my %mapping = ( ARRAY  => '@',
                    HASH   => '%',
                    SCALAR => '$',
#                    GLOB   => '?',
#                    REF    => '?',
#                    CODE   => '?',
                  );
    if (grep { $_ eq $type } keys %mapping) {
        if (isa($_[0], $type)) {
            return eval "$mapping{$type}{$_[0]}";
        } else {
            return @_;
        }
    } else {
        return ();
    }