# stl_list.h

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    00001 // List implementation -*- C++ -*-
    00002
    00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005 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 2, 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 // You should have received a copy of the GNU General Public License along
    00017 // with this library; see the file COPYING.  If not, write to the Free
    00018 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    00019 // USA.
    00020
    00021 // As a special exception, you may use this file as part of a free software
    00022 // library without restriction.  Specifically, if other files instantiate
    00023 // templates or use macros or inline functions from this file, or you compile
    00024 // this file and link it with other files to produce an executable, this
    00025 // file does not by itself cause the resulting executable to be covered by
    00026 // the GNU General Public License.  This exception does not however
    00027 // invalidate any other reasons why the executable file might be covered by
    00028 // the GNU General Public License.
    00029
    00030 /*
    00031  *
    00032  * Copyright (c) 1994
    00033  * Hewlett-Packard Company
    00034  *
    00035  * Permission to use, copy, modify, distribute and sell this software
    00036  * and its documentation for any purpose is hereby granted without fee,
    00037  * provided that the above copyright notice appear in all copies and
    00038  * that both that copyright notice and this permission notice appear
    00039  * in supporting documentation.  Hewlett-Packard Company makes no
    00040  * representations about the suitability of this software for any
    00041  * purpose.  It is provided "as is" without express or implied warranty.
    00042  *
    00043  *
    00044  * Copyright (c) 1996,1997
    00045  * Silicon Graphics Computer Systems, Inc.
    00046  *
    00047  * Permission to use, copy, modify, distribute and sell this software
    00048  * and its documentation for any purpose is hereby granted without fee,
    00049  * provided that the above copyright notice appear in all copies and
    00050  * that both that copyright notice and this permission notice appear
    00051  * in supporting documentation.  Silicon Graphics makes no
    00052  * representations about the suitability of this software for any
    00053  * purpose.  It is provided "as is" without express or implied warranty.
    00054  */
    00055
    00056 /** @file stl_list.h
    00057  *  This is an internal header file, included by other library headers.
    00058  *  You should not attempt to use it directly.
    00059  */
    00060
    00061 #ifndef _LIST_H
    00062 #define _LIST_H 1
    00063
    00064 #include <bits/concept_check.h>
    00065
    00066 namespace _GLIBCXX_STD
    00067 {
    00068   // Supporting structures are split into common and templated types; the
    00069   // latter publicly inherits from the former in an effort to reduce code
    00070   // duplication.  This results in some "needless" static_cast'ing later on,
    00071   // but it's all safe downcasting.
    00072
    00073   /// @if maint Common part of a node in the %list.  @endif
    00074   struct _List_node_base
    00075   {
    00076     _List_node_base* _M_next;   ///< Self-explanatory
    00077     _List_node_base* _M_prev;   ///< Self-explanatory
    00078
    00079     static void
    00080     swap(_List_node_base& __x, _List_node_base& __y);
    00081
    00082     void
    00083     transfer(_List_node_base * const __first,
    00084          _List_node_base * const __last);
    00085
    00086     void
    00087     reverse();
    00088
    00089     void
    00090     hook(_List_node_base * const __position);
    00091
    00092     void
    00093     unhook();
    00094   };
    00095
    00096   /// @if maint An actual node in the %list.  @endif
    00097   template<typename _Tp>
    00098     struct _List_node : public _List_node_base
    00099     {
    00100       _Tp _M_data;                ///< User's data.
    00101     };
    00102
    00103   /**
    00104    *  @brief A list::iterator.
    00105    *
    00106    *  @if maint
    00107    *  All the functions are op overloads.
    00108    *  @endif
    00109   */
    00110   template<typename _Tp>
    00111     struct _List_iterator
    00112     {
    00113       typedef _List_iterator<_Tp>           _Self;
    00114       typedef _List_node<_Tp>               _Node;
    00115
    00116       typedef ptrdiff_t                     difference_type;
    00117       typedef bidirectional_iterator_tag    iterator_category;
    00118       typedef _Tp                           value_type;
    00119       typedef _Tp*                          pointer;
    00120       typedef _Tp&                          reference;
    00121
    00122       _List_iterator()
    00123       : _M_node() { }
    00124
    00125       _List_iterator(_List_node_base* __x)
    00126       : _M_node(__x) { }
    00127
    00128       // Must downcast from List_node_base to _List_node to get to _M_data.
    00129       reference
    00130       operator*() const
    00131       { return static_cast<_Node*>(_M_node)->_M_data; }
    00132
    00133       pointer
    00134       operator->() const
    00135       { return &static_cast<_Node*>(_M_node)->_M_data; }
    00136
    00137       _Self&
    00138       operator++()
    00139       {
    00140     _M_node = _M_node->_M_next;
    00141     return *this;
    00142       }
    00143
    00144       _Self
    00145       operator++(int)
    00146       {
    00147     _Self __tmp = *this;
    00148     _M_node = _M_node->_M_next;
    00149     return __tmp;
    00150       }
    00151
    00152       _Self&
    00153       operator--()
    00154       {
    00155     _M_node = _M_node->_M_prev;
    00156     return *this;
    00157       }
    00158
    00159       _Self
    00160       operator--(int)
    00161       {
    00162     _Self __tmp = *this;
    00163     _M_node = _M_node->_M_prev;
    00164     return __tmp;
    00165       }
    00166
    00167       bool
    00168       operator==(const _Self& __x) const
    00169       { return _M_node == __x._M_node; }
    00170
    00171       bool
    00172       operator!=(const _Self& __x) const
    00173       { return _M_node != __x._M_node; }
    00174
    00175       // The only member points to the %list element.
