title: Can not print C++ String when use lldb in Xcode8
body: <p>It says:</p>
  
  <pre><code>xcode lldb no location, value may have been optimized out
  </code></pre>
  
  <p>Try:</p>
  
  <ol>
  <li>make sure is deubg in scheme</li>
  <li>optimisation leve is set to None</li>
  <li>"Enable Address Sanitizer" is off.</li>
  <li>Other C Flags is empty</li>
  </ol>
  
  <p>Not Work </p>