Defines TRUE and FALSE constants in callers namespace. You could use
simple values like empty string or zero for false, or any non-empty and
non-zero string value as true, but the TRUE and FALSE constants are more
It is virtually the same as:
# double "not" operator is used for converting scalar to boolean value
use constant TRUE => !! 1;
use constant FALSE => !! ;
The constants exported by constant::boolean are not reported by
Test::Pod::Coverage, so it is more convenient to use this module than to
define TRUE and FALSE constants by yourself.
The constants can be removed from class API with no constant::boolean
pragma or some universal tool like namespace::clean.