C++ templates! I keep on running into places where I'm debugging, then I find myself in a maze formed by template overuse, then debug around that instead.
just having parametric polymorphism
I think that could be workable in Go. I can imagine how debugging that would be straightforward.
I'm having a hard time understanding where using generics would cause problems.
C++ templates, sure, but those are much more powerful than just having parametric polymorphism.