newApply

newApply.js

function F(){}
function newApply(ctor, args) {
    var i, 
    fp = F.prototype = ctor.prototype; // Copy prototype.
    if(fp) {
        fp.constructor = ctor;
    }
    i = new F;
    ctor.apply(i, args); // Apply the original constructor.
    return i;
}

// Example:
function Cat(a, b){
    this.a = a;
    this.b = b;
}
newApply(Cat, [1,2]);