#!perl -w

use strict;
use Benchmark ':all';

our @unsorted = map {
    join('', map { ('a'..'z','A'..'Z',0..9)[rand 62] } 1..50)
} 1..5000;

sub uniq_dragonchild { my %x; @x{@_} = @_; values %x }
sub uniq_BrowserUk { my %x; @x{@_} = (); keys %x }
sub uniq_Zaxo { keys %{ { map { $_ => undef } @_ } } }
sub uniq_Roy { my %x; grep {!$x{$_}++} @_ }

our( @a, @b, @c, @d );

cmpthese( -1, {
        uniq_dragonchild  => '@a = uniq_dragonchild( @unsorted )',
        uniq_BrowserUk    => '@b = uniq_BrowserUk( @unsorted )',
        uniq_Zaxo         => '@c = uniq_Zaxo(@unsorted)',
        uniq_Roy		  => '@d = uniq_Roy( @unsorted )',
});

#my $a='a'; print $/, $a++, ' : ', "@{[ sort @$_ ]}" for ( \@a, \@b, \@c, \@d );

__END__
P:\test>363760
                   Rate uniq_dragonchild   uniq_Zaxo     uniq_Roy uniq_BrowserUk
uniq_dragonchild 18.1/s               --        -21%         -31%           -41%
uniq_Zaxo        22.8/s              26%          --         -13%           -25%
uniq_Roy         26.3/s              45%         15%           --           -14%
uniq_BrowserUk   30.6/s              69%         34%          16%             --