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
, _Tp
> _Tp_alloc_type
;
293 typedef __alloc_rebind
<_Alloc
, _Fwd_list_node
<_Tp
>> _Node_alloc_type
;
294 typedef __gnu_cxx::__alloc_traits
<_Node_alloc_type
> _Node_alloc_traits
;
296 struct _Fwd_list_impl
297 : public _Node_alloc_type
299 _Fwd_list_node_base _M_head
;
302 noexcept( noexcept(_Node_alloc_type()) )
303 : _Node_alloc_type(), _M_head()
306 _Fwd_list_impl(_Fwd_list_impl
&&) = default;
308 _Fwd_list_impl(_Fwd_list_impl
&& __fl
, _Node_alloc_type
&& __a
)
309 : _Node_alloc_type(std::move(__a
)), _M_head(std::move(__fl
._M_head
))
312 _Fwd_list_impl(_Node_alloc_type
&& __a
)
313 : _Node_alloc_type(std::move(__a
)), _M_head()
317 _Fwd_list_impl _M_impl
;
320 typedef _Fwd_list_iterator
<_Tp
> iterator
;
321 typedef _Fwd_list_const_iterator
<_Tp
> const_iterator
;
322 typedef _Fwd_list_node
<_Tp
> _Node
;
325 _M_get_Node_allocator() noexcept
326 { return this->_M_impl
; }
328 const _Node_alloc_type
&
329 _M_get_Node_allocator() const noexcept
330 { return this->_M_impl
; }
332 _Fwd_list_base() = default;
334 _Fwd_list_base(_Node_alloc_type
&& __a
)
335 : _M_impl(std::move(__a
)) { }
337 // When allocators are always equal.
338 _Fwd_list_base(_Fwd_list_base
&& __lst
, _Node_alloc_type
&& __a
,
340 : _M_impl(std::move(__lst
._M_impl
), std::move(__a
))
343 // When allocators are not always equal.
344 _Fwd_list_base(_Fwd_list_base
&& __lst
, _Node_alloc_type
&& __a
);
346 _Fwd_list_base(_Fwd_list_base
&&) = default;
349 { _M_erase_after(&_M_impl
._M_head
, nullptr); }
355 auto __ptr
= _Node_alloc_traits::allocate(_M_get_Node_allocator(), 1);
356 return std::__to_address(__ptr
);
359 template<typename
... _Args
>
361 _M_create_node(_Args
&&... __args
)
363 _Node
* __node
= this->_M_get_node();
366 _Tp_alloc_type
__a(_M_get_Node_allocator());
367 typedef allocator_traits
<_Tp_alloc_type
> _Alloc_traits
;
368 ::new ((void*)__node
) _Node
;
369 _Alloc_traits::construct(__a
, __node
->_M_valptr(),
370 std::forward
<_Args
>(__args
)...);
374 this->_M_put_node(__node
);
375 __throw_exception_again
;
380 template<typename
... _Args
>
382 _M_insert_after(const_iterator __pos
, _Args
&&... __args
);
385 _M_put_node(_Node
* __p
)
387 typedef typename
_Node_alloc_traits::pointer _Ptr
;
388 auto __ptr
= std::pointer_traits
<_Ptr
>::pointer_to(*__p
);
389 _Node_alloc_traits::deallocate(_M_get_Node_allocator(), __ptr
, 1);
393 _M_erase_after(_Fwd_list_node_base
* __pos
);
396 _M_erase_after(_Fwd_list_node_base
* __pos
,
397 _Fwd_list_node_base
* __last
);
401 * @brief A standard container with linear time access to elements,
402 * and fixed time insertion/deletion at any point in the sequence.
406 * @tparam _Tp Type of element.
407 * @tparam _Alloc Allocator type, defaults to allocator<_Tp>.
409 * Meets the requirements of a <a href="tables.html#65">container</a>, a
410 * <a href="tables.html#67">sequence</a>, including the
411 * <a href="tables.html#68">optional sequence requirements</a> with the
412 * %exception of @c at and @c operator[].
414 * This is a @e singly @e linked %list. Traversal up the
415 * %list requires linear time, but adding and removing elements (or
416 * @e nodes) is done in constant time, regardless of where the
417 * change takes place. Unlike std::vector and std::deque,
418 * random-access iterators are not provided, so subscripting ( @c
419 * [] ) access is not allowed. For algorithms which only need
420 * sequential access, this lack makes no difference.
422 * Also unlike the other standard containers, std::forward_list provides
423 * specialized algorithms %unique to linked lists, such as
424 * splicing, sorting, and in-place reversal.
