11 files changed, 442 insertions, 80 deletions

diff --git a/core/extension/gdnative_interface.cpp b/core/extension/gdnative_interface.cpp
index 324933d7b7..8f68b8d848 100644
--- a/core/extension/gdnative_interface.cpp
+++ b/core/extension/gdnative_interface.cpp
@@ -520,6 +520,11 @@ static GDNativeObjectPtr gdnative_global_get_singleton(const char *p_name) {
 	return (GDNativeObjectPtr)Engine::get_singleton()->get_singleton_object(String(p_name));
 }
 
+static void *gdnative_object_get_instance_binding(GDNativeObjectPtr p_instance, void *p_token, GDNativeInstanceBindingCallbacks *p_callbacks) {
+	Object *o = (Object *)p_instance;
+	return o->get_instance_binding(p_token, p_callbacks);
+}
+
 static GDNativeObjectPtr gdnative_object_get_instance_from_id(GDObjectInstanceID p_instance_id) {
 	return (GDNativeObjectPtr)ObjectDB::get_instance(ObjectID(p_instance_id));
 }
@@ -665,6 +670,7 @@ void gdnative_setup_interface(GDNativeInterface *p_interface) {
 	gdni.object_method_bind_ptrcall = gdnative_object_method_bind_ptrcall;
 	gdni.object_destroy = gdnative_object_destroy;
 	gdni.global_get_singleton = gdnative_global_get_singleton;
+	gdni.object_get_instance_binding = gdnative_object_get_instance_binding;
 
 	gdni.object_cast_to = gdnative_object_cast_to;
 	gdni.object_get_instance_from_id = gdnative_object_get_instance_from_id;
diff --git a/core/extension/gdnative_interface.h b/core/extension/gdnative_interface.h
index 318912e889..c1ebb3e76a 100644
--- a/core/extension/gdnative_interface.h
+++ b/core/extension/gdnative_interface.h
@@ -171,6 +171,16 @@ typedef void (*GDNativePtrUtilityFunction)(GDNativeTypePtr r_return, const GDNat
 
 typedef GDNativeObjectPtr (*GDNativeClassConstructor)();
 
+typedef void *(*GDNativeInstanceBindingCreateCallback)(void *p_token, void *p_instance);
+typedef void (*GDNativeInstanceBindingFreeCallback)(void *p_token, void *p_instance, void *p_binding);
+typedef GDNativeBool (*GDNativeInstanceBindingReferenceCallback)(void *p_token, void *p_instance, GDNativeBool p_reference);
+
+struct GDNativeInstanceBindingCallbacks {
+	GDNativeInstanceBindingCreateCallback create_callback;
+	GDNativeInstanceBindingFreeCallback free_callback;
+	GDNativeInstanceBindingReferenceCallback reference_callback;
+};
+
 /* EXTENSION CLASSES */
 
 typedef void *GDExtensionClassInstancePtr;
@@ -373,6 +383,7 @@ typedef struct {
 	void (*object_method_bind_ptrcall)(GDNativeMethodBindPtr p_method_bind, GDNativeObjectPtr p_instance, const GDNativeTypePtr *p_args, GDNativeTypePtr r_ret);
 	void (*object_destroy)(GDNativeObjectPtr p_o);
 	GDNativeObjectPtr (*global_get_singleton)(const char *p_name);
+	void *(*object_get_instance_binding)(GDNativeObjectPtr p_o, void *p_token, GDNativeInstanceBindingCallbacks *p_callbacks);
 
 	GDNativeObjectPtr (*object_cast_to)(const GDNativeObjectPtr p_object, void *p_class_tag);
 	GDNativeObjectPtr (*object_get_instance_from_id)(GDObjectInstanceID p_instance_id);
diff --git a/core/object/object.cpp b/core/object/object.cpp
index 1c8db89e5e..296d876701 100644
--- a/core/object/object.cpp
+++ b/core/object/object.cpp
@@ -1769,42 +1769,41 @@ uint32_t Object::get_edited_version() const {
 }
 #endif
 
