Logical operators don't work

The logical operators '&', '|', '<<' and '>>' as documented on the page
http://www.postgresql.org/devel-corner/docs/postgres/functions.html don't
appear to work as advertised.

darcy=# SELECT 91 & 15;
ERROR:  Unable to identify an operator '&' for types 'int4' and 'int4'       You will have to retype this query using
anexplicit cast
 

Should this be fixed or should the documentation be changed?

-- 
D'Arcy J.M. Cain <darcy@{druid|vex}.net>   |  Democracy is three wolves
http://www.druid.net/darcy/                |  and a sheep voting on
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