title: Pass default value instead of reference
body: <p>I have a function like this (using PHP 7.1):</p>
  <pre><code>function myfunction(&amp;$first = null, $second = null)
  {   // do something
  }
  </code></pre>
  <p>What I want to achieve is to pass null as the first parameter and pass something as the second parameter:</p>
  <pre><code>myfunction(null, $something);
  </code></pre>
  <p>When I do that I get the &quot;<strong>Only variables can be passed by reference</strong>&quot; error.</p>
  <p>But of course, null is the default of the first parameter, so the function was designed to handle null as the first parameter.</p>
  <p>Is there a way to do it?</p>