my @a = (1,2,3);
my $c = $a[-1];

#for (@a) {      # prints 1..10
for ((), @a) {   # prints 1..3
    push @a, ++$c if $c < 10;
    print "$_\n";
}

##</code><code>##

...
for ((), @a) {
    push @a, ++$c if $c < 10;
    $_ *= 2;      # modify aliased elements
    print "$_\n";
}

use Data::Dumper;
print Dumper \@a;

__END__
2
4
6
$VAR1 = [
          2,
          4,
          6,
          4,
          5,
          6
        ];