title: Access the parent selector from within a SASS mixin
body: <p>I have set up a mixin for a button using display:inline-block. I am trying to get to the parent of whatever class that will eventually end up using the mixim, so I can add the font-size: 0px line there to make sure that I don't need to make adjustments to my HTML to avoid unwanted space between each button.</p>
  
  <p>Here's an example... I want the. parent class to receive the font-size: 0px line.</p>
  
  <pre><code>@mixin button() {
      display:inline-block;
      font-size: 1em;
      //other stuff to make a pretty button
      &amp;&amp; { font-size: 0px; }
  }
  
  .parent{
      .child {
          @include button();
      }
  }
  </code></pre>