I don't think those namings are inconsistent. primitive types and abstract types are not structs, and it would be misleading to label them as such. structs and

I don't think those namings are inconsistent. primitive types and abstract types are not structs, and it would be misleading to label them as such. structs and mutable structs on the other hand are. So, using 'only struct' or 'only type' "consistently" would be more homogeneous, it would be, respectively, wrong and under-specific. I think it's good that the concepts of type and struct are separated like that.