-void *Object::get_script_instance_binding(int p_script_language_index) {
-#ifdef DEBUG_ENABLED
-	ERR_FAIL_INDEX_V(p_script_language_index, MAX_SCRIPT_INSTANCE_BINDINGS, nullptr);
-#endif
-
-	//it's up to the script language to make this thread safe, if the function is called twice due to threads being out of sync
-	//just return the same pointer.
-	//if you want to put a big lock in the entire function and keep allocated pointers in a map or something, feel free to do it
-	//as it should not really affect performance much (won't be called too often), as in far most cases the condition below will be false afterwards
-
-	if (!_script_instance_bindings[p_script_language_index]) {
-		void *script_data = ScriptServer::get_language(p_script_language_index)->alloc_instance_binding_data(this);
-		if (script_data) {
-			instance_binding_count.increment();
-			_script_instance_bindings[p_script_language_index] = script_data;
+void *Object::get_instance_binding(void *p_token, const GDNativeInstanceBindingCallbacks *p_callbacks) {
+	void *binding = nullptr;
+	_instance_binding_mutex.lock();
+	for (uint32_t i = 0; i < _instance_binding_count; i++) {
+		if (_instance_bindings[i].token == p_token) {
+			binding = _instance_bindings[i].binding;
+			break;
 		}
 	}
+	if (unlikely(!binding)) {
+		uint32_t current_size = next_power_of_2(_instance_binding_count);
+		uint32_t new_size = next_power_of_2(_instance_binding_count + 1);
 
-	return _script_instance_bindings[p_script_language_index];
-}
+		if (current_size == 0 || new_size > current_size) {
+			_instance_bindings = (InstanceBinding *)memrealloc(_instance_bindings, new_size * sizeof(InstanceBinding));
+		}
 
-bool Object::has_script_instance_binding(int p_script_language_index) {
-	return _script_instance_bindings[p_script_language_index] != nullptr;
-}
+		_instance_bindings[_instance_binding_count].free_callback = p_callbacks->free_callback;
+		_instance_bindings[_instance_binding_count].reference_callback = p_callbacks->reference_callback;
+		_instance_bindings[_instance_binding_count].token = p_token;
 
-void Object::set_script_instance_binding(int p_script_language_index, void *p_data) {
-#ifdef DEBUG_ENABLED
-	CRASH_COND(_script_instance_bindings[p_script_language_index] != nullptr);
-#endif
-	_script_instance_bindings[p_script_language_index] = p_data;
+		binding = p_callbacks->create_callback(p_token, this);
+		_instance_bindings[_instance_binding_count].binding = binding;
+
+		_instance_binding_count++;
+	}
+
+	_instance_binding_mutex.unlock();
+
+	return binding;
 }
 
 void Object::_construct_object(bool p_reference) {
 	type_is_reference = p_reference;
 	_instance_id = ObjectDB::add_instance(this);
-	memset(_script_instance_bindings, 0, sizeof(void *) * MAX_SCRIPT_INSTANCE_BINDINGS);
 
 	ClassDB::instance_get_native_extension_data(&_extension, &_extension_instance);
 
@@ -1864,12 +1863,13 @@ Object::~Object() {
 	_instance_id = ObjectID();
 	_predelete_ok = 2;
 
-	if (!ScriptServer::are_languages_finished()) {
-		for (int i = 0; i < MAX_SCRIPT_INSTANCE_BINDINGS; i++) {
-			if (_script_instance_bindings[i]) {
-				ScriptServer::get_language(i)->free_instance_binding_data(_script_instance_bindings[i]);
+	if (_instance_bindings != nullptr) {
+		for (uint32_t i = 0; i < _instance_binding_count; i++) {
+			if (_instance_bindings[i].free_callback) {
+				_instance_bindings[i].free_callback(_instance_bindings[i].token, _instance_bindings[i].binding, this);
 			}
 		}
+		memfree(_instance_bindings);
 	}
 }
 
