libstdc++-v3/src/list.cc

   1 // std::list utilities implementation -*- C++ -*-
   2
   3 // Copyright (C) 2003, 2005, 2009, 2010 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /*
  26  *
  27  * Copyright (c) 1994
  28  * Hewlett-Packard Company
  29  *
  30  * Permission to use, copy, modify, distribute and sell this software
  31  * and its documentation for any purpose is hereby granted without fee,
  32  * provided that the above copyright notice appear in all copies and
  33  * that both that copyright notice and this permission notice appear
  34  * in supporting documentation.  Hewlett-Packard Company makes no
  35  * representations about the suitability of this software for any
  36  * purpose.  It is provided "as is" without express or implied warranty.
  37  *
  38  *
  39  * Copyright (c) 1996,1997
  40  * Silicon Graphics Computer Systems, Inc.
  41  *
  42  * Permission to use, copy, modify, distribute and sell this software
  43  * and its documentation for any purpose is hereby granted without fee,
  44  * provided that the above copyright notice appear in all copies and
  45  * that both that copyright notice and this permission notice appear
  46  * in supporting documentation.  Silicon Graphics makes no
  47  * representations about the suitability of this software for any
  48  * purpose.  It is provided "as is" without express or implied warranty.
  49  */
  50
  51 #include <list>
  52
  53 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
  54
  55   void
  56   _List_node_base::swap(_List_node_base& __x, _List_node_base& __y) throw()
  57   {
  58     if ( __x._M_next != &__x )
  59     {
  60       if ( __y._M_next != &__y )
  61       {
  62         // Both __x and __y are not empty.
  63         std::swap(__x._M_next,__y._M_next);
  64         std::swap(__x._M_prev,__y._M_prev);
  65         __x._M_next->_M_prev = __x._M_prev->_M_next = &__x;
  66         __y._M_next->_M_prev = __y._M_prev->_M_next = &__y;
  67       }
  68       else
  69       {
  70         // __x is not empty, __y is empty.
  71         __y._M_next = __x._M_next;
  72         __y._M_prev = __x._M_prev;
  73         __y._M_next->_M_prev = __y._M_prev->_M_next = &__y;
  74         __x._M_next = __x._M_prev = &__x;
  75       }
  76     }
  77     else if ( __y._M_next != &__y )
  78     {
  79       // __x is empty, __y is not empty.
  80       __x._M_next = __y._M_next;
  81       __x._M_prev = __y._M_prev;
  82       __x._M_next->_M_prev = __x._M_prev->_M_next = &__x;
  83       __y._M_next = __y._M_prev = &__y;
  84     }
  85   }
  86
  87   void
  88   _List_node_base::_M_transfer(_List_node_base * const __first,
  89                                _List_node_base * const __last) throw()
  90   {
  91     if (this != __last)
  92     {
  93       // Remove [first, last) from its old position.
  94       __last->_M_prev->_M_next  = this;
  95       __first->_M_prev->_M_next = __last;
  96       this->_M_prev->_M_next    = __first;
  97
  98       // Splice [first, last) into its new position.
  99       _List_node_base* const __tmp = this->_M_prev;
 100       this->_M_prev                = __last->_M_prev;
 101       __last->_M_prev              = __first->_M_prev;
 102       __first->_M_prev             = __tmp;
 103     }
 104   }
 105
 106   void
 107   _List_node_base::_M_reverse() throw()
 108   {
 109     _List_node_base* __tmp = this;
 110     do
 111     {
 112       std::swap(__tmp->_M_next, __tmp->_M_prev);
 113
 114       // Old next node is now prev.
 115       __tmp = __tmp->_M_prev;
 116     }
 117     while (__tmp != this);
 118   }
 119
 120   void
 121   _List_node_base::_M_hook(_List_node_base* const __position) throw()
 122   {
 123     this->_M_next = __position;
 124     this->_M_prev = __position->_M_prev;
 125     __position->_M_prev->_M_next = this;
 126     __position->_M_prev = this;
 127   }
 128
 129   void
 130   _List_node_base::_M_unhook() throw()
 131   {
 132     _List_node_base* const __next_node = this->_M_next;
 133     _List_node_base* const __prev_node = this->_M_prev;
 134     __prev_node->_M_next = __next_node;
 135     __next_node->_M_prev = __prev_node;
 136   }
 137
 138 _GLIBCXX_END_NESTED_NAMESPACE