title: Qt4: QMap causing "strict-aliasing rules" compilation error
body: <p>I'm trying to create the following data structure in Qt 4.5 in C++: </p>
  
  <p><code>QMap&lt;int, QMap&lt;QString, QVector&lt;QPointF&gt; &gt; &gt; animation;</code></p>
  
  <p>However, the inclusion of this line in my code results in the following error:</p>
  
  <pre><code>cc1plus: warnings being treated as errors
  In file included from XXX/XXX/XXX/MainWindow.qt.C.tmp.C:113:
  /usr/lib/qt4/include/QtCore/qmap.h: In member function ‘void MainWindow::exportAnn()’:
  /usr/lib/qt4/include/QtCore/qmap.h:588: error: dereferencing pointer ‘y’ does break strict-aliasing rules
  /usr/lib/qt4/include/QtCore/qmap.h:586: note: initialized from here
  Command exited with non-zero status 1
  </code></pre>
  
  <p>My organization requires me to treat all warnings as errors, so I can't simply ignore this. Is this a bug in Qt, or is there something I'm doing wrong?</p>