    00176       _List_node_base* _M_node;
    00177     };
    00178
    00179   /**
    00180    *  @brief A list::const_iterator.
    00181    *
    00182    *  @if maint
    00183    *  All the functions are op overloads.
    00184    *  @endif
    00185   */
    00186   template<typename _Tp>
    00187     struct _List_const_iterator
    00188     {
    00189       typedef _List_const_iterator<_Tp>     _Self;
    00190       typedef const _List_node<_Tp>         _Node;
    00191       typedef _List_iterator<_Tp>           iterator;
    00192
    00193       typedef ptrdiff_t                     difference_type;
    00194       typedef bidirectional_iterator_tag    iterator_category;
    00195       typedef _Tp                           value_type;
    00196       typedef const _Tp*                    pointer;
    00197       typedef const _Tp&                    reference;
    00198
    00199       _List_const_iterator()
    00200       : _M_node() { }
    00201
    00202       _List_const_iterator(const _List_node_base* __x)
    00203       : _M_node(__x) { }
    00204
    00205       _List_const_iterator(const iterator& __x)
    00206       : _M_node(__x._M_node) { }
    00207
    00208       // Must downcast from List_node_base to _List_node to get to
    00209       // _M_data.
    00210       reference
    00211       operator*() const
    00212       { return static_cast<_Node*>(_M_node)->_M_data; }
    00213
    00214       pointer
    00215       operator->() const
    00216       { return &static_cast<_Node*>(_M_node)->_M_data; }
    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       _Self&
    00234       operator--()
    00235       {
    00236     _M_node = _M_node->_M_prev;
    00237     return *this;
    00238       }
    00239
    00240       _Self
    00241       operator--(int)
    00242       {
    00243     _Self __tmp = *this;
    00244     _M_node = _M_node->_M_prev;
    00245     return __tmp;
    00246       }
    00247
    00248       bool
    00249       operator==(const _Self& __x) const
    00250       { return _M_node == __x._M_node; }
    00251
    00252       bool
    00253       operator!=(const _Self& __x) const
    00254       { return _M_node != __x._M_node; }
    00255
    00256       // The only member points to the %list element.
    00257       const _List_node_base* _M_node;
    00258     };
    00259
    00260   template<typename _Val>
    00261     inline bool
    00262     operator==(const _List_iterator<_Val>& __x,
    00263            const _List_const_iterator<_Val>& __y)
    00264     { return __x._M_node == __y._M_node; }
    00265
    00266   template<typename _Val>
    00267     inline bool
    00268     operator!=(const _List_iterator<_Val>& __x,
    00269                const _List_const_iterator<_Val>& __y)
    00270     { return __x._M_node != __y._M_node; }
    00271
    00272
    00273   /**
    00274    *  @if maint
    00275    *  See bits/stl_deque.h's _Deque_base for an explanation.
    00276    *  @endif
    00277   */
    00278   template<typename _Tp, typename _Alloc>
    00279     class _List_base
    00280     {
    00281     protected:
    00282       // NOTA BENE
    00283       // The stored instance is not actually of "allocator_type"'s
    00284       // type.  Instead we rebind the type to
    00285       // Allocator<List_node<Tp>>, which according to [20.1.5]/4
    00286       // should probably be the same.  List_node<Tp> is not the same
    00287       // size as Tp (it's two pointers larger), and specializations on
    00288       // Tp may go unused because List_node<Tp> is being bound
    00289       // instead.
    00290       //
    00291       // We put this to the test in the constructors and in
    00292       // get_allocator, where we use conversions between
    00293       // allocator_type and _Node_Alloc_type. The conversion is
    00294       // required by table 32 in [20.1.5].
    00295       typedef typename _Alloc::template rebind<_List_node<_Tp> >::other
    00296
    00297       _Node_Alloc_type;
    00298
    00299       struct _List_impl
    00300       : public _Node_Alloc_type
    00301       {
    00302     _List_node_base _M_node;
    00303     _List_impl (const _Node_Alloc_type& __a)
    00304     : _Node_Alloc_type(__a)
    00305     { }
    00306       };
    00307
    00308       _List_impl _M_impl;
    00309
    00310       _List_node<_Tp>*
    00311       _M_get_node()
    00312       { return _M_impl._Node_Alloc_type::allocate(1); }
    00313
    00314       void
    00315       _M_put_node(_List_node<_Tp>* __p)
    00316       { _M_impl._Node_Alloc_type::deallocate(__p, 1); }
    00317
    00318   public:
    00319       typedef _Alloc allocator_type;
    00320
    00321       allocator_type
    00322       get_allocator() const
    00323       { return allocator_type(*static_cast<
    00324                   const _Node_Alloc_type*>(&this->_M_impl)); }
    00325
    00326       _List_base(const allocator_type& __a)
    00327       : _M_impl(__a)
    00328       { _M_init(); }
    00329
    00330       // This is what actually destroys the list.
    00331       ~_List_base()
    00332       { _M_clear(); }
    00333
    00334       void
    00335       _M_clear();
    00336
    00337       void
    00338       _M_init()
    00339       {
    00340         this->_M_impl._M_node._M_next = &this->_M_impl._M_node;
    00341         this->_M_impl._M_node._M_prev = &this->_M_impl._M_node;
    00342       }
    00343     };
    00344
    00345   /**
    00346    *  @brief A standard container with linear time access to elements,
    00347    *  and fixed time insertion/deletion at any point in the sequence.
