Thanks to Steve Downey and others, optional<T&> is officially adopted into C++26.
It would've been great during C++17, but the uphill battle had to be fought first. But, hey. The first best time was 9 years ago,
but the second best time is now.
The history: https://thephd.dev/to-bind-and-loose-a-reference-optional
The final result, after scrapping tooth and nail for this. https://wg21.link/p2988
