use Modern::Perl;

package Testing;
use Bit::Vector;
use Moose;

has 'thing' => (
    isa     => 'Bit::Vector',
    is      => 'rw',
    default => sub {
        return Bit::Vector->new(32);
    },
);

no Moose;
__PACKAGE__->meta->make_immutable;
1;

##</code><code>##

use Modern::Perl;
use Testing;
use Data::Dump qw/dump/;

my $object = Testing->new;
say dump($object);

##</code><code>##

bless({ thing => bless(do{\(my $o = 39557684)}, "Bit::Vector") }, "Testing")

##</code><code>##

my $object = Testing->new({thing => undef});