@@ -1887,7 +1887,6 @@ void ObjectDB::debug_objects(DebugFunc p_func) {
 	for (uint32_t i = 0, count = slot_count; i < slot_max && count != 0; i++) {
 		if (object_slots[i].validator) {
 			p_func(object_slots[i].object);
-
 			count--;
 		}
 	}
diff --git a/core/object/object.h b/core/object/object.h
index e6eb6d1aaf..8389d80afc 100644
--- a/core/object/object.h
+++ b/core/object/object.h
@@ -480,10 +480,6 @@ public:
 	};
 
 private:
-	enum {
-		MAX_SCRIPT_INSTANCE_BINDINGS = 8
-	};
-
 #ifdef DEBUG_ENABLED
 	friend struct _ObjectDebugLock;
 #endif
@@ -542,12 +538,35 @@ private:
 
 	friend class RefCounted;
 	bool type_is_reference = false;
-	SafeNumeric<uint32_t> instance_binding_count;
-	void *_script_instance_bindings[MAX_SCRIPT_INSTANCE_BINDINGS];
+
+	std::mutex _instance_binding_mutex;
+	struct InstanceBinding {
+		void *binding;
+		void *token;
+		GDNativeInstanceBindingFreeCallback free_callback = nullptr;
+		GDNativeInstanceBindingReferenceCallback reference_callback = nullptr;
+	};
+	InstanceBinding *_instance_bindings = nullptr;
+	uint32_t _instance_binding_count = 0;
 
 	Object(bool p_reference);
 
 protected:
+	_FORCE_INLINE_ bool _instance_binding_reference(bool p_reference) {
+		bool can_die = true;
+		if (_instance_bindings) {
+			_instance_binding_mutex.lock();
+			for (uint32_t i = 0; i < _instance_binding_count; i++) {
+				if (_instance_bindings[i].reference_callback) {
+					if (!_instance_bindings[i].reference_callback(_instance_bindings[i].token, _instance_bindings[i].binding, p_reference)) {
+						can_die = false;
+					}
+				}
+			}
+			_instance_binding_mutex.unlock();
+		}
+		return can_die;
+	}
 	friend class NativeExtensionMethodBind;
 	_ALWAYS_INLINE_ const ObjectNativeExtension *_get_extension() const { return _extension; }
 	_ALWAYS_INLINE_ GDExtensionClassInstancePtr _get_extension_instance() const { return _extension_instance; }
@@ -785,9 +804,7 @@ public:
 #endif
 
 	//used by script languages to store binding data
-	void *get_script_instance_binding(int p_script_language_index);
-	bool has_script_instance_binding(int p_script_language_index);
-	void set_script_instance_binding(int p_script_language_index, void *p_data);
+	void *get_instance_binding(void *p_token, const GDNativeInstanceBindingCallbacks *p_callbacks);
 
 	void clear_internal_resource_paths();
 
diff --git a/core/object/ref_counted.cpp b/core/object/ref_counted.cpp
index 9862624972..2833f774dc 100644
--- a/core/object/ref_counted.cpp
+++ b/core/object/ref_counted.cpp
@@ -65,13 +65,8 @@ bool RefCounted::reference() {
 		if (_get_extension() && _get_extension()->reference) {
 			_get_extension()->reference(_get_extension_instance());
 		}
-		if (instance_binding_count.get() > 0 && !ScriptServer::are_languages_finished()) {
-			for (int i = 0; i < MAX_SCRIPT_INSTANCE_BINDINGS; i++) {
-				if (_script_instance_bindings[i]) {
-					ScriptServer::get_language(i)->refcount_incremented_instance_binding(this);
-				}
-			}
-		}
+
+		_instance_binding_reference(true);
 	}
 