    00348    *
    00349    *  @ingroup Containers
    00350    *  @ingroup Sequences
    00351    *
    00352    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
    00353    *  <a href="tables.html#66">reversible container</a>, and a
    00354    *  <a href="tables.html#67">sequence</a>, including the
    00355    *  <a href="tables.html#68">optional sequence requirements</a> with the
    00356    *  %exception of @c at and @c operator[].
    00357    *
    00358    *  This is a @e doubly @e linked %list.  Traversal up and down the
    00359    *  %list requires linear time, but adding and removing elements (or
    00360    *  @e nodes) is done in constant time, regardless of where the
    00361    *  change takes place.  Unlike std::vector and std::deque,
    00362    *  random-access iterators are not provided, so subscripting ( @c
    00363    *  [] ) access is not allowed.  For algorithms which only need
    00364    *  sequential access, this lack makes no difference.
    00365    *
    00366    *  Also unlike the other standard containers, std::list provides
    00367    *  specialized algorithms %unique to linked lists, such as
    00368    *  splicing, sorting, and in-place reversal.
    00369    *
    00370    *  @if maint
    00371    *  A couple points on memory allocation for list<Tp>:
    00372    *
    00373    *  First, we never actually allocate a Tp, we allocate
    00374    *  List_node<Tp>'s and trust [20.1.5]/4 to DTRT.  This is to ensure
    00375    *  that after elements from %list<X,Alloc1> are spliced into
    00376    *  %list<X,Alloc2>, destroying the memory of the second %list is a
    00377    *  valid operation, i.e., Alloc1 giveth and Alloc2 taketh away.
    00378    *
    00379    *  Second, a %list conceptually represented as
    00380    *  @code
    00381    *    A <---> B <---> C <---> D
    00382    *  @endcode
    00383    *  is actually circular; a link exists between A and D.  The %list
    00384    *  class holds (as its only data member) a private list::iterator
    00385    *  pointing to @e D, not to @e A!  To get to the head of the %list,
    00386    *  we start at the tail and move forward by one.  When this member
    00387    *  iterator's next/previous pointers refer to itself, the %list is
    00388    *  %empty.  @endif
    00389   */
    00390   template<typename _Tp, typename _Alloc = allocator<_Tp> >
    00391     class list : protected _List_base<_Tp, _Alloc>
    00392     {
    00393       // concept requirements
    00394       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
    00395
    00396       typedef _List_base<_Tp, _Alloc>                   _Base;
    00397
    00398     public:
    00399       typedef _Tp                                        value_type;
    00400       typedef typename _Alloc::pointer                   pointer;
    00401       typedef typename _Alloc::const_pointer             const_pointer;
    00402       typedef typename _Alloc::reference                 reference;
    00403       typedef typename _Alloc::const_reference           const_reference;
    00404       typedef _List_iterator<_Tp>                        iterator;
    00405       typedef _List_const_iterator<_Tp>                  const_iterator;
    00406       typedef std::reverse_iterator<const_iterator>      const_reverse_iterator;
    00407       typedef std::reverse_iterator<iterator>            reverse_iterator;
    00408       typedef size_t                                     size_type;
    00409       typedef ptrdiff_t                                  difference_type;
    00410       typedef typename _Base::allocator_type             allocator_type;
    00411
    00412     protected:
    00413       // Note that pointers-to-_Node's can be ctor-converted to
    00414       // iterator types.
    00415       typedef _List_node<_Tp>               _Node;
    00416
    00417       /** @if maint
    00418        *  One data member plus two memory-handling functions.  If the
    00419        *  _Alloc type requires separate instances, then one of those
    00420        *  will also be included, accumulated from the topmost parent.
    00421        *  @endif
    00422        */
    00423       using _Base::_M_impl;
    00424       using _Base::_M_put_node;
    00425       using _Base::_M_get_node;
    00426
    00427       /**
    00428        *  @if maint
    00429        *  @param  x  An instance of user data.
    00430        *
    00431        *  Allocates space for a new node and constructs a copy of @a x in it.
    00432        *  @endif
    00433        */
    00434       _Node*
    00435       _M_create_node(const value_type& __x)
    00436       {
    00437     _Node* __p = this->_M_get_node();
    00438     try
    00439       {
    00440         this->get_allocator().construct(&__p->_M_data, __x);
    00441       }
    00442     catch(...)
    00443       {
    00444         _M_put_node(__p);
    00445         __throw_exception_again;
    00446       }
    00447     return __p;
    00448       }
    00449
    00450     public:
    00451       // [23.2.2.1] construct/copy/destroy
    00452       // (assign() and get_allocator() are also listed in this section)
    00453       /**
    00454        *  @brief  Default constructor creates no elements.
    00455        */
    00456       explicit
    00457       list(const allocator_type& __a = allocator_type())
    00458       : _Base(__a) { }
    00459
    00460       /**
    00461        *  @brief  Create a %list with copies of an exemplar element.
    00462        *  @param  n  The number of elements to initially create.
    00463        *  @param  value  An element to copy.
    00464        *
    00465        *  This constructor fills the %list with @a n copies of @a value.
    00466        */
    00467       list(size_type __n, const value_type& __value,
    00468        const allocator_type& __a = allocator_type())
    00469       : _Base(__a)
    00470       { this->insert(begin(), __n, __value); }
    00471
    00472       /**
    00473        *  @brief  Create a %list with default elements.
    00474        *  @param  n  The number of elements to initially create.
    00475        *
    00476        *  This constructor fills the %list with @a n copies of a
    00477        *  default-constructed element.
