Using current_database() in a grant

In 7.3b1 I am trying to use current_database in a grant statement to
give access to the current database in a script. Since I really
only have one database I plan on using the script for I can just
hard code the name. However I would think it would be nice to allow
this to work so people can keep their scripts more general without
having to do more complicated mechanisms.

Here is what happens when I try this:
area=# grant create on database current_database() to bruno;
ERROR:  parser: parse error at or near "(" at character 42