The BoundMethodMember specialization for the void return type is only needed to avoid accessing the ret_ member variable that is lacking from the corresponding BoundMethodPack specialization. By adding a BoundMethodPack::returnValue() function to read the member variable, we can remove the complete BoundMethodMember specialization. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>