INT_MAX+1 is actually a great example of UB because it demonstrates how UB is a problem even if there's a completely reasonable runtime behavior. One of the big

INT_MAX+1 is actually a great example of UB because it demonstrates how UB is a problem even if there's a completely reasonable runtime behavior. One of the big reasons UB is problematic is that it invalidates the semantic guarantees the standard makes about all your other code. That signed integer overflow completely invalidates any sort of formal proofs or error handling you might otherwise have.