By that logic there's no such thing as a non-type-safe language, because all programs have behaviour.
Normally one would say a checked downcast like that is not type-safe, because you can't reason locally about the type behaviour of the downcast based on knowing the type of v. You would have to know the value of v, which is a Turing-complete problem in the general case.
Normally one would say a checked downcast like that is not type-safe, because you can't reason locally about the type behaviour of the downcast based on knowing the type of v. You would have to know the value of v, which is a Turing-complete problem in the general case.