Nope.

  foreach my $foo (@bar) { $foo .= 'ack' ; ... } ;
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will affect the contents of the array just as surely as:

  foreach (@bar) { $_ .= 'ack' ; ... } ;
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To avoid this you need to:

  foreach (@bar) { my $s = $_ . 'ack' ; ... } ;
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or similar.

It's genuine Perl magic. Useful once you know it. A chunk out of your backside when you don't.