Typesystem and accessory models

Hi!

I was wondering if it's possible to define types in the typesystem with accessory models?

I have made some "baseclasses" for Int, String and Boolean for my project with accessory models:

In my structure I have StringConstant, BoolConstant and IntConstant

I was wondering if it's possible to define the type of these constants to be the ones in the accessory model?

Like this:

Is this possible or is there another approach?