libstdc++
forward_list.h
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00001 // <forward_list.h> -*- C++ -*-
00002 
00003 // Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 3, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /** @file bits/forward_list.h
00026  *  This is an internal header file, included by other library headers.
00027  *  Do not attempt to use it directly. @headername{forward_list}
00028  */
00029 
00030 #ifndef _FORWARD_LIST_H
00031 #define _FORWARD_LIST_H 1
00032 
00033 #pragma GCC system_header
00034 
00035 #include <memory>
00036 #ifdef __GXX_EXPERIMENTAL_CXX0X__
00037 #include <initializer_list>
00038 #endif
00039 
00040 namespace std _GLIBCXX_VISIBILITY(default)
00041 {
00042 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
00043 
00044   /**
00045    *  @brief  A helper basic node class for %forward_list.
00046    *          This is just a linked list with nothing inside it.
00047    *          There are purely list shuffling utility methods here.
00048    */
00049   struct _Fwd_list_node_base
00050   {
00051     _Fwd_list_node_base() : _M_next(0) { }
00052 
00053     _Fwd_list_node_base* _M_next;
00054 
00055     _Fwd_list_node_base*
00056     _M_transfer_after(_Fwd_list_node_base* __begin)
00057     {
00058       _Fwd_list_node_base* __end = __begin;
00059       while (__end && __end->_M_next)
00060     __end = __end->_M_next;
00061       return _M_transfer_after(__begin, __end);
00062     }
00063 
00064     _Fwd_list_node_base*
00065     _M_transfer_after(_Fwd_list_node_base* __begin,
00066               _Fwd_list_node_base* __end)
00067     {
00068       _Fwd_list_node_base* __keep = __begin->_M_next;
00069       if (__end)
00070     {
00071       __begin->_M_next = __end->_M_next;
00072       __end->_M_next = _M_next;
00073     }
00074       else
00075     __begin->_M_next = 0;
00076       _M_next = __keep;
00077       return __end;
00078     }
00079 
00080     void
00081     _M_reverse_after() noexcept
00082     {
00083       _Fwd_list_node_base* __tail = _M_next;
00084       if (!__tail)
00085     return;
00086       while (_Fwd_list_node_base* __temp = __tail->_M_next)
00087     {
00088       _Fwd_list_node_base* __keep = _M_next;
00089       _M_next = __temp;
00090       __tail->_M_next = __temp->_M_next;
00091       _M_next->_M_next = __keep;
00092     }
00093     }
00094   };
00095 
00096   /**
00097    *  @brief  A helper node class for %forward_list.
00098    *          This is just a linked list with a data value in each node.
00099    *          There is a sorting utility method.
00100    */
00101   template<typename _Tp>
00102     struct _Fwd_list_node
00103     : public _Fwd_list_node_base
00104     {
00105       template<typename... _Args>
00106         _Fwd_list_node(_Args&&... __args)
00107         : _Fwd_list_node_base(), 
00108           _M_value(std::forward<_Args>(__args)...) { }
00109 
00110       _Tp _M_value;
00111     };
00112 
00113   /**
00114    *   @brief A forward_list::iterator.
00115    * 
00116    *   All the functions are op overloads.
00117    */
00118   template<typename _Tp>
00119     struct _Fwd_list_iterator
00120     {
00121       typedef _Fwd_list_iterator<_Tp>            _Self;
00122       typedef _Fwd_list_node<_Tp>                _Node;
00123 
00124       typedef _Tp                                value_type;
00125       typedef _Tp*                               pointer;
00126       typedef _Tp&                               reference;
00127       typedef ptrdiff_t                          difference_type;
00128       typedef std::forward_iterator_tag          iterator_category;
00129 
00130       _Fwd_list_iterator()
00131       : _M_node() { }
00132 
00133       explicit
00134       _Fwd_list_iterator(_Fwd_list_node_base* __n) 
00135       : _M_node(__n) { }
00136 
00137       reference
00138       operator*() const
00139       { return static_cast<_Node*>(this->_M_node)->_M_value; }
00140 
00141       pointer
00142       operator->() const
00143       { return std::__addressof(static_cast<_Node*>
00144                 (this->_M_node)->_M_value); }
00145 
00146       _Self&
00147       operator++()
00148       {
00149         _M_node = _M_node->_M_next;
00150         return *this;
00151       }
00152 
00153       _Self
00154       operator++(int)
00155       {
00156         _Self __tmp(*this);
00157         _M_node = _M_node->_M_next;
00158         return __tmp;
00159       }
00160 
00161       bool
00162       operator==(const _Self& __x) const
00163       { return _M_node == __x._M_node; }
00164 
00165       bool
00166       operator!=(const _Self& __x) const
00167       { return _M_node != __x._M_node; }
00168 
00169       _Self
00170       _M_next() const
00171       {
00172         if (_M_node)
00173           return _Fwd_list_iterator(_M_node->_M_next);
00174         else
00175           return _Fwd_list_iterator(0);
00176       }
00177 
00178       _Fwd_list_node_base* _M_node;
00179     };
00180 
00181   /**
00182    *   @brief A forward_list::const_iterator.
00183    * 
00184    *   All the functions are op overloads.
