#include <QtGui>

int main(int argc, char **argv)
{
   QApplication app(argc, argv);

   QGraphicsScene scene(0.0, 0.0, 500.0, 500.0);
   QGraphicsView view(&scene);

   // Create a parent and child QGraphicsProxyWidget
   QGraphicsProxyWidget* parent(new QGraphicsProxyWidget);
   QGraphicsProxyWidget* child(new QGraphicsProxyWidget);
   child->setParentItem(parent);

   // Create two different labels that will be assigned to the parent.
   QLabel* label0(new QLabel);
   label0->setText("First");
   QLabel* label1(new QLabel);
   label1->setText("Second");

   // Set the first label as the proxied widget.
   parent->setWidget(label0);

   // If we attempt to change the proxied widget we get a crash.
   parent->setWidget(label1);

   scene.addItem(parent);
   view.show();

   return app.exec();
}