Comment by falcolas

As a programmer who is writing Go for a living: the lack of generics is not actually that big of a problem in your day to day work.

Yes, if you want to generalize code to release a library to a much wider audience, you'll either end up writing quite a bit of duplicate code, using the code generation tools, or diving into the "reflect" package (which would let you write Sum in one method).

That said, I've never had to do either of these in writing about 10k lines of Go code.