dispatch macro doesn't support dispatching on overall types and variants at the same time

[Tortar]

e.g. in the example in the readme, let's say only B has a special value

@dispatch value(::B) = 2

then it would be useful if this would also work to reduce verbosity:

@dispatch value(::A) = 1

which would mean that all other kinds have that value

[Tortar]

Now this is partially supported because it is possible to use @dispatch with @sum_structs types, but still mixing these types with variants in the signature is not supported

[Tortar]

new methodology solves this