How to determine in PL/SQL if a user has a certain role?

Hello,

I need to determine if a certain user has a certain role in a PL/SQL procedure, something like

IF 'fred' HAS ROLE 'clerk' THEN ...

However, I cannot find a role operator (like the hypothetical HAS ROLE above) in the PL/SQL reference. What is the proper way to achieve my need?

Thanks for your advice,
Holger.

-- 
Dr. Holger Peine
Fraunhofer IESE, Kaiserslautern, Germany
Phone +49-6301-707-134, Fax -200 (shared)
www.iese.fraunhofer.de/Staff/peine -- PGP key on request or via pgp.mit.edu