I suspect both optional<bool> and expected<bool> will be somewhat common uses (considering the number of tri-bool classes in existence), so I think this is a real problem that we need to resolve. (And I expect to write up something after BoostCon/C++Now)
Agreed. I could try the std-proposal forum or c++std-lib-ext@accu.orgif you don't mind.
You of course could, but I think std-proposal and the committee has probably had enough of optional for a while. I think the next best step is a paper clearly showing all the issues and offering clear recommendations/options.
So I advised against bringing it up... and then I brought it up on std-proposal myself. (Well, the existing conversation just went in that direction...) Oh well. Some day I'll learn to listen to my own advice.