Point_neo_moose2.pl

use MooseX::Declare;

role DoesNegated {
    method negated { $self->new( x => -$self->x, y => -$self->y ) }
}

role DoesTranspose {
    method transpose { $self->new( x => $self->y, y => $self->x ) }
}

class Point with DoesNegated with DoesTranspose {    
    has x => ( isa => 'Int', is => 'rw' );
    has y => ( isa => 'Int', is => 'rw' );

    method inspect { say $self->x . ' @ ' . $self->y }
}