# stl_list.h

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    00001 // List implementation -*- C++ -*-
    00002
    00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
    00004 // Free Software Foundation, Inc.
    00005 //
    00006 // This file is part of the GNU ISO C++ Library.  This library is free
    00007 // software; you can redistribute it and/or modify it under the
    00008 // terms of the GNU General Public License as published by the
    00009 // Free Software Foundation; either version 2, or (at your option)
    00010 // any later version.
    00011
    00012 // This library is distributed in the hope that it will be useful,
    00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015 // GNU General Public License for more details.
    00016
    00017 // You should have received a copy of the GNU General Public License along
    00018 // with this library; see the file COPYING.  If not, write to the Free
    00019 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
    00020 // USA.
    00021
    00022 // As a special exception, you may use this file as part of a free software
    00023 // library without restriction.  Specifically, if other files instantiate
    00024 // templates or use macros or inline functions from this file, or you compile
    00025 // this file and link it with other files to produce an executable, this
    00026 // file does not by itself cause the resulting executable to be covered by
    00027 // the GNU General Public License.  This exception does not however
    00028 // invalidate any other reasons why the executable file might be covered by
    00029 // the GNU General Public License.
    00030
    00031 /*
    00032  *
    00033  * Copyright (c) 1994
    00034  * Hewlett-Packard Company
    00035  *
    00036  * Permission to use, copy, modify, distribute and sell this software
    00037  * and its documentation for any purpose is hereby granted without fee,
    00038  * provided that the above copyright notice appear in all copies and
    00039  * that both that copyright notice and this permission notice appear
    00040  * in supporting documentation.  Hewlett-Packard Company makes no
    00041  * representations about the suitability of this software for any
    00042  * purpose.  It is provided "as is" without express or implied warranty.
    00043  *
    00044  *
    00045  * Copyright (c) 1996,1997
    00046  * Silicon Graphics Computer Systems, Inc.
    00047  *
    00048  * Permission to use, copy, modify, distribute and sell this software
    00049  * and its documentation for any purpose is hereby granted without fee,
    00050  * provided that the above copyright notice appear in all copies and
    00051  * that both that copyright notice and this permission notice appear
    00052  * in supporting documentation.  Silicon Graphics makes no
    00053  * representations about the suitability of this software for any
    00054  * purpose.  It is provided "as is" without express or implied warranty.
    00055  */
    00056
    00057 /** @file stl_list.h
    00058  *  This is an internal header file, included by other library headers.
    00059  *  You should not attempt to use it directly.
    00060  */
    00061
    00062 #ifndef _LIST_H
    00063 #define _LIST_H 1
    00064
    00065 #include <bits/concept_check.h>
    00066
    00067 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD)
    00068
    00069   // Supporting structures are split into common and templated types; the
    00070   // latter publicly inherits from the former in an effort to reduce code
    00071   // duplication.  This results in some "needless" static_cast'ing later on,
    00072   // but it's all safe downcasting.
    00073
    00074   /// @if maint Common part of a node in the %list.  @endif
    00075   struct _List_node_base
    00076   {
    00077     _List_node_base* _M_next;   ///< Self-explanatory
    00078     _List_node_base* _M_prev;   ///< Self-explanatory
    00079
    00080     static void
    00081     swap(_List_node_base& __x, _List_node_base& __y);
    00082
    00083     void
    00084     transfer(_List_node_base * const __first,
    00085          _List_node_base * const __last);
    00086
    00087     void
    00088     reverse();
    00089
    00090     void
    00091     hook(_List_node_base * const __position);
    00092
    00093     void
    00094     unhook();
    00095   };
    00096
    00097   /// @if maint An actual node in the %list.  @endif
    00098   template<typename _Tp>
    00099     struct _List_node : public _List_node_base
    00100     {
    00101       _Tp _M_data;                ///< User's data.
    00102     };
    00103
    00104   /**
    00105    *  @brief A list::iterator.
    00106    *
    00107    *  @if maint
    00108    *  All the functions are op overloads.
    00109    *  @endif
    00110   */
    00111   template<typename _Tp>
    00112     struct _List_iterator
    00113     {
    00114       typedef _List_iterator<_Tp>                _Self;
    00115       typedef _List_node<_Tp>                    _Node;
    00116
    00117       typedef ptrdiff_t                          difference_type;
    00118       typedef std::bidirectional_iterator_tag    iterator_category;
    00119       typedef _Tp                                value_type;
    00120       typedef _Tp*                               pointer;
    00121       typedef _Tp&                               reference;
    00122
    00123       _List_iterator()
    00124       : _M_node() { }
    00125
    00126       explicit
    00127       _List_iterator(_List_node_base* __x)
    00128       : _M_node(__x) { }
    00129
    00130       // Must downcast from List_node_base to _List_node to get to _M_data.
    00131       reference
    00132       operator*() const
    00133       { return static_cast<_Node*>(_M_node)->_M_data; }
    00134
    00135       pointer
    00136       operator->() const
    00137       { return &static_cast<_Node*>(_M_node)->_M_data; }
    00138
    00139       _Self&
    00140       operator++()
    00141       {
    00142     _M_node = _M_node->_M_next;
    00143     return *this;
    00144       }
    00145
    00146       _Self
    00147       operator++(int)
    00148       {
    00149     _Self __tmp = *this;
    00150     _M_node = _M_node->_M_next;
    00151     return __tmp;
    00152       }
    00153
    00154       _Self&
    00155       operator--()
    00156       {
    00157     _M_node = _M_node->_M_prev;
    00158     return *this;
    00159       }
    00160
    00161       _Self
    00162       operator--(int)
    00163       {
    00164     _Self __tmp = *this;
    00165     _M_node = _M_node->_M_prev;
    00166     return __tmp;
    00167       }
    00168
    00169       bool
    00170       operator==(const _Self& __x) const
    00171       { return _M_node == __x._M_node; }
    00172
    00173       bool
    00174       operator!=(const _Self& __x) const
    00175       { return _M_node != __x._M_node; }
    00176
    00177       // The only member points to the %list element.