 	return success;
@@ -89,14 +84,8 @@ bool RefCounted::unreference() {
 		if (_get_extension() && _get_extension()->unreference) {
 			_get_extension()->unreference(_get_extension_instance());
 		}
-		if (instance_binding_count.get() > 0 && !ScriptServer::are_languages_finished()) {
-			for (int i = 0; i < MAX_SCRIPT_INSTANCE_BINDINGS; i++) {
-				if (_script_instance_bindings[i]) {
-					bool script_ret = ScriptServer::get_language(i)->refcount_decremented_instance_binding(this);
-					die = die && script_ret;
-				}
-			}
-		}
+
+		die = die && _instance_binding_reference(false);
 	}
 
 	return die;
diff --git a/core/templates/list.h b/core/templates/list.h
index 010e35eed8..6047b89670 100644
--- a/core/templates/list.h
+++ b/core/templates/list.h
@@ -135,6 +135,83 @@ public:
 		_FORCE_INLINE_ Element() {}
 	};
 
+	typedef T ValueType;
+
+	struct Iterator {
+		_FORCE_INLINE_ T &operator*() const {
+			return E->get();
+		}
+		_FORCE_INLINE_ T *operator->() const { return &E->get(); }
+		_FORCE_INLINE_ Iterator &operator++() {
+			E = E->next();
+			return *this;
+		}
+		_FORCE_INLINE_ Iterator &operator--() {
+			E = E->prev();
+			return *this;
+		}
+
+		_FORCE_INLINE_ bool operator==(const Iterator &b) const { return E == b.E; }
+		_FORCE_INLINE_ bool operator!=(const Iterator &b) const { return E != b.E; }
+
+		Iterator(Element *p_E) { E = p_E; }
+		Iterator() {}
+		Iterator(const Iterator &p_it) { E = p_it.E; }
+
+	private:
+		Element *E = nullptr;
+	};
+
+	struct ConstIterator {
+		_FORCE_INLINE_ const T &operator*() const {
+			return E->get();
+		}
+		_FORCE_INLINE_ const T *operator->() const { return &E->get(); }
+		_FORCE_INLINE_ ConstIterator &operator++() {
+			E = E->next();
+			return *this;
+		}
+		_FORCE_INLINE_ ConstIterator &operator--() {
+			E = E->prev();
+			return *this;
+		}
+
+		_FORCE_INLINE_ bool operator==(const Iterator &b) const { return E == b.E; }
+		_FORCE_INLINE_ bool operator!=(const Iterator &b) const { return E != b.E; }
+
+		_FORCE_INLINE_ ConstIterator(const Element *p_E) { E = p_E; }
+		_FORCE_INLINE_ ConstIterator() {}
+		_FORCE_INLINE_ ConstIterator(const ConstIterator &p_it) { E = p_it.E; }
+
+	private:
+		const Element *E = nullptr;
+	};
+
+	_FORCE_INLINE_ Iterator begin() {
+		return Iterator(front());
+	}
+	_FORCE_INLINE_ Iterator end() {
+		return Iterator(nullptr);
+	}
+
+#if 0
+	//to use when replacing find()
+	_FORCE_INLINE_ Iterator find(const K &p_key) {
+		return Iterator(find(p_key));
+	}
+#endif
+	_FORCE_INLINE_ ConstIterator begin() const {
+		return ConstIterator(front());
+	}
+	_FORCE_INLINE_ ConstIterator end() const {
+		return ConstIterator(nullptr);
+	}
+#if 0
+	//to use when replacing find()
+	_FORCE_INLINE_ ConstIterator find(const K &p_key) const {
+		return ConstIterator(find(p_key));
+	}
+#endif
 private:
 	struct _Data {
 		Element *first = nullptr;
diff --git a/core/templates/map.h b/core/templates/map.h
index 7dfee13d2c..a47547d355 100644
--- a/core/templates/map.h
+++ b/core/templates/map.h
@@ -33,6 +33,7 @@
 
