate iterators and references.
957 template<typename _InputIterator
,
958 typename
= std::_RequireInputIter
<_InputIterator
>>
960 insert_after(const_iterator __pos
,
961 _InputIterator __first
, _InputIterator __last
);
964 * @brief Inserts the contents of an initializer_list into
965 * %forward_list after the specified iterator.
966 * @param __pos An iterator into the %forward_list.
967 * @param __il An initializer_list of value_type.
968 * @return An iterator pointing to the last inserted element
969 * or @a __pos if @a __il is empty.
971 * This function will insert copies of the data in the
972 * initializer_list @a __il into the %forward_list before the location
973 * specified by @a __pos.
975 * This operation is linear in the number of elements inserted and
976 * does not invalidate iterators and references.
979 insert_after(const_iterator __pos
, std::initializer_list
<_Tp
> __il
)
980 { return insert_after(__pos
, __il
.begin(), __il
.end()); }
983 * @brief Removes the element pointed to by the iterator following
985 * @param __pos Iterator pointing before element to be erased.
986 * @return An iterator pointing to the element following the one
987 * that was erased, or end() if no such element exists.
989 * This function will erase the element at the given position and
990 * thus shorten the %forward_list by one.
992 * Due to the nature of a %forward_list this operation can be done
993 * in constant time, and only invalidates iterators/references to
994 * the element being removed. The user is also cautioned that
995 * this function only erases the element, and that if the element
996 * is itself a pointer, the pointed-to memory is not touched in
997 * any way. Managing the pointer is the user's responsibility.
1000 erase_after(const_iterator __pos
)
1001 { return iterator(this->_M_erase_after(const_cast<_Node_base
*>
1002 (__pos
._M_node
))); }
1005 * @brief Remove a range of elements.
1006 * @param __pos Iterator pointing before the first element to be
1008 * @param __last Iterator pointing to one past the last element to be
1012 * This function will erase the elements in the range
1013 * @a (__pos,__last) and shorten the %forward_list accordingly.
1015 * This operation is linear time in the size of the range and only
1016 * invalidates iterators/references to the element being removed.
1017 * The user is also cautioned that this function only erases the
1018 * elements, and that if the elements themselves are pointers, the
1019 * pointed-to memory is not touched in any way. Managing the pointer
1020 * is the user's responsibility.
1023 erase_after(const_iterator __pos
, const_iterator __last
)
1024 { return iterator(this->_M_erase_after(const_cast<_Node_base
*>
1026 const_cast<_Node_base
*>
1027 (__last
._M_node
))); }
1030 * @brief Swaps data with another %forward_list.
1031 * @param __list A %forward_list of the same element and allocator
1034 * This exchanges the elements between two lists in constant
1035 * time. Note that the global std::swap() function is
1036 * specialized such that std::swap(l1,l2) will feed to this
1039 * Whether the allocators are swapped depends on the allocator traits.
1042 swap(forward_list
& __list
) noexcept
1044 std::swap(this->_M_impl
._M_head
._M_next
,
1045 __list
._M_impl
._M_head
._M_next
);
1046 _Node_alloc_traits::_S_on_swap(this->_M_get_Node_allocator(),
1047 __list
._M_get_Node_allocator());
1051 * @brief Resizes the %forward_list to the specified number of
1053 * @param __sz Number of elements the %forward_list should contain.
1055 * This function will %resize the %forward_list to the specified
1056 * number of elements. If the number is smaller than the
1057 * %forward_list's current number of elements the %forward_list
1058 * is truncated, otherwise the %forward_list is extended and the
1059 * new elements are default constructed.
1062 resize(size_type __sz
);
1065 * @brief Resizes the %forward_list to the specified number of
1067 * @param __sz Number of elements the %forward_list should contain.
1068 * @param __val Data with which new elements should be populated.
1070 * This function will %resize the %forward_list to the specified
1071 * number of elements. If the number is smaller than the
1072 * %forward_list's current number of elements the %forward_list
1073 * is truncated, otherwise the %forward_list is extended and new
1074 * elements are populated with given data.
1077 resize(size_type __sz
, const value_type
& __val
);
1080 * @brief Erases all the elements.
1082 * Note that this function only erases
1083 * the elements, and that if the elements themselves are
1084 * pointers, the pointed-to memory is not touched in any way.
1085 * Managing the pointer is the user's responsibility.
