Good question. My response would be: only where it is not used as an enum.
The example in the article is one example (although I've never seen that idiom in the wild) or for doing things like bitfields (the opposite of the to_underlying section).
Minutes ago, the ISO C++ committee finished its meeting in-person in Varna, Bulgaria and online via Zoom, where we formally began adopting features into C++26. Our hosts, VMware and Chaos, arranged…