Domain casting still not working right?

This particular case arose during work on the information schema:

-- good

select cast(55::oid AS varchar);varchar
---------55
(1 row)

-- bad

create domain test as varchar;
CREATE DOMAIN
select cast(55::oid AS test);
ERROR:  Cannot cast type oid to test

-- 
Peter Eisentraut   peter_e@gmx.net