 #include "core/error/error_macros.h"
 #include "core/os/memory.h"
+#include "core/templates/pair.h"
 
 // based on the very nice implementation of rb-trees by:
 // https://web.archive.org/web/20120507164830/http://web.mit.edu/~emin/www/source_code/red_black_tree/index.html
@@ -55,11 +56,12 @@ public:
 		Element *parent = nullptr;
 		Element *_next = nullptr;
 		Element *_prev = nullptr;
-		K _key;
-		V _value;
-		//_Data *data;
+		KeyValue<K, V> _data;
 
 	public:
+		KeyValue<K, V> &key_value() { return _data; }
+		const KeyValue<K, V> &key_value() const { return _data; }
+
 		const Element *next() const {
 			return _next;
 		}
@@ -73,23 +75,106 @@ public:
 			return _prev;
 		}
 		const K &key() const {
-			return _key;
+			return _data.key;
 		}
 		V &value() {
-			return _value;
+			return _data.value;
 		}
 		const V &value() const {
-			return _value;
+			return _data.value;
 		}
 		V &get() {
-			return _value;
+			return _data.value;
 		}
 		const V &get() const {
-			return _value;
+			return _data.value;
 		}
-		Element() {}
+		Element(const KeyValue<K, V> &p_data) :
+				_data(p_data) {}
 	};
 
+	typedef KeyValue<K, V> ValueType;
+
+	struct Iterator {
+		_FORCE_INLINE_ KeyValue<K, V> &operator*() const {
+			return E->key_value();
+		}
+		_FORCE_INLINE_ KeyValue<K, V> *operator->() const { return &E->key_value(); }
+		_FORCE_INLINE_ Iterator &operator++() {
+			E = E->next();
+			return *this;
+		}
+		_FORCE_INLINE_ Iterator &operator--() {
+			E = E->prev();
+			return *this;
+		}
+
+		_FORCE_INLINE_ bool operator==(const Iterator &b) const { return E == b.E; }
+		_FORCE_INLINE_ bool operator!=(const Iterator &b) const { return E != b.E; }
+
+		Iterator(Element *p_E) { E = p_E; }
+		Iterator() {}
+		Iterator(const Iterator &p_it) { E = p_it.E; }
+
+	private:
+		Element *E = nullptr;
+	};
+
+	struct ConstIterator {
+		_FORCE_INLINE_ const KeyValue<K, V> &operator*() const {
+			return E->key_value();
+		}
+		_FORCE_INLINE_ const KeyValue<K, V> *operator->() const { return &E->key_value(); }
+		_FORCE_INLINE_ ConstIterator &operator++() {
+			E = E->next();
+			return *this;
+		}
+		_FORCE_INLINE_ ConstIterator &operator--() {
+			E = E->prev();
+			return *this;
+		}
+
+		_FORCE_INLINE_ bool operator==(const ConstIterator &b) const { return E == b.E; }
+		_FORCE_INLINE_ bool operator!=(const ConstIterator &b) const { return E != b.E; }
+
+		ConstIterator(const Element *p_E) { E = p_E; }
+		ConstIterator() {}
+		ConstIterator(const ConstIterator &p_it) { E = p_it.E; }
+
+	private:
+		const Element *E = nullptr;
+	};
+
+	_FORCE_INLINE_ Iterator begin() {
+		return Iterator(front());
+	}
+	_FORCE_INLINE_ Iterator end() {
+		return Iterator(nullptr);
+	}
+
+#if 0
+	//to use when replacing find()
+	_FORCE_INLINE_ Iterator find(const K &p_key) {
+		return Iterator(find(p_key));
+	}
+#endif
+	_FORCE_INLINE_ void remove(const Iterator &p_iter) {
+		return erase(p_iter.E);
+	}
+
+	_FORCE_INLINE_ ConstIterator begin() const {
+		return ConstIterator(front());
+	}
+	_FORCE_INLINE_ ConstIterator end() const {
+		return ConstIterator(nullptr);
+	}
+
+#if 0
+	//to use when replacing find()
+	_FORCE_INLINE_ ConstIterator find(const K &p_key) const {
+		return ConstIterator(find(p_key));
+	}
+#endif
 private:
 	struct _Data {
 		Element *_root = nullptr;
@@ -107,7 +192,7 @@ private:
 		}
 