1089 { this->_M_erase_after(&this->_M_impl
._M_head
, nullptr); }
1091 // 23.3.4.6 forward_list operations:
1094 * @brief Insert contents of another %forward_list.
1095 * @param __pos Iterator referencing the element to insert after.
1096 * @param __list Source list.
1098 * The elements of @a list are inserted in constant time after
1099 * the element referenced by @a pos. @a list becomes an empty
1102 * Requires this != @a x.
1105 splice_after(const_iterator __pos
, forward_list
&& __list
) noexcept
1107 if (!__list
.empty())
1108 _M_splice_after(__pos
, __list
.before_begin(), __list
.end());
1112 splice_after(const_iterator __pos
, forward_list
& __list
) noexcept
1113 { splice_after(__pos
, std::move(__list
)); }
1116 * @brief Insert element from another %forward_list.
1117 * @param __pos Iterator referencing the element to insert after.
1118 * @param __list Source list.
1119 * @param __i Iterator referencing the element before the element
1122 * Removes the element in list @a list referenced by @a i and
1123 * inserts it into the current list after @a pos.
1126 splice_after(const_iterator __pos
, forward_list
&& __list
,
1127 const_iterator __i
) noexcept
;
1130 splice_after(const_iterator __pos
, forward_list
& __list
,
1131 const_iterator __i
) noexcept
1132 { splice_after(__pos
, std::move(__list
), __i
); }
1135 * @brief Insert range from another %forward_list.
1136 * @param __pos Iterator referencing the element to insert after.
1137 * @param __list Source list.
1138 * @param __before Iterator referencing before the start of range
1140 * @param __last Iterator referencing the end of range in list.
1142 * Removes elements in the range (__before,__last) and inserts them
1143 * after @a __pos in constant time.
1145 * Undefined if @a __pos is in (__before,__last).
1149 splice_after(const_iterator __pos
, forward_list
&&,
1150 const_iterator __before
, const_iterator __last
) noexcept
1151 { _M_splice_after(__pos
, __before
, __last
); }
1154 splice_after(const_iterator __pos
, forward_list
&,
1155 const_iterator __before
, const_iterator __last
) noexcept
1156 { _M_splice_after(__pos
, __before
, __last
); }
1160 #if __cplusplus > 201703L
1161 # define __cpp_lib_list_remove_return_type 201806L
1162 using __remove_return_type
= size_type
;
1163 # define _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG \
1164 __attribute__((__abi_tag__("__cxx20")))
1166 using __remove_return_type
= void;
1167 # define _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
1172 * @brief Remove all elements equal to value.
1173 * @param __val The value to remove.
1175 * Removes every element in the list equal to @a __val.
1176 * Remaining elements stay in list order. Note that this
1177 * function only erases the elements, and that if the elements
1178 * themselves are pointers, the pointed-to memory is not
1179 * touched in any way. Managing the pointer is the user's
1182 _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
1183 __remove_return_type
1184 remove(const _Tp
& __val
);
1187 * @brief Remove all elements satisfying a predicate.
1188 * @param __pred Unary predicate function or object.
1190 * Removes every element in the list for which the predicate
1191 * returns true. Remaining elements stay in list order. Note
1192 * that this function only erases the elements, and that if the
1193 * elements themselves are pointers, the pointed-to memory is
1194 * not touched in any way. Managing the pointer is the user's
1197 template<typename _Pred
>
1198 __remove_return_type
1199 remove_if(_Pred __pred
);
1202 * @brief Remove consecutive duplicate elements.
1204 * For each consecutive set of elements with the same value,
1205 * remove all but the first one. Remaining elements stay in
1206 * list order. Note that this function only erases the
1207 * elements, and that if the elements themselves are pointers,
1208 * the pointed-to memory is not touched in any way. Managing
1209 * the pointer is the user's responsibility.
1211 _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
1212 __remove_return_type
1214 { return unique(std::equal_to
<_Tp
>()); }
1216 #undef _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG
1219 * @brief Remove consecutive elements satisfying a predicate.
1220 * @param __binary_pred Binary predicate function or object.
1222 * For each consecutive set of elements [first,last) that
1223 * satisfy predicate(first,i) where i is an iterator in
1224 * [first,last), remove all but the first one. Remaining
1225 * elements stay in list order. Note that this function only
1226 * erases the elements, and that if the elements themselves are
1227 * pointers, the pointed-to memory is not touched in any way.
1228 * Managing the pointer is the user's responsibility.
