Yes, the synthax forbids an assignement of the callback from AnotherThing
class AnotherThing {
constructor(cb) {
/* any except @ref forbidden */ = cb
}
}
It ensure that the syntax prevent any memory race. If you want to get the referenced value to manipulate you need to introduce a specific keyword to copy the intrinsic value (eg.: ```copy &ref````, from Explicit Ownership syntax)