    00478        */
    00479       explicit
    00480       list(size_type __n)
    00481       : _Base(allocator_type())
    00482       { this->insert(begin(), __n, value_type()); }
    00483
    00484       /**
    00485        *  @brief  %List copy constructor.
    00486        *  @param  x  A %list of identical element and allocator types.
    00487        *
    00488        *  The newly-created %list uses a copy of the allocation object used
    00489        *  by @a x.
    00490        */
    00491       list(const list& __x)
    00492       : _Base(__x.get_allocator())
    00493       { this->insert(begin(), __x.begin(), __x.end()); }
    00494
    00495       /**
    00496        *  @brief  Builds a %list from a range.
    00497        *  @param  first  An input iterator.
    00498        *  @param  last  An input iterator.
    00499        *
    00500        *  Create a %list consisting of copies of the elements from
    00501        *  [@a first,@a last).  This is linear in N (where N is
    00502        *  distance(@a first,@a last)).
    00503        *
    00504        *  @if maint
    00505        *  We don't need any dispatching tricks here, because insert does all of
    00506        *  that anyway.
    00507        *  @endif
    00508        */
    00509       template<typename _InputIterator>
    00510         list(_InputIterator __first, _InputIterator __last,
    00511          const allocator_type& __a = allocator_type())
    00512         : _Base(__a)
    00513         { this->insert(begin(), __first, __last); }
    00514
    00515       /**
    00516        *  No explicit dtor needed as the _Base dtor takes care of
    00517        *  things.  The _Base dtor only erases the elements, and note
    00518        *  that if the elements themselves are pointers, the pointed-to
    00519        *  memory is not touched in any way.  Managing the pointer is
    00520        *  the user's responsibilty.
    00521        */
    00522
    00523       /**
    00524        *  @brief  %List assignment operator.
    00525        *  @param  x  A %list of identical element and allocator types.
    00526        *
    00527        *  All the elements of @a x are copied, but unlike the copy
    00528        *  constructor, the allocator object is not copied.
    00529        */
    00530       list&
    00531       operator=(const list& __x);
    00532
    00533       /**
    00534        *  @brief  Assigns a given value to a %list.
    00535        *  @param  n  Number of elements to be assigned.
    00536        *  @param  val  Value to be assigned.
    00537        *
    00538        *  This function fills a %list with @a n copies of the given
    00539        *  value.  Note that the assignment completely changes the %list
    00540        *  and that the resulting %list's size is the same as the number
    00541        *  of elements assigned.  Old data may be lost.
    00542        */
    00543       void
    00544       assign(size_type __n, const value_type& __val)
    00545       { _M_fill_assign(__n, __val); }
    00546
    00547       /**
    00548        *  @brief  Assigns a range to a %list.
    00549        *  @param  first  An input iterator.
    00550        *  @param  last   An input iterator.
    00551        *
    00552        *  This function fills a %list with copies of the elements in the
    00553        *  range [@a first,@a last).
    00554        *
    00555        *  Note that the assignment completely changes the %list and
    00556        *  that the resulting %list's size is the same as the number of
    00557        *  elements assigned.  Old data may be lost.
    00558        */
    00559       template<typename _InputIterator>
    00560         void
    00561         assign(_InputIterator __first, _InputIterator __last)
    00562         {
    00563       // Check whether it's an integral type.  If so, it's not an iterator.
    00564       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
    00565       _M_assign_dispatch(__first, __last, _Integral());
    00566     }
    00567
    00568       /// Get a copy of the memory allocation object.
    00569       allocator_type
    00570       get_allocator() const
    00571       { return _Base::get_allocator(); }
    00572
    00573       // iterators
    00574       /**
    00575        *  Returns a read/write iterator that points to the first element in the
    00576        *  %list.  Iteration is done in ordinary element order.
    00577        */
    00578       iterator
    00579       begin()
    00580       { return this->_M_impl._M_node._M_next; }
    00581
    00582       /**
    00583        *  Returns a read-only (constant) iterator that points to the
    00584        *  first element in the %list.  Iteration is done in ordinary
    00585        *  element order.
    00586        */
    00587       const_iterator
    00588       begin() const
    00589       { return this->_M_impl._M_node._M_next; }
    00590
    00591       /**
    00592        *  Returns a read/write iterator that points one past the last
    00593        *  element in the %list.  Iteration is done in ordinary element
    00594        *  order.
    00595        */
    00596       iterator
    00597       end() { return &this->_M_impl._M_node; }
    00598
    00599       /**
    00600        *  Returns a read-only (constant) iterator that points one past
    00601        *  the last element in the %list.  Iteration is done in ordinary
    00602        *  element order.
    00603        */
    00604       const_iterator
    00605       end() const
    00606       { return &this->_M_impl._M_node; }
    00607
    00608       /**
    00609        *  Returns a read/write reverse iterator that points to the last
    00610        *  element in the %list.  Iteration is done in reverse element
    00611        *  order.
    00612        */
    00613       reverse_iterator
    00614       rbegin()
    00615       { return reverse_iterator(end()); }
    00616
    00617       /**
    00618        *  Returns a read-only (constant) reverse iterator that points to
    00619        *  the last element in the %list.  Iteration is done in reverse
    00620        *  element order.
    00621        */
    00622       const_reverse_iterator
    00623       rbegin() const
    00624       { return const_reverse_iterator(end()); }
    00625
    00626       /**
    00627        *  Returns a read/write reverse iterator that points to one
    00628        *  before the first element in the %list.  Iteration is done in
    00629        *  reverse element order.
