Create instance of class based on function argument

Suppose I have three classes:

import Foundation

class A {

    init() {
      print("A")
    }

}

class B {

    init() {
        print("B")
    }

}

class C {

    init() {
       print("C")
    }
}

I want to dinamically pass a string ("A", "B" or "C") as a function argument and then, inside the body of this function, create an instance of the class I passed. Is this possible? How?

I tried this one (and other variants) but with no luck:

func test(c:AnyObject){
    let _class = c()
    //...
}

test(c:A)

[UPDATE] Maybe the question is no different from the one @Code Different suggests but that question is old and there were so many changes in the language that one should try any suggested solution before finding the one that works as of today