426 template<typename _Tp
, typename _Alloc
= allocator
<_Tp
>>
427 class forward_list
: private _Fwd_list_base
<_Tp
, _Alloc
>
429 static_assert(is_same
<typename remove_cv
<_Tp
>::type
, _Tp
>::value
,
430 "std::forward_list must have a non-const, non-volatile value_type");
431 #ifdef __STRICT_ANSI__
432 static_assert(is_same
<typename
_Alloc::value_type
, _Tp
>::value
,
433 "std::forward_list must have the same value_type as its allocator");
437 typedef _Fwd_list_base
<_Tp
, _Alloc
> _Base
;
438 typedef _Fwd_list_node
<_Tp
> _Node
;
439 typedef _Fwd_list_node_base _Node_base
;
440 typedef typename
_Base::_Tp_alloc_type _Tp_alloc_type
;
441 typedef typename
_Base::_Node_alloc_type _Node_alloc_type
;
442 typedef typename
_Base::_Node_alloc_traits _Node_alloc_traits
;
443 typedef __gnu_cxx::__alloc_traits
<_Tp_alloc_type
> _Alloc_traits
;
447 typedef _Tp value_type
;
448 typedef typename
_Alloc_traits::pointer pointer
;
449 typedef typename
_Alloc_traits::const_pointer const_pointer
;
450 typedef value_type
& reference
;
451 typedef const value_type
& const_reference
;
453 typedef _Fwd_list_iterator
<_Tp
> iterator
;
454 typedef _Fwd_list_const_iterator
<_Tp
> const_iterator
;
455 typedef std::size_t size_type
;
456 typedef std::ptrdiff_t difference_type
;
457 typedef _Alloc allocator_type
;
459 // 23.3.4.2 construct/copy/destroy:
462 * @brief Creates a %forward_list with no elements.
464 forward_list() = default;
467 * @brief Creates a %forward_list with no elements.
468 * @param __al An allocator object.
471 forward_list(const _Alloc
& __al
) noexcept
472 : _Base(_Node_alloc_type(__al
))
476 * @brief Copy constructor with allocator argument.
477 * @param __list Input list to copy.
478 * @param __al An allocator object.
480 forward_list(const forward_list
& __list
, const _Alloc
& __al
)
481 : _Base(_Node_alloc_type(__al
))
482 { _M_range_initialize(__list
.begin(), __list
.end()); }
485 forward_list(forward_list
&& __list
, _Node_alloc_type
&& __al
,
487 : _Base(std::move(__list
), std::move(__al
))
489 // If __list is not empty it means its allocator is not equal to __a,
490 // so we need to move from each element individually.
491 insert_after(cbefore_begin(),
492 std::__make_move_if_noexcept_iterator(__list
.begin()),
493 std::__make_move_if_noexcept_iterator(__list
.end()));
496 forward_list(forward_list
&& __list
, _Node_alloc_type
&& __al
,
499 : _Base(std::move(__list
), _Node_alloc_type(__al
), true_type
{})
504 * @brief Move constructor with allocator argument.
505 * @param __list Input list to move.
506 * @param __al An allocator object.
508 forward_list(forward_list
&& __list
, const _Alloc
& __al
)
509 noexcept(_Node_alloc_traits::_S_always_equal())
510 : forward_list(std::move(__list
), _Node_alloc_type(__al
),
511 typename
_Node_alloc_traits::is_always_equal
{})
515 * @brief Creates a %forward_list with default constructed elements.
516 * @param __n The number of elements to initially create.
517 * @param __al An allocator object.
519 * This constructor creates the %forward_list with @a __n default
520 * constructed elements.
523 forward_list(size_type __n
, const _Alloc
& __al
= _Alloc())
524 : _Base(_Node_alloc_type(__al
))
525 { _M_default_initialize(__n
); }
528 * @brief Creates a %forward_list with copies of an exemplar element.
529 * @param __n The number of elements to initially create.
530 * @param __value An element to copy.
531 * @param __al An allocator object.
533 * This constructor fills the %forward_list with @a __n copies of
536 forward_list(size_type __n
, const _Tp
& __value
,
537 const _Alloc
& __al
= _Alloc())
538 : _Base(_Node_alloc_type(__al
))
539 { _M_fill_initialize(__n
, __value
); }
542 * @brief Builds a %forward_list from a range.
543 * @param __first An input iterator.
544 * @param __last An input iterator.
545 * @param __al An allocator object.
547 * Create a %forward_list consisting of copies of the elements from
548 * [@a __first,@a __last). This is linear in N (where N is
549 * distance(@a __first,@a __last)).
