This smart casting thing, the more I think about it the more work it becomes:

fun `kotlin is pretty smart`(){
    val nullableSet: Set<Int>? = setOf(1, 2, 3)
    
    when(nullableSet?.size){ 
        null -> {}
        else -> { nullableSet.first() }
    }
}

I would've thought that I'd need a

nullableSet!!

in the second case. does that mean the smart-cast system was able to infer that

well the expression

nullableSet?.size

wasn't null, and

size

can never be null, so

nullableSet

must also not be null, so I can smart-cast it to

Set<Int>

if so, that kotlinc is one sharp cookie

Dominic is incorrect, it did infer it from the

null

case in the

when

expression. Kotlinc is very good at smart-casting