    00178       _List_node_base* _M_node;
    00179     };
    00180
    00181   /**
    00182    *  @brief A list::const_iterator.
    00183    *
    00184    *  @if maint
    00185    *  All the functions are op overloads.
    00186    *  @endif
    00187   */
    00188   template<typename _Tp>
    00189     struct _List_const_iterator
    00190     {
    00191       typedef _List_const_iterator<_Tp>          _Self;
    00192       typedef const _List_node<_Tp>              _Node;
    00193       typedef _List_iterator<_Tp>                iterator;
    00194
    00195       typedef ptrdiff_t                          difference_type;
    00196       typedef std::bidirectional_iterator_tag    iterator_category;
    00197       typedef _Tp                                value_type;
    00198       typedef const _Tp*                         pointer;
    00199       typedef const _Tp&                         reference;
    00200
    00201       _List_const_iterator()
    00202       : _M_node() { }
    00203
    00204       explicit
    00205       _List_const_iterator(const _List_node_base* __x)
    00206       : _M_node(__x) { }
    00207
    00208       _List_const_iterator(const iterator& __x)
    00209       : _M_node(__x._M_node) { }
    00210
    00211       // Must downcast from List_node_base to _List_node to get to
    00212       // _M_data.
    00213       reference
    00214       operator*() const
    00215       { return static_cast<_Node*>(_M_node)->_M_data; }
    00216
    00217       pointer
    00218       operator->() const
    00219       { return &static_cast<_Node*>(_M_node)->_M_data; }
    00220
    00221       _Self&
    00222       operator++()
    00223       {
    00224     _M_node = _M_node->_M_next;
    00225     return *this;
    00226       }
    00227
    00228       _Self
    00229       operator++(int)
    00230       {
    00231     _Self __tmp = *this;
    00232     _M_node = _M_node->_M_next;
    00233     return __tmp;
    00234       }
    00235
    00236       _Self&
    00237       operator--()
    00238       {
    00239     _M_node = _M_node->_M_prev;
    00240     return *this;
    00241       }
    00242
    00243       _Self
    00244       operator--(int)
    00245       {
    00246     _Self __tmp = *this;
    00247     _M_node = _M_node->_M_prev;
    00248     return __tmp;
    00249       }
    00250
    00251       bool
    00252       operator==(const _Self& __x) const
    00253       { return _M_node == __x._M_node; }
    00254
    00255       bool
    00256       operator!=(const _Self& __x) const
    00257       { return _M_node != __x._M_node; }
    00258
    00259       // The only member points to the %list element.
    00260       const _List_node_base* _M_node;
    00261     };
    00262
    00263   template<typename _Val>
    00264     inline bool
    00265     operator==(const _List_iterator<_Val>& __x,
    00266            const _List_const_iterator<_Val>& __y)
    00267     { return __x._M_node == __y._M_node; }
    00268
    00269   template<typename _Val>
    00270     inline bool
    00271     operator!=(const _List_iterator<_Val>& __x,
    00272                const _List_const_iterator<_Val>& __y)
    00273     { return __x._M_node != __y._M_node; }
    00274
    00275
    00276   /**
    00277    *  @if maint
    00278    *  See bits/stl_deque.h's _Deque_base for an explanation.
    00279    *  @endif
    00280   */
    00281   template<typename _Tp, typename _Alloc>
    00282     class _List_base
    00283     {
    00284     protected:
    00285       // NOTA BENE
    00286       // The stored instance is not actually of "allocator_type"'s
    00287       // type.  Instead we rebind the type to
    00288       // Allocator<List_node<Tp>>, which according to [20.1.5]/4
    00289       // should probably be the same.  List_node<Tp> is not the same
    00290       // size as Tp (it's two pointers larger), and specializations on
    00291       // Tp may go unused because List_node<Tp> is being bound
    00292       // instead.
    00293       //
    00294       // We put this to the test in the constructors and in
    00295       // get_allocator, where we use conversions between
    00296       // allocator_type and _Node_alloc_type. The conversion is
    00297       // required by table 32 in [20.1.5].
    00298       typedef typename _Alloc::template rebind<_List_node<_Tp> >::other
    00299         _Node_alloc_type;
    00300
    00301       typedef typename _Alloc::template rebind<_Tp>::other _Tp_alloc_type;
    00302
    00303       struct _List_impl
    00304       : public _Node_alloc_type
    00305       {
    00306     _List_node_base _M_node;
    00307
    00308     _List_impl(const _Node_alloc_type& __a)
    00309     : _Node_alloc_type(__a), _M_node()
    00310     { }
    00311       };
    00312
    00313       _List_impl _M_impl;
    00314
    00315       _List_node<_Tp>*
    00316       _M_get_node()
    00317       { return _M_impl._Node_alloc_type::allocate(1); }
    00318
    00319       void
    00320       _M_put_node(_List_node<_Tp>* __p)
    00321       { _M_impl._Node_alloc_type::deallocate(__p, 1); }
    00322
    00323   public:
    00324       typedef _Alloc allocator_type;
    00325
    00326       _Node_alloc_type&
    00327       _M_get_Node_allocator()
    00328       { return *static_cast<_Node_alloc_type*>(&this->_M_impl); }
    00329
    00330       const _Node_alloc_type&
    00331       _M_get_Node_allocator() const
    00332       { return *static_cast<const _Node_alloc_type*>(&this->_M_impl); }
    00333
    00334       _Tp_alloc_type
    00335       _M_get_Tp_allocator() const
    00336       { return _Tp_alloc_type(_M_get_Node_allocator()); }
    00337
    00338       allocator_type
    00339       get_allocator() const
    00340       { return allocator_type(_M_get_Node_allocator()); }
    00341
    00342       _List_base(const allocator_type& __a)
    00343       : _M_impl(__a)
    00344       { _M_init(); }
    00345
    00346       // This is what actually destroys the list.