551 template<typename _InputIterator
,
552 typename
= std::_RequireInputIter
<_InputIterator
>>
553 forward_list(_InputIterator __first
, _InputIterator __last
,
554 const _Alloc
& __al
= _Alloc())
555 : _Base(_Node_alloc_type(__al
))
556 { _M_range_initialize(__first
, __last
); }
559 * @brief The %forward_list copy constructor.
560 * @param __list A %forward_list of identical element and allocator
563 forward_list(const forward_list
& __list
)
564 : _Base(_Node_alloc_traits::_S_select_on_copy(
565 __list
._M_get_Node_allocator()))
566 { _M_range_initialize(__list
.begin(), __list
.end()); }
569 * @brief The %forward_list move constructor.
570 * @param __list A %forward_list of identical element and allocator
573 * The newly-created %forward_list contains the exact contents of the
574 * moved instance. The contents of the moved instance are a valid, but
575 * unspecified %forward_list.
577 forward_list(forward_list
&&) = default;
580 * @brief Builds a %forward_list from an initializer_list
581 * @param __il An initializer_list of value_type.
582 * @param __al An allocator object.
584 * Create a %forward_list consisting of copies of the elements
585 * in the initializer_list @a __il. This is linear in __il.size().
587 forward_list(std::initializer_list
<_Tp
> __il
,
588 const _Alloc
& __al
= _Alloc())
589 : _Base(_Node_alloc_type(__al
))
590 { _M_range_initialize(__il
.begin(), __il
.end()); }
593 * @brief The forward_list dtor.
595 ~forward_list() noexcept
599 * @brief The %forward_list assignment operator.
600 * @param __list A %forward_list of identical element and allocator
603 * All the elements of @a __list are copied.
605 * Whether the allocator is copied depends on the allocator traits.
608 operator=(const forward_list
& __list
);
611 * @brief The %forward_list move assignment operator.
612 * @param __list A %forward_list of identical element and allocator
615 * The contents of @a __list are moved into this %forward_list
616 * (without copying, if the allocators permit it).
618 * Afterwards @a __list is a valid, but unspecified %forward_list
620 * Whether the allocator is moved depends on the allocator traits.
623 operator=(forward_list
&& __list
)
624 noexcept(_Node_alloc_traits::_S_nothrow_move())
626 constexpr bool __move_storage
=
627 _Node_alloc_traits::_S_propagate_on_move_assign()
628 || _Node_alloc_traits::_S_always_equal();
629 _M_move_assign(std::move(__list
), __bool_constant
<__move_storage
>());
634 * @brief The %forward_list initializer list assignment operator.
635 * @param __il An initializer_list of value_type.
637 * Replace the contents of the %forward_list with copies of the
638 * elements in the initializer_list @a __il. This is linear in
642 operator=(std::initializer_list
<_Tp
> __il
)
649 * @brief Assigns a range to a %forward_list.
650 * @param __first An input iterator.
651 * @param __last An input iterator.
653 * This function fills a %forward_list with copies of the elements
654 * in the range [@a __first,@a __last).
656 * Note that the assignment completely changes the %forward_list and
657 * that the number of elements of the resulting %forward_list is the
658 * same as the number of elements assigned.
660 template<typename _InputIterator
,
661 typename
= std::_RequireInputIter
<_InputIterator
>>
663 assign(_InputIterator __first
, _InputIterator __last
)
665 typedef is_assignable
<_Tp
, decltype(*__first
)> __assignable
;
666 _M_assign(__first
, __last
, __assignable());
670 * @brief Assigns a given value to a %forward_list.
671 * @param __n Number of elements to be assigned.
672 * @param __val Value to be assigned.
674 * This function fills a %forward_list with @a __n copies of the
675 * given value. Note that the assignment completely changes the
676 * %forward_list, and that the resulting %forward_list has __n
680 assign(size_type __n
, const _Tp
& __val
)
681 { _M_assign_n(__n
, __val
, is_copy_assignable
<_Tp
>()); }
684 * @brief Assigns an initializer_list to a %forward_list.
685 * @param __il An initializer_list of value_type.
687 * Replace the contents of the %forward_list with copies of the
688 * elements in the initializer_list @a __il. This is linear in
692 assign(std::initializer_list
<_Tp
> __il
)
693 { assign(__il
.begin(), __il
.end()); }
695 /// Get a copy of the memory allocation object.
697 get_allocator() const noexcept
698 { return allocator_type(this->_M_get_Node_allocator()); }
700 // 23.3.4.3 iterators:
703 * Returns a read/write iterator that points before the first element
704 * in the %forward_list. Iteration is done in ordinary element order.
707 before_begin() noexcept
708 { return iterator(&this->_M_impl
._M_head
); }
711 * Returns a read-only (constant) iterator that points before the
712 * first element in the %forward_list. Iteration is done in ordinary
716 before_begin() const noexcept
717 { return const_iterator(&this->_M_impl
._M_head
); }
720 * Returns a read/write iterator that points to the first element
721 * in the %forward_list. Iteration is done in ordinary element order.
