title: What does "Class* &cls" mean in C++'s function definition?
body: <p>I know Class *cls is a pointer, and Class &amp;cls takes the address, but what is </p>
  
  <pre><code>void fucction1( Class *&amp;cls)
  </code></pre>
  
  <p>If I have <code>Class c</code>, what should I pass to <code>function1()</code>?</p>
  
  <p>Thanks!</p>