Get all constants from a class

Question

Possible duplicate:
Can I get CONST in a PHP class?

Is it possible to get all defined constants from a class? That is, I have the following class:

class Cl {
    const AAA = 1;
    const BBB = 2;
}

and I would like to get an array:

array (
    'AAA' => 1,
    'BBB' => 2,
)