title: assert() with message
body: <p>I saw somewhere assert used with a message in the following way:</p>
  
  <pre><code>assert(("message", condition));
  </code></pre>
  
  <p>This seems to work great, except that gcc throws the following warning:</p>
  
  <pre><code>warning: left-hand operand of comma expression has no effect
  </code></pre>
  
  <p>How can I stop the warning?</p>