c:\@Work\Perl\monks\marek1703>perl -wMstrict -le
"my $sans_esc = qr/[#$%&~_}{^]/;
 print $sans_esc;
 ;;
 my $with_esc = qr/[#\$%&~_}{^]/;
 print $with_esc;
"
(?^:[#0&~_}{^])
(?^:[#\$%&~_}{^])