That's awesome!!! I'm actually really interested in the semantics of how a defer{} statement might work in C. If you have any kind of a draft or anything, I'd get a kick out of reading over it.

Re: developing a paper for constexpr, that's an interesting idea. I hadn't really thought about writing one up myself but it'd be an interesting thing to try out. Can you recommend a good example proposal that I could read? Shoot me an email at nicholas dot clark on the gmail if you ever see this.