You might also have luck with
@-, brand-new to 5.6.0 (it says here in perlretut).
$-[0] is the offset of the start of the last successful
match. $-[n] is the offset of the start of the substring
matched by n-th subpattern, or undef if the subpattern
did not match.
for (qw(foo bar baz)) {
if (/(foo)|(bar)|(baz)/) {
print "\$+ = $+\n";
print "\@- = " . join('/',@-) . "\n";
print "scalar \@- = " . scalar(@-) . "\n";
}
}
__END__
$+ = foo
@- = 0/0
scalar @- = 2
$+ = bar
@- = 0//0
scalar @- = 3
$+ = baz
@- = 0///0
scalar @- = 4
which would seem to indicate that you could do
$sub[scalar(@-)-2]->();,
although I think I'd prefer something easier to understand, if I
were going to maintain this.