Heritage

#include <QObject>class Model {  private:    double data;  public:    Model(double data) : data(data) {}    ~Model(void) {}    double getData(void) const { return this->data; }  signals:    void dataChanged(double data);  public slots:    void setData(double data) {      this->data = data;      emit dataChanged(data);    }}class GModel : public QObject, public Model{  public:    GModel(double data) : Model(data) {}}