    00347       ~_List_base()
    00348       { _M_clear(); }
    00349
    00350       void
    00351       _M_clear();
    00352
    00353       void
    00354       _M_init()
    00355       {
    00356         this->_M_impl._M_node._M_next = &this->_M_impl._M_node;
    00357         this->_M_impl._M_node._M_prev = &this->_M_impl._M_node;
    00358       }
    00359     };
    00360
    00361   /**
    00362    *  @brief A standard container with linear time access to elements,
    00363    *  and fixed time insertion/deletion at any point in the sequence.
    00364    *
    00365    *  @ingroup Containers
    00366    *  @ingroup Sequences
    00367    *
    00368    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
    00369    *  <a href="tables.html#66">reversible container</a>, and a
    00370    *  <a href="tables.html#67">sequence</a>, including the
    00371    *  <a href="tables.html#68">optional sequence requirements</a> with the
    00372    *  %exception of @c at and @c operator[].
    00373    *
    00374    *  This is a @e doubly @e linked %list.  Traversal up and down the
    00375    *  %list requires linear time, but adding and removing elements (or
    00376    *  @e nodes) is done in constant time, regardless of where the
    00377    *  change takes place.  Unlike std::vector and std::deque,
    00378    *  random-access iterators are not provided, so subscripting ( @c
    00379    *  [] ) access is not allowed.  For algorithms which only need
    00380    *  sequential access, this lack makes no difference.
    00381    *
    00382    *  Also unlike the other standard containers, std::list provides
    00383    *  specialized algorithms %unique to linked lists, such as
    00384    *  splicing, sorting, and in-place reversal.
    00385    *
    00386    *  @if maint
    00387    *  A couple points on memory allocation for list<Tp>:
    00388    *
    00389    *  First, we never actually allocate a Tp, we allocate
    00390    *  List_node<Tp>'s and trust [20.1.5]/4 to DTRT.  This is to ensure
    00391    *  that after elements from %list<X,Alloc1> are spliced into
    00392    *  %list<X,Alloc2>, destroying the memory of the second %list is a
    00393    *  valid operation, i.e., Alloc1 giveth and Alloc2 taketh away.
    00394    *
    00395    *  Second, a %list conceptually represented as
    00396    *  @code
    00397    *    A <---> B <---> C <---> D
    00398    *  @endcode
    00399    *  is actually circular; a link exists between A and D.  The %list
    00400    *  class holds (as its only data member) a private list::iterator
    00401    *  pointing to @e D, not to @e A!  To get to the head of the %list,
    00402    *  we start at the tail and move forward by one.  When this member
    00403    *  iterator's next/previous pointers refer to itself, the %list is
    00404    *  %empty.  @endif
    00405   */
    00406   template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
    00407     class list : protected _List_base<_Tp, _Alloc>
    00408     {
    00409       // concept requirements
    00410       typedef typename _Alloc::value_type                _Alloc_value_type;
    00411       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
    00412       __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
    00413
    00414       typedef _List_base<_Tp, _Alloc>                    _Base;
    00415       typedef typename _Base::_Tp_alloc_type         _Tp_alloc_type;
    00416
    00417     public:
    00418       typedef _Tp                                        value_type;
    00419       typedef typename _Tp_alloc_type::pointer           pointer;
    00420       typedef typename _Tp_alloc_type::const_pointer     const_pointer;
    00421       typedef typename _Tp_alloc_type::reference         reference;
    00422       typedef typename _Tp_alloc_type::const_reference   const_reference;
    00423       typedef _List_iterator<_Tp>                        iterator;
    00424       typedef _List_const_iterator<_Tp>                  const_iterator;
    00425       typedef std::reverse_iterator<const_iterator>      const_reverse_iterator;
    00426       typedef std::reverse_iterator<iterator>            reverse_iterator;
    00427       typedef size_t                                     size_type;
    00428       typedef ptrdiff_t                                  difference_type;
    00429       typedef _Alloc                                     allocator_type;
    00430
    00431     protected:
    00432       // Note that pointers-to-_Node's can be ctor-converted to
    00433       // iterator types.
    00434       typedef _List_node<_Tp>                _Node;
    00435
    00436       using _Base::_M_impl;
    00437       using _Base::_M_put_node;
    00438       using _Base::_M_get_node;
    00439       using _Base::_M_get_Tp_allocator;
    00440       using _Base::_M_get_Node_allocator;
    00441
    00442       /**
    00443        *  @if maint
    00444        *  @param  x  An instance of user data.
    00445        *
    00446        *  Allocates space for a new node and constructs a copy of @a x in it.
    00447        *  @endif
    00448        */
    00449       _Node*
    00450       _M_create_node(const value_type& __x)
    00451       {
    00452     _Node* __p = this->_M_get_node();
    00453     try
    00454       {
    00455         _M_get_Tp_allocator().construct(&__p->_M_data, __x);
    00456       }
    00457     catch(...)
    00458       {
    00459         _M_put_node(__p);
    00460         __throw_exception_again;
    00461       }
    00462     return __p;
    00463       }
    00464
    00465     public:
    00466       // [23.2.2.1] construct/copy/destroy
    00467       // (assign() and get_allocator() are also listed in this section)
    00468       /**
    00469        *  @brief  Default constructor creates no elements.
    00470        */
    00471       explicit
    00472       list(const allocator_type& __a = allocator_type())
    00473       : _Base(__a) { }
    00474
    00475       /**
    00476        *  @brief  Create a %list with copies of an exemplar element.
    00477        *  @param  n  The number of elements to initially create.
    00478        *  @param  value  An element to copy.
    00479        *
    00480        *  This constructor fills the %list with @a n copies of @a value.
    00481        */
    00482       explicit
    00483       list(size_type __n, const value_type& __value = value_type(),
    00484        const allocator_type& __a = allocator_type())
    00485       : _Base(__a)
    00486       { _M_fill_initialize(__n, __value); }
    00487
    00488       /**
    00489        *  @brief  %List copy constructor.
    00490        *  @param  x  A %list of identical element and allocator types.
    00491        *
    00492        *  The newly-created %list uses a copy of the allocation object used
    00493        *  by @a x.
    00494        */
    00495       list(const list& __x)
    00496       : _Base(__x._M_get_Node_allocator())
    00497       { _M_initialize_dispatch(__x.begin(), __x.end(), __false_type()); }
    00498
    00499       /**
    00500        *  @brief  Builds a %list from a range.
    00501        *  @param  first  An input iterator.
    00502        *  @param  last  An input iterator.
    00503        *
    00504        *  Create a %list consisting of copies of the elements from
    00505        *  [@a first,@a last).  This is linear in N (where N is
    00506        *  distance(@a first,@a last)).
    00507        */
    00508       template<typename _InputIterator>
    00509         list(_InputIterator __first, _InputIterator __last,
    00510          const allocator_type& __a = allocator_type())
    00511         : _Base(__a)
    00512         {
    00513       // Check whether it's an integral type.  If so, it's not an iterator.
    00514       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
    00515       _M_initialize_dispatch(__first, __last, _Integral());
    00516     }
    00517
    00518       /**
    00519        *  No explicit dtor needed as the _Base dtor takes care of
    00520        *  things.  The _Base dtor only erases the elements, and note
    00521        *  that if the elements themselves are pointers, the pointed-to
    00522        *  memory is not touched in any way.  Managing the pointer is
    00523        *  the user's responsibilty.
    00524        */
    00525
    00526       /**
    00527        *  @brief  %List assignment operator.
    00528        *  @param  x  A %list of identical element and allocator types.
    00529        *
    00530        *  All the elements of @a x are copied, but unlike the copy
    00531        *  constructor, the allocator object is not copied.
    00532        */
    00533       list&
    00534       operator=(const list& __x);
    00535
    00536       /**
    00537        *  @brief  Assigns a given value to a %list.
    00538        *  @param  n  Number of elements to be assigned.
    00539        *  @param  val  Value to be assigned.
    00540        *
    00541        *  This function fills a %list with @a n copies of the given
    00542        *  value.  Note that the assignment completely changes the %list
    00543        *  and that the resulting %list's size is the same as the number
    00544        *  of elements assigned.  Old data may be lost.
    00545        */
    00546       void
    00547       assign(size_type __n, const value_type& __val)
    00548       { _M_fill_assign(__n, __val); }
    00549
    00550       /**
    00551        *  @brief  Assigns a range to a %list.
    00552        *  @param  first  An input iterator.
    00553        *  @param  last   An input iterator.
    00554        *
    00555        *  This function fills a %list with copies of the elements in the
    00556        *  range [@a first,@a last).
    00557        *
    00558        *  Note that the assignment completely changes the %list and
    00559        *  that the resulting %list's size is the same as the number of
    00560        *  elements assigned.  Old data may be lost.
    00561        */
    00562       template<typename _InputIterator>
    00563         void
    00564         assign(_InputIterator __first, _InputIterator __last)
    00565         {
    00566       // Check whether it's an integral type.  If so, it's not an iterator.
    00567       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
    00568       _M_assign_dispatch(__first, __last, _Integral());
    00569     }
    00570
    00571       /// Get a copy of the memory allocation object.
    00572       allocator_type
    00573       get_allocator() const
    00574       { return _Base::get_allocator(); }
    00575
    00576       // iterators
    00577       /**
    00578        *  Returns a read/write iterator that points to the first element in the
    00579        *  %list.  Iteration is done in ordinary element order.
    00580        */
    00581       iterator
    00582       begin()
    00583       { return iterator(this->_M_impl._M_node._M_next); }
    00584
    00585       /**
    00586        *  Returns a read-only (constant) iterator that points to the
    00587        *  first element in the %list.  Iteration is done in ordinary
    00588        *  element order.
    00589        */
    00590       const_iterator
    00591       begin() const
    00592       { return const_iterator(this->_M_impl._M_node._M_next); }
    00593
    00594       /**
    00595        *  Returns a read/write iterator that points one past the last
    00596        *  element in the %list.  Iteration is done in ordinary element
    00597        *  order.
    00598        */
    00599       iterator
    00600       end()
    00601       { return iterator(&this->_M_impl._M_node); }
    00602
    00603       /**
    00604        *  Returns a read-only (constant) iterator that points one past
    00605        *  the last element in the %list.  Iteration is done in ordinary
    00606        *  element order.
    00607        */
    00608       const_iterator
    00609       end() const
    00610       { return const_iterator(&this->_M_impl._M_node); }
    00611
    00612       /**
    00613        *  Returns a read/write reverse iterator that points to the last
    00614        *  element in the %list.  Iteration is done in reverse element
    00615        *  order.
    00616        */
    00617       reverse_iterator
    00618       rbegin()
    00619       { return reverse_iterator(end()); }
    00620
    00621       /**
    00622        *  Returns a read-only (constant) reverse iterator that points to
    00623        *  the last element in the %list.  Iteration is done in reverse
    00624        *  element order.
