ERROR: could not identify an equality operator for type box

Hi there,

create table qq (b box);
CREATE TABLE
select count(*), b from qq group by b;
ERROR: could not identify an equality operator for type box
LINE 1: select count(*), b from qq group by b;

but following select works fine

select ' (43.6038,48.8664536),(1.3620777,1.44327)'::box = ' (43.6038,48.8664536),(1.3620777,1.44327)'::box;
?column?
----------
t
(1 row)
^
What does it means ?

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83