title: What does the parameter type void*& mean and what's its use?
body: <p>I'm looking through an API written in C++ and I'm confused as to what the following parameter type means: </p>
  
  <p><code>void*&amp; data</code></p>
  
  <p>Does that mean the user would pass in a reference to a void pointer? If that's true, what's the point? I mean void* is already indirected so why would you ever want to redirect it again?</p>