Both forms are correct. If you crack open constant.pm, you will discover all it does is play some neat games with constant functions.

An optimization in the Perl compiler recognizes does some special optimizations when a function is declared with a () prototype is not called with either a do or an &. If after all the smoke and magic the function returns a constant value, this value will be substituted directly into the code, instead of incurring the subroutine call overhead each time.

I have done both - there are times when use constant is more useful ( standardized, don't have to think how it works, etc ) and there are times when declaring you own subroutines is useful ( lots of them, defining all your constants in one file, etc ).

For more information, read perldoc perlsub and search on the string 'Constant Functions'

mikfire