Part 1 code complete

generic-singleton-factory-pt1.kt

class ThingFactory {
    inline fun <reified T: Any> run() {
        if (myThing == null) {
        	createThing<T>()
        }
        myThing!!.run()
    }
    
    inline fun <reified T: Any> play() {
        if (myThing == null) {
        	createThing<T>()
        }
        myThing!!.play()
    }
    
    inline fun <reified T: Any> createThing() {
        when(T::class) {
              Thing1::class -> myThing = Thing1()
              Thing2::class -> myThing = Thing2()
              else -> throw IllegalArgumentException("Unknown thing")
        }
    }
        
    companion object {
        var myThing: SomeThing? = null
    }
}