You have to add special handling for the case that T == std::reference_wrapper<T> so you can call .get() on it to expose the underlying value. In the case of st

You have to add special handling for the case that T == std::reference_wrapper<T> so you can call .get() on it to expose the underlying value. In the case of std::optional vs a pointer type (raw or smart) you can consistently use operator* to get to the underlying value. I think this is what was meant.