sub uniq {
            my %hash = map { $_ => 1 } @_;
            return keys %hash;
        }
    

##</code><code>##

        sub uniq {
            return keys map { $_ => 1 } @_;
        }
    

##</code><code>##

        sub uniq {
            # two pairs of braces around map
            return keys %{ { map { $_ => 1 } @_ } };
        }
    

##</code><code>##

        sub uniq {
            # single pair of braces around map
            return keys %{ map { $_ => 1 } @_ };
        }