title: How to ignore "-Ywarn-unused" warning in Scala?
body: <p>How do I ignore "Ywarn-unused" warning for a piece of code in Scala? I want it to be enabled generally, but I want to make an exclusion for a particular class (or, say, method). How do I do that?</p>
  
  <p>The code in question is macro-generated, so I have no power over it (though I raised an issue for the library that generates the strange code <a href="https://github.com/ReactiveMongo/ReactiveMongo/issues/641" rel="nofollow noreferrer">https://github.com/ReactiveMongo/ReactiveMongo/issues/641</a>).</p>