If you don't have parametric polymorphism, you only have two options to implement new containers: a new implementation for each type or using interface{}. The f

If you don't have parametric polymorphism, you only have two options to implement new containers: a new implementation for each type or using interface{}. The first leads to a lot of duplicate code, the latter requires you to use introspection to use safely. So, it does happen a lot, or you are making duplicate code.