725 { return iterator(this->_M_impl
._M_head
._M_next
); }
728 * Returns a read-only (constant) iterator that points to the first
729 * element in the %forward_list. Iteration is done in ordinary
733 begin() const noexcept
734 { return const_iterator(this->_M_impl
._M_head
._M_next
); }
737 * Returns a read/write iterator that points one past the last
738 * element in the %forward_list. Iteration is done in ordinary
743 { return iterator(nullptr); }
746 * Returns a read-only iterator that points one past the last
747 * element in the %forward_list. Iteration is done in ordinary
752 { return const_iterator(nullptr); }
755 * Returns a read-only (constant) iterator that points to the
756 * first element in the %forward_list. Iteration is done in ordinary
760 cbegin() const noexcept
761 { return const_iterator(this->_M_impl
._M_head
._M_next
); }
764 * Returns a read-only (constant) iterator that points before the
765 * first element in the %forward_list. Iteration is done in ordinary
769 cbefore_begin() const noexcept
770 { return const_iterator(&this->_M_impl
._M_head
); }
773 * Returns a read-only (constant) iterator that points one past
774 * the last element in the %forward_list. Iteration is done in
775 * ordinary element order.
778 cend() const noexcept
779 { return const_iterator(nullptr); }
782 * Returns true if the %forward_list is empty. (Thus begin() would
786 empty() const noexcept
787 { return this->_M_impl
._M_head
._M_next
== nullptr; }
790 * Returns the largest possible number of elements of %forward_list.
793 max_size() const noexcept
794 { return _Node_alloc_traits::max_size(this->_M_get_Node_allocator()); }
796 // 23.3.4.4 element access:
799 * Returns a read/write reference to the data at the first
800 * element of the %forward_list.
805 _Node
* __front
= static_cast<_Node
*>(this->_M_impl
._M_head
._M_next
);
806 return *__front
->_M_valptr();
810 * Returns a read-only (constant) reference to the data at the first
811 * element of the %forward_list.
816 _Node
* __front
= static_cast<_Node
*>(this->_M_impl
._M_head
._M_next
);
817 return *__front
->_M_valptr();
820 // 23.3.4.5 modifiers:
823 * @brief Constructs object in %forward_list at the front of the
825 * @param __args Arguments.
827 * This function will insert an object of type Tp constructed
828 * with Tp(std::forward<Args>(args)...) at the front of the list
829 * Due to the nature of a %forward_list this operation can
830 * be done in constant time, and does not invalidate iterators
833 template<typename
... _Args
>
834 #if __cplusplus > 201402L
839 emplace_front(_Args
&&... __args
)
841 this->_M_insert_after(cbefore_begin(),
842 std::forward
<_Args
>(__args
)...);
843 #if __cplusplus > 201402L
849 * @brief Add data to the front of the %forward_list.
850 * @param __val Data to be added.
852 * This is a typical stack operation. The function creates an
853 * element at the front of the %forward_list and assigns the given
854 * data to it. Due to the nature of a %forward_list this operation
855 * can be done in constant time, and does not invalidate iterators
859 push_front(const _Tp
& __val
)
860 { this->_M_insert_after(cbefore_begin(), __val
); }
866 push_front(_Tp
&& __val
)
867 { this->_M_insert_after(cbefore_begin(), std::move(__val
)); }
870 * @brief Removes first element.
872 * This is a typical stack operation. It shrinks the %forward_list
873 * by one. Due to the nature of a %forward_list this operation can
874 * be done in constant time, and only invalidates iterators/references
875 * to the element being removed.
877 * Note that no data is returned, and if the first element's data
878 * is needed, it should be retrieved before pop_front() is
883 { this->_M_erase_after(&this->_M_impl
._M_head
); }
886 * @brief Constructs object in %forward_list after the specified
888 * @param __pos A const_iterator into the %forward_list.
889 * @param __args Arguments.
890 * @return An iterator that points to the inserted data.
892 * This function will insert an object of type T constructed
893 * with T(std::forward<Args>(args)...) after the specified
894 * location. Due to the nature of a %forward_list this operation can
895 * be done in constant time, and does not invalidate iterators
898 template<typename
... _Args
>
900 emplace_after(const_iterator __pos
, _Args
&&... __args
)
901 { return iterator(this->_M_insert_after(__pos
,
902 std::forward
<_Args
>(__args
)...)); }
905 * @brief Inserts given value into %forward_list after specified
907 * @param __pos An iterator into the %forward_list.
