Smart cast to non-null invalidated by the elvis operator?

[dalewking]

@bj0

I was surprised, however, that the following did not work in the same way:

fun function(val intent: Intent?) {
val action = intent?.action ?: return

intent.getParcableExtra(...)  //  compiler error because intent is nullable

As I understand it, if intent is null, the elvis operator short-circuits and the function ends, but there is no smart cast. I thought this might be a bug in the AndroidStudio plugin at first, but I get the same behavior from try.kotlinlang.org. Is there a reason I am missing that a smart cast cannot work in this situation?

There has to be some limit on how in depth of an analysis Kotlin goes through to determine smart casts. Here you are returning if intent?.action is null which could be null if intent is null or if the intent’s action is null. This is only one level of indirection from intent being null, but what if you added more expressions in there? Where does it draw the line? They are smart casts not genius casts