1247738Sbapt// std::list utilities implementation -*- C++ -*-
2247738Sbapt
3247738Sbapt// Copyright (C) 2003, 2005 Free Software Foundation, Inc.
4247738Sbapt//
5247738Sbapt// This file is part of the GNU ISO C++ Library.  This library is free
6247738Sbapt// software; you can redistribute it and/or modify it under the
7247738Sbapt// terms of the GNU General Public License as published by the
8247738Sbapt// Free Software Foundation; either version 2, or (at your option)
9247738Sbapt// any later version.
10247738Sbapt
11247738Sbapt// This library is distributed in the hope that it will be useful,
12247738Sbapt// but WITHOUT ANY WARRANTY; without even the implied warranty of
13247738Sbapt// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14247738Sbapt// GNU General Public License for more details.
15247738Sbapt
16247738Sbapt// You should have received a copy of the GNU General Public License along
17247738Sbapt// with this library; see the file COPYING.  If not, write to the Free
18247738Sbapt// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
19247738Sbapt// USA.
20247738Sbapt
21247738Sbapt// As a special exception, you may use this file as part of a free software
22247738Sbapt// library without restriction.  Specifically, if other files instantiate
23247738Sbapt// templates or use macros or inline functions from this file, or you compile
24247738Sbapt// this file and link it with other files to produce an executable, this
25247738Sbapt// file does not by itself cause the resulting executable to be covered by
26247738Sbapt// the GNU General Public License.  This exception does not however
27247738Sbapt// invalidate any other reasons why the executable file might be covered by
28247738Sbapt// the GNU General Public License.
29247738Sbapt
30247738Sbapt/*
31247738Sbapt *
32247738Sbapt * Copyright (c) 1994
33247738Sbapt * Hewlett-Packard Company
34247738Sbapt *
35247738Sbapt * Permission to use, copy, modify, distribute and sell this software
36247738Sbapt * and its documentation for any purpose is hereby granted without fee,
37247738Sbapt * provided that the above copyright notice appear in all copies and
38247738Sbapt * that both that copyright notice and this permission notice appear
39247738Sbapt * in supporting documentation.  Hewlett-Packard Company makes no
40247738Sbapt * representations about the suitability of this software for any
41247738Sbapt * purpose.  It is provided "as is" without express or implied warranty.
42247738Sbapt *
43247738Sbapt *
44247738Sbapt * Copyright (c) 1996,1997
45247738Sbapt * Silicon Graphics Computer Systems, Inc.
46247738Sbapt *
47247738Sbapt * Permission to use, copy, modify, distribute and sell this software
48247738Sbapt * and its documentation for any purpose is hereby granted without fee,
49247738Sbapt * provided that the above copyright notice appear in all copies and
50247738Sbapt * that both that copyright notice and this permission notice appear
51247738Sbapt * in supporting documentation.  Silicon Graphics makes no
52247738Sbapt * representations about the suitability of this software for any
53247738Sbapt * purpose.  It is provided "as is" without express or implied warranty.
54247738Sbapt */
55247738Sbapt
56247738Sbapt#include <list>
57247738Sbapt
58247738Sbapt_GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD)
59247738Sbapt
60247738Sbapt  void
61247738Sbapt  _List_node_base::swap(_List_node_base& __x, _List_node_base& __y)
62247738Sbapt  {
63247738Sbapt    if ( __x._M_next != &__x )
64247738Sbapt    {
65247738Sbapt      if ( __y._M_next != &__y )
66247738Sbapt      {
67247738Sbapt        // Both __x and __y are not empty.
68247738Sbapt        std::swap(__x._M_next,__y._M_next);
69247738Sbapt        std::swap(__x._M_prev,__y._M_prev);
70247738Sbapt        __x._M_next->_M_prev = __x._M_prev->_M_next = &__x;
71247738Sbapt        __y._M_next->_M_prev = __y._M_prev->_M_next = &__y;
72      }
73      else
74      {
75        // __x is not empty, __y is empty.
76        __y._M_next = __x._M_next;
77        __y._M_prev = __x._M_prev;
78        __y._M_next->_M_prev = __y._M_prev->_M_next = &__y;
79        __x._M_next = __x._M_prev = &__x;
80      }
81    }
82    else if ( __y._M_next != &__y )
83    {
84      // __x is empty, __y is not empty.
85      __x._M_next = __y._M_next;
86      __x._M_prev = __y._M_prev;
87      __x._M_next->_M_prev = __x._M_prev->_M_next = &__x;
88      __y._M_next = __y._M_prev = &__y;
89    }
90  }
91
92  void
93  _List_node_base::transfer(_List_node_base * const __first,
94                            _List_node_base * const __last)
95  {
96    if (this != __last)
97    {
98      // Remove [first, last) from its old position.
99      __last->_M_prev->_M_next  = this;
100      __first->_M_prev->_M_next = __last;
101      this->_M_prev->_M_next    = __first;
102
103      // Splice [first, last) into its new position.
104      _List_node_base* const __tmp = this->_M_prev;
105      this->_M_prev                = __last->_M_prev;
106      __last->_M_prev              = __first->_M_prev;
107      __first->_M_prev             = __tmp;
108    }
109  }
110
111  void
112  _List_node_base::reverse()
113  {
114    _List_node_base* __tmp = this;
115    do
116    {
117      std::swap(__tmp->_M_next, __tmp->_M_prev);
118      __tmp = __tmp->_M_prev;     // Old next node is now prev.
119    }
120    while (__tmp != this);
121  }
122
123  void
124  _List_node_base::hook(_List_node_base* const __position)
125  {
126    this->_M_next = __position;
127    this->_M_prev = __position->_M_prev;
128    __position->_M_prev->_M_next = this;
129    __position->_M_prev = this;
130  }
131
132  void
133  _List_node_base::unhook()
134  {
135    _List_node_base* const __next_node = this->_M_next;
136    _List_node_base* const __prev_node = this->_M_prev;
137    __prev_node->_M_next = __next_node;
138    __next_node->_M_prev = __prev_node;
139  }
140
141_GLIBCXX_END_NESTED_NAMESPACE
142