Marking decision needed as this changes C++20 code; I personally believe that it should be treated as a DR tho.

I'm in favor of implementing this basically-a-bugfix paper in C++20 mode. This is consistent with our usual policy: major features (especially those introducing any new names) are always guarded, but if it's a similar size to an LWG issue resolution, avoids disrupting all but the most pathological user code, and affects existing product code that would be a pain to maintain two variants of, then implementing it downlevel is reasonable. (The enable_shared_from_this overhaul is the prime example, and this feels very similar.)

Alright, I'm good with that then.

I'm mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed.

Thanks for investigating and implementing the necessary changes here! ✅ 🕵️ 🚀