908 * @param __val Data to be inserted.
909 * @return An iterator that points to the inserted data.
911 * This function will insert a copy of the given value after
912 * the specified location. Due to the nature of a %forward_list this
913 * operation can be done in constant time, and does not
914 * invalidate iterators and references.
917 insert_after(const_iterator __pos
, const _Tp
& __val
)
918 { return iterator(this->_M_insert_after(__pos
, __val
)); }
924 insert_after(const_iterator __pos
, _Tp
&& __val
)
925 { return iterator(this->_M_insert_after(__pos
, std::move(__val
))); }
928 * @brief Inserts a number of copies of given data into the
930 * @param __pos An iterator into the %forward_list.
931 * @param __n Number of elements to be inserted.
932 * @param __val Data to be inserted.
933 * @return An iterator pointing to the last inserted copy of
934 * @a val or @a pos if @a n == 0.
936 * This function will insert a specified number of copies of the
937 * given data after the location specified by @a pos.
939 * This operation is linear in the number of elements inserted and
940 * does not invalidate iterators and references.
943 insert_after(const_iterator __pos
, size_type __n
, const _Tp
& __val
);
946 * @brief Inserts a range into the %forward_list.
947 * @param __pos An iterator into the %forward_list.
948 * @param __first An input iterator.
949 * @param __last An input iterator.
950 * @return An iterator pointing to the last inserted element or
951 * @a __pos if @a __first == @a __last.
953 * This function will insert copies of the data in the range
954 * [@a __first,@a __last) into the %forward_list after the
955 * location specified by @a __pos.
957 * This operation is linear in the number of elements inserted and
958 * does not invalidate iterators and references.
960 template<typename _InputIterator
,
961 typename
= std::_RequireInputIter
<_InputIterator
>>
963 insert_after(const_iterator __pos
,
964 _InputIterator __first
, _InputIterator __last
);
967 * @brief Inserts the contents of an initializer_list into
968 * %forward_list after the specified iterator.
969 * @param __pos An iterator into the %forward_list.
970 * @param __il An initializer_list of value_type.
971 * @return An iterator pointing to the last inserted element
972 * or @a __pos if @a __il is empty.
974 * This function will insert copies of the data in the
975 * initializer_list @a __il into the %forward_list before the location
976 * specified by @a __pos.
978 * This operation is linear in the number of elements inserted and
979 * does not invalidate iterators and references.
982 insert_after(const_iterator __pos
, std::initializer_list
<_Tp
> __il
)
983 { return insert_after(__pos
, __il
.begin(), __il
.end()); }
986 * @brief Removes the element pointed to by the iterator following
988 * @param __pos Iterator pointing before element to be erased.
989 * @return An iterator pointing to the element following the one
990 * that was erased, or end() if no such element exists.
992 * This function will erase the element at the given position and
993 * thus shorten the %forward_list by one.
995 * Due to the nature of a %forward_list this operation can be done
996 * in constant time, and only invalidates iterators/references to
997 * the element being removed. The user is also cautioned that
998 * this function only erases the element, and that if the element
999 * is itself a pointer, the pointed-to memory is not touched in
1000 * any way. Managing the pointer is the user's responsibility.
1003 erase_after(const_iterator __pos
)
1004 { return iterator(this->_M_erase_after(const_cast<_Node_base
*>
1005 (__pos
._M_node
))); }
1008 * @brief Remove a range of elements.
1009 * @param __pos Iterator pointing before the first element to be
1011 * @param __last Iterator pointing to one past the last element to be
1015 * This function will erase the elements in the range
1016 * @a (__pos,__last) and shorten the %forward_list accordingly.
1018 * This operation is linear time in the size of the range and only
1019 * invalidates iterators/references to the element being removed.
1020 * The user is also cautioned that this function only erases the
1021 * elements, and that if the elements themselves are pointers, the
1022 * pointed-to memory is not touched in any way. Managing the pointer
1023 * is the user's responsibility.
1026 erase_after(const_iterator __pos
, const_iterator __last
)
1027 { return iterator(this->_M_erase_after(const_cast<_Node_base
*>
1029 const_cast<_Node_base
*>
1030 (__last
._M_node
))); }
1033 * @brief Swaps data with another %forward_list.
1034 * @param __list A %forward_list of the same element and allocator
1037 * This exchanges the elements between two lists in constant
1038 * time. Note that the global std::swap() function is
1039 * specialized such that std::swap(l1,l2) will feed to this
1042 * Whether the allocators are swapped depends on the allocator traits.