    00625        */
    00626       const_reverse_iterator
    00627       rbegin() const
    00628       { return const_reverse_iterator(end()); }
    00629
    00630       /**
    00631        *  Returns a read/write reverse iterator that points to one
    00632        *  before the first element in the %list.  Iteration is done in
    00633        *  reverse element order.
    00634        */
    00635       reverse_iterator
    00636       rend()
    00637       { return reverse_iterator(begin()); }
    00638
    00639       /**
    00640        *  Returns a read-only (constant) reverse iterator that points to one
    00641        *  before the first element in the %list.  Iteration is done in reverse
    00642        *  element order.
    00643        */
    00644       const_reverse_iterator
    00645       rend() const
    00646       { return const_reverse_iterator(begin()); }
    00647
    00648       // [23.2.2.2] capacity
    00649       /**
    00650        *  Returns true if the %list is empty.  (Thus begin() would equal
    00651        *  end().)
    00652        */
    00653       bool
    00654       empty() const
    00655       { return this->_M_impl._M_node._M_next == &this->_M_impl._M_node; }
    00656
    00657       /**  Returns the number of elements in the %list.  */
    00658       size_type
    00659       size() const
    00660       { return std::distance(begin(), end()); }
    00661
    00662       /**  Returns the size() of the largest possible %list.  */
    00663       size_type
    00664       max_size() const
    00665       { return _M_get_Tp_allocator().max_size(); }
    00666
    00667       /**
    00668        *  @brief Resizes the %list to the specified number of elements.
    00669        *  @param new_size Number of elements the %list should contain.
    00670        *  @param x Data with which new elements should be populated.
    00671        *
    00672        *  This function will %resize the %list to the specified number
    00673        *  of elements.  If the number is smaller than the %list's
    00674        *  current size the %list is truncated, otherwise the %list is
    00675        *  extended and new elements are populated with given data.
    00676        */
    00677       void
    00678       resize(size_type __new_size, value_type __x = value_type());
    00679
    00680       // element access
    00681       /**
    00682        *  Returns a read/write reference to the data at the first
    00683        *  element of the %list.
    00684        */
    00685       reference
    00686       front()
    00687       { return *begin(); }
    00688
    00689       /**
    00690        *  Returns a read-only (constant) reference to the data at the first
    00691        *  element of the %list.
    00692        */
    00693       const_reference
    00694       front() const
    00695       { return *begin(); }
    00696
    00697       /**
    00698        *  Returns a read/write reference to the data at the last element
    00699        *  of the %list.
    00700        */
    00701       reference
    00702       back()
    00703       {
    00704     iterator __tmp = end();
    00705     --__tmp;
    00706     return *__tmp;
    00707       }
    00708
    00709       /**
    00710        *  Returns a read-only (constant) reference to the data at the last
    00711        *  element of the %list.
    00712        */
    00713       const_reference
    00714       back() const
    00715       {
    00716     const_iterator __tmp = end();
    00717     --__tmp;
    00718     return *__tmp;
    00719       }
    00720
    00721       // [23.2.2.3] modifiers
    00722       /**
    00723        *  @brief  Add data to the front of the %list.
    00724        *  @param  x  Data to be added.
    00725        *
    00726        *  This is a typical stack operation.  The function creates an
    00727        *  element at the front of the %list and assigns the given data
    00728        *  to it.  Due to the nature of a %list this operation can be
    00729        *  done in constant time, and does not invalidate iterators and
    00730        *  references.
    00731        */
    00732       void
    00733       push_front(const value_type& __x)
    00734       { this->_M_insert(begin(), __x); }
    00735
    00736       /**
    00737        *  @brief  Removes first element.
    00738        *
    00739        *  This is a typical stack operation.  It shrinks the %list by
    00740        *  one.  Due to the nature of a %list this operation can be done
    00741        *  in constant time, and only invalidates iterators/references to
    00742        *  the element being removed.
    00743        *
    00744        *  Note that no data is returned, and if the first element's data
    00745        *  is needed, it should be retrieved before pop_front() is
    00746        *  called.
    00747        */
    00748       void
    00749       pop_front()
    00750       { this->_M_erase(begin()); }
    00751
    00752       /**
    00753        *  @brief  Add data to the end of the %list.
    00754        *  @param  x  Data to be added.
    00755        *
    00756        *  This is a typical stack operation.  The function creates an
    00757        *  element at the end of the %list and assigns the given data to
    00758        *  it.  Due to the nature of a %list this operation can be done
    00759        *  in constant time, and does not invalidate iterators and
    00760        *  references.
    00761        */
    00762       void
    00763       push_back(const value_type& __x)
    00764       { this->_M_insert(end(), __x); }
    00765
    00766       /**
    00767        *  @brief  Removes last element.
    00768        *
    00769        *  This is a typical stack operation.  It shrinks the %list by
    00770        *  one.  Due to the nature of a %list this operation can be done
    00771        *  in constant time, and only invalidates iterators/references to
    00772        *  the element being removed.
    00773        *
    00774        *  Note that no data is returned, and if the last element's data
    00775        *  is needed, it should be retrieved before pop_back() is called.
    00776        */
    00777       void
    00778       pop_back()
    00779       { this->_M_erase(iterator(this->_M_impl._M_node._M_prev)); }
    00780
    00781       /**
    00782        *  @brief  Inserts given value into %list before specified iterator.
    00783        *  @param  position  An iterator into the %list.
    00784        *  @param  x  Data to be inserted.
    00785        *  @return  An iterator that points to the inserted data.
    00786        *
    00787        *  This function will insert a copy of the given value before
    00788        *  the specified location.  Due to the nature of a %list this
    00789        *  operation can be done in constant time, and does not
    00790        *  invalidate iterators and references.
    00791        */
    00792       iterator
    00793       insert(iterator __position, const value_type& __x);
    00794
    00795       /**
    00796        *  @brief  Inserts a number of copies of given data into the %list.
