maxost

data class Sms(val phone: String, val text: String)

object SmsBus {
    private val bus by lazy { PublishSubject.create<Sms>() }

    fun incomingSms(): Observable<Sms> = bus
    fun postSms(sms: Sms) = bus.onNext(sms)
}

maxost

sealed class Option<out A> {

    abstract fun get(): A

    object None : Option<Nothing>() {
        override fun get(): Nothing = throw NoSuchElementException("None.get")
    }

    data class Some<out A>(val value: A) : Option<A>() {
        override fun get(): A = value