inherits clause for CREATE TYPE? -

Hi

I had a talk with one boy about development in plpgsql. He uses table's
functions. More times he uses returns types based on some table type + few
attributes. Now he use a ugly hack - he create a view on table plus some
columns - and then he use the view related type as table function result
type. For similar uses cases there can be interesting to have a possibility
to create types by extending other types. Probably almost all functionality
is inside now - so it should not be hard work.

My idea is implement inherits clause for CREATE TYPE command.

Some like

CREATE TYPE fx_rt (xx int) INHERITS(pg_class);

What do you think about this idea?

Regards

Pavel