WeTutoriaL

One of the most Fastidious limits in Code Igniter is the fact you can’t use the multiple extension on CI_Controller. This cause artificious solutions in the creation of sites with public and admin contoller.

Thanks to Phil Sturgeon, adding this patch at the end of application/config.php you can easily resolve the problem:

/*
| -------------------------------------------------------------------
|  Native Auto-load
| -------------------------------------------------------------------
|
| Nothing to do with cnfig/autoload.php, this allows PHP autoload to work
| for base controllers and some third-party libraries: Pubblic Controller,
| Admin Controller and so on.
|
| Credits to: Phil Sturgeon
|
*/

function __autoload($class)
{
 if(strpos($class, 'CI_') !== 0)
 {
  include_once( APPPATH . 'core/'. $class . EXT );
 }
}