1 // std::list utilities implementation -*- C++ -*- 2 3 // Copyright (C) 2003-2018 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 /* 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 namespace std _GLIBCXX_VISIBILITY(default) 54 { 55 _GLIBCXX_BEGIN_NAMESPACE_VERSION 56 57 namespace __detail 58 { 59 void 60 _List_node_base::swap(_List_node_base& __x, 61 _List_node_base& __y) _GLIBCXX_USE_NOEXCEPT 62 { 63 if ( __x._M_next != &__x ) 64 { 65 if ( __y._M_next != &__y ) 66 { 67 // Both __x and __y are not empty. 68 std::swap(__x._M_next,__y._M_next); 69 std::swap(__x._M_prev,__y._M_prev); 70 __x._M_next->_M_prev = __x._M_prev->_M_next = &__x; 71 __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:: 94 _M_transfer(_List_node_base * const __first, 95 _List_node_base * const __last) _GLIBCXX_USE_NOEXCEPT 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 113 _List_node_base::_M_reverse() _GLIBCXX_USE_NOEXCEPT 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 127 _List_node_base:: 128 _M_hook(_List_node_base* const __position) _GLIBCXX_USE_NOEXCEPT 129 { 130 this->_M_next = __position; 131 this->_M_prev = __position->_M_prev; 132 __position->_M_prev->_M_next = this; 133 __position->_M_prev = this; 134 } 135 136 void 137 _List_node_base::_M_unhook() _GLIBCXX_USE_NOEXCEPT 138 { 139 _List_node_base* const __next_node = this->_M_next; 140 _List_node_base* const __prev_node = this->_M_prev; 141 __prev_node->_M_next = __next_node; 142 __next_node->_M_prev = __prev_node; 143 } 144 } // namespace __detail 145 146 _GLIBCXX_END_NAMESPACE_VERSION 147 } // namespace std 148