    00630        */
    00631       reverse_iterator
    00632       rend()
    00633       { return reverse_iterator(begin()); }
    00634
    00635       /**
    00636        *  Returns a read-only (constant) reverse iterator that points to one
    00637        *  before the first element in the %list.  Iteration is done in reverse
    00638        *  element order.
    00639        */
    00640       const_reverse_iterator
    00641       rend() const
    00642       { return const_reverse_iterator(begin()); }
    00643
    00644       // [23.2.2.2] capacity
    00645       /**
    00646        *  Returns true if the %list is empty.  (Thus begin() would equal
    00647        *  end().)
    00648        */
    00649       bool
    00650       empty() const
    00651       { return this->_M_impl._M_node._M_next == &this->_M_impl._M_node; }
    00652
    00653       /**  Returns the number of elements in the %list.  */
    00654       size_type
    00655       size() const
    00656       { return std::distance(begin(), end()); }
    00657
    00658       /**  Returns the size() of the largest possible %list.  */
    00659       size_type
    00660       max_size() const
    00661       { return size_type(-1); }
    00662
    00663       /**
    00664        *  @brief Resizes the %list to the specified number of elements.
    00665        *  @param new_size Number of elements the %list should contain.
    00666        *  @param x Data with which new elements should be populated.
    00667        *
    00668        *  This function will %resize the %list to the specified number
    00669        *  of elements.  If the number is smaller than the %list's
    00670        *  current size the %list is truncated, otherwise the %list is
    00671        *  extended and new elements are populated with given data.
    00672        */
    00673       void
    00674       resize(size_type __new_size, const value_type& __x);
    00675
    00676       /**
    00677        *  @brief  Resizes the %list to the specified number of elements.
    00678        *  @param  new_size  Number of elements the %list should contain.
    00679        *
    00680        *  This function will resize the %list to the specified number of
    00681        *  elements.  If the number is smaller than the %list's current
    00682        *  size the %list is truncated, otherwise the %list is extended
    00683        *  and new elements are default-constructed.
    00684        */
    00685       void
    00686       resize(size_type __new_size)
    00687       { this->resize(__new_size, value_type()); }
    00688
    00689       // element access
    00690       /**
    00691        *  Returns a read/write reference to the data at the first
    00692        *  element of the %list.
    00693        */
    00694       reference
    00695       front()
    00696       { return *begin(); }
    00697
    00698       /**
    00699        *  Returns a read-only (constant) reference to the data at the first
    00700        *  element of the %list.
    00701        */
    00702       const_reference
    00703       front() const
    00704       { return *begin(); }
    00705
    00706       /**
    00707        *  Returns a read/write reference to the data at the last element
    00708        *  of the %list.
    00709        */
    00710       reference
    00711       back()
    00712       {
    00713     iterator __tmp = end();
    00714     --__tmp;
    00715     return *__tmp;
    00716       }
    00717
    00718       /**
    00719        *  Returns a read-only (constant) reference to the data at the last
    00720        *  element of the %list.
    00721        */
    00722       const_reference
    00723       back() const
    00724       {
    00725     const_iterator __tmp = end();
    00726     --__tmp;
    00727     return *__tmp;
    00728       }
    00729
    00730       // [23.2.2.3] modifiers
    00731       /**
    00732        *  @brief  Add data to the front of the %list.
    00733        *  @param  x  Data to be added.
    00734        *
    00735        *  This is a typical stack operation.  The function creates an
    00736        *  element at the front of the %list and assigns the given data
    00737        *  to it.  Due to the nature of a %list this operation can be
    00738        *  done in constant time, and does not invalidate iterators and
    00739        *  references.
    00740        */
    00741       void
    00742       push_front(const value_type& __x)
    00743       { this->_M_insert(begin(), __x); }
    00744
    00745       /**
    00746        *  @brief  Removes first element.
    00747        *
    00748        *  This is a typical stack operation.  It shrinks the %list by
    00749        *  one.  Due to the nature of a %list this operation can be done
    00750        *  in constant time, and only invalidates iterators/references to
    00751        *  the element being removed.
    00752        *
    00753        *  Note that no data is returned, and if the first element's data
    00754        *  is needed, it should be retrieved before pop_front() is
    00755        *  called.
    00756        */
    00757       void
    00758       pop_front()
    00759       { this->_M_erase(begin()); }
    00760
    00761       /**
    00762        *  @brief  Add data to the end of the %list.
    00763        *  @param  x  Data to be added.
    00764        *
    00765        *  This is a typical stack operation.  The function creates an
    00766        *  element at the end of the %list and assigns the given data to
    00767        *  it.  Due to the nature of a %list this operation can be done
    00768        *  in constant time, and does not invalidate iterators and
    00769        *  references.
    00770        */
    00771       void
    00772       push_back(const value_type& __x)
    00773       { this->_M_insert(end(), __x); }
    00774
    00775       /**
    00776        *  @brief  Removes last element.
    00777        *
    00778        *  This is a typical stack operation.  It shrinks the %list by
    00779        *  one.  Due to the nature of a %list this operation can be done
    00780        *  in constant time, and only invalidates iterators/references to
    00781        *  the element being removed.
    00782        *
    00783        *  Note that no data is returned, and if the last element's data
    00784        *  is needed, it should be retrieved before pop_back() is called.
    00785        */
    00786       void
    00787       pop_back()
    00788       { this->_M_erase(this->_M_impl._M_node._M_prev); }
    00789
    00790       /**
    00791        *  @brief  Inserts given value into %list before specified iterator.
    00792        *  @param  position  An iterator into the %list.
    00793        *  @param  x  Data to be inserted.
