Eloquent quicksort implementation (Perl)

quicksort.pl

#!/usr/bin/env perl

use strict;
use warnings;

use Test::Deep;

sub quicksort {
    return unless @_;

    my $pivot = shift;
    return (
        quicksort(grep { $_ < $pivot } @_),
        $pivot,
        quicksort(grep { $_ >= $pivot } @_)
    );
}


my @unsorted = (12, 4, 5, -12, 66, 0, 1111, 2);
my @sorted   = (-12, 0, 2, 4, 5, 12, 66, 1111);

cmp_deeply([@sorted], [quicksort(@unsorted)]);