Why is box <-> point missing, and box <-> box not indexable?

point <-> point, circle <-> point and polygon <-> point all exist as
orderable-by-operator operators (in fact they are the only ones by
default). But there's no box <-> point operator at all, and no index
support for box <-> box.

Was this intentional, or just a strange oversight?

-- 
Andrew (irc:RhodiumToad)