Creates a function that invokes func with the arguments of the created function. If func is a property name the created callback returns the property value for a given element. If func is an object the created callback returns true for elements that contain the equivalent object properties, otherwise it returns false.

var users = [
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 }
];

// wrap to create custom callback shorthands
_.iteratee = _.wrap(_.iteratee, function(callback, func, thisArg) {
  var match = /^(.+?)__([gl]t)(.+)$/.exec(func);
  if (!match) {
    return callback(func, thisArg);
  }
  return function(object) {
    return match[2] == 'gt'
      ? object[match[1]] > match[3]
      : object[match[1]] < match[3];
  };
});

_.filter(users, 'age__gt36');
// => [{ 'user': 'fred', 'age': 40 }]