Note that you can also work around the lack of overloading at the implementation level through default parameters in TypeScript, e.g.:
interface IBox {
x : number;
y : number;
height : number;
width : number;
}
class Box {
public x: number;
public y: number;
public height: number;
public width: number;
constructor(obj : IBox = {x:0,y:0, height:0, width:0}) {
this.x = obj.x;
this.y = obj.y;
this.height = obj.height;
this.width = obj.width;
}
}
Edit: As of Dec 5 '16, see Benson's answer for a more elaborate solution that allows more flexibility.