Altering the Return Value: Prewrappers

• Scalar context could have worked the same way as list context

• Perhaps something like this:

        $prereturn = $return = [];
        $dummy = $wrapper{pre}->(@_,$return) if $wrapper{pre};
        if (ref $return eq 'ARRAY' && $return == $prereturn && !@$return) {
                $return = &$original;
                $dummy = $wrapper{post}->(@_, $return)
                        if $wrapper{post};
        }
        return $return;

• Except for one little problem

• The manual promises:

        In a pre-wrapper, $_[-1] is -- for obvious reasons -- undef. 

• If the code were as above, $_[-1] would not appear to be undef

• It would appear to be a listref

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Copyright © 2003 M. J. Dominus