Kotlin - when with smart cast example

whenWithSmartCastExample.kt

interface House

class Stark : House{
    fun wolves() = arrayListOf("Ghost", "Grey Wind", "Summer", "Lady", "ShaggyDog", "Nymeria")
}

class Targeryen : House{
    fun daenerysDragons() = arrayListOf("Drogon", "Viserion", "Rhaegal")
}

fun printAnimalsOf(house: House) =
        when (house) {
            is Stark -> house.wolves()
            is Targeryen -> house.daenerysDragons()
            else -> throw IllegalArgumentException("Unknown house")
        }

fun main(args: Array<String>) {
    println(printAnimalsOf(Targeryen()))
    // [Drogon, Viserion, Rhaegal]
}