Perhaps something like this:

use strict;
use warnings;

my $x = "Mmm...donut, thought Homer";
if (my @matches = $x =~ /^(Mmm|Yech)\.\.\.(donut|peas)/)
{
    unshift @matches => undef;
    foreach my $expr (1..$#-) 
    {
        print "Match $expr: '$matches[$expr]' at position ($-[$expr],$
++[$expr])\n";
    }
}
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Note the trick is to capture the return value of the =~ into an array (which I've called @matches above).

Trick number two is to unshift a dummy value into $matches[0]. This is because arrays are indexed from 0 and regex matches are numbered from 1. Unshifting the dummy value makes @matches line up better with $- and $+.