(PHP 5 >= 5.1.0, PHP 7) Count the elements in an iterator

(PHP 5 >= 5.1.0, PHP 7) Return the interfaces which are implemented by the given class or interface

(PHP 5 >= 5.1.0, PHP 7) Return the parent classes of the given class

(PHP 5 >= 5.1.2, PHP 7) Return all registered __autoload() functions