00185    */
00186   template<typename _Tp>
00187     struct _Fwd_list_const_iterator
00188     {
00189       typedef _Fwd_list_const_iterator<_Tp>      _Self;
00190       typedef const _Fwd_list_node<_Tp>          _Node;
00191       typedef _Fwd_list_iterator<_Tp>            iterator;
00192 
00193       typedef _Tp                                value_type;
00194       typedef const _Tp*                         pointer;
00195       typedef const _Tp&                         reference;
00196       typedef ptrdiff_t                          difference_type;
00197       typedef std::forward_iterator_tag          iterator_category;
00198 
00199       _Fwd_list_const_iterator()
00200       : _M_node() { }
00201 
00202       explicit
00203       _Fwd_list_const_iterator(const _Fwd_list_node_base* __n) 
00204       : _M_node(__n) { }
00205 
00206       _Fwd_list_const_iterator(const iterator& __iter)
00207       : _M_node(__iter._M_node) { }
00208 
00209       reference
00210       operator*() const
00211       { return static_cast<_Node*>(this->_M_node)->_M_value; }
00212 
00213       pointer
00214       operator->() const
00215       { return std::__addressof(static_cast<_Node*>
00216                 (this->_M_node)->_M_value); }
00217 
00218       _Self&
00219       operator++()
00220       {
00221         _M_node = _M_node->_M_next;
00222         return *this;
00223       }
00224 
00225       _Self
00226       operator++(int)
00227       {
00228         _Self __tmp(*this);
00229         _M_node = _M_node->_M_next;
00230         return __tmp;
00231       }
00232 
00233       bool
00234       operator==(const _Self& __x) const
00235       { return _M_node == __x._M_node; }
00236 
00237       bool
00238       operator!=(const _Self& __x) const
00239       { return _M_node != __x._M_node; }
00240 
00241       _Self
00242       _M_next() const
00243       {
00244         if (this->_M_node)
00245           return _Fwd_list_const_iterator(_M_node->_M_next);
00246         else
00247           return _Fwd_list_const_iterator(0);
00248       }
00249 
00250       const _Fwd_list_node_base* _M_node;
00251     };
00252 
00253   /**
00254    *  @brief  Forward list iterator equality comparison.
00255    */
00256   template<typename _Tp>
00257     inline bool
00258     operator==(const _Fwd_list_iterator<_Tp>& __x,
00259                const _Fwd_list_const_iterator<_Tp>& __y)
00260     { return __x._M_node == __y._M_node; }
00261 
00262   /**
00263    *  @brief  Forward list iterator inequality comparison.
00264    */
00265   template<typename _Tp>
00266     inline bool
00267     operator!=(const _Fwd_list_iterator<_Tp>& __x,
00268                const _Fwd_list_const_iterator<_Tp>& __y)
00269     { return __x._M_node != __y._M_node; }
00270 
00271   /**
00272    *  @brief  Base class for %forward_list.
00273    */
00274   template<typename _Tp, typename _Alloc>
00275     struct _Fwd_list_base
00276     {
00277     protected:
00278       typedef typename _Alloc::template rebind<_Tp>::other _Tp_alloc_type;
00279 
00280       typedef typename _Alloc::template 
00281         rebind<_Fwd_list_node<_Tp>>::other _Node_alloc_type;
00282 
00283       struct _Fwd_list_impl 
00284       : public _Node_alloc_type
00285       {
00286         _Fwd_list_node_base _M_head;
00287 
00288         _Fwd_list_impl()
00289         : _Node_alloc_type(), _M_head()
00290         { }
00291 
00292         _Fwd_list_impl(const _Node_alloc_type& __a)
00293         : _Node_alloc_type(__a), _M_head()
00294         { }
00295 
00296         _Fwd_list_impl(_Node_alloc_type&& __a)
00297     : _Node_alloc_type(std::move(__a)), _M_head()
00298         { }
00299       };
00300 
00301       _Fwd_list_impl _M_impl;
00302 
00303     public:
00304       typedef _Fwd_list_iterator<_Tp>                 iterator;
00305       typedef _Fwd_list_const_iterator<_Tp>           const_iterator;
00306       typedef _Fwd_list_node<_Tp>                     _Node;
00307 
00308       _Node_alloc_type&
00309       _M_get_Node_allocator() noexcept
00310       { return *static_cast<_Node_alloc_type*>(&this->_M_impl); }
00311 
00312       const _Node_alloc_type&
00313       _M_get_Node_allocator() const noexcept
00314       { return *static_cast<const _Node_alloc_type*>(&this->_M_impl); }
00315 
00316       _Fwd_list_base()
00317       : _M_impl() { }
00318 
00319       _Fwd_list_base(const _Node_alloc_type& __a)
00320       : _M_impl(__a) { }
00321 
00322       _Fwd_list_base(const _Fwd_list_base& __lst, const _Node_alloc_type& __a);
00323 
00324       _Fwd_list_base(_Fwd_list_base&& __lst, const _Node_alloc_type& __a)
00325       : _M_impl(__a)
00326       {
00327     this->_M_impl._M_head._M_next = __lst._M_impl._M_head._M_next;
00328     __lst._M_impl._M_head._M_next = 0;
00329       }
00330 
00331       _Fwd_list_base(_Fwd_list_base&& __lst)
00332       : _M_impl(std::move(__lst._M_get_Node_allocator()))
00333       {
00334     this->_M_impl._M_head._M_next = __lst._M_impl._M_head._M_next;
00335     __lst._M_impl._M_head._M_next = 0;
00336       }
00337 
00338       ~_Fwd_list_base()
00339       { _M_erase_after(&_M_impl._M_head, 0); }
00340 
00341     protected:
00342 
00343       _Node*
00344       _M_get_node()
00345       { return _M_get_Node_allocator().allocate(1); }
00346 
00347       template<typename... _Args>
00348         _Node*
00349         _M_create_node(_Args&&... __args)
00350         {
00351           _Node* __node = this->_M_get_node();
00352           __try
00353             {
00354               _M_get_Node_allocator().construct(__node,
00355                                               std::forward<_Args>(__args)...);
00356               __node->_M_next = 0;
00357             }
00358           __catch(...)
00359             {
00360               this->_M_put_node(__node);
00361               __throw_exception_again;
00362             }
00363           return __node;
00364         }
00365 
00366       template<typename... _Args>
00367         _Fwd_list_node_base*
00368         _M_insert_after(const_iterator __pos, _Args&&... __args);
00369 
00370       void
00371       _M_put_node(_Node* __p)
00372       { _M_get_Node_allocator().deallocate(__p, 1); }
00373 
00374       _Fwd_list_node_base*
00375       _M_erase_after(_Fwd_list_node_base* __pos);
00376 
00377       _Fwd_list_node_base*
00378       _M_erase_after(_Fwd_list_node_base* __pos, 
00379                      _Fwd_list_node_base* __last);
00380     };
00381 
00382   /**
00383    *  @brief A standard container with linear time access to elements,
00384    *  and fixed time insertion/deletion at any point in the sequence.
