<?php class A { public function d() { } } class B extends ReflectionClass { } function c() { } $a = new ReflectionClass('A'); $b = new ReflectionClass('B'); $c = new ReflectionFunction('c'); $d = $a->getMethod('d'); $rc = new ReflectionClass('ReflectionClass'); var_dump($a->isHack()); var_dump($b->isHack()); var_dump($c->isHack()); var_dump($d->isHack()); var_dump($rc->isHack());