    00794        *  @return  An iterator that points to the inserted data.
    00795        *
    00796        *  This function will insert a copy of the given value before
    00797        *  the specified location.  Due to the nature of a %list this
    00798        *  operation can be done in constant time, and does not
    00799        *  invalidate iterators and references.
    00800        */
    00801       iterator
    00802       insert(iterator __position, const value_type& __x);
    00803
    00804       /**
    00805        *  @brief  Inserts a number of copies of given data into the %list.
    00806        *  @param  position  An iterator into the %list.
    00807        *  @param  n  Number of elements to be inserted.
    00808        *  @param  x  Data to be inserted.
    00809        *
    00810        *  This function will insert a specified number of copies of the
    00811        *  given data before the location specified by @a position.
    00812        *
    00813        *  Due to the nature of a %list this operation can be done in
    00814        *  constant time, and does not invalidate iterators and
    00815        *  references.
    00816        */
    00817       void
    00818       insert(iterator __position, size_type __n, const value_type& __x)
    00819       { _M_fill_insert(__position, __n, __x); }
    00820
    00821       /**
    00822        *  @brief  Inserts a range into the %list.
    00823        *  @param  position  An iterator into the %list.
    00824        *  @param  first  An input iterator.
    00825        *  @param  last   An input iterator.
    00826        *
    00827        *  This function will insert copies of the data in the range [@a
    00828        *  first,@a last) into the %list before the location specified by
    00829        *  @a position.
    00830        *
    00831        *  Due to the nature of a %list this operation can be done in
    00832        *  constant time, and does not invalidate iterators and
    00833        *  references.
    00834        */
    00835       template<typename _InputIterator>
    00836         void
    00837         insert(iterator __position, _InputIterator __first,
    00838            _InputIterator __last)
    00839         {
    00840       // Check whether it's an integral type.  If so, it's not an iterator.
    00841       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
    00842       _M_insert_dispatch(__position, __first, __last, _Integral());
    00843     }
    00844
    00845       /**
    00846        *  @brief  Remove element at given position.
    00847        *  @param  position  Iterator pointing to element to be erased.
    00848        *  @return  An iterator pointing to the next element (or end()).
    00849        *
    00850        *  This function will erase the element at the given position and thus
    00851        *  shorten the %list by one.
    00852        *
    00853        *  Due to the nature of a %list this operation can be done in
    00854        *  constant time, and only invalidates iterators/references to
    00855        *  the element being removed.  The user is also cautioned that
    00856        *  this function only erases the element, and that if the element
    00857        *  is itself a pointer, the pointed-to memory is not touched in
    00858        *  any way.  Managing the pointer is the user's responsibilty.
    00859        */
    00860       iterator
    00861       erase(iterator __position);
    00862
    00863       /**
    00864        *  @brief  Remove a range of elements.
    00865        *  @param  first  Iterator pointing to the first element to be erased.
    00866        *  @param  last  Iterator pointing to one past the last element to be
    00867        *                erased.
    00868        *  @return  An iterator pointing to the element pointed to by @a last
    00869        *           prior to erasing (or end()).
    00870        *
    00871        *  This function will erase the elements in the range @a
    00872        *  [first,last) and shorten the %list accordingly.
    00873        *
    00874        *  Due to the nature of a %list this operation can be done in
    00875        *  constant time, and only invalidates iterators/references to
    00876        *  the element being removed.  The user is also cautioned that
    00877        *  this function only erases the elements, and that if the
    00878        *  elements themselves are pointers, the pointed-to memory is not
    00879        *  touched in any way.  Managing the pointer is the user's
    00880        *  responsibilty.
    00881        */
    00882       iterator
    00883       erase(iterator __first, iterator __last)
    00884       {
    00885     while (__first != __last)
    00886       __first = erase(__first);
    00887     return __last;
    00888       }
    00889
    00890       /**
    00891        *  @brief  Swaps data with another %list.
    00892        *  @param  x  A %list of the same element and allocator types.
    00893        *
    00894        *  This exchanges the elements between two lists in constant
    00895        *  time.  Note that the global std::swap() function is
    00896        *  specialized such that std::swap(l1,l2) will feed to this
    00897        *  function.
    00898        */
    00899       void
    00900       swap(list& __x)
    00901       { _List_node_base::swap(this->_M_impl._M_node, __x._M_impl._M_node); }
    00902
    00903       /**
    00904        *  Erases all the elements.  Note that this function only erases
    00905        *  the elements, and that if the elements themselves are
    00906        *  pointers, the pointed-to memory is not touched in any way.
    00907        *  Managing the pointer is the user's responsibilty.
    00908        */
    00909       void
    00910       clear()
    00911       {
    00912         _Base::_M_clear();
    00913         _Base::_M_init();
    00914       }
    00915
    00916       // [23.2.2.4] list operations
    00917       /**
    00918        *  @brief  Insert contents of another %list.
    00919        *  @param  position  Iterator referencing the element to insert before.
    00920        *  @param  x  Source list.
    00921        *
    00922        *  The elements of @a x are inserted in constant time in front of
    00923        *  the element referenced by @a position.  @a x becomes an empty
    00924        *  list.
    00925        */
    00926       void
    00927       splice(iterator __position, list& __x)
    00928       {
    00929     if (!__x.empty())
    00930       this->_M_transfer(__position, __x.begin(), __x.end());
    00931       }
    00932
    00933       /**
    00934        *  @brief  Insert element from another %list.
    00935        *  @param  position  Iterator referencing the element to insert before.
    00936        *  @param  x  Source list.
    00937        *  @param  i  Iterator referencing the element to move.
