Php : create a class with eval -

i watching code of prestashop, , see following :

eval(($class_infos->isabstract() ? 'abstract ' : '').'class '.$classname.' extends '.$classname.'core {}'); 

they use in order override core class, in autoload method (complete file prestashop / classes / autoload.php) wondering if thing create dynamic class this:

• will class cached apc or op code optimizer?
• what performance?

i wondering if thing create dynamic class this:

no.

will class cached apc or op code optimizer?

no.

what performance?

no!

^{(cw-ified. feel free flesh out answer.)}