Best way to handle such scenario where “smart cast is imposible”

Question

I wonder what is the best way to handle such scenario

class Person(var name:String? = null, var age:Int? = null){
    fun test(){
        if(name != null &am         


        

Answer 1

If you want to take it a little "extreme" you could define an extension function on Pair<String?,Int?> that hides the logic for you:

fun Pair<String?,Int?>.test(block: (String, Int) -> Unit) {
    if(first != null && second != null) {
         block(first, second)
    }
}

then, calling it will be a little more concise

(name to age).test { n, a ->
   println("name: $n age: $a")
}

However, it won't really help you (since you could as well define this as a function inside the Person class itself), unless you need this kind of functionality really often throughout the whole project. Like I said, it seems overkill.

edit you could actually make it (a little) more useful, by going fully generic:

fun <T,R> Pair<T?,R?>.ifBothNotNull(block: (T, R) -> Unit) {
    if(first != null && second != null){
         block(first, second)
    }
}