TypeSwitch.swift

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

extension A: CustomStringConvertible {
    var description: String {
        return "type of: \(type(of: self))"
    }
}

let one = B()
let two = B()

print(type(of: one) == type(of: two)) // true

let p: A = two

switch p {
case let some as B:
    print("B \(some)")
case is C:
    print("C")
default:
    print("don`t know")
}

// B type of: B