1230 template<typename _BinPred
>
1231 __remove_return_type
1232 unique(_BinPred __binary_pred
);
1235 * @brief Merge sorted lists.
1236 * @param __list Sorted list to merge.
1238 * Assumes that both @a list and this list are sorted according to
1239 * operator<(). Merges elements of @a __list into this list in
1240 * sorted order, leaving @a __list empty when complete. Elements in
1241 * this list precede elements in @a __list that are equal.
1244 merge(forward_list
&& __list
)
1245 { merge(std::move(__list
), std::less
<_Tp
>()); }
1248 merge(forward_list
& __list
)
1249 { merge(std::move(__list
)); }
1252 * @brief Merge sorted lists according to comparison function.
1253 * @param __list Sorted list to merge.
1254 * @param __comp Comparison function defining sort order.
1256 * Assumes that both @a __list and this list are sorted according to
1257 * comp. Merges elements of @a __list into this list
1258 * in sorted order, leaving @a __list empty when complete. Elements
1259 * in this list precede elements in @a __list that are equivalent
1260 * according to comp().
1262 template<typename _Comp
>
1264 merge(forward_list
&& __list
, _Comp __comp
);
1266 template<typename _Comp
>
1268 merge(forward_list
& __list
, _Comp __comp
)
1269 { merge(std::move(__list
), __comp
); }
1272 * @brief Sort the elements of the list.
1274 * Sorts the elements of this list in NlogN time. Equivalent
1275 * elements remain in list order.
1279 { sort(std::less
<_Tp
>()); }
1282 * @brief Sort the forward_list using a comparison function.
1284 * Sorts the elements of this list in NlogN time. Equivalent
1285 * elements remain in list order.
1287 template<typename _Comp
>
1292 * @brief Reverse the elements in list.
1294 * Reverse the order of elements in the list in linear time.
1298 { this->_M_impl
._M_head
._M_reverse_after(); }
1301 // Called by the range constructor to implement [23.3.4.2]/9
1302 template<typename _InputIterator
>
1304 _M_range_initialize(_InputIterator __first
, _InputIterator __last
);
1306 // Called by forward_list(n,v,a), and the range constructor when it
1307 // turns out to be the same thing.
1309 _M_fill_initialize(size_type __n
, const value_type
& __value
);
1311 // Called by splice_after and insert_after.
1313 _M_splice_after(const_iterator __pos
, const_iterator __before
,
1314 const_iterator __last
);
1316 // Called by forward_list(n).
1318 _M_default_initialize(size_type __n
);
1320 // Called by resize(sz).
1322 _M_default_insert_after(const_iterator __pos
, size_type __n
);
1324 // Called by operator=(forward_list&&)
1326 _M_move_assign(forward_list
&& __list
, true_type
) noexcept
1329 this->_M_impl
._M_head
._M_next
= __list
._M_impl
._M_head
._M_next
;
1330 __list
._M_impl
._M_head
._M_next
= nullptr;
1331 std::__alloc_on_move(this->_M_get_Node_allocator(),
1332 __list
._M_get_Node_allocator());
1335 // Called by operator=(forward_list&&)
1337 _M_move_assign(forward_list
&& __list
, false_type
)
1339 if (__list
._M_get_Node_allocator() == this->_M_get_Node_allocator())
1340 _M_move_assign(std::move(__list
), true_type());
1342 // The rvalue's allocator cannot be moved, or is not equal,
1343 // so we need to individually move each element.
