Why doesn't this cast?

Not a Qt-specific question, but here's a funny compiler error:

error: no matching function for call to ‘QCoreApplication::sendEvent(QWidget*, QMouseEvent*&)’
/usr/include/qt4/QtCore/qcoreapplication.h:214: note: candidates are: static bool QCoreApplication::sendEvent(QObject*, QEvent*)

Since QWidget is a QObject and QMouseEvent is a QEvent, why is my compiler (gcc 4.2.4) complaining?

Thanks

Please show us your code.

Make sure that second value for sendEvent is pointer.

Probably either one of the classes is forward declared only. Adding suitable include directives should fix the problem.