#! /usr/bin/env perl
package Foo;
use strict;
use warnings;
sub new { bless {}, shift }
sub uniq { shift; my %h; $h{$_}++ for @_; grep { $h{$_} == 1 } keys %h }

package main;
print "@{[Foo->new->uniq(@ARGV)]}\n";

##</code><code>##

./11911 hi hi hi hey lo hey may ':-)'
may lo :-)