A simple library adding the function overloading capability to javascript

Overload.js

Function.overload = function(f) {
  if(!(f instanceof Function)) return;
  var _$ = function() {
    var $ = [arguments, , this, _$._overloads],
        _ = function(type, index) {
      if(type instanceof Array) return type.some(function(type) {
        return _(type, index);
      });
      if(!($[0][index] instanceof Object))
           $[0][index] = Object($[0][index]);
      if((typeof type === "string" &&
          typeof $[0][index] === type) ||
         (type instanceof String &&
          typeof $[0][index] === type.valueOf()) || (
         $[0][index] instanceof Object &&
          type instanceof Function &&
         $[0][index] instanceof type)) return true;
    };
    return !$[3].args.some(function(overload, index) {
      if(overload.length === $[0].length && (!$[0].length || overload.every(_)))
         return !void($[1] = $[3].functions[index].apply($[2], $[0]));
    }) && $[3].default?$[3].default.apply($[2], $[0]):$[1];
  };
  _$._overloads = {
    args: [Array.prototype.slice.call(arguments, 1)],
    functions: [f]
  };
  return _$;
};
 
Function.prototype.overload = function(f) {
  if(!this._overloads || !(f instanceof Function)) return;
  this._overloads.args.unshift(Array.prototype.slice.call(arguments, 1));
  this._overloads.functions.unshift(f);
};
 
Function.prototype.noSuchOverload = function(f) {
  if(!this._overloads) return;
  this._overloads.default = f;
};