In 5.10+, see also named capture buffers:

>perl -wMstrict -le
"my $str = 'The CEO of WidgeCo resigned today.';
 ;;
 $str =~ m{ (?<BIGWIG> chairman | president | ceo ) }xmsi;
 ;;
 if (exists $+{BIGWIG}) {
   print qq{a $+{BIGWIG} was mentioned};
   }
"
a CEO was mentioned
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Update: For the position in the string of the match(es), see @- and @+ in perlvar.