/**
* Flash the old input to the session and return the Redirect instance.
*
* Once the input has been flashed, it can be retrieved via the Input::old method.
*
* <code>
* // Redirect and flash all of the input data to the session
* return Redirect::to('login')->with_input();
*
* // Redirect and flash only a few of the input items
* return Redirect::to('login')->with_input('only', array('email', 'username'));
*
* // Redirect and flash all but a few of the input items
* return Redirect::to('login')->with_input('except', array('password', 'ssn'));
* </code>
*
* @param string $filter
* @param array $items
* @return Redirect
*/
public function with_input($filter = null, $items = array())
{
Input::flash($filter, $items);
return $this;
}