00385    *
00386    *  @ingroup sequences
00387    *
00388    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
00389    *  <a href="tables.html#67">sequence</a>, including the
00390    *  <a href="tables.html#68">optional sequence requirements</a> with the
00391    *  %exception of @c at and @c operator[].
00392    *
00393    *  This is a @e singly @e linked %list.  Traversal up the
00394    *  %list requires linear time, but adding and removing elements (or
00395    *  @e nodes) is done in constant time, regardless of where the
00396    *  change takes place.  Unlike std::vector and std::deque,
00397    *  random-access iterators are not provided, so subscripting ( @c
00398    *  [] ) access is not allowed.  For algorithms which only need
00399    *  sequential access, this lack makes no difference.
00400    *
00401    *  Also unlike the other standard containers, std::forward_list provides
00402    *  specialized algorithms %unique to linked lists, such as
00403    *  splicing, sorting, and in-place reversal.
00404    *
00405    *  A couple points on memory allocation for forward_list<Tp>:
00406    *
00407    *  First, we never actually allocate a Tp, we allocate
00408    *  Fwd_list_node<Tp>'s and trust [20.1.5]/4 to DTRT.  This is to ensure
00409    *  that after elements from %forward_list<X,Alloc1> are spliced into
00410    *  %forward_list<X,Alloc2>, destroying the memory of the second %list is a
00411    *  valid operation, i.e., Alloc1 giveth and Alloc2 taketh away.
00412    */
00413   template<typename _Tp, typename _Alloc = allocator<_Tp> >
00414     class forward_list : private _Fwd_list_base<_Tp, _Alloc>
00415     {
00416     private:
00417       typedef _Fwd_list_base<_Tp, _Alloc>                  _Base;
00418       typedef _Fwd_list_node<_Tp>                          _Node;
00419       typedef _Fwd_list_node_base                          _Node_base;
00420       typedef typename _Base::_Tp_alloc_type               _Tp_alloc_type;
00421       typedef typename _Base::_Node_alloc_type             _Node_alloc_type;
00422 
00423     public:
00424       // types:
00425       typedef _Tp                                          value_type;
00426       typedef typename _Tp_alloc_type::pointer             pointer;
00427       typedef typename _Tp_alloc_type::const_pointer       const_pointer;
00428       typedef typename _Tp_alloc_type::reference           reference;
00429       typedef typename _Tp_alloc_type::const_reference     const_reference;
00430  
00431       typedef _Fwd_list_iterator<_Tp>                      iterator;
00432       typedef _Fwd_list_const_iterator<_Tp>                const_iterator;
00433       typedef std::size_t                                  size_type;
00434       typedef std::ptrdiff_t                               difference_type;
00435       typedef _Alloc                                       allocator_type;
00436 
00437       // 23.2.3.1 construct/copy/destroy:
00438 
00439       /**
00440        *  @brief  Creates a %forward_list with no elements.
00441        *  @param  __al  An allocator object.
00442        */
00443       explicit
00444       forward_list(const _Alloc& __al = _Alloc())
00445       : _Base(_Node_alloc_type(__al))
00446       { }
00447 
00448       /**
00449        *  @brief  Copy constructor with allocator argument.
00450        *  @param  __list  Input list to copy.
00451        *  @param  __al    An allocator object.
00452        */
00453       forward_list(const forward_list& __list, const _Alloc& __al)
00454       : _Base(__list, _Node_alloc_type(__al))
00455       { }
00456 
00457       /**
00458        *  @brief  Move constructor with allocator argument.
00459        *  @param  __list  Input list to move.
00460        *  @param  __al    An allocator object.
00461        */
00462       forward_list(forward_list&& __list, const _Alloc& __al)
00463       : _Base(std::move(__list), _Node_alloc_type(__al))
00464       { }
00465 
00466       /**
00467        *  @brief  Creates a %forward_list with default constructed elements.
00468        *  @param  __n  The number of elements to initially create.
00469        *
00470        *  This constructor creates the %forward_list with @a __n default
00471        *  constructed elements.
00472        */
00473       explicit
00474       forward_list(size_type __n)
00475       : _Base()
00476       { _M_default_initialize(__n); }
00477 
00478       /**
00479        *  @brief  Creates a %forward_list with copies of an exemplar element.
00480        *  @param  __n      The number of elements to initially create.
00481        *  @param  __value  An element to copy.
00482        *  @param  __al     An allocator object.
00483        *
00484        *  This constructor fills the %forward_list with @a __n copies of
00485        *  @a __value.
00486        */
00487       forward_list(size_type __n, const _Tp& __value,
00488                    const _Alloc& __al = _Alloc())
00489       : _Base(_Node_alloc_type(__al))
00490       { _M_fill_initialize(__n, __value); }
00491 
00492       /**
00493        *  @brief  Builds a %forward_list from a range.
00494        *  @param  __first  An input iterator.
00495        *  @param  __last   An input iterator.
00496        *  @param  __al     An allocator object.
00497        *
00498        *  Create a %forward_list consisting of copies of the elements from
00499        *  [@a __first,@a __last).  This is linear in N (where N is
00500        *  distance(@a __first,@a __last)).
00501        */
00502       template<typename _InputIterator>
00503         forward_list(_InputIterator __first, _InputIterator __last,
00504                      const _Alloc& __al = _Alloc())
00505     : _Base(_Node_alloc_type(__al))
00506         {
00507           // Check whether it's an integral type.  If so, it's not an iterator.
