子类被强制转换为父类，有什么方法可以提取字段吗？

class Parent {
public:
    int parentField;
};

class Child : public Parent {
public:
    int childField;
};

int main() {
    Child childObj;
    childObj.parentField = 10;
    childObj.childField = 20;

    Parent& parentRef = childObj; // 强制转换为父类类型
    int extractedField = parentRef.parentField; // 提取字段

    return 0;
}

class Parent {
public:
    virtual int getField() {
        return 0;
    }
};

class Child : public Parent {
public:
    int childField;

    int getField() override {
        return childField;
    }
};

int main() {
    Child childObj;
    childObj.childField = 20;

    Parent* parentPtr = &childObj; