c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le
"my $s = 'apathetic';
 ;;
 my @captures = $s =~ m{ (pat) | (te) | (rn) }xms;
 dd \@captures;
 ;;
 @captures = $s =~ m{ (?| (pat) | (te) | (rn)) }xms;
 dd \@captures;
"
["pat", undef, undef]

["pat"]