What I'm not seeing is why you would think that $c or $e could have a name better than undef. 

sub foo1 {
    my (undef, $d, undef, $f) = @_;
    return $d * $f;
}

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... works just fine, produces no warnings, and has the added advantage of immediately giving the parameter a name that makes it absolutely clear that the value will be discarded.

In reply to Re^5: Warnings on unused variables? by AZed
in thread Warnings on unused variables? by AZed

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