    00797        *  @param  position  An iterator into the %list.
    00798        *  @param  n  Number of elements to be inserted.
    00799        *  @param  x  Data to be inserted.
    00800        *
    00801        *  This function will insert a specified number of copies of the
    00802        *  given data before the location specified by @a position.
    00803        *
    00804        *  This operation is linear in the number of elements inserted and
    00805        *  does not invalidate iterators and references.
    00806        */
    00807       void
    00808       insert(iterator __position, size_type __n, const value_type& __x)
    00809       {
    00810     list __tmp(__n, __x, _M_get_Node_allocator());
    00811     splice(__position, __tmp);
    00812       }
    00813
    00814       /**
    00815        *  @brief  Inserts a range into the %list.
    00816        *  @param  position  An iterator into the %list.
    00817        *  @param  first  An input iterator.
    00818        *  @param  last   An input iterator.
    00819        *
    00820        *  This function will insert copies of the data in the range [@a
    00821        *  first,@a last) into the %list before the location specified by
    00822        *  @a position.
    00823        *
    00824        *  This operation is linear in the number of elements inserted and
    00825        *  does not invalidate iterators and references.
    00826        */
    00827       template<typename _InputIterator>
    00828         void
    00829         insert(iterator __position, _InputIterator __first,
    00830            _InputIterator __last)
    00831         {
    00832       list __tmp(__first, __last, _M_get_Node_allocator());
    00833       splice(__position, __tmp);
    00834     }
    00835
    00836       /**
    00837        *  @brief  Remove element at given position.
    00838        *  @param  position  Iterator pointing to element to be erased.
    00839        *  @return  An iterator pointing to the next element (or end()).
    00840        *
    00841        *  This function will erase the element at the given position and thus
    00842        *  shorten the %list by one.
    00843        *
    00844        *  Due to the nature of a %list this operation can be done in
    00845        *  constant time, and only invalidates iterators/references to
    00846        *  the element being removed.  The user is also cautioned that
    00847        *  this function only erases the element, and that if the element
    00848        *  is itself a pointer, the pointed-to memory is not touched in
    00849        *  any way.  Managing the pointer is the user's responsibilty.
    00850        */
    00851       iterator
    00852       erase(iterator __position);
    00853
    00854       /**
    00855        *  @brief  Remove a range of elements.
    00856        *  @param  first  Iterator pointing to the first element to be erased.
    00857        *  @param  last  Iterator pointing to one past the last element to be
    00858        *                erased.
    00859        *  @return  An iterator pointing to the element pointed to by @a last
    00860        *           prior to erasing (or end()).
    00861        *
    00862        *  This function will erase the elements in the range @a
    00863        *  [first,last) and shorten the %list accordingly.
    00864        *
    00865        *  This operation is linear time in the size of the range and only
    00866        *  invalidates iterators/references to the element being removed.
    00867        *  The user is also cautioned that this function only erases the
    00868        *  elements, and that if the elements themselves are pointers, the
    00869        *  pointed-to memory is not touched in any way.  Managing the pointer
    00870        *  is the user's responsibilty.
    00871        */
    00872       iterator
    00873       erase(iterator __first, iterator __last)
    00874       {
    00875     while (__first != __last)
    00876       __first = erase(__first);
    00877     return __last;
    00878       }
    00879
    00880       /**
    00881        *  @brief  Swaps data with another %list.
    00882        *  @param  x  A %list of the same element and allocator types.
    00883        *
    00884        *  This exchanges the elements between two lists in constant
    00885        *  time.  Note that the global std::swap() function is
    00886        *  specialized such that std::swap(l1,l2) will feed to this
    00887        *  function.
    00888        */
    00889       void
    00890       swap(list& __x)
    00891       {
    00892     _List_node_base::swap(this->_M_impl._M_node, __x._M_impl._M_node);
    00893
    00894     // _GLIBCXX_RESOLVE_LIB_DEFECTS
    00895     // 431. Swapping containers with unequal allocators.
    00896     std::__alloc_swap<typename _Base::_Node_alloc_type>::
    00897 	  _S_do_it(_M_get_Node_allocator(), __x._M_get_Node_allocator());
    00898       }
    00899
    00900       /**
    00901        *  Erases all the elements.  Note that this function only erases
    00902        *  the elements, and that if the elements themselves are
    00903        *  pointers, the pointed-to memory is not touched in any way.
    00904        *  Managing the pointer is the user's responsibilty.
    00905        */
    00906       void
    00907       clear()
    00908       {
    00909         _Base::_M_clear();
    00910         _Base::_M_init();
    00911       }
    00912
    00913       // [23.2.2.4] list operations
    00914       /**
    00915        *  @brief  Insert contents of another %list.
    00916        *  @param  position  Iterator referencing the element to insert before.
    00917        *  @param  x  Source list.
    00918        *
    00919        *  The elements of @a x are inserted in constant time in front of
    00920        *  the element referenced by @a position.  @a x becomes an empty
    00921        *  list.
    00922        *
    00923        *  Requires this != @a x.
    00924        */
    00925       void
    00926       splice(iterator __position, list& __x)
    00927       {
    00928     if (!__x.empty())
    00929       {
    00930         _M_check_equal_allocators(__x);
    00931
    00932         this->_M_transfer(__position, __x.begin(), __x.end());
    00933       }
    00934       }
    00935
    00936       /**
    00937        *  @brief  Insert element from another %list.
    00938        *  @param  position  Iterator referencing the element to insert before.
    00939        *  @param  x  Source list.
    00940        *  @param  i  Iterator referencing the element to move.
    00941        *
    00942        *  Removes the element in list @a x referenced by @a i and
    00943        *  inserts it into the current list before @a position.
