If you develop C or C++ haphazardly in such a way that you leave a bunch of UB on the table during development then there's little to no chance that you'll have

If you develop C or C++ haphazardly in such a way that you leave a bunch of UB on the table during development then there's little to no chance that you'll have actually erased all presence of it by the end of development. There currently exist no tools which with complete reliability point out all UB in your program. If any part of your program can have UB and you didn't write it with the explicit intention of not having UB in it at any point then you're going to be left with a tough situation to deal with. I've read a lot of C in my time and there's codebases which I read and find easy and quick to review because they stick to the rules and only bend them sparingly and then there's codebases which are a pain to evaluate even the most basic parts for errors and UB. There's no such thing as "detectable UB", there's only UB which your tools have luckily managed to detect. Leave the UB to the people who can't avoid it, stick to safe languages when you can.