Actually there is. As soon as you add that ampersand the constants cease to be constants. And instead of inlining the value during compile-time, Perl actually calls the functions each time. Therefore I'd rather add an empty pair of braces:

%hash = ( FOO() => 'FOO description, ...)
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Try to run these three and see the difference:

perl -MO=Deparse -e "use constant FOO => 5; print FOO,qq{\n};"

perl -MO=Deparse -e "use constant FOO => 5; print &FOO,qq{\n};"

perl -MO=Deparse -e "use constant FOO => 5; print FOO(),qq{\n};"
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Jenda
Always code as if the guy who ends up maintaining your code will be a violent psychopath who knows where you live.
   -- Rick Osborne

Edit by castaway: Closed small tag in signature