Is there any way to make a function such as `handl...

# announcements

[toxara]

Is there any way to make a function such as handleBox typecheck without unsafe casting?

Box.kt

[Leonid Popescu]

but why you need to have the abstract val value in the first place ?

[Leonid Popescu]

wait, got it.

[karelpeeters]

Isn't box smartcasted to IntBox?

[Andreas Sinz]

yes it is, but the compiler doesn't realize that T has the same type as box.value

[karelpeeters]

Does something like

val box: Box = ...
if (box is IntBox)
    println(box.value * 2)

also not work?

[Andreas Sinz]

that works fine, the problem is that when(box) { .. } has the return type Any instead of T

[karelpeeters]

Damm missed the return part, okay that makes sense.

[Andreas Sinz]

1.3 added new type inference to better support intersection types Int & String, maybe we get sum types Int | T with 1.4? 🧌

[karelpeeters]

I remember there being a youtrack issue similar to this, can't find it though.

[karelpeeters]

@Andreas Sinz lots of us would like that!

[Andreas Sinz]

BTT, @toxara its not possible right now