1 // Compatibility symbols for previous versions, list bits -*- C++ -*-
2 
3 // Copyright (C) 2010-2018 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 #include <bits/move.h>
26 
27 #ifndef _GLIBCXX_BEGIN_NAMESPACE_COMPAT
28 # define _GLIBCXX_BEGIN_NAMESPACE_COMPAT
29 #endif
30 
31 #ifndef _GLIBCXX_END_NAMESPACE_COMPAT
32 # define _GLIBCXX_END_NAMESPACE_COMPAT
33 #endif
34 
35 namespace std _GLIBCXX_VISIBILITY(default)
36 {
37 _GLIBCXX_BEGIN_NAMESPACE_COMPAT
38 
39   struct _List_node_base
40   {
41     _List_node_base* _M_next;
42     _List_node_base* _M_prev;
43 
44     static void
45     swap(_List_node_base& __x, _List_node_base& __y) throw ();
46 
47     void
48     transfer(_List_node_base * const __first,
49 	     _List_node_base * const __last) throw ();
50 
51     void
52     reverse() throw ();
53 
54     void
55     hook(_List_node_base * const __position) throw ();
56 
57     void
58     unhook() throw ();
59   };
60 
61   void
swap(_List_node_base & __x,_List_node_base & __y)62   _List_node_base::swap(_List_node_base& __x, _List_node_base& __y) throw()
63   {
64     if ( __x._M_next != &__x )
65       {
66 	if ( __y._M_next != &__y )
67 	  {
68 	    // Both __x and __y are not empty.
69 	    std::swap(__x._M_next,__y._M_next);
70 	    std::swap(__x._M_prev,__y._M_prev);
71 	    __x._M_next->_M_prev = __x._M_prev->_M_next = &__x;
72 	    __y._M_next->_M_prev = __y._M_prev->_M_next = &__y;
73 	  }
74 	else
75 	  {
76 	    // __x is not empty, __y is empty.
77 	    __y._M_next = __x._M_next;
78 	    __y._M_prev = __x._M_prev;
79 	    __y._M_next->_M_prev = __y._M_prev->_M_next = &__y;
80 	    __x._M_next = __x._M_prev = &__x;
81 	  }
82       }
83     else if ( __y._M_next != &__y )
84       {
85 	// __x is empty, __y is not empty.
86 	__x._M_next = __y._M_next;
87 	__x._M_prev = __y._M_prev;
88 	__x._M_next->_M_prev = __x._M_prev->_M_next = &__x;
89 	__y._M_next = __y._M_prev = &__y;
90       }
91   }
92 
93   void
transfer(_List_node_base * const __first,_List_node_base * const __last)94   _List_node_base::transfer(_List_node_base * const __first,
95 			    _List_node_base * const __last) throw ()
96   {
97     if (this != __last)
98     {
99       // Remove [first, last) from its old position.
100       __last->_M_prev->_M_next  = this;
101       __first->_M_prev->_M_next = __last;
102       this->_M_prev->_M_next    = __first;
103 
104       // Splice [first, last) into its new position.
105       _List_node_base* const __tmp = this->_M_prev;
106       this->_M_prev                = __last->_M_prev;
107       __last->_M_prev              = __first->_M_prev;
108       __first->_M_prev             = __tmp;
109     }
110   }
111 
112   void
reverse()113   _List_node_base::reverse() throw ()
114   {
115     _List_node_base* __tmp = this;
116     do
117     {
118       std::swap(__tmp->_M_next, __tmp->_M_prev);
119 
120       // Old next node is now prev.
121       __tmp = __tmp->_M_prev;
122     }
123     while (__tmp != this);
124   }
125 
126   void
hook(_List_node_base * const __position)127   _List_node_base::hook(_List_node_base* const __position) throw ()
128   {
129     this->_M_next = __position;
130     this->_M_prev = __position->_M_prev;
131     __position->_M_prev->_M_next = this;
132     __position->_M_prev = this;
133   }
134 
135   void
unhook()136   _List_node_base::unhook() throw ()
137   {
138     _List_node_base* const __next_node = this->_M_next;
139     _List_node_base* const __prev_node = this->_M_prev;
140     __prev_node->_M_next = __next_node;
141     __next_node->_M_prev = __prev_node;
142   }
143 
144 _GLIBCXX_END_NAMESPACE_COMPAT
145 
146 } // namespace std
147