Hi there! I've seen that with 1.4 SAM intefaces ar...

# announcements

[addamsson]

Hi there! I've seen that with 1.4 SAM intefaces are now converted properly between Kotlin and Java. This is great, but there is a problem, however: I still can't define functions that return void. For example if I have a signature like this:

fun someFun(fn: (SomeClass) -> Unit)

I have to explicitly return Unit.INSTANCE from Java code. Is there a way to fix this (besides writing a helper function)

[Big Chungus]

Try returning Nothing

[ephemient]

Kotlin has a single interface Function<out R> type so as far as Java is concerned, you always need to return some value for R.
for the sake of interop, you could define your own SAM or use Java's specialized SAMs returning void, e.g.

fun someFun(fn: Consumer<SomeClass>)

[addamsson]

Thanks.