Function.prototype.bind = function(oThis) {

  if (typeof this !== "function") {

    // closest thing possible to the ECMAScript 5

    // internal IsCallable function

    throw new TypeError( "Function.prototype.bind - what " +

                        "is trying to be bound is not callable"

                       );

  }

​

  var aArgs = Array.prototype.slice.call( arguments, 1 ),

      fToBind = this,

      fNOP = function(){},

      fBound = function(){

        return fToBind.apply(

          (

            this instanceof fNOP /* && <-- FIX

            oThis */ ? this : oThis

          ),

          aArgs.concat( Array.prototype.slice.call( arguments ) )

        );

      }

  ;

​

  fNOP.prototype = this.prototype;

  fBound.prototype = new fNOP();

​

  return fBound;

};

​

​

​

function foo(p1,p2) {

    this.val = p1 + p2;

}

​

// using `null` here because we don't care about

// the `this` hard-binding in this scenario, and

// it will be overridden by the `new` call anyway!

var bar = foo.bind( null, "p1" );

​

bar.prototype.newshit = 'shit';

​

var baz = new bar( "p2" );

​

console.log(baz.val); // p1p2