I guess you can define union Union<T1, T2>(T1, T2); Add a bunch of overloads and you'd replicate for T1|T2 syntax the equivalent mess to (Value)Tuple<...> t

I guess you can define union Union<T1, T2>(T1, T2); Add a bunch of overloads and you'd replicate for T1|T2 syntax the equivalent mess to (Value)Tuple<...> that eventually became the backing for actual tuple syntax.