title: Operator << for QString
body: <p>It makes sense to implement &lt;&lt; for QString like:</p>
  
  <pre><code>std::ostream&amp;  operator &lt;&lt;(std::ostream &amp;stream,const QString &amp;str)
  {
     stream &lt;&lt; str.toAscii().constData(); //or: stream &lt;&lt; str.toStdString(); //??
     return stream;
  }
  </code></pre>
  
  <p>instead of writing</p>
  
  <pre><code>stream &lt;&lt; str.toAscii().constData();
  </code></pre>
  
  <p>every time in the code. </p>
  
  <p>However, since it is not in standard Qt library, I'm assuming there is any particular reason not to do so. What are the risks/inconvenience of overloading &lt;&lt; as specified above?  </p>