Within your L<MooseX::Types> declared library module:
+ use Set::Scalar;
use MooseX::Types::Parameterizable qw(Parameterizable);
+ use MooseX::Types::Moose qw(Int );
+ use MooseX::Types -declare=>[qw(Set UniqueInt PositiveSet)];
subtype Set,
as class_type("Set::Scalar");