1045 swap(forward_list
& __list
) noexcept
1047 std::swap(this->_M_impl
._M_head
._M_next
,
1048 __list
._M_impl
._M_head
._M_next
);
1049 _Node_alloc_traits::_S_on_swap(this->_M_get_Node_allocator(),
1050 __list
._M_get_Node_allocator());
1054 * @brief Resizes the %forward_list to the specified number of
1056 * @param __sz Number of elements the %forward_list should contain.
1058 * This function will %resize the %forward_list to the specified
1059 * number of elements. If the number is smaller than the
1060 * %forward_list's current number of elements the %forward_list
1061 * is truncated, otherwise the %forward_list is extended and the
1062 * new elements are default constructed.
1065 resize(size_type __sz
);
1068 * @brief Resizes the %forward_list to the specified number of
1070 * @param __sz Number of elements the %forward_list should contain.
1071 * @param __val Data with which new elements should be populated.
1073 * This function will %resize the %forward_list to the specified
1074 * number of elements. If the number is smaller than the
1075 * %forward_list's current number of elements the %forward_list
1076 * is truncated, otherwise the %forward_list is extended and new
1077 * elements are populated with given data.
1080 resize(size_type __sz
, const value_type
& __val
);
1083 * @brief Erases all the elements.
1085 * Note that this function only erases
1086 * the elements, and that if the elements themselves are
1087 * pointers, the pointed-to memory is not touched in any way.
1088 * Managing the pointer is the user's responsibility.
1092 { this->_M_erase_after(&this->_M_impl
._M_head
, nullptr); }
1094 // 23.3.4.6 forward_list operations:
1097 * @brief Insert contents of another %forward_list.
1098 * @param __pos Iterator referencing the element to insert after.
1099 * @param __list Source list.
1101 * The elements of @a list are inserted in constant time after
1102 * the element referenced by @a pos. @a list becomes an empty
1105 * Requires this != @a x.
1108 splice_after(const_iterator __pos
, forward_list
&& __list
) noexcept
1110 if (!__list
.empty())
1111 _M_splice_after(__pos
, __list
.before_begin(), __list
.end());
1115 splice_after(const_iterator __pos
, forward_list
& __list
) noexcept
1116 { splice_after(__pos
, std::move(__list
)); }
1119 * @brief Insert element from another %forward_list.
1120 * @param __pos Iterator referencing the element to insert after.
1121 * @param __list Source list.
1122 * @param __i Iterator referencing the element before the element
1125 * Removes the element in list @a list referenced by @a i and
1126 * inserts it into the current list after @a pos.
1129 splice_after(const_iterator __pos
, forward_list
&& __list
,
1130 const_iterator __i
) noexcept
;
1133 splice_after(const_iterator __pos
, forward_list
& __list
,
1134 const_iterator __i
) noexcept
1135 { splice_after(__pos
, std::move(__list
), __i
); }
1138 * @brief Insert range from another %forward_list.
1139 * @param __pos Iterator referencing the element to insert after.
1140 * @param __list Source list.
1141 * @param __before Iterator referencing before the start of range
1143 * @param __last Iterator referencing the end of range in list.
1145 * Removes elements in the range (__before,__last) and inserts them
1146 * after @a __pos in constant time.
1148 * Undefined if @a __pos is in (__before,__last).
1152 splice_after(const_iterator __pos
, forward_list
&&,
1153 const_iterator __before
, const_iterator __last
) noexcept
1154 { _M_splice_after(__pos
, __before
, __last
); }
1157 splice_after(const_iterator __pos
, forward_list
&,
1158 const_iterator __before
, const_iterator __last
) noexcept
1159 { _M_splice_after(__pos
, __before
, __last
); }
1163 * @brief Remove all elements equal to value.
1164 * @param __val The value to remove.
1166 * Removes every element in the list equal to @a __val.
1167 * Remaining elements stay in list order. Note that this
1168 * function only erases the elements, and that if the elements
1169 * themselves are pointers, the pointed-to memory is not
1170 * touched in any way. Managing the pointer is the user's
1174 remove(const _Tp
& __val
);
1177 * @brief Remove all elements satisfying a predicate.
1178 * @param __pred Unary predicate function or object.
1180 * Removes every element in the list for which the predicate
1181 * returns true. Remaining elements stay in list order. Note
1182 * that this function only erases the elements, and that if the
1183 * elements themselves are pointers, the pointed-to memory is
1184 * not touched in any way. Managing the pointer is the user's
1187 template<typename _Pred
>
1189 remove_if(_Pred __pred
);
1192 * @brief Remove consecutive duplicate elements.
1194 * For each consecutive set of elements with the same value,
1195 * remove all but the first one. Remaining elements stay in
1196 * list order. Note that this function only erases the
1197 * elements, and that if the elements themselves are pointers,
1198 * the pointed-to memory is not touched in any way. Managing
1199 * the pointer is the user's responsibility.
