[Interest] moc code : incomplete type 'void' is not assignable

[Jason H]

I'm getting an error in moc-generated file, and I don't know why. 

error: incomplete type 'void' is not assignable
        case 1: *reinterpret_cast< void*>(_v) = _t->camera(); break;
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^

The header file contains:
#include <QObject>
#include <QCamera>
class FlashControl : public QObject
{
	Q_OBJECT
	QCamera *_camera;
public:
...
	Q_PROPERTY(void setCamera READ camera WRITE setCamera)

public slots:
...
	void setCamera(QObject *qmlCamera);
	QObject* camera();


};

Does anyone have any ... pointers? (Sorry for the pun!)