If your comment never makes it out of moderation limbo (or maybe even if it does), would you mind posting it here? How does not being able to assume the absenc

If your comment never makes it out of moderation limbo (or maybe even if it does), would you mind posting it here? How does not being able to assume the absence of UB prevent optimizations like those you listed? Not that I'm doubting you; this is an area I'm not very familiar with.