Function.prototype.create

create.js

// Function.prototype.create

(function() {
	var Surrogate = function() {};

	Function.prototype.create = function() {
		if (this.__inst) {
			return this.__inst;
		}

		// Instantiate the instance with support for arbitary constructor arity
		Surrogate.prototype = this.prototype;
		Surrogate.prototype.constructor = this;
		this.__inst = new Surrogate();
		this.apply(this.__inst, arguments);

		return this.__inst;
	};
}());

// Usage

var MyThing = function() {};
var MyOtherThing = function() {
	this.args = arguments;
};

var mt1 = MyThing.create();
var mt2 = MyThing.create();
var mot1 = MyOtherThing.create(1, 2, 3);
var mot2 = MyOtherThing.create();

console.log(mt1 instanceof MyThing);
console.log(mt1 === mt2);

console.log(mot1 instanceof MyOtherThing);
console.log(mot1 === mot2);
console.log(mot1.args.length === 3);