Could you elaborate on 13-16? I have no idea what you could possibly mean, and the linked blog post doesn't help. As far as I know UB needs to execute for it to

Could you elaborate on 13-16? I have no idea what you could possibly mean, and the linked blog post doesn't help. As far as I know UB needs to execute for it to apply and make a program invalid. The linked rust blog post is about how in rust, creating some values in and of itself is UB (It's not that there is unreachable UB later on that uses the invalid value, it's that there was already UB executed earlier in the program in the creation of the invalid value). I know there are some "global" UBs that do not need to "execute" at runtime, but those can simply be thought of as executing at compile time.