use Sort::Key::Top 'natpos';

use Benchmark qw(cmpthese);

my @f = map rand, 0..1e7;

my ($r1, $r2);

cmpthese -1, { sort => sub { $r1 = (sort { $a <=> $b } @f)[@f/2] },
               skt  => sub { $r2 = natpos @f/2, @f } };

print "median $r1, $r2\n";