00508           typedef typename std::__is_integer<_InputIterator>::__type _Integral;
00509           _M_initialize_dispatch(__first, __last, _Integral());
00510         }
00511 
00512       /**
00513        *  @brief  The %forward_list copy constructor.
00514        *  @param  __list  A %forward_list of identical element and allocator
00515        *                types.
00516        *
00517        *  The newly-created %forward_list uses a copy of the allocation
00518        *  object used by @a __list.
00519        */
00520       forward_list(const forward_list& __list)
00521       : _Base(__list._M_get_Node_allocator())
00522       { _M_initialize_dispatch(__list.begin(), __list.end(), __false_type()); }
00523 
00524       /**
00525        *  @brief  The %forward_list move constructor.
00526        *  @param  __list  A %forward_list of identical element and allocator
00527        *                types.
00528        *
00529        *  The newly-created %forward_list contains the exact contents of @a
00530        *  forward_list. The contents of @a __list are a valid, but unspecified
00531        *  %forward_list.
00532        */
00533       forward_list(forward_list&& __list) noexcept
00534       : _Base(std::move(__list)) { }
00535 
00536       /**
00537        *  @brief  Builds a %forward_list from an initializer_list
00538        *  @param  __il  An initializer_list of value_type.
00539        *  @param  __al  An allocator object.
00540        *
00541        *  Create a %forward_list consisting of copies of the elements
00542        *  in the initializer_list @a __il.  This is linear in __il.size().
00543        */
00544       forward_list(std::initializer_list<_Tp> __il,
00545                    const _Alloc& __al = _Alloc())
00546       : _Base(_Node_alloc_type(__al))
00547       { _M_initialize_dispatch(__il.begin(), __il.end(), __false_type()); }
00548 
00549       /**
00550        *  @brief  The forward_list dtor.
00551        */
00552       ~forward_list() noexcept
00553       { }
00554 
00555       /**
00556        *  @brief  The %forward_list assignment operator.
00557        *  @param  __list  A %forward_list of identical element and allocator
00558        *                types.
00559        *
00560        *  All the elements of @a __list are copied, but unlike the copy
00561        *  constructor, the allocator object is not copied.
00562        */
00563       forward_list&
00564       operator=(const forward_list& __list);
00565 
00566       /**
00567        *  @brief  The %forward_list move assignment operator.
00568        *  @param  __list  A %forward_list of identical element and allocator
00569        *                types.
00570        *
00571        *  The contents of @a __list are moved into this %forward_list
00572        *  (without copying). @a __list is a valid, but unspecified
00573        *  %forward_list
00574        */
00575       forward_list&
00576       operator=(forward_list&& __list)
00577       {
00578     // NB: DR 1204.
00579     // NB: DR 675.
00580     this->clear();
00581     this->swap(__list);
00582     return *this;
00583       }
00584 
00585       /**
00586        *  @brief  The %forward_list initializer list assignment operator.
00587        *  @param  __il  An initializer_list of value_type.
00588        *
00589        *  Replace the contents of the %forward_list with copies of the
00590        *  elements in the initializer_list @a __il.  This is linear in
00591        *  __il.size().
00592        */
00593       forward_list&
00594       operator=(std::initializer_list<_Tp> __il)
00595       {
00596         assign(__il);
00597         return *this;
00598       }
00599 
00600       /**
00601        *  @brief  Assigns a range to a %forward_list.
00602        *  @param  __first  An input iterator.
00603        *  @param  __last   An input iterator.
00604        *
00605        *  This function fills a %forward_list with copies of the elements
00606        *  in the range [@a __first,@a __last).
00607        *
00608        *  Note that the assignment completely changes the %forward_list and
00609        *  that the resulting %forward_list's size is the same as the number
00610        *  of elements assigned.  Old data may be lost.
00611        */
00612       template<typename _InputIterator>
00613         void
00614         assign(_InputIterator __first, _InputIterator __last)
00615         {
00616           clear();
00617           insert_after(cbefore_begin(), __first, __last);
00618         }
00619 
00620       /**
00621        *  @brief  Assigns a given value to a %forward_list.
00622        *  @param  __n  Number of elements to be assigned.
00623        *  @param  __val  Value to be assigned.
00624        *
00625        *  This function fills a %forward_list with @a __n copies of the given
00626        *  value.  Note that the assignment completely changes the
00627        *  %forward_list and that the resulting %forward_list's size is the
00628        *  same as the number of elements assigned.  Old data may be lost.
00629        */
00630       void
00631       assign(size_type __n, const _Tp& __val)
00632       {
00633         clear();
00634         insert_after(cbefore_begin(), __n, __val);
00635       }
00636 
00637       /**
00638        *  @brief  Assigns an initializer_list to a %forward_list.
00639        *  @param  __il  An initializer_list of value_type.
00640        *
00641        *  Replace the contents of the %forward_list with copies of the
00642        *  elements in the initializer_list @a __il.  This is linear in
00643        *  il.size().
00644        */
00645       void
00646       assign(std::initializer_list<_Tp> __il)
00647       {
00648         clear();
00649         insert_after(cbefore_begin(), __il);
00650       }
00651 
00652       /// Get a copy of the memory allocation object.
00653       allocator_type
00654       get_allocator() const noexcept
00655       { return allocator_type(this->_M_get_Node_allocator()); }
00656 
00657       // 23.2.3.2 iterators:
00658 
00659       /**
00660        *  Returns a read/write iterator that points before the first element
00661        *  in the %forward_list.  Iteration is done in ordinary element order.
00662        */
00663       iterator
00664       before_begin() noexcept
00665       { return iterator(&this->_M_impl._M_head); }
00666 
00667       /**
00668        *  Returns a read-only (constant) iterator that points before the
00669        *  first element in the %forward_list.  Iteration is done in ordinary
00670        *  element order.
00671        */
00672       const_iterator
00673       before_begin() const noexcept
00674       { return const_iterator(&this->_M_impl._M_head); }
00675 
00676       /**
00677        *  Returns a read/write iterator that points to the first element
00678        *  in the %forward_list.  Iteration is done in ordinary element order.
