&gt; It&#x27;s somewhat controversial in the Rust community<p>We added a lint to clippy that detects places where you <i>could</i> rely on elision but don&#x27;t. I&#x27;m particularly fond of it, because many Rust programmers (including me) still default to the pre-input-output rule regime by explicitly typing out `fn&lt;&#x27;a&gt;(&amp;&#x27;a u8)-&gt; &amp;&#x27;a u8`. It&#x27;s caught a lot of this and made code nice and clean.<p>However, we&#x27;ve have multiple people ask the lint to be off-by-default for input-output cases where one of the two sides has a struct&#x2F;enum lifetime (`Foo&lt;&#x27;a&gt;`, not `&amp;&#x27;a _`), because it&#x27;s nice for that to be explicit. (At the same time, multiple people feel like it should stay)<p>We&#x27;ll have to see what happens when we RfC the clippy defaults.