std::optional<std::monostate> has two values, Option<Infallible> has one, so by my counting that's a 100% error. It is likely the best that can be done, but th

std::optional<std::monostate> has two values, Option<Infallible> has one, so by my counting that's a 100% error. It is likely the best that can be done, but that's my point, C++ can't do this because the foundational type system isn't up to the task.