objcで [[self class] new] とするのを Swift で

result

Hello, I'm an instance of A.
Hello, I'm an instance of A.
Hello, I'm an instance of B.
Hello, I'm an instance of B.

who_are_you.swift

class A {
    
    // required を付けた init() が必要
    required init() {}
    
    func hello() {
        print("Hello, I'm an instance of A.")
    }
    
    func newInstance() -> A {
        return type(of: self).init()
    }
}

class B: A {
    override func hello() {
        print("Hello, I'm an instance of B.")
    }
}

let a = A()
let a2 = a.newInstance()
let b = B()
let b2 = b.newInstance()
a.hello()
a2.hello()
b.hello()
b2.hello()