C and C++ prioritize performance over correctness (2023)

It's not really that they prioritize performance over correctness (your code becomes no more correct if out-of-bounds write was well-defined to reboot the machine...), it's that they give unnecessary latitude to UB instead of constraining the valid behaviors to the minimal set that are plausibly useful for maximizing performance. E.g. it is just complete insanity to allow signed integer overflow to format your drive. Simply reducing it to "produces an undefined result" would seem plenty adequate for performance.

The author points out near the bottom that “performance” was not one of the original justifications for its UB decisions, afatct.

Your example is a slippery slope but I get your point. I agree that there needs to be a “reasonable UB”

But I’ve moved on from c++.