 		void _create_root() {
-			_root = memnew_allocator(Element, A);
+			_root = memnew_allocator(Element(KeyValue<K, V>(K(), V())), A);
 			_root->parent = _root->left = _root->right = _nil;
 			_root->color = BLACK;
 		}
@@ -216,9 +301,9 @@ private:
 		C less;
 
 		while (node != _data._nil) {
-			if (less(p_key, node->_key)) {
+			if (less(p_key, node->_data.key)) {
 				node = node->left;
-			} else if (less(node->_key, p_key)) {
+			} else if (less(node->_data.key, p_key)) {
 				node = node->right;
 			} else {
 				return node; // found
@@ -236,9 +321,9 @@ private:
 		while (node != _data._nil) {
 			prev = node;
 
-			if (less(p_key, node->_key)) {
+			if (less(p_key, node->_data.key)) {
 				node = node->left;
-			} else if (less(node->_key, p_key)) {
+			} else if (less(node->_data.key, p_key)) {
 				node = node->right;
 			} else {
 				return node; // found
@@ -249,7 +334,7 @@ private:
 			return nullptr; // tree empty
 		}
 
-		if (less(p_key, prev->_key)) {
+		if (less(p_key, prev->_data.key)) {
 			prev = prev->_prev;
 		}
 
@@ -312,25 +397,25 @@ private:
 		while (node != _data._nil) {
 			new_parent = node;
 
-			if (less(p_key, node->_key)) {
+			if (less(p_key, node->_data.key)) {
 				node = node->left;
-			} else if (less(node->_key, p_key)) {
+			} else if (less(node->_data.key, p_key)) {
 				node = node->right;
 			} else {
-				node->_value = p_value;
+				node->_data.value = p_value;
 				return node; // Return existing node with new value
 			}
 		}
 
-		Element *new_node = memnew_allocator(Element, A);
+		typedef KeyValue<K, V> KV;
+		Element *new_node = memnew_allocator(Element(KV(p_key, p_value)), A);
 		new_node->parent = new_parent;
 		new_node->right = _data._nil;
 		new_node->left = _data._nil;
-		new_node->_key = p_key;
-		new_node->_value = p_value;
+
 		//new_node->data=_data;
 
-		if (new_parent == _data._root || less(p_key, new_parent->_key)) {
+		if (new_parent == _data._root || less(p_key, new_parent->_data.key)) {
 			new_parent->left = new_node;
 		} else {
 			new_parent->right = new_node;
@@ -575,7 +660,7 @@ public:
 		CRASH_COND(!_data._root);
 		const Element *e = find(p_key);
 		CRASH_COND(!e);
-		return e->_value;
+		return e->_data.value;
 	}
 
 	V &operator[](const K &p_key) {
@@ -588,7 +673,7 @@ public:
 			e = insert(p_key, V());
 		}
 
-		return e->_value;
+		return e->_data.value;
 	}
 
 	Element *front() const {
diff --git a/core/templates/pair.h b/core/templates/pair.h
index bc1a764694..31706b6ecb 100644
--- a/core/templates/pair.h
+++ b/core/templates/pair.h
@@ -31,6 +31,8 @@
 #ifndef PAIR_H
 #define PAIR_H
 
+#include "core/typedefs.h"
+
 template <class F, class S>
 struct Pair {
 	F first;
@@ -64,4 +66,37 @@ struct PairSort {
 	}
 };
 