00679        */
00680       iterator
00681       begin() noexcept
00682       { return iterator(this->_M_impl._M_head._M_next); }
00683 
00684       /**
00685        *  Returns a read-only (constant) iterator that points to the first
00686        *  element in the %forward_list.  Iteration is done in ordinary
00687        *  element order.
00688        */
00689       const_iterator
00690       begin() const noexcept
00691       { return const_iterator(this->_M_impl._M_head._M_next); }
00692 
00693       /**
00694        *  Returns a read/write iterator that points one past the last
00695        *  element in the %forward_list.  Iteration is done in ordinary
00696        *  element order.
00697        */
00698       iterator
00699       end() noexcept
00700       { return iterator(0); }
00701 
00702       /**
00703        *  Returns a read-only iterator that points one past the last
00704        *  element in the %forward_list.  Iteration is done in ordinary
00705        *  element order.
00706        */
00707       const_iterator
00708       end() const noexcept
00709       { return const_iterator(0); }
00710 
00711       /**
00712        *  Returns a read-only (constant) iterator that points to the
00713        *  first element in the %forward_list.  Iteration is done in ordinary
00714        *  element order.
00715        */
00716       const_iterator
00717       cbegin() const noexcept
00718       { return const_iterator(this->_M_impl._M_head._M_next); }
00719 
00720       /**
00721        *  Returns a read-only (constant) iterator that points before the
00722        *  first element in the %forward_list.  Iteration is done in ordinary
00723        *  element order.
00724        */
00725       const_iterator
00726       cbefore_begin() const noexcept
00727       { return const_iterator(&this->_M_impl._M_head); }
00728 
00729       /**
00730        *  Returns a read-only (constant) iterator that points one past
00731        *  the last element in the %forward_list.  Iteration is done in
00732        *  ordinary element order.
00733        */
00734       const_iterator
00735       cend() const noexcept
00736       { return const_iterator(0); }
00737 
00738       /**
00739        *  Returns true if the %forward_list is empty.  (Thus begin() would
00740        *  equal end().)
00741        */
00742       bool
00743       empty() const noexcept
00744       { return this->_M_impl._M_head._M_next == 0; }
00745 
00746       /**
00747        *  Returns the largest possible size of %forward_list.
00748        */
00749       size_type
00750       max_size() const noexcept
00751       { return this->_M_get_Node_allocator().max_size(); }
00752 
00753       // 23.2.3.3 element access:
00754 
00755       /**
00756        *  Returns a read/write reference to the data at the first
00757        *  element of the %forward_list.
00758        */
00759       reference
00760       front()
00761       {
00762         _Node* __front = static_cast<_Node*>(this->_M_impl._M_head._M_next);
00763         return __front->_M_value;
00764       }
00765 
00766       /**
00767        *  Returns a read-only (constant) reference to the data at the first
00768        *  element of the %forward_list.
00769        */
00770       const_reference
00771       front() const
00772       {
00773         _Node* __front = static_cast<_Node*>(this->_M_impl._M_head._M_next);
00774         return __front->_M_value;
00775       }
00776 
00777       // 23.2.3.4 modiļ¬ers:
00778 
00779       /**
00780        *  @brief  Constructs object in %forward_list at the front of the
00781        *          list.
00782        *  @param  __args  Arguments.
00783        *
00784        *  This function will insert an object of type Tp constructed
00785        *  with Tp(std::forward<Args>(args)...) at the front of the list
00786        *  Due to the nature of a %forward_list this operation can
00787        *  be done in constant time, and does not invalidate iterators
00788        *  and references.
00789        */
00790       template<typename... _Args>
00791         void
00792         emplace_front(_Args&&... __args)
00793         { this->_M_insert_after(cbefore_begin(),
00794                                 std::forward<_Args>(__args)...); }
00795 
00796       /**
00797        *  @brief  Add data to the front of the %forward_list.
00798        *  @param  __val  Data to be added.
00799        *
00800        *  This is a typical stack operation.  The function creates an
00801        *  element at the front of the %forward_list and assigns the given
00802        *  data to it.  Due to the nature of a %forward_list this operation
00803        *  can be done in constant time, and does not invalidate iterators
00804        *  and references.
00805        */
00806       void
00807       push_front(const _Tp& __val)
00808       { this->_M_insert_after(cbefore_begin(), __val); }
00809 
00810       /**
00811        *
00812        */
00813       void
00814       push_front(_Tp&& __val)
00815       { this->_M_insert_after(cbefore_begin(), std::move(__val)); }
00816 
00817       /**
00818        *  @brief  Removes first element.
00819        *
00820        *  This is a typical stack operation.  It shrinks the %forward_list
00821        *  by one.  Due to the nature of a %forward_list this operation can
00822        *  be done in constant time, and only invalidates iterators/references
00823        *  to the element being removed.
00824        *
00825        *  Note that no data is returned, and if the first element's data
00826        *  is needed, it should be retrieved before pop_front() is
00827        *  called.
00828        */
00829       void
00830       pop_front()
00831       { this->_M_erase_after(&this->_M_impl._M_head); }
00832 
00833       /**
00834        *  @brief  Constructs object in %forward_list after the specified
00835        *          iterator.
00836        *  @param  __pos  A const_iterator into the %forward_list.
00837        *  @param  __args  Arguments.
00838        *  @return  An iterator that points to the inserted data.
00839        *
00840        *  This function will insert an object of type T constructed
00841        *  with T(std::forward<Args>(args)...) after the specified
00842        *  location.  Due to the nature of a %forward_list this operation can
00843        *  be done in constant time, and does not invalidate iterators
00844        *  and references.
00845        */
00846       template<typename... _Args>
00847         iterator
00848         emplace_after(const_iterator __pos, _Args&&... __args)
00849         { return iterator(this->_M_insert_after(__pos,
00850                                           std::forward<_Args>(__args)...)); }
00851 
00852       /**
00853        *  @brief  Inserts given value into %forward_list after specified
00854        *          iterator.
