From 3e97626b67f8415309a1bf21a246103509485be6 Mon Sep 17 00:00:00 2001
From: Ricardo Buring <ricardo.buring@gmail.com>
Date: Tue, 13 Sep 2022 11:32:12 +0200
Subject: [PATCH] Add SelfList template

---
 include/godot_cpp/templates/self_list.hpp | 143 ++++++++++++++++++++++
 test/src/tests.h                          |   1 +
 2 files changed, 144 insertions(+)
 create mode 100644 include/godot_cpp/templates/self_list.hpp

diff --git a/include/godot_cpp/templates/self_list.hpp b/include/godot_cpp/templates/self_list.hpp
new file mode 100644
index 00000000..a89306ff
--- /dev/null
+++ b/include/godot_cpp/templates/self_list.hpp
@@ -0,0 +1,143 @@
+/*************************************************************************/
+/*  self_list.hpp                                                        */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef SELF_LIST_HPP
+#define SELF_LIST_HPP
+
+#include <godot_cpp/core/error_macros.hpp>
+#include <godot_cpp/core/defs.hpp>
+
+namespace godot {
+
+template <class T>
+class SelfList {
+public:
+	class List {
+		SelfList<T> *_first = nullptr;
+		SelfList<T> *_last = nullptr;
+
+	public:
+		void add(SelfList<T> *p_elem) {
+			ERR_FAIL_COND(p_elem->_root);
+
+			p_elem->_root = this;
+			p_elem->_next = _first;
+			p_elem->_prev = nullptr;
+
+			if (_first) {
+				_first->_prev = p_elem;
+
+			} else {
+				_last = p_elem;
+			}
+
+			_first = p_elem;
+		}
+
+		void add_last(SelfList<T> *p_elem) {
+			ERR_FAIL_COND(p_elem->_root);
+
+			p_elem->_root = this;
+			p_elem->_next = nullptr;
+			p_elem->_prev = _last;
+
+			if (_last) {
+				_last->_next = p_elem;
+
+			} else {
+				_first = p_elem;
+			}
+
+			_last = p_elem;
+		}
+
+		void remove(SelfList<T> *p_elem) {
+			ERR_FAIL_COND(p_elem->_root != this);
+			if (p_elem->_next) {
+				p_elem->_next->_prev = p_elem->_prev;
+			}
+
+			if (p_elem->_prev) {
+				p_elem->_prev->_next = p_elem->_next;
+			}
+
+			if (_first == p_elem) {
+				_first = p_elem->_next;
+			}
+
+			if (_last == p_elem) {
+				_last = p_elem->_prev;
+			}
+
+			p_elem->_next = nullptr;
+			p_elem->_prev = nullptr;
+			p_elem->_root = nullptr;
+		}
+
+		_FORCE_INLINE_ SelfList<T> *first() { return _first; }
+		_FORCE_INLINE_ const SelfList<T> *first() const { return _first; }
+
+		_FORCE_INLINE_ List() {}
+		_FORCE_INLINE_ ~List() { ERR_FAIL_COND(_first != nullptr); }
+	};
+
+private:
+	List *_root = nullptr;
+	T *_self = nullptr;
+	SelfList<T> *_next = nullptr;
+	SelfList<T> *_prev = nullptr;
+
+public:
+	_FORCE_INLINE_ bool in_list() const { return _root; }
+	_FORCE_INLINE_ void remove_from_list() {
+		if (_root) {
+			_root->remove(this);
+		}
+	}
+	_FORCE_INLINE_ SelfList<T> *next() { return _next; }
+	_FORCE_INLINE_ SelfList<T> *prev() { return _prev; }
+	_FORCE_INLINE_ const SelfList<T> *next() const { return _next; }
+	_FORCE_INLINE_ const SelfList<T> *prev() const { return _prev; }
+	_FORCE_INLINE_ T *self() const { return _self; }
+
+	_FORCE_INLINE_ SelfList(T *p_self) {
+		_self = p_self;
+	}
+
+	_FORCE_INLINE_ ~SelfList() {
+		if (_root) {
+			_root->remove(this);
+		}
+	}
+};
+
+} // namespace godot
+
+#endif // SELF_LIST_HPP
diff --git a/test/src/tests.h b/test/src/tests.h
index f41e4263..36ff420b 100644
--- a/test/src/tests.h
+++ b/test/src/tests.h
@@ -42,6 +42,7 @@
 #include "godot_cpp/templates/rid_owner.hpp"
 #include "godot_cpp/templates/safe_refcount.hpp"
 #include "godot_cpp/templates/search_array.hpp"
+#include "godot_cpp/templates/self_list.hpp"
 #include "godot_cpp/templates/sort_array.hpp"
 #include "godot_cpp/templates/spin_lock.hpp"
 #include "godot_cpp/templates/thread_work_pool.hpp"