+template <class K, class V>
+struct KeyValue {
+	const K key;
+	V value;
+
+	void operator=(const KeyValue &p_kv) = delete;
+	_FORCE_INLINE_ KeyValue(const KeyValue &p_kv) :
+			key(p_kv.key),
+			value(p_kv.value) {
+	}
+	_FORCE_INLINE_ KeyValue(const K &p_key, const V &p_value) :
+			key(p_key),
+			value(p_value) {
+	}
+};
+
+template <class K, class V>
+bool operator==(const KeyValue<K, V> &pair, const KeyValue<K, V> &other) {
+	return (pair.key == other.key) && (pair.value == other.value);
+}
+
+template <class K, class V>
+bool operator!=(const KeyValue<K, V> &pair, const KeyValue<K, V> &other) {
+	return (pair.key != other.key) || (pair.value != other.value);
+}
+
+template <class K, class V>
+struct KeyValueSort {
+	bool operator()(const KeyValue<K, V> &A, const KeyValue<K, V> &B) const {
+		return A.key < B.key;
+	}
+};
+
 #endif // PAIR_H
diff --git a/core/templates/rid_owner.h b/core/templates/rid_owner.h
index e4964f744e..4f5c74ca46 100644
--- a/core/templates/rid_owner.h
+++ b/core/templates/rid_owner.h
@@ -193,7 +193,7 @@ public:
 			if (THREAD_SAFE) {
 				spin_lock.unlock();
 			}
-			if (validator_chunks[idx_chunk][idx_element] & 0x80000000) {
+			if ((validator_chunks[idx_chunk][idx_element] & 0x80000000) && validator_chunks[idx_chunk][idx_element] != 0xFFFFFFFF) {
 				ERR_FAIL_V_MSG(nullptr, "Attempting to use an uninitialized RID");
 			}
 			return nullptr;
diff --git a/core/templates/set.h b/core/templates/set.h
index 3036ecf27d..245c174862 100644
--- a/core/templates/set.h
+++ b/core/templates/set.h
@@ -77,6 +77,85 @@ public:
 		Element() {}
 	};
 
+	typedef T ValueType;
+
+	struct Iterator {
+		_FORCE_INLINE_ T &operator*() const {
+			return E->get();
+		}
+		_FORCE_INLINE_ T *operator->() const { return &E->get(); }
+		_FORCE_INLINE_ Iterator &operator++() {
+			E = E->next();
+			return *this;
+		}
+		_FORCE_INLINE_ Iterator &operator--() {
+			E = E->prev();
+			return *this;
+		}
+
+		_FORCE_INLINE_ bool operator==(const Iterator &b) const { return E == b.E; }
+		_FORCE_INLINE_ bool operator!=(const Iterator &b) const { return E != b.E; }
+
+		Iterator(Element *p_E) { E = p_E; }
+		Iterator() {}
+		Iterator(const Iterator &p_it) { E = p_it.E; }
+
+	private:
+		Element *E = nullptr;
+	};
+
+	struct ConstIterator {
+		_FORCE_INLINE_ const T &operator*() const {
+			return E->get();
+		}
+		_FORCE_INLINE_ const T *operator->() const { return &E->get(); }
+		_FORCE_INLINE_ ConstIterator &operator++() {
+			E = E->next();
+			return *this;
+		}
+		_FORCE_INLINE_ ConstIterator &operator--() {
+			E = E->prev();
+			return *this;
+		}
+
+		_FORCE_INLINE_ bool operator==(const Iterator &b) const { return E == b.E; }
+		_FORCE_INLINE_ bool operator!=(const Iterator &b) const { return E != b.E; }
+
+		_FORCE_INLINE_ ConstIterator(const Element *p_E) { E = p_E; }
+		_FORCE_INLINE_ ConstIterator() {}
+		_FORCE_INLINE_ ConstIterator(const ConstIterator &p_it) { E = p_it.E; }
+
+	private:
+		const Element *E = nullptr;
+	};
+
+	_FORCE_INLINE_ Iterator begin() {
+		return Iterator(front());
+	}
+	_FORCE_INLINE_ Iterator end() {
+		return Iterator(nullptr);
+	}
+
+#if 0
+	//to use when replacing find()
+	_FORCE_INLINE_ Iterator find(const K &p_key) {
+		return Iterator(find(p_key));
+	}
+#endif
+
+	_FORCE_INLINE_ ConstIterator begin() const {
+		return ConstIterator(front());
+	}
+	_FORCE_INLINE_ ConstIterator end() const {
+		return ConstIterator(nullptr);
+	}
+
+#if 0
+	//to use when replacing find()
+	_FORCE_INLINE_ ConstIterator find(const K &p_key) const {
+		return ConstIterator(find(p_key));
+	}
+#endif
 private:
 	struct _Data {
 		Element *_root = nullptr;
diff --git a/core/templates/vector.h b/core/templates/vector.h
index dae8874a87..08cbef6ba4 100644
--- a/core/templates/vector.h
+++ b/core/templates/vector.h
@@ -187,6 +187,70 @@ public:
 		return false;
 	}
 
