The problem is the solution is often to make the compiler ignore types all together and use interface {} wholesale, then test interfaces with type assertions.

The problem is the solution is often to make the compiler ignore types all together and use interface {} wholesale, then test interfaces with type assertions. If Go had a least unions, it would be a bit less painful to describe a range of finite types while keeping things strictly typed in functions and methods. Unions are a limited form of type polymorphism in a garbage collected language.