ctor

gistfile1.js

function ctor(fn) {
    function F () {
        var obj = Object.create(F.prototype);
        fn.apply(obj, arguments);        
        return obj;
    }
    F.prototype = Object.create(fn.prototype);
    return F;
}


//Example
var Foo = ctor(function (a, b, c) {
    this.a = a;
    this.b = b;
    this.c = c;
});

Foo.prototype.sum = function () {
    return this.a + this.b + this.c;
};

var foo = Foo(1, 2, 3);
console.log(foo.sum()); //6

// Calling the constructor with 
// pre-alocated arguments in array.
var args = [1, 2, 3];
var foo1 = Foo.apply(null, args);
console.log(foo1.sum()); //6