    00944        */
    00945       void
    00946       splice(iterator __position, list& __x, iterator __i)
    00947       {
    00948     iterator __j = __i;
    00949     ++__j;
    00950     if (__position == __i || __position == __j)
    00951       return;
    00952
    00953     if (this != &__x)
    00954       _M_check_equal_allocators(__x);
    00955
    00956     this->_M_transfer(__position, __i, __j);
    00957       }
    00958
    00959       /**
    00960        *  @brief  Insert range from another %list.
    00961        *  @param  position  Iterator referencing the element to insert before.
    00962        *  @param  x  Source list.
    00963        *  @param  first  Iterator referencing the start of range in x.
    00964        *  @param  last  Iterator referencing the end of range in x.
    00965        *
    00966        *  Removes elements in the range [first,last) and inserts them
    00967        *  before @a position in constant time.
    00968        *
    00969        *  Undefined if @a position is in [first,last).
    00970        */
    00971       void
    00972       splice(iterator __position, list& __x, iterator __first, iterator __last)
    00973       {
    00974     if (__first != __last)
    00975       {
    00976         if (this != &__x)
    00977           _M_check_equal_allocators(__x);
    00978
    00979         this->_M_transfer(__position, __first, __last);
    00980       }
    00981       }
    00982
    00983       /**
    00984        *  @brief  Remove all elements equal to value.
    00985        *  @param  value  The value to remove.
    00986        *
    00987        *  Removes every element in the list equal to @a value.
    00988        *  Remaining elements stay in list order.  Note that this
    00989        *  function only erases the elements, and that if the elements
    00990        *  themselves are pointers, the pointed-to memory is not
    00991        *  touched in any way.  Managing the pointer is the user's
    00992        *  responsibilty.
    00993        */
    00994       void
    00995       remove(const _Tp& __value);
    00996
    00997       /**
    00998        *  @brief  Remove all elements satisfying a predicate.
    00999        *  @param  Predicate  Unary predicate function or object.
    01000        *
    01001        *  Removes every element in the list for which the predicate
    01002        *  returns true.  Remaining elements stay in list order.  Note
    01003        *  that this function only erases the elements, and that if the
    01004        *  elements themselves are pointers, the pointed-to memory is
    01005        *  not touched in any way.  Managing the pointer is the user's
    01006        *  responsibilty.
    01007        */
    01008       template<typename _Predicate>
    01009         void
    01010         remove_if(_Predicate);
    01011
    01012       /**
    01013        *  @brief  Remove consecutive duplicate elements.
    01014        *
    01015        *  For each consecutive set of elements with the same value,
    01016        *  remove all but the first one.  Remaining elements stay in
    01017        *  list order.  Note that this function only erases the
    01018        *  elements, and that if the elements themselves are pointers,
    01019        *  the pointed-to memory is not touched in any way.  Managing
    01020        *  the pointer is the user's responsibilty.
    01021        */
    01022       void
    01023       unique();
    01024
    01025       /**
    01026        *  @brief  Remove consecutive elements satisfying a predicate.
    01027        *  @param  BinaryPredicate  Binary predicate function or object.
    01028        *
    01029        *  For each consecutive set of elements [first,last) that
    01030        *  satisfy predicate(first,i) where i is an iterator in
    01031        *  [first,last), remove all but the first one.  Remaining
    01032        *  elements stay in list order.  Note that this function only
    01033        *  erases the elements, and that if the elements themselves are
    01034        *  pointers, the pointed-to memory is not touched in any way.
    01035        *  Managing the pointer is the user's responsibilty.
    01036        */
    01037       template<typename _BinaryPredicate>
    01038         void
    01039         unique(_BinaryPredicate);
    01040
    01041       /**
    01042        *  @brief  Merge sorted lists.
    01043        *  @param  x  Sorted list to merge.
    01044        *
    01045        *  Assumes that both @a x and this list are sorted according to
    01046        *  operator<().  Merges elements of @a x into this list in
    01047        *  sorted order, leaving @a x empty when complete.  Elements in
    01048        *  this list precede elements in @a x that are equal.
    01049        */
    01050       void
    01051       merge(list& __x);
    01052
    01053       /**
    01054        *  @brief  Merge sorted lists according to comparison function.
    01055        *  @param  x  Sorted list to merge.
    01056        *  @param StrictWeakOrdering Comparison function definining
    01057        *  sort order.
    01058        *
    01059        *  Assumes that both @a x and this list are sorted according to
    01060        *  StrictWeakOrdering.  Merges elements of @a x into this list
    01061        *  in sorted order, leaving @a x empty when complete.  Elements
    01062        *  in this list precede elements in @a x that are equivalent
    01063        *  according to StrictWeakOrdering().
    01064        */
    01065       template<typename _StrictWeakOrdering>
    01066         void
    01067         merge(list&, _StrictWeakOrdering);
    01068
    01069       /**
    01070        *  @brief  Reverse the elements in list.
    01071        *
    01072        *  Reverse the order of elements in the list in linear time.
    01073        */
    01074       void
    01075       reverse()
    01076       { this->_M_impl._M_node.reverse(); }
    01077
    01078       /**
    01079        *  @brief  Sort the elements.
    01080        *
    01081        *  Sorts the elements of this list in NlogN time.  Equivalent
    01082        *  elements remain in list order.
    01083        */
    01084       void
    01085       sort();
    01086
    01087       /**
    01088        *  @brief  Sort the elements according to comparison function.
    01089        *
    01090        *  Sorts the elements of this list in NlogN time.  Equivalent
    01091        *  elements remain in list order.
    01092        */
    01093       template<typename _StrictWeakOrdering>
    01094         void
    01095         sort(_StrictWeakOrdering);
    01096
    01097     protected:
    01098       // Internal constructor functions follow.
