I have a

sealed interface MyInterface

where every implementor is

MySealedClass()

(why? because

MySealedClass

is a huge class and I need a subset of the subclasses). is there any way to make Kotlin understand this property? the best I can think of is to give the interface an infallible

fun toMySealedClass(): MySealedClass = when (this) { is MySealedClass -> this }

function which statically validates this property, but ideally I'd like not having to keep using it every time I have something that is

MyInterface

and instead have Kotlin understand that it's a

MySealedClass

.

Does MySealedClass need to be a class? Maybe you can extract an interface out of it, and then have MyInterface implement that

yes,

MySealedClass

is a major, already-existing class. it is unlikely that I'll be allowed to significantly change it.

Currently not possible.

I see, that's good to know