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
139