    00938        *
    00939        *  Removes the element in list @a x referenced by @a i and
    00940        *  inserts it into the current list before @a position.
    00941        */
    00942       void
    00943       splice(iterator __position, list&, iterator __i)
    00944       {
    00945     iterator __j = __i;
    00946     ++__j;
    00947     if (__position == __i || __position == __j)
    00948       return;
    00949     this->_M_transfer(__position, __i, __j);
    00950       }
    00951
    00952       /**
    00953        *  @brief  Insert range from another %list.
    00954        *  @param  position  Iterator referencing the element to insert before.
    00955        *  @param  x  Source list.
    00956        *  @param  first  Iterator referencing the start of range in x.
    00957        *  @param  last  Iterator referencing the end of range in x.
    00958        *
    00959        *  Removes elements in the range [first,last) and inserts them
    00960        *  before @a position in constant time.
    00961        *
    00962        *  Undefined if @a position is in [first,last).
    00963        */
    00964       void
    00965       splice(iterator __position, list&, iterator __first, iterator __last)
    00966       {
    00967     if (__first != __last)
    00968       this->_M_transfer(__position, __first, __last);
    00969       }
    00970
    00971       /**
    00972        *  @brief  Remove all elements equal to value.
    00973        *  @param  value  The value to remove.
    00974        *
    00975        *  Removes every element in the list equal to @a value.
    00976        *  Remaining elements stay in list order.  Note that this
    00977        *  function only erases the elements, and that if the elements
    00978        *  themselves are pointers, the pointed-to memory is not
    00979        *  touched in any way.  Managing the pointer is the user's
    00980        *  responsibilty.
    00981        */
    00982       void
    00983       remove(const _Tp& __value);
    00984
    00985       /**
    00986        *  @brief  Remove all elements satisfying a predicate.
    00987        *  @param  Predicate  Unary predicate function or object.
    00988        *
    00989        *  Removes every element in the list for which the predicate
    00990        *  returns true.  Remaining elements stay in list order.  Note
    00991        *  that this function only erases the elements, and that if the
    00992        *  elements themselves are pointers, the pointed-to memory is
    00993        *  not touched in any way.  Managing the pointer is the user's
    00994        *  responsibilty.
    00995        */
    00996       template<typename _Predicate>
    00997       void
    00998       remove_if(_Predicate);
    00999
    01000       /**
    01001        *  @brief  Remove consecutive duplicate elements.
    01002        *
    01003        *  For each consecutive set of elements with the same value,
    01004        *  remove all but the first one.  Remaining elements stay in
    01005        *  list order.  Note that this function only erases the
    01006        *  elements, and that if the elements themselves are pointers,
    01007        *  the pointed-to memory is not touched in any way.  Managing
    01008        *  the pointer is the user's responsibilty.
    01009        */
    01010       void
    01011       unique();
    01012
    01013       /**
    01014        *  @brief  Remove consecutive elements satisfying a predicate.
    01015        *  @param  BinaryPredicate  Binary predicate function or object.
    01016        *
    01017        *  For each consecutive set of elements [first,last) that
    01018        *  satisfy predicate(first,i) where i is an iterator in
    01019        *  [first,last), remove all but the first one.  Remaining
    01020        *  elements stay in list order.  Note that this function only
    01021        *  erases the elements, and that if the elements themselves are
    01022        *  pointers, the pointed-to memory is not touched in any way.
    01023        *  Managing the pointer is the user's responsibilty.
    01024        */
    01025       template<typename _BinaryPredicate>
    01026         void
    01027         unique(_BinaryPredicate);
    01028
    01029       /**
    01030        *  @brief  Merge sorted lists.
    01031        *  @param  x  Sorted list to merge.
    01032        *
    01033        *  Assumes that both @a x and this list are sorted according to
    01034        *  operator<().  Merges elements of @a x into this list in
    01035        *  sorted order, leaving @a x empty when complete.  Elements in
    01036        *  this list precede elements in @a x that are equal.
    01037        */
    01038       void
    01039       merge(list& __x);
    01040
    01041       /**
    01042        *  @brief  Merge sorted lists according to comparison function.
    01043        *  @param  x  Sorted list to merge.
    01044        *  @param StrictWeakOrdering Comparison function definining
    01045        *  sort order.
    01046        *
    01047        *  Assumes that both @a x and this list are sorted according to
    01048        *  StrictWeakOrdering.  Merges elements of @a x into this list
    01049        *  in sorted order, leaving @a x empty when complete.  Elements
    01050        *  in this list precede elements in @a x that are equivalent
    01051        *  according to StrictWeakOrdering().
    01052        */
    01053       template<typename _StrictWeakOrdering>
    01054         void
    01055         merge(list&, _StrictWeakOrdering);
    01056
    01057       /**
    01058        *  @brief  Reverse the elements in list.
    01059        *
    01060        *  Reverse the order of elements in the list in linear time.
    01061        */
    01062       void
    01063       reverse()
    01064       { this->_M_impl._M_node.reverse(); }
    01065
    01066       /**
    01067        *  @brief  Sort the elements.
    01068        *
    01069        *  Sorts the elements of this list in NlogN time.  Equivalent
    01070        *  elements remain in list order.
    01071        */
    01072       void
    01073       sort();
    01074
    01075       /**
    01076        *  @brief  Sort the elements according to comparison function.
    01077        *
    01078        *  Sorts the elements of this list in NlogN time.  Equivalent
    01079        *  elements remain in list order.
