use 5.010;
use strict;
use warnings;

my %hash;

say ref \%hash;
bless \%hash, "Whatever";
say ref \%hash;
__END__
HASH
Whatever

##</code><code>##

use 5.010;
use strict;
use warnings;

my %hash;
my $ref = \%hash;

bless $ref, 'Array';
bless \$ref,  'Whatever';
say ref \%hash;
say ref \$ref;
__END__
Array
Whatever