+	struct Iterator {
+		_FORCE_INLINE_ T &operator*() const {
+			return *elem_ptr;
+		}
+		_FORCE_INLINE_ T *operator->() const { return elem_ptr; }
+		_FORCE_INLINE_ Iterator &operator++() {
+			elem_ptr++;
+			return *this;
+		}
+		_FORCE_INLINE_ Iterator &operator--() {
+			elem_ptr--;
+			return *this;
+		}
+
+		_FORCE_INLINE_ bool operator==(const Iterator &b) const { return elem_ptr == b.elem_ptr; }
+		_FORCE_INLINE_ bool operator!=(const Iterator &b) const { return elem_ptr != b.elem_ptr; }
+
+		Iterator(T *p_ptr) { elem_ptr = p_ptr; }
+		Iterator() {}
+		Iterator(const Iterator &p_it) { elem_ptr = p_it.elem_ptr; }
+
+	private:
+		T *elem_ptr = nullptr;
+	};
+
+	struct ConstIterator {
+		_FORCE_INLINE_ const T &operator*() const {
+			return *elem_ptr;
+		}
+		_FORCE_INLINE_ const T *operator->() const { return elem_ptr; }
+		_FORCE_INLINE_ ConstIterator &operator++() {
+			elem_ptr++;
+			return *this;
+		}
+		_FORCE_INLINE_ ConstIterator &operator--() {
+			elem_ptr--;
+			return *this;
+		}
+
+		_FORCE_INLINE_ bool operator==(const ConstIterator &b) const { return elem_ptr == b.elem_ptr; }
+		_FORCE_INLINE_ bool operator!=(const ConstIterator &b) const { return elem_ptr != b.elem_ptr; }
+
+		ConstIterator(T *p_ptr) { elem_ptr = p_ptr; }
+		ConstIterator() {}
+		ConstIterator(const ConstIterator &p_it) { elem_ptr = p_it.elem_ptr; }
+
+	private:
+		const T *elem_ptr = nullptr;
+	};
+
+	_FORCE_INLINE_ Iterator begin() {
+		return Iterator(ptrw());
+	}
+	_FORCE_INLINE_ Iterator end() {
+		return Iterator(ptrw() + size());
+	}
+
+	_FORCE_INLINE_ ConstIterator begin() const {
+		return ConstIterator(ptr());
+	}
+	_FORCE_INLINE_ ConstIterator end() const {
+		return ConstIterator(ptr() + size());
+	}
+
 	_FORCE_INLINE_ Vector() {}
 	_FORCE_INLINE_ Vector(const Vector &p_from) { _cowdata._ref(p_from._cowdata); }