libstdc++: erase_fn_imps.hpp Source File

libstdc++

rb_tree_map_/erase_fn_imps.hpp
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1// -*- C++ -*-
2
3// Copyright (C) 2005-2026 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 terms
7// of the GNU General Public License as published by the Free Software
8// Foundation; either version 3, or (at your option) any later
9// version.
10
11// This library is distributed in the hope that it will be useful, but
12// WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14// 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// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
26
27// Permission to use, copy, modify, sell, and distribute this software
28// is hereby granted without fee, provided that the above copyright
29// notice appears in all copies, and that both that copyright notice
30// and this permission notice appear in supporting documentation. None
31// of the above authors, nor IBM Haifa Research Laboratories, make any
32// representation about the suitability of this software for any
33// purpose. It is provided "as is" without express or implied
34// warranty.
35
36/**
37 * @file rb_tree_map_/erase_fn_imps.hpp
38 * Contains an implementation for rb_tree_.
39 */
40
41#ifdef PB_DS_CLASS_C_DEC
42
43PB_DS_CLASS_T_DEC
44inline bool
45PB_DS_CLASS_C_DEC::
46erase(key_const_reference r_key)
47{
48 point_iterator it = this->find(r_key);
49 if (it == base_type::end())
50 return false;
51 erase(it);
52 return true;
53}
54
55PB_DS_CLASS_T_DEC
56inline typename PB_DS_CLASS_C_DEC::iterator
57PB_DS_CLASS_C_DEC::
58erase(iterator it)
59{
60 PB_DS_ASSERT_VALID((*this))
61 if (it == base_type::end())
62 return it;
63
64 iterator ret_it = it;
65 ++ret_it;
66 erase_node(it.m_p_nd);
67 PB_DS_ASSERT_VALID((*this))
68 return ret_it;
69}
70
71PB_DS_CLASS_T_DEC
72inline typename PB_DS_CLASS_C_DEC::reverse_iterator
73PB_DS_CLASS_C_DEC::
74erase(reverse_iterator it)
75{
76 PB_DS_ASSERT_VALID((*this))
77 if (it.m_p_nd == base_type::m_p_head)
78 return it;
79
80 reverse_iterator ret_it = it;
81 ++ret_it;
82 erase_node(it.m_p_nd);
83 PB_DS_ASSERT_VALID((*this))
84 return ret_it;
85}
86
87PB_DS_CLASS_T_DEC
88template<typename Pred>
89inline typename PB_DS_CLASS_C_DEC::size_type
90PB_DS_CLASS_C_DEC::
91erase_if(Pred pred)
92{
93 PB_DS_ASSERT_VALID((*this))
94 size_type num_ersd = 0;
95 iterator it = base_type::begin();
96 while (it != base_type::end())
97 {
98 if (pred(*it))
99 {
100 ++num_ersd;
101 it = erase(it);
102 }
103 else
104 ++it;
105 }
106
107 PB_DS_ASSERT_VALID((*this))
108 return num_ersd;
109}
110
111PB_DS_CLASS_T_DEC
112void
113PB_DS_CLASS_C_DEC::
114erase_node(node_pointer p_nd)
115{
116 remove_node(p_nd);
117 base_type::actual_erase_node(p_nd);
118 PB_DS_ASSERT_VALID((*this))
119}
120
121PB_DS_CLASS_T_DEC
122void
123PB_DS_CLASS_C_DEC::
124remove_node(node_pointer p_z)
125{
126 this->update_min_max_for_erased_node(p_z);
127 node_pointer p_y = p_z;
128 node_pointer p_x = 0;
129 node_pointer p_new_x_parent = 0;
130
131 if (p_y->m_p_left == 0)
132 p_x = p_y->m_p_right;
133 else if (p_y->m_p_right == 0)
134 p_x = p_y->m_p_left;
135 else
136 {
137 p_y = p_y->m_p_right;
138 while (p_y->m_p_left != 0)
139 p_y = p_y->m_p_left;
140 p_x = p_y->m_p_right;
141 }
142
143 if (p_y == p_z)
144 {
145 p_new_x_parent = p_y->m_p_parent;
146 if (p_x != 0)
147 p_x->m_p_parent = p_y->m_p_parent;
148
149 if (base_type::m_p_head->m_p_parent == p_z)