1203 { unique(std::equal_to
<_Tp
>()); }
1206 * @brief Remove consecutive elements satisfying a predicate.
1207 * @param __binary_pred Binary predicate function or object.
1209 * For each consecutive set of elements [first,last) that
1210 * satisfy predicate(first,i) where i is an iterator in
1211 * [first,last), remove all but the first one. Remaining
1212 * elements stay in list order. Note that this function only
1213 * erases the elements, and that if the elements themselves are
1214 * pointers, the pointed-to memory is not touched in any way.
1215 * Managing the pointer is the user's responsibility.
1217 template<typename _BinPred
>
1219 unique(_BinPred __binary_pred
);
1222 * @brief Merge sorted lists.
1223 * @param __list Sorted list to merge.
1225 * Assumes that both @a list and this list are sorted according to
1226 * operator<(). Merges elements of @a __list into this list in
1227 * sorted order, leaving @a __list empty when complete. Elements in
1228 * this list precede elements in @a __list that are equal.
1231 merge(forward_list
&& __list
)
1232 { merge(std::move(__list
), std::less
<_Tp
>()); }
1235 merge(forward_list
& __list
)
1236 { merge(std::move(__list
)); }
1239 * @brief Merge sorted lists according to comparison function.
1240 * @param __list Sorted list to merge.
1241 * @param __comp Comparison function defining sort order.
1243 * Assumes that both @a __list and this list are sorted according to
1244 * comp. Merges elements of @a __list into this list
1245 * in sorted order, leaving @a __list empty when complete. Elements
1246 * in this list precede elements in @a __list that are equivalent
1247 * according to comp().
1249 template<typename _Comp
>
1251 merge(forward_list
&& __list
, _Comp __comp
);
1253 template<typename _Comp
>
1255 merge(forward_list
& __list
, _Comp __comp
)
1256 { merge(std::move(__list
), __comp
); }
1259 * @brief Sort the elements of the list.
1261 * Sorts the elements of this list in NlogN time. Equivalent
1262 * elements remain in list order.
1266 { sort(std::less
<_Tp
>()); }
1269 * @brief Sort the forward_list using a comparison function.
1271 * Sorts the elements of this list in NlogN time. Equivalent
1272 * elements remain in list order.
1274 template<typename _Comp
>
1279 * @brief Reverse the elements in list.
1281 * Reverse the order of elements in the list in linear time.
1285 { this->_M_impl
._M_head
._M_reverse_after(); }
1288 // Called by the range constructor to implement [23.3.4.2]/9
1289 template<typename _InputIterator
>
1291 _M_range_initialize(_InputIterator __first
, _InputIterator __last
);
1293 // Called by forward_list(n,v,a), and the range constructor when it
1294 // turns out to be the same thing.
1296 _M_fill_initialize(size_type __n
, const value_type
& __value
);
1298 // Called by splice_after and insert_after.
1300 _M_splice_after(const_iterator __pos
, const_iterator __before
,
1301 const_iterator __last
);
1303 // Called by forward_list(n).
1305 _M_default_initialize(size_type __n
);
1307 // Called by resize(sz).
1309 _M_default_insert_after(const_iterator __pos
, size_type __n
);
1311 // Called by operator=(forward_list&&)
1313 _M_move_assign(forward_list
&& __list
, true_type
) noexcept
1316 this->_M_impl
._M_head
._M_next
= __list
._M_impl
._M_head
._M_next
;
1317 __list
._M_impl
._M_head
._M_next
= nullptr;
1318 std::__alloc_on_move(this->_M_get_Node_allocator(),
1319 __list
._M_get_Node_allocator());
1322 // Called by operator=(forward_list&&)
1324 _M_move_assign(forward_list
&& __list
, false_type
)
1326 if (__list
._M_get_Node_allocator() == this->_M_get_Node_allocator())
1327 _M_move_assign(std::move(__list
), true_type());
1329 // The rvalue's allocator cannot be moved, or is not equal,
1330 // so we need to individually move each element.
