c:\@Work\Perl\monks>perl -wMstrict -le
"if ('night' eq 'day') {
   use constant FOO => 42;
   }
 ;;
 print FOO;
"
42

##</code><code>##

c:\@Work\Perl\monks>perl -wMstrict -le
"use if 'night' eq 'day', constant => FOO => 42;
 ;;
 print FOO;
"
Name "main::FOO" used only once: possible typo at -e line 1.
print() on unopened filehandle FOO at -e line 1.