historical/toontown-classic.git/panda/include/linkedListNode.I
2024-01-16 11:20:27 -06:00

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/**
* PANDA 3D SOFTWARE
* Copyright (c) Carnegie Mellon University. All rights reserved.
*
* All use of this software is subject to the terms of the revised BSD
* license. You should have received a copy of this license along
* with this source code in a file named "LICENSE."
*
* @file linkedListNode.I
* @author drose
* @date 2006-03-16
*/
/**
*
*/
INLINE LinkedListNode::
LinkedListNode() {
#ifndef NDEBUG
_next = nullptr;
_prev = nullptr;
#endif
}
/**
* This constructor should be invoked for any LinkedListNodes that will be
* used to serve as the root of a list. It sets up the pointers as an empty
* list.
*/
INLINE LinkedListNode::
LinkedListNode(bool) {
_next = this;
_prev = this;
}
/**
* This move constructor replaces the other link with this one.
*/
INLINE LinkedListNode::
LinkedListNode(LinkedListNode &&from) noexcept {
if (from._prev != nullptr) {
nassertv(from._prev->_next == &from);
from._prev->_next = this;
}
_prev = from._prev;
if (from._next != nullptr) {
nassertv(from._next->_prev == &from);
from._next->_prev = this;
}
_next = from._next;
from._next = nullptr;
from._prev = nullptr;
}
/**
*
*/
INLINE LinkedListNode::
~LinkedListNode() {
nassertv((_next == nullptr && _prev == nullptr) || (_next == this && _prev == this));
}
/**
* Replaces the given other node with this node.
*/
INLINE LinkedListNode &LinkedListNode::
operator = (LinkedListNode &&from) {
nassertr((_next == nullptr && _prev == nullptr) || (_next == this && _prev == this), *this);
nassertr(from._prev != nullptr && from._next != nullptr, *this);
nassertr(from._prev->_next == &from && from._next->_prev == &from, *this);
from._prev->_next = this;
from._next->_prev = this;
_prev = from._prev;
_next = from._next;
from._next = nullptr;
from._prev = nullptr;
return *this;
}
/**
* Returns true if the node is member of any list, false if it has been
* removed or never added. The head of a list generally appears to to always
* be a member of itself.
*/
INLINE bool LinkedListNode::
is_on_list() const {
return (_next != nullptr);
}
/**
* Removes a LinkedListNode record from the doubly-linked list.
*/
INLINE void LinkedListNode::
remove_from_list() {
nassertv(_prev != nullptr && _next != nullptr);
nassertv(_prev->_next == this && _next->_prev == this);
_prev->_next = _next;
_next->_prev = _prev;
#ifndef NDEBUG
_next = nullptr;
_prev = nullptr;
#endif
}
/**
* Adds a LinkedListNode record before the indicated node in the doubly-linked
* list.
*/
INLINE void LinkedListNode::
insert_before(LinkedListNode *node) {
nassertv(node->_prev != nullptr && node->_prev->_next == node && node->_next->_prev == node);
nassertv(_prev == nullptr &&
_next == nullptr);
_prev = node->_prev;
_next = node;
_prev->_next = this;
node->_prev = this;
}
/**
* Adds a LinkedListNode record after the indicated node in the doubly-linked
* list.
*/
INLINE void LinkedListNode::
insert_after(LinkedListNode *node) {
nassertv(node->_prev != nullptr && node->_prev->_next == node && node->_next->_prev == node);
nassertv(_prev == nullptr &&
_next == nullptr);
_next = node->_next;
_prev = node;
_next->_prev = this;
node->_next = this;
}
/**
* Given that this LinkedListNode represents the root of a list, and the other
* pointer represents the root of a different list, move all of the nodes
* (except the root itself) from other_root onto this list.
*/
INLINE void LinkedListNode::
take_list_from(LinkedListNode *other_root) {
other_root->_next->_prev = _prev;
_prev->_next = other_root->_next;
other_root->_prev->_next = this;
_prev = other_root->_prev;
other_root->_next = other_root;
other_root->_prev = other_root;
}