Something that I haven't seen discussed is why it wouldn't be a better solution would be for the code you listed to be a warnings or errors; get the user to wri

Something that I haven't seen discussed is why it wouldn't be a better solution would be for the code you listed to be a warnings or errors; get the user to write size_t then it is efficient without needing to go to UB. Another common example is a null-check after a deref; it seems like that should also just be a compiler error since the UB optimization is based on "you wrote code that the compiler can just directly tell is wrong, so it's going to pretend you didn't do that". There's surely cases where it would be hard to suggest a "equally efficient without UB" replacement (eg when it wants to fuse two i64 into one), but it feels like the current position is too far on the axis of "provided with suspicious code, the compiler should just make that garbage run as fast as possible and call it a day"