It doesn't have the equivalent of variadic templates, which means you can't have something like std::tuple unless you either codegen it or make it not type-safe

It doesn't have the equivalent of variadic templates, which means you can't have something like std::tuple unless you either codegen it or make it not type-safe. I did the exact same thing in Java for an internal library in order to provide type-safe Unit, Singleton<T1>, Pair<T1, T2>, etc.