1331 this->assign(std::__make_move_if_noexcept_iterator(__list
.begin()),
1332 std::__make_move_if_noexcept_iterator(__list
.end()));
1335 // Called by assign(_InputIterator, _InputIterator) if _Tp is
1337 template<typename _InputIterator
>
1339 _M_assign(_InputIterator __first
, _InputIterator __last
, true_type
)
1341 auto __prev
= before_begin();
1342 auto __curr
= begin();
1344 while (__curr
!= __end
&& __first
!= __last
)
1351 if (__first
!= __last
)
1352 insert_after(__prev
, __first
, __last
);
1353 else if (__curr
!= __end
)
1354 erase_after(__prev
, __end
);
1357 // Called by assign(_InputIterator, _InputIterator) if _Tp is not
1359 template<typename _InputIterator
>
1361 _M_assign(_InputIterator __first
, _InputIterator __last
, false_type
)
1364 insert_after(cbefore_begin(), __first
, __last
);
1367 // Called by assign(size_type, const _Tp&) if Tp is CopyAssignable
1369 _M_assign_n(size_type __n
, const _Tp
& __val
, true_type
)
1371 auto __prev
= before_begin();
1372 auto __curr
= begin();
1374 while (__curr
!= __end
&& __n
> 0)
1382 insert_after(__prev
, __n
, __val
);
1383 else if (__curr
!= __end
)
1384 erase_after(__prev
, __end
);
1387 // Called by assign(size_type, const _Tp&) if Tp is non-CopyAssignable
1389 _M_assign_n(size_type __n
, const _Tp
& __val
, false_type
)
1392 insert_after(cbefore_begin(), __n
, __val
);
1396 #if __cpp_deduction_guides >= 201606
1397 template<typename _InputIterator
, typename _ValT
1398 = typename iterator_traits
<_InputIterator
>::value_type
,
1399 typename _Allocator
= allocator
<_ValT
>,
1400 typename
= _RequireInputIter
<_InputIterator
>,
1401 typename
= _RequireAllocator
<_Allocator
>>
1402 forward_list(_InputIterator
, _InputIterator
, _Allocator
= _Allocator())
1403 -> forward_list
<_ValT
, _Allocator
>;
1407 * @brief Forward list equality comparison.
1408 * @param __lx A %forward_list
1409 * @param __ly A %forward_list of the same type as @a __lx.
1410 * @return True iff the elements of the forward lists are equal.
1412 * This is an equivalence relation. It is linear in the number of
1413 * elements of the forward lists. Deques are considered equivalent
1414 * if corresponding elements compare equal.
1416 template<typename _Tp
, typename _Alloc
>
1418 operator==(const forward_list
<_Tp
, _Alloc
>& __lx
,
1419 const forward_list
<_Tp
, _Alloc
>& __ly
);
1422 * @brief Forward list ordering relation.
1423 * @param __lx A %forward_list.
1424 * @param __ly A %forward_list of the same type as @a __lx.
1425 * @return True iff @a __lx is lexicographically less than @a __ly.
1427 * This is a total ordering relation. It is linear in the number of
1428 * elements of the forward lists. The elements must be comparable
1431 * See std::lexicographical_compare() for how the determination is made.
1433 template<typename _Tp
, typename _Alloc
>
1435 operator<(const forward_list
<_Tp
, _Alloc
>& __lx
,
1436 const forward_list
<_Tp
, _Alloc
>& __ly
)
1437 { return std::lexicographical_compare(__lx
.cbegin(), __lx
.cend(),
1438 __ly
.cbegin(), __ly
.cend()); }
1440 /// Based on operator==
1441 template<typename _Tp
, typename _Alloc
>
1443 operator!=(const forward_list
<_Tp
, _Alloc
>& __lx
,
1444 const forward_list
<_Tp
, _Alloc
>& __ly
)
1445 { return !(__lx
== __ly
); }
1447 /// Based on operator<
1448 template<typename _Tp
, typename _Alloc
>
1450 operator>(const forward_list
<_Tp
, _Alloc
>& __lx
,
1451 const forward_list
<_Tp
, _Alloc
>& __ly
)
1452 { return (__ly
< __lx
); }
1454 /// Based on operator<
1455 template<typename _Tp
, typename _Alloc
>
1457 operator>=(const forward_list
<_Tp
, _Alloc
>& __lx
,
1458 const forward_list
<_Tp
, _Alloc
>& __ly
)
1459 { return !(__lx
< __ly
); }
1461 /// Based on operator<
1462 template<typename _Tp
, typename _Alloc
>
1464 operator<=(const forward_list
<_Tp
, _Alloc
>& __lx
,
1465 const forward_list
<_Tp
, _Alloc
>& __ly
)
1466 { return !(__ly
< __lx
); }
1468 /// See std::forward_list::swap().
1469 template<typename _Tp
, typename _Alloc
>
1471 swap(forward_list
<_Tp
, _Alloc
>& __lx
,
1472 forward_list
<_Tp
, _Alloc
>& __ly
)
1473 noexcept(noexcept(__lx
.swap(__ly
)))
1474 { __lx
.swap(__ly
); }
1476 _GLIBCXX_END_NAMESPACE_CONTAINER
1477 _GLIBCXX_END_NAMESPACE_VERSION
1480 #endif // _FORWARD_LIST_H