title: How to add definition QT_NO_DEBUG_OUTPUT in a CMake file?
body: <p>I am using ROS, therefore writing CMake files.
  In Qt <code>.pro</code> file, we can use:</p>
  
  <pre><code>DEFINE+=QT_NO_DEBUG_OUTPUT
  </code></pre>
  
  <p>How can we do that in a CMake file? I tried:</p>
  
  <pre><code>add_definitions(QT_NO_DEBUG_OUTPUT)
  </code></pre>
  
  <p>but it gives me the following error:</p>
  
  <blockquote>
    <p>c++: error: QT_NO_DEBUG_OUTPUT: No such file or directory</p>
  </blockquote>