{
	package Binary::Humax::HmtData::Trait::Attribute;
	use Moose::Role;
	has unpack      => (is => 'ro', isa => 'Str');
	has postprocess => (is => 'ro', isa => 'CodeRef');
	
	before _process_options => sub
	{
		my ($meta, $name, $spec) = @_;
		if ($spec->{unpack})
		{
			$spec->{lazy}    //= 1;
			$spec->{builder} //= "_build_$name";
			$spec->{is}      //= 'rw';
		}
	};
	
	after attach_to_class => sub
	{
		my $attr   = shift;
		my $class  = $attr->associated_class;
		my $unpack = $attr->unpack or return;
		
		if (my $postprocess = $attr->postprocess)
		{
			$class->add_method($attr->builder, sub {
				my $self = shift;
				local $_ = unpack($unpack, $self->raw_data_block);
				$postprocess->();
			});
		}
		else
		{
			$class->add_method($attr->builder, sub {
				my $self = shift;
				return unpack($unpack, $self->raw_data_block);
			});
		}
	};
}

{
	package Binary::Humax::HmtData;
	
	use DateTime;
	use Moose;
	use constant MAGIC => 'Binary::Humax::HmtData::Trait::Attribute';
	
	has raw_data_block => (
		is       => 'rw',
		isa      => 'Str',
		required => 1,
	);
	
	has last_play => (
		traits => [ MAGIC ],
		isa    => 'Int',
		unpack => '@5 S',
	);
	
	has chan_num => (
		traits => [ MAGIC ],
		isa    => 'Int',
		unpack => '@17 S',
	);
	
	has start_time => (
		traits => [ MAGIC ],
		isa    => 'DateTime',
		unpack => '@5 S',
		postprocess => sub {
			DateTime->from_epoch(epoch => $_, time_zone => 'GMT');
		},
	);
	
	has file_name => (
		traits => [ MAGIC ],
		isa    => 'Str',
		unpack => '@33 A512',
	);
}

# Attribute introspection
print Binary::Humax::HmtData->meta->get_attribute('start_time')->unpack, "\n";