I mean your (only?) argument for the constexpr keyword at this point is "it can be a keyword and I feel like it should be, even when I acknowledge it's redundant" then by all means go ahead. Personally I don't think that's a good way to do language design, but I can't argue with subjective feelings and aesthetics and I was never intending to. I'm pretty sure that's not one of the bases on which it made it into the standard though, and those are what I'm trying to address.