What is the reason for variant classes being returned by value rather than by reference?

[Benjamin-Dobell]

I've been digging into GodotJS' internals. I'm new to Godot and v8, so a lot to learn 😓 I'm curious as to the motivation of choosing by value over by reference for the variant classes. C# bindings operate similarly, so it's by no means a show-stopper. However, it would be nice to have similar capabilities to GDScript and do stuff like node.position.x = 5. I'm assuming there's performance concerns?

Somewhat related, what's the reason for going with SetAccessorProperty over SetNativeDataProperty?

[ialex32x]

I think the gdscript magic happen in the gdscript compiler, it compiles the statement node.position.x = 5 into node.position = Vector2(5, node.position.y)

// I don't know too much details about the internals of gdscript compiler, 
// but the assignment is actually run as this statement:

/*gdscript_vm.cpp line 1216*/ bool ok = ClassDB::set_property(p_instance->owner, *index, *src, &valid); // src is Vector2(x, y) here

So, it's impossible to implement in the same way in most third-party language integrations. node.position is node.get_position() under the hood which is not a reference of the original position.

And for the second question, no special reason of using SetAccessorProperty instead of SetNativeDataProperty.
SetNativeDataProperty is also a feasible approach to implement it. Maybe the only reason is that the binding functions could follow the same signature v8::FunctionCallback :P