SYNOPSIS package ThirdDimension; use Moose::Role; has 'z' => (is => 'rw', isa => 'Int'); package Point; use Moose; use MooseX::Storage; with Storage( base => 'SerializedClass', traits => [ 'WithRoles' ] ); has 'x' => (is => 'rw', isa => 'Int'); has 'y' => (is => 'rw', isa => 'Int'); 1; use Moose::Util qw/ with_traits /; my $p = with_traits( 'Point', 'ThirdDimension' )->new(x => 10, y => 10, z => 10); my $packed = $p->pack(); # { __CLASS__ => 'Point', '__ROLES__' => [ 'ThirdDimension' ], x => 10, y => 10, z => 10 } # unpack the hash into a class my $p2 = Point->unpack($packed); print $p2->z; DESCRIPTION This trait is meant to be used when a base class will be consuming roles at runtime via (for example) with_traits. Without this trait, the '__CLASS__' attribute of the serialized object would be the name of the resulting anonymous class, which is useless to reconstruct the class after the fact. When this trait is used, the serialized __CLASS__ value will be the base class, and __ROLES__ will contain the list of roles that it consumes. If used in conjecture with MooseX::Storage::Base::SerializedClass, unpack() will reinflate the data in the right class augmented by the given roles. Oh yeah, and the trait also works with MooseX::Role::Parameterized roles. You're welcome, Sartak. ;-)