interface I {
    fun a(): String
    fun b(): String
}

class C {
    fun a() = "C.a"
    fun b() = "C.b"
}

fun C.toI() = object : I {
    override fun a() = this@toI.a()
    override fun b() = this@toI.b()
}

fun f(i: I) {
    println(i.a())
    println(i.b())
}

fun main() {
    f(C().toI())
}