``` fun foo bar Long elsewhere fun whatever baz Long = return when baz 0 gt 0 gt foo baz here else gt null ``` why is there no smart cast for baz being non null here

Can t you just do `baz = null amp amp baz gt 0` or something

Yes but if `baz 0 gt 0` then `baz` is certainly not null

``` fun foo bar Long elsewhere fun whatever baz Long = retur kotlinlang #announcements

Benoit Duffez

11/03/2018, 9:15 PM

fun foo(bar: Long) { ... }
//elsewhere:
fun whatever(baz: Long?) = return when {
  baz ?: 0 > 0 -> foo(baz) // here
  else -> null
}

why is there no smart cast for baz being non null here?

karelpeeters

11/03/2018, 9:21 PM

The compiler simply doesn't try to be too smart about stuff like this.

Benoit Duffez

11/03/2018, 9:26 PM

OK, thanks for the reply

I don't like the

!!

operator but I guess it is safe here.

karelpeeters

11/03/2018, 9:27 PM

Can't you just do

baz != null && baz > 0

or something?

11/03/2018, 9:46 PM

Or maybe change whatever to whatever(baz: Long) and use baz ?: 0 at the call site.

Benoit Duffez

11/04/2018, 12:45 PM

the question was more about why the compiler doesn't smart cast rather than how to deal with the consequences

11/04/2018, 5:35 PM

But there’s nothing to smart-cast. If

baz

null

, it still continues to be

null

karelpeeters

11/04/2018, 5:36 PM

baz ?: 0 > 0

baz

is certainly not null.

11/04/2018, 5:37 PM

Aha. Right. Missed that