Eric Veldhuyzen <ericv(at)xs4all(dot)net> writes:
> # select 0::boolean;
> bool=20
> ------
> f
> (1 row)
> Perfect.
Not so perfect as you think --- 7.2 does not allow casting from int to
bool any more than 7.3 does. Try this:
regression=# select 1::int::boolean;
ERROR: Cannot cast type 'integer' to 'boolean'
7.2 is interpreting your query like
regression=# select '1'::boolean;
bool
------
t
(1 row)
which still works in 7.3 --- but we tightened up the other case, for
reasons I don't recall at the moment but you can find in the mailing
list archives.
regards, tom lane