title: Ternary condition on class in Sass
body: <p>Is there a possibility to use a ternary condition in Sass especially on class object ?
  Something which would look like : </p>
  
  <pre><code>[class*="fa-caret-"]{
     &amp;:left ? 'top: -45' : 'top: 45';
  }
  </code></pre>