elegant perl quick sort

quick-sort.pl

use strict;
use warnings;
use v5.10;

sub sort_
{
    my @xs = @_;
    if(scalar(@xs) == 0) {return ();}
    my @lesser = sort_(grep { $_ <  $xs[0] } @xs);
    my @greater = sort_(grep { $_ > $xs[0]  } @xs);
    return (@lesser, $xs[0], @greater);
}


my @items = (101, 1,90,10,4,2,100);
say join ",", sort_ @items;

It doesn't work with equal values in the list.