    01080        */
    01081       template<typename _StrictWeakOrdering>
    01082         void
    01083         sort(_StrictWeakOrdering);
    01084
    01085     protected:
    01086       // Internal assign functions follow.
    01087
    01088       // Called by the range assign to implement [23.1.1]/9
    01089       template<typename _Integer>
    01090         void
    01091         _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
    01092         {
    01093       _M_fill_assign(static_cast<size_type>(__n),
    01094              static_cast<value_type>(__val));
    01095     }
    01096
    01097       // Called by the range assign to implement [23.1.1]/9
    01098       template<typename _InputIterator>
    01099         void
    01100         _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
    01101                __false_type);
    01102
    01103       // Called by assign(n,t), and the range assign when it turns out
    01104       // to be the same thing.
    01105       void
    01106       _M_fill_assign(size_type __n, const value_type& __val);
    01107
    01108
    01109       // Internal insert functions follow.
    01110
    01111       // Called by the range insert to implement [23.1.1]/9
    01112       template<typename _Integer>
    01113         void
    01114         _M_insert_dispatch(iterator __pos, _Integer __n, _Integer __x,
    01115                __true_type)
    01116         {
    01117       _M_fill_insert(__pos, static_cast<size_type>(__n),
    01118              static_cast<value_type>(__x));
    01119     }
    01120
    01121       // Called by the range insert to implement [23.1.1]/9
    01122       template<typename _InputIterator>
    01123         void
    01124         _M_insert_dispatch(iterator __pos,
    01125                _InputIterator __first, _InputIterator __last,
    01126                __false_type)
    01127         {
    01128       for (; __first != __last; ++__first)
    01129         _M_insert(__pos, *__first);
    01130     }
    01131
    01132       // Called by insert(p,n,x), and the range insert when it turns out
    01133       // to be the same thing.
    01134       void
    01135       _M_fill_insert(iterator __pos, size_type __n, const value_type& __x)
    01136       {
    01137     for (; __n > 0; --__n)
    01138       _M_insert(__pos, __x);
    01139       }
    01140
    01141
    01142       // Moves the elements from [first,last) before position.
    01143       void
    01144       _M_transfer(iterator __position, iterator __first, iterator __last)
    01145       { __position._M_node->transfer(__first._M_node, __last._M_node); }
    01146
    01147       // Inserts new element at position given and with value given.
    01148       void
    01149       _M_insert(iterator __position, const value_type& __x)
    01150       {
    01151         _Node* __tmp = _M_create_node(__x);
    01152         __tmp->hook(__position._M_node);
    01153       }
    01154
    01155       // Erases element at position given.
    01156       void
    01157       _M_erase(iterator __position)
    01158       {
    01159         __position._M_node->unhook();
    01160         _Node* __n = static_cast<_Node*>(__position._M_node);
    01161         this->get_allocator().destroy(&__n->_M_data);
    01162         _M_put_node(__n);
    01163       }
    01164     };
    01165
    01166   /**
    01167    *  @brief  List equality comparison.
    01168    *  @param  x  A %list.
    01169    *  @param  y  A %list of the same type as @a x.
    01170    *  @return  True iff the size and elements of the lists are equal.
    01171    *
    01172    *  This is an equivalence relation.  It is linear in the size of
    01173    *  the lists.  Lists are considered equivalent if their sizes are
    01174    *  equal, and if corresponding elements compare equal.
    01175   */
    01176   template<typename _Tp, typename _Alloc>
    01177     inline bool
    01178     operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01179     {
    01180       typedef typename list<_Tp, _Alloc>::const_iterator const_iterator;
    01181       const_iterator __end1 = __x.end();
    01182       const_iterator __end2 = __y.end();
    01183
    01184       const_iterator __i1 = __x.begin();
    01185       const_iterator __i2 = __y.begin();
    01186       while (__i1 != __end1 && __i2 != __end2 && *__i1 == *__i2)
    01187     {
    01188       ++__i1;
    01189       ++__i2;
    01190     }
    01191       return __i1 == __end1 && __i2 == __end2;
    01192     }
    01193
    01194   /**
    01195    *  @brief  List ordering relation.
    01196    *  @param  x  A %list.
    01197    *  @param  y  A %list of the same type as @a x.
    01198    *  @return  True iff @a x is lexicographically less than @a y.
    01199    *
    01200    *  This is a total ordering relation.  It is linear in the size of the
    01201    *  lists.  The elements must be comparable with @c <.
    01202    *
    01203    *  See std::lexicographical_compare() for how the determination is made.
    01204   */
    01205   template<typename _Tp, typename _Alloc>
    01206     inline bool
    01207     operator<(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01208     { return std::lexicographical_compare(__x.begin(), __x.end(),
    01209                       __y.begin(), __y.end()); }
    01210
    01211   /// Based on operator==
    01212   template<typename _Tp, typename _Alloc>
    01213     inline bool
    01214     operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01215     { return !(__x == __y); }
    01216
    01217   /// Based on operator<
    01218   template<typename _Tp, typename _Alloc>
    01219     inline bool
    01220     operator>(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01221     { return __y < __x; }
    01222
    01223   /// Based on operator<
    01224   template<typename _Tp, typename _Alloc>
    01225     inline bool
    01226     operator<=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
    01227     { return !(__y < __x); }
    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   /// See std::list::swap().
    01236   template<typename _Tp, typename _Alloc>
    01237     inline void
    01238     swap(list<_Tp, _Alloc>& __x, list<_Tp, _Alloc>& __y)
    01239     { __x.swap(__y); }
    01240 } // namespace std
    01241
    01242 #endif /* _LIST_H */
    01243