&gt; ... and those posts have instilled the fear of god in me.<p>But why? Yeah, hitting UB can be a terrifying idea but rarely happens in practice.<p>In two decades of C programming, I have hit an UB bug exactly once when a piece of code was ran on an ARM platform for the first time. It took a little bit of staring at disassembly and reading some docs to sort out but it wasn&#x27;t the end of the world.<p>Understanding the basic cases is a good idea but the darkest corners of undefined behavior are only important if you&#x27;re a compiler writer like Chris Lattner is.