I&#x27;d <i>personally</i> be fine with being forced to specify what sort of undefined behaviors I want to allow to be &quot;assumed I didn&#x27;t mean&quot;; it&#x27;s not a problem for me if some code refuses to compile until I e.g. type-annotate my u32s with &quot;they&#x27;re not going to overflow, don&#x27;t worry.&quot;<p>I was about to say that &quot;this would break a ton of other projects&quot;—but actually, it seems like it&#x27;d be fine as long as it was an opt-in -W switch.