# presented in perlfaq4 - How can I remove duplicate elements from a list or array?
sub my_uniq {
  my %h;
  grep { !$h{$_}++ } @_;
}

# vs.

# List::MoreUtils::uniq
sub LM_uniq {
  my %h;
  map { $h{$_}++ == 0 ? $_ : () } @_;
}