00855        *  @param  __pos  An iterator into the %forward_list.
00856        *  @param  __val  Data to be inserted.
00857        *  @return  An iterator that points to the inserted data.
00858        *
00859        *  This function will insert a copy of the given value after
00860        *  the specified location.  Due to the nature of a %forward_list this
00861        *  operation can be done in constant time, and does not
00862        *  invalidate iterators and references.
00863        */
00864       iterator
00865       insert_after(const_iterator __pos, const _Tp& __val)
00866       { return iterator(this->_M_insert_after(__pos, __val)); }
00867 
00868       /**
00869        *
00870        */
00871       iterator
00872       insert_after(const_iterator __pos, _Tp&& __val)
00873       { return iterator(this->_M_insert_after(__pos, std::move(__val))); }
00874 
00875       /**
00876        *  @brief  Inserts a number of copies of given data into the
00877        *          %forward_list.
00878        *  @param  __pos  An iterator into the %forward_list.
00879        *  @param  __n  Number of elements to be inserted.
00880        *  @param  __val  Data to be inserted.
00881        *  @return  An iterator pointing to the last inserted copy of
00882        *           @a val or @a pos if @a n == 0.
00883        *
00884        *  This function will insert a specified number of copies of the
00885        *  given data after the location specified by @a pos.
00886        *
00887        *  This operation is linear in the number of elements inserted and
00888        *  does not invalidate iterators and references.
00889        */
00890       iterator
00891       insert_after(const_iterator __pos, size_type __n, const _Tp& __val);
00892 
00893       /**
00894        *  @brief  Inserts a range into the %forward_list.
00895        *  @param  __pos  An iterator into the %forward_list.
00896        *  @param  __first  An input iterator.
00897        *  @param  __last   An input iterator.
00898        *  @return  An iterator pointing to the last inserted element or
00899        *           @a __pos if @a __first == @a __last.
00900        *
00901        *  This function will insert copies of the data in the range
00902        *  [@a __first,@a __last) into the %forward_list after the
00903        *  location specified by @a __pos.
00904        *
00905        *  This operation is linear in the number of elements inserted and
00906        *  does not invalidate iterators and references.
00907        */
00908       template<typename _InputIterator>
00909         iterator
00910         insert_after(const_iterator __pos,
00911                      _InputIterator __first, _InputIterator __last);
00912 
00913       /**
00914        *  @brief  Inserts the contents of an initializer_list into
00915        *          %forward_list after the specified iterator.
00916        *  @param  __pos  An iterator into the %forward_list.
00917        *  @param  __il  An initializer_list of value_type.
00918        *  @return  An iterator pointing to the last inserted element
00919        *           or @a __pos if @a __il is empty.
00920        *
00921        *  This function will insert copies of the data in the
00922        *  initializer_list @a __il into the %forward_list before the location
00923        *  specified by @a __pos.
00924        *
00925        *  This operation is linear in the number of elements inserted and
00926        *  does not invalidate iterators and references.
00927        */
00928       iterator
00929       insert_after(const_iterator __pos, std::initializer_list<_Tp> __il);
00930 
00931       /**
00932        *  @brief  Removes the element pointed to by the iterator following
00933        *          @c pos.
00934        *  @param  __pos  Iterator pointing before element to be erased.
00935        *  @return  An iterator pointing to the element following the one
00936        *           that was erased, or end() if no such element exists.
00937        *
00938        *  This function will erase the element at the given position and
00939        *  thus shorten the %forward_list by one.
00940        *
00941        *  Due to the nature of a %forward_list this operation can be done
00942        *  in constant time, and only invalidates iterators/references to
00943        *  the element being removed.  The user is also cautioned that
00944        *  this function only erases the element, and that if the element
00945        *  is itself a pointer, the pointed-to memory is not touched in
00946        *  any way.  Managing the pointer is the user's responsibility.
00947        */
00948       iterator
00949       erase_after(const_iterator __pos)
00950       { return iterator(this->_M_erase_after(const_cast<_Node_base*>
00951                          (__pos._M_node))); }
00952 
00953       /**
00954        *  @brief  Remove a range of elements.
00955        *  @param  __pos  Iterator pointing before the first element to be
00956        *                 erased.
00957        *  @param  __last  Iterator pointing to one past the last element to be
00958        *                  erased.
00959        *  @return  @ __last.
00960        *
00961        *  This function will erase the elements in the range
00962        *  @a (__pos,__last) and shorten the %forward_list accordingly.
00963        *
00964        *  This operation is linear time in the size of the range and only
00965        *  invalidates iterators/references to the element being removed.
00966        *  The user is also cautioned that this function only erases the
00967        *  elements, and that if the elements themselves are pointers, the
00968        *  pointed-to memory is not touched in any way.  Managing the pointer
00969        *  is the user's responsibility.
00970        */
00971       iterator
00972       erase_after(const_iterator __pos, const_iterator __last)
00973       { return iterator(this->_M_erase_after(const_cast<_Node_base*>
00974                          (__pos._M_node),
00975                          const_cast<_Node_base*>
00976                          (__last._M_node))); }
00977 
00978       /**
00979        *  @brief  Swaps data with another %forward_list.
00980        *  @param  __list  A %forward_list of the same element and allocator
00981        *                  types.
00982        *
00983        *  This exchanges the elements between two lists in constant
00984        *  time.  Note that the global std::swap() function is
00985        *  specialized such that std::swap(l1,l2) will feed to this
00986        *  function.
00987        */
00988       void
00989       swap(forward_list& __list)
00990       { std::swap(this->_M_impl._M_head._M_next,
00991           __list._M_impl._M_head._M_next); }
00992 
00993       /**
00994        *  @brief Resizes the %forward_list to the specified number of
00995        *         elements.
00996        *  @param __sz Number of elements the %forward_list should contain.
