Add conversions between Variant and ObjectID

include/godot_cpp/variant/variant.hpp

@@ -42,6 +42,8 @@
 
 namespace godot {
 
+class ObjectID;
+
 class Variant {
 	uint8_t opaque[GODOT_CPP_VARIANT_SIZE]{ 0 };
 
@@ -187,6 +189,7 @@ public:
 	Variant(const StringName &v);
 	Variant(const NodePath &v);
 	Variant(const godot::RID &v);
+	Variant(const ObjectID &v);
 	Variant(const Object *v);
 	Variant(const Callable &v);
 	Variant(const Signal &v);
@@ -230,6 +233,7 @@ public:
 	operator StringName() const;
 	operator NodePath() const;
 	operator godot::RID() const;
+	operator ObjectID() const;
 	operator Object *() const;
 	operator Callable() const;
 	operator Signal() const;

src/variant/variant.cpp

@@ -191,6 +191,10 @@ Variant::Variant(const Object *v) {
 	}
 }
 
+Variant::Variant(const ObjectID &p_id) :
+		Variant(p_id.operator uint64_t()) {
+}
+
 Variant::Variant(const Callable &v) {
 	from_type_constructor[CALLABLE](_native_ptr(), v._native_ptr());
 }
@@ -410,6 +414,21 @@ Variant::operator Object *() const {
 	return reinterpret_cast<Object *>(internal::gde_interface->object_get_instance_binding(obj, internal::token, &Object::___binding_callbacks));
 }
 
+Variant::operator ObjectID() const {
+	if (get_type() == Type::INT) {
+		return ObjectID(operator uint64_t());
+	} else if (get_type() == Type::OBJECT) {
+		Object *obj = operator Object *();
+		if (obj != nullptr) {
+			return ObjectID(obj->get_instance_id());
+		} else {
+			return ObjectID();
+		}
+	} else {
+		return ObjectID();
+	}
+}
+
 Variant::operator Callable() const {
 	Callable result;
 	to_type_constructor[CALLABLE](result._native_ptr(), _native_ptr());