1344 this->assign(std::__make_move_if_noexcept_iterator(__list
.begin()),
1345 std::__make_move_if_noexcept_iterator(__list
.end()));
1348 // Called by assign(_InputIterator, _InputIterator) if _Tp is
1350 template<typename _InputIterator
>
1352 _M_assign(_InputIterator __first
, _InputIterator __last
, true_type
)
1354 auto __prev
= before_begin();
1355 auto __curr
= begin();
1357 while (__curr
!= __end
&& __first
!= __last
)
1364 if (__first
!= __last
)
1365 insert_after(__prev
, __first
, __last
);
1366 else if (__curr
!= __end
)
1367 erase_after(__prev
, __end
);
1370 // Called by assign(_InputIterator, _InputIterator) if _Tp is not
1372 template<typename _InputIterator
>
1374 _M_assign(_InputIterator __first
, _InputIterator __last
, false_type
)
1377 insert_after(cbefore_begin(), __first
, __last
);
1380 // Called by assign(size_type, const _Tp&) if Tp is CopyAssignable
1382 _M_assign_n(size_type __n
, const _Tp
& __val
, true_type
)
1384 auto __prev
= before_begin();
1385 auto __curr
= begin();
1387 while (__curr
!= __end
&& __n
> 0)
1395 insert_after(__prev
, __n
, __val
);
1396 else if (__curr
!= __end
)
1397 erase_after(__prev
, __end
);
1400 // Called by assign(size_type, const _Tp&) if Tp is non-CopyAssignable
1402 _M_assign_n(size_type __n
, const _Tp
& __val
, false_type
)
1405 insert_after(cbefore_begin(), __n
, __val
);
1409 #if __cpp_deduction_guides >= 201606
1410 template<typename _InputIterator
, typename _ValT
1411 = typename iterator_traits
<_InputIterator
>::value_type
,
1412 typename _Allocator
= allocator
<_ValT
>,
1413 typename
= _RequireInputIter
<_InputIterator
>,
1414 typename
= _RequireAllocator
<_Allocator
>>
1415 forward_list(_InputIterator
, _InputIterator
, _Allocator
= _Allocator())
1416 -> forward_list
<_ValT
, _Allocator
>;
1420 * @brief Forward list equality comparison.
1421 * @param __lx A %forward_list
1422 * @param __ly A %forward_list of the same type as @a __lx.
1423 * @return True iff the elements of the forward lists are equal.
1425 * This is an equivalence relation. It is linear in the number of
1426 * elements of the forward lists. Deques are considered equivalent
1427 * if corresponding elements compare equal.
1429 template<typename _Tp
, typename _Alloc
>
1431 operator==(const forward_list
<_Tp
, _Alloc
>& __lx
,
1432 const forward_list
<_Tp
, _Alloc
>& __ly
);
1435 * @brief Forward list ordering relation.
1436 * @param __lx A %forward_list.
1437 * @param __ly A %forward_list of the same type as @a __lx.
1438 * @return True iff @a __lx is lexicographically less than @a __ly.
1440 * This is a total ordering relation. It is linear in the number of
1441 * elements of the forward lists. The elements must be comparable
1444 * See std::lexicographical_compare() for how the determination is made.
1446 template<typename _Tp
, typename _Alloc
>
1448 operator<(const forward_list
<_Tp
, _Alloc
>& __lx
,
1449 const forward_list
<_Tp
, _Alloc
>& __ly
)
1450 { return std::lexicographical_compare(__lx
.cbegin(), __lx
.cend(),
1451 __ly
.cbegin(), __ly
.cend()); }
1453 /// Based on operator==
1454 template<typename _Tp
, typename _Alloc
>
1456 operator!=(const forward_list
<_Tp
, _Alloc
>& __lx
,
1457 const forward_list
<_Tp
, _Alloc
>& __ly
)
1458 { return !(__lx
== __ly
); }
1460 /// Based on operator<
1461 template<typename _Tp
, typename _Alloc
>
1463 operator>(const forward_list
<_Tp
, _Alloc
>& __lx
,
1464 const forward_list
<_Tp
, _Alloc
>& __ly
)
1465 { return (__ly
< __lx
); }
1467 /// Based on operator<
1468 template<typename _Tp
, typename _Alloc
>
1470 operator>=(const forward_list
<_Tp
, _Alloc
>& __lx
,
1471 const forward_list
<_Tp
, _Alloc
>& __ly
)
1472 { return !(__lx
< __ly
); }
1474 /// Based on operator<
1475 template<typename _Tp
, typename _Alloc
>
1477 operator<=(const forward_list
<_Tp
, _Alloc
>& __lx
,
1478 const forward_list
<_Tp
, _Alloc
>& __ly
)
1479 { return !(__ly
< __lx
); }
1481 /// See std::forward_list::swap().
1482 template<typename _Tp
, typename _Alloc
>
1484 swap(forward_list
<_Tp
, _Alloc
>& __lx
,
1485 forward_list
<_Tp
, _Alloc
>& __ly
)
1486 noexcept(noexcept(__lx
.swap(__ly
)))
1487 { __lx
.swap(__ly
); }
1489 _GLIBCXX_END_NAMESPACE_CONTAINER
1490 _GLIBCXX_END_NAMESPACE_VERSION
1493 #endif // _FORWARD_LIST_H