150 base_type::m_p_head->m_p_parent = p_x;
151 else if (p_z->m_p_parent->m_p_left == p_z)
152 {
153 p_y->m_p_left = p_z->m_p_parent;
154 p_z->m_p_parent->m_p_left = p_x;
155 }
156 else
157 {
158 p_y->m_p_left = 0;
159 p_z->m_p_parent->m_p_right = p_x;
160 }
161 }
162 else
163 {
164 p_z->m_p_left->m_p_parent = p_y;
165 p_y->m_p_left = p_z->m_p_left;
166 if (p_y != p_z->m_p_right)
167 {
168 p_new_x_parent = p_y->m_p_parent;
169 if (p_x != 0)
170 p_x->m_p_parent = p_y->m_p_parent;
171 p_y->m_p_parent->m_p_left = p_x;
172 p_y->m_p_right = p_z->m_p_right;
173 p_z->m_p_right->m_p_parent = p_y;
174 }
175 else
176 p_new_x_parent = p_y;
177
178 if (base_type::m_p_head->m_p_parent == p_z)
179 base_type::m_p_head->m_p_parent = p_y;
180 else if (p_z->m_p_parent->m_p_left == p_z)
181 p_z->m_p_parent->m_p_left = p_y;
182 else
183 p_z->m_p_parent->m_p_right = p_y;
184
185 p_y->m_p_parent = p_z->m_p_parent;
186 std::swap(p_y->m_red, p_z->m_red);
187 p_y = p_z;
188 }
189
190 this->update_to_top(p_new_x_parent, (node_update* )this);
191
192 if (p_y->m_red)
193 return;
194
195 remove_fixup(p_x, p_new_x_parent);
196}
197
198PB_DS_CLASS_T_DEC
199void
200PB_DS_CLASS_C_DEC::
201remove_fixup(node_pointer p_x, node_pointer p_new_x_parent)
202{
203 _GLIBCXX_DEBUG_ASSERT(p_x == 0 || p_x->m_p_parent == p_new_x_parent);
204
205 while (p_x != base_type::m_p_head->m_p_parent && is_effectively_black(p_x))
206 if (p_x == p_new_x_parent->m_p_left)
207 {
208 node_pointer p_w = p_new_x_parent->m_p_right;
209 if (p_w->m_red)
210 {
211 p_w->m_red = false;
212 p_new_x_parent->m_red = true;
213 base_type::rotate_left(p_new_x_parent);
214 p_w = p_new_x_parent->m_p_right;
215 }
216
217 if (is_effectively_black(p_w->m_p_left)
218 && is_effectively_black(p_w->m_p_right))
219 {
220 p_w->m_red = true;
221 p_x = p_new_x_parent;
222 p_new_x_parent = p_new_x_parent->m_p_parent;
223 }
224 else
225 {
226 if (is_effectively_black(p_w->m_p_right))
227 {
228 if (p_w->m_p_left != 0)
229 p_w->m_p_left->m_red = false;
230
231 p_w->m_red = true;
232 base_type::rotate_right(p_w);
233 p_w = p_new_x_parent->m_p_right;
234 }
235
236 p_w->m_red = p_new_x_parent->m_red;
237 p_new_x_parent->m_red = false;
238
239 if (p_w->m_p_right != 0)
240 p_w->m_p_right->m_red = false;
241
242 base_type::rotate_left(p_new_x_parent);
243 this->update_to_top(p_new_x_parent, (node_update* )this);
244 break;
245 }
246 }
247 else
248 {
249 node_pointer p_w = p_new_x_parent->m_p_left;
250 if (p_w->m_red == true)
251 {
252 p_w->m_red = false;
253 p_new_x_parent->m_red = true;
254 base_type::rotate_right(p_new_x_parent);
255 p_w = p_new_x_parent->m_p_left;
256 }
257
258 if (is_effectively_black(p_w->m_p_right)
259 && is_effectively_black(p_w->m_p_left))
260 {
261 p_w->m_red = true;
262 p_x = p_new_x_parent;
263 p_new_x_parent = p_new_x_parent->m_p_parent;
264 }
265 else
266 {
267 if (is_effectively_black(p_w->m_p_left))
268 {
269 if (p_w->m_p_right != 0)
270 p_w->m_p_right->m_red = false;
271
272 p_w->m_red = true;
273 base_type::rotate_left(p_w);
274 p_w = p_new_x_parent->m_p_left;
275 }
276
277 p_w->m_red = p_new_x_parent->m_red;
278 p_new_x_parent->m_red = false;
279
280 if (p_w->m_p_left != 0)
281 p_w->m_p_left->m_red = false;
282
283 base_type::rotate_right(p_new_x_parent);
284 this->update_to_top(p_new_x_parent, (node_update* )this);
285 break;
286 }
287 }
288
289 if (p_x != 0)
290 p_x->m_red = false;
291}
292#endif