    01099
    01100       // Called by the range constructor to implement [23.1.1]/9
    01101       template<typename _Integer>
    01102         void
    01103         _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
    01104         {
    01105       _M_fill_initialize(static_cast<size_type>(__n),
    01106                  static_cast<value_type>(__x));
    01107     }
    01108
    01109       // Called by the range constructor to implement [23.1.1]/9
    01110       template<typename _InputIterator>
    01111         void
    01112         _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
    01113                    __false_type)
    01114         {
    01115       for (; __first != __last; ++__first)
    01116         push_back(*__first);
    01117     }
    01118
    01119       // Called by list(n,v,a), and the range constructor when it turns out
    01120       // to be the same thing.
    01121       void
    01122       _M_fill_initialize(size_type __n, const value_type& __x)
    01123       {
    01124     for (; __n > 0; --__n)
    01125       push_back(__x);
    01126       }
    01127
    01128
    01129       // Internal assign functions follow.
    01130
    01131       // Called by the range assign to implement [23.1.1]/9
    01132       template<typename _Integer>
    01133         void
    01134         _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
    01135         {
    01136       _M_fill_assign(static_cast<size_type>(__n),
    01137              static_cast<value_type>(__val));
    01138     }
    01139
    01140       // Called by the range assign to implement [23.1.1]/9
    01141       template<typename _InputIterator>
    01142         void
    01143         _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
    01144                __false_type);
    01145
    01146       // Called by assign(n,t), and the range assign when it turns out
    01147       // to be the same thing.
    01148       void
    01149       _M_fill_assign(size_type __n, const value_type& __val);
    01150
    01151
    01152       // Moves the elements from [first,last) before position.
    01153       void
    01154       _M_transfer(iterator __position, iterator __first, iterator __last)
    01155       { __position._M_node->transfer(__first._M_node, __last._M_node); }
    01156
    01157       // Inserts new element at position given and with value given.
    01158       void
    01159       _M_insert(iterator __position, const value_type& __x)
    01160       {
    01161         _Node* __tmp = _M_create_node(__x);
    01162         __tmp->hook(__position._M_node);
    01163       }
    01164
    01165       // Erases element at position given.
    01166       void
    01167       _M_erase(iterator __position)
    01168       {
    01169         __position._M_node->unhook();
    01170         _Node* __n = static_cast<_Node*>(__position._M_node);
    01171         _M_get_Tp_allocator().destroy(&__n->_M_data);
    01172         _M_put_node(__n);
    01173       }
    01174
    01175       // To implement the splice (and merge) bits of N1599.
    01176       void
    01177       _M_check_equal_allocators(list& __x)
    01178       {
    01179     if (_M_get_Node_allocator() != __x._M_get_Node_allocator())
    01180       __throw_runtime_error(__N("list::_M_check_equal_allocators"));
    01181       }
    01182     };
    01183
    01184   /**
    01185    *  @brief  List equality comparison.
    01186    *  @param  x  A %list.
    01187    *  @param  y  A %list of the same type as @a x.
    01188    *  @return  True iff the size and elements of the lists are equal.
    01189    *
    01190    *  This is an equivalence relation.  It is linear in the size of
    01191    *  the lists.  Lists are considered equivalent if their sizes are
    01192    *  equal, and if corresponding elements compare equal.
    01193   */
    01194   template<typename _Tp, typename _Alloc>
    01195     inline bool
    01196     operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01197     {
    01198       typedef typename list<_Tp, _Alloc>::const_iterator const_iterator;
    01199       const_iterator __end1 = __x.end();
    01200       const_iterator __end2 = __y.end();
    01201
    01202       const_iterator __i1 = __x.begin();
    01203       const_iterator __i2 = __y.begin();
    01204       while (__i1 != __end1 && __i2 != __end2 && *__i1 == *__i2)
    01205     {
    01206       ++__i1;
    01207       ++__i2;
    01208     }
    01209       return __i1 == __end1 && __i2 == __end2;
    01210     }
    01211
    01212   /**
    01213    *  @brief  List ordering relation.
    01214    *  @param  x  A %list.
    01215    *  @param  y  A %list of the same type as @a x.
    01216    *  @return  True iff @a x is lexicographically less than @a y.
    01217    *
    01218    *  This is a total ordering relation.  It is linear in the size of the
    01219    *  lists.  The elements must be comparable with @c <.
    01220    *
    01221    *  See std::lexicographical_compare() for how the determination is made.
    01222   */
    01223   template<typename _Tp, typename _Alloc>
    01224     inline bool
    01225     operator<(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01226     { return std::lexicographical_compare(__x.begin(), __x.end(),
    01227                       __y.begin(), __y.end()); }
    01228
    01229   /// Based on operator==
    01230   template<typename _Tp, typename _Alloc>
    01231     inline bool
    01232     operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01233     { return !(__x == __y); }
    01234
    01235   /// Based on operator<
    01236   template<typename _Tp, typename _Alloc>
    01237     inline bool
    01238     operator>(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01239     { return __y < __x; }
    01240
    01241   /// Based on operator<
    01242   template<typename _Tp, typename _Alloc>
    01243     inline bool
    01244     operator<=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01245     { return !(__y < __x); }
    01246
    01247   /// Based on operator<
    01248   template<typename _Tp, typename _Alloc>
    01249     inline bool
    01250     operator>=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01251     { return !(__x < __y); }
    01252
    01253   /// See std::list::swap().
    01254   template<typename _Tp, typename _Alloc>
    01255     inline void
    01256     swap(list<_Tp, _Alloc>& __x, list<_Tp, _Alloc>& __y)
    01257     { __x.swap(__y); }
    01258
    01259 _GLIBCXX_END_NESTED_NAMESPACE
    01260
    01261 #endif /* _LIST_H */
    01262