# The $x is a hashreference and here :

      my $ones = {};

      $ones{a}={b=>1};

      print "[$ones{a}]\n";
      print "[$ones->{a}]\n";
      print "[$ones{a}->{b}]\n";
      print "[$ones{a}{b}]\n";


    __END__

    [HASH(0xe01d8)]
    []
    [1]
    [1]