TypeScript: self-referencing return type for static methods in inheriting classes

Question

With Polymorphic this in TypeScript 1.7, as I discovered here, we can define a method in a class with a return type of this, and automatically, any classes that

Answer 1

What are you expecting this static method to return in the inherited subclass? Is it something like this:

class A {
    private static _instances = new Array();
    static instances(): A[] { return A._instances; }
    constructor() { A._instances.push(this); }
}

class B extends A {

    static instances(): B[] { 
        return (A.instances().filter(i => i instanceof B)); 
    }
    constructor() { super(); }; 
}

var a = new A();
var b = new B();

console.log(
     "A count: " + A.instances().length + 
    " B count: " + B.instances().length);

This will output "A count: 2 B count: 1". Or what are you expecting?