In this specific case, sure. But it&#x27;s not really about this specific case; it&#x27;s about the general idea of &quot;I know that this won&#x27;t fail, even though you, the compiler, do not.&quot; Unless you have full-on dependent types, (and even then), there&#x27;s going to be times where that&#x27;s true; it&#x27;s the nature of type systems. They have to be conservative, there will always be valid programs that are not expressible.