00997        *
00998        *  This function will %resize the %forward_list to the specified
00999        *  number of elements.  If the number is smaller than the
01000        *  %forward_list's current size the %forward_list is truncated,
01001        *  otherwise the %forward_list is extended and the new elements
01002        *  are default constructed.
01003        */
01004       void
01005       resize(size_type __sz);
01006 
01007       /**
01008        *  @brief Resizes the %forward_list to the specified number of
01009        *         elements.
01010        *  @param __sz Number of elements the %forward_list should contain.
01011        *  @param __val Data with which new elements should be populated.
01012        *
01013        *  This function will %resize the %forward_list to the specified
01014        *  number of elements.  If the number is smaller than the
01015        *  %forward_list's current size the %forward_list is truncated,
01016        *  otherwise the %forward_list is extended and new elements are
01017        *  populated with given data.
01018        */
01019       void
01020       resize(size_type __sz, const value_type& __val);
01021 
01022       /**
01023        *  @brief  Erases all the elements.
01024        *
01025        *  Note that this function only erases
01026        *  the elements, and that if the elements themselves are
01027        *  pointers, the pointed-to memory is not touched in any way.
01028        *  Managing the pointer is the user's responsibility.
01029        */
01030       void
01031       clear() noexcept
01032       { this->_M_erase_after(&this->_M_impl._M_head, 0); }
01033 
01034       // 23.2.3.5 forward_list operations:
01035 
01036       /**
01037        *  @brief  Insert contents of another %forward_list.
01038        *  @param  __pos  Iterator referencing the element to insert after.
01039        *  @param  __list  Source list.
01040        *
01041        *  The elements of @a list are inserted in constant time after
01042        *  the element referenced by @a pos.  @a list becomes an empty
01043        *  list.
01044        *
01045        *  Requires this != @a x.
01046        */
01047       void
01048       splice_after(const_iterator __pos, forward_list&& __list)
01049       {
01050     if (!__list.empty())
01051       _M_splice_after(__pos, std::move(__list));
01052       }
01053 
01054       /**
01055        *  @brief  Insert element from another %forward_list.
01056        *  @param  __pos  Iterator referencing the element to insert after.
01057        *  @param  __list  Source list.
01058        *  @param  __i   Iterator referencing the element before the element
01059        *                to move.
01060        *
01061        *  Removes the element in list @a list referenced by @a i and
01062        *  inserts it into the current list after @a pos.
01063        */
01064       void
01065       splice_after(const_iterator __pos, forward_list&& __list,
01066                    const_iterator __i)
01067       {
01068     const_iterator __j = __i;
01069     ++__j;
01070     if (__pos == __i || __pos == __j)
01071       return;
01072 
01073     splice_after(__pos, std::move(__list), __i, __j);
01074       }
01075 
01076       /**
01077        *  @brief  Insert range from another %forward_list.
01078        *  @param  __pos  Iterator referencing the element to insert after.
01079        *  @param  __list  Source list.
01080        *  @param  __before  Iterator referencing before the start of range
01081        *                    in list.
01082        *  @param  __last  Iterator referencing the end of range in list.
01083        *
01084        *  Removes elements in the range (__before,__last) and inserts them
01085        *  after @a __pos in constant time.
01086        *
01087        *  Undefined if @a __pos is in (__before,__last).
01088        */
01089       void
01090       splice_after(const_iterator __pos, forward_list&& __list,
01091                    const_iterator __before, const_iterator __last);
01092 
01093       /**
01094        *  @brief  Remove all elements equal to value.
01095        *  @param  __val  The value to remove.
01096        *
01097        *  Removes every element in the list equal to @a __val.
01098        *  Remaining elements stay in list order.  Note that this
01099        *  function only erases the elements, and that if the elements
01100        *  themselves are pointers, the pointed-to memory is not
01101        *  touched in any way.  Managing the pointer is the user's
01102        *  responsibility.
01103        */
01104       void
01105       remove(const _Tp& __val);
01106 
01107       /**
01108        *  @brief  Remove all elements satisfying a predicate.
01109        *  @param  __pred  Unary predicate function or object.
01110        *
01111        *  Removes every element in the list for which the predicate
01112        *  returns true.  Remaining elements stay in list order.  Note
01113        *  that this function only erases the elements, and that if the
01114        *  elements themselves are pointers, the pointed-to memory is
01115        *  not touched in any way.  Managing the pointer is the user's
01116        *  responsibility.
01117        */
01118       template<typename _Pred>
01119         void
01120         remove_if(_Pred __pred);
01121 
01122       /**
01123        *  @brief  Remove consecutive duplicate elements.
01124        *
01125        *  For each consecutive set of elements with the same value,
01126        *  remove all but the first one.  Remaining elements stay in
01127        *  list order.  Note that this function only erases the
01128        *  elements, and that if the elements themselves are pointers,
01129        *  the pointed-to memory is not touched in any way.  Managing
01130        *  the pointer is the user's responsibility.
01131        */
01132       void
01133       unique()
01134       { this->unique(std::equal_to<_Tp>()); }
01135 
01136       /**
01137        *  @brief  Remove consecutive elements satisfying a predicate.
01138        *  @param  __binary_pred  Binary predicate function or object.
01139        *
01140        *  For each consecutive set of elements [first,last) that
01141        *  satisfy predicate(first,i) where i is an iterator in
01142        *  [first,last), remove all but the first one.  Remaining
01143        *  elements stay in list order.  Note that this function only
01144        *  erases the elements, and that if the elements themselves are
01145        *  pointers, the pointed-to memory is not touched in any way.
01146        *  Managing the pointer is the user's responsibility.
01147        */
01148       template<typename _BinPred>
01149         void
01150         unique(_BinPred __binary_pred);
01151 
01152       /**
01153        *  @brief  Merge sorted lists.
01154        *  @param  __list  Sorted list to merge.
01155        *
01156        *  Assumes that both @a list and this list are sorted according to
01157        *  operator<().  Merges elements of @a __list into this list in
01158        *  sorted order, leaving @a __list empty when complete.  Elements in
01159        *  this list precede elements in @a __list that are equal.
01160        */
01161       void
01162       merge(forward_list&& __list)
01163       { this->merge(std::move(__list), std::less<_Tp>()); }
01164 
01165       /**
01166        *  @brief  Merge sorted lists according to comparison function.
01167        *  @param  __list  Sorted list to merge.
01168        *  @param  __comp Comparison function defining sort order.
01169        *
01170        *  Assumes that both @a __list and this list are sorted according to
01171        *  comp.  Merges elements of @a __list into this list
01172        *  in sorted order, leaving @a __list empty when complete.  Elements
01173        *  in this list precede elements in @a __list that are equivalent
01174        *  according to comp().
01175        */
01176       template<typename _Comp>
01177         void
01178         merge(forward_list&& __list, _Comp __comp);
01179 
01180       /**
01181        *  @brief  Sort the elements of the list.
01182        *
01183        *  Sorts the elements of this list in NlogN time.  Equivalent
01184        *  elements remain in list order.
01185        */
01186       void
01187       sort()
01188       { this->sort(std::less<_Tp>()); }
01189 
01190       /**
01191        *  @brief  Sort the forward_list using a comparison function.
01192        *
01193        *  Sorts the elements of this list in NlogN time.  Equivalent
01194        *  elements remain in list order.
01195        */
01196       template<typename _Comp>
01197         void
01198         sort(_Comp __comp);
01199 
01200       /**
01201        *  @brief  Reverse the elements in list.
01202        *
01203        *  Reverse the order of elements in the list in linear time.
01204        */
01205       void
01206       reverse() noexcept
01207       { this->_M_impl._M_head._M_reverse_after(); }
01208 
01209     private:
01210       template<typename _Integer>
01211         void
01212         _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
01213         { _M_fill_initialize(static_cast<size_type>(__n), __x); }
01214 
01215       // Called by the range constructor to implement [23.1.1]/9
01216       template<typename _InputIterator>
01217         void
01218         _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
01219                                __false_type);
01220 
01221       // Called by forward_list(n,v,a), and the range constructor when it
01222       // turns out to be the same thing.
01223       void
01224       _M_fill_initialize(size_type __n, const value_type& __value);
01225 
01226       // Called by splice_after and insert_after.
01227       iterator
01228       _M_splice_after(const_iterator __pos, forward_list&& __list);
01229 
01230       // Called by forward_list(n).
01231       void
01232       _M_default_initialize(size_type __n);
01233 
01234       // Called by resize(sz).
01235       void
01236       _M_default_insert_after(const_iterator __pos, size_type __n);
01237     };
01238 
01239   /**
01240    *  @brief  Forward list equality comparison.
01241    *  @param  __lx  A %forward_list
01242    *  @param  __ly  A %forward_list of the same type as @a __lx.
01243    *  @return  True iff the size and elements of the forward lists are equal.
01244    *
01245    *  This is an equivalence relation.  It is linear in the size of the
01246    *  forward lists.  Deques are considered equivalent if corresponding
01247    *  elements compare equal.
01248    */
01249   template<typename _Tp, typename _Alloc>
01250     bool
01251     operator==(const forward_list<_Tp, _Alloc>& __lx,
01252                const forward_list<_Tp, _Alloc>& __ly);
01253 
01254   /**
01255    *  @brief  Forward list ordering relation.
01256    *  @param  __lx  A %forward_list.
01257    *  @param  __ly  A %forward_list of the same type as @a __lx.
01258    *  @return  True iff @a __lx is lexicographically less than @a __ly.
01259    *
01260    *  This is a total ordering relation.  It is linear in the size of the
01261    *  forward lists.  The elements must be comparable with @c <.
01262    *
01263    *  See std::lexicographical_compare() for how the determination is made.
01264    */
01265   template<typename _Tp, typename _Alloc>
01266     inline bool
01267     operator<(const forward_list<_Tp, _Alloc>& __lx,
01268               const forward_list<_Tp, _Alloc>& __ly)
01269     { return std::lexicographical_compare(__lx.cbegin(), __lx.cend(),
01270                       __ly.cbegin(), __ly.cend()); }
01271 
01272   /// Based on operator==
01273   template<typename _Tp, typename _Alloc>
01274     inline bool
01275     operator!=(const forward_list<_Tp, _Alloc>& __lx,
01276                const forward_list<_Tp, _Alloc>& __ly)
01277     { return !(__lx == __ly); }
01278 
01279   /// Based on operator<
01280   template<typename _Tp, typename _Alloc>
01281     inline bool
01282     operator>(const forward_list<_Tp, _Alloc>& __lx,
01283               const forward_list<_Tp, _Alloc>& __ly)
01284     { return (__ly < __lx); }
01285 
01286   /// Based on operator<
01287   template<typename _Tp, typename _Alloc>
01288     inline bool
01289     operator>=(const forward_list<_Tp, _Alloc>& __lx,
01290                const forward_list<_Tp, _Alloc>& __ly)
01291     { return !(__lx < __ly); }
01292 
01293   /// Based on operator<
01294   template<typename _Tp, typename _Alloc>
01295     inline bool
01296     operator<=(const forward_list<_Tp, _Alloc>& __lx,
01297                const forward_list<_Tp, _Alloc>& __ly)
01298     { return !(__ly < __lx); }
01299 
01300   /// See std::forward_list::swap().
01301   template<typename _Tp, typename _Alloc>
01302     inline void
01303     swap(forward_list<_Tp, _Alloc>& __lx,
01304      forward_list<_Tp, _Alloc>& __ly)
01305     { __lx.swap(__ly); }
01306 
01307 _GLIBCXX_END_NAMESPACE_CONTAINER
01308 } // namespace std
01309 
01310 #endif // _FORWARD_LIST_H