Overloading Playground

overloading.swift

class A { }
class B: A { }
class C: A { }

func play(_ a: A) {
    print("playing with A")
}

func play(_ b: B) {
    print("playing with B")
}

func play(_ c: C) {
    print("playing with C")
}

let a = A()
let b = B()
let c = C()

play(a)
play(b)
play(c)


// What should happen here? What happens instead?
//let x: A = B()
//play(x)