It seems like there's no function that determines all the *static* variables of a class.
I've come out with this one as I needed it in a project:
<?php
function get_class_static_vars($object) {
return array_diff(get_class_vars(get_class($object)), get_object_vars($object));
}
?>
It relies on an interesting property: the fact that get_object_vars only returns the non-static variables of an object.