class Field : public QAbstractListModel
{
    Q_OBJECT
public:
    Field(int width = 0, int height = 0);

    QVector<int>& operator[](int n) {return (v_field.begin()[n]);}

private:
    int width, height;
    QVector< QVector<int> > v_field;

};

field[0][0] = 0; // Экземпляр класса Field

qDebug() << "<<<<<<<<<<" << this->field[0][0];

QVector<int>& operator[](int n) {return v_field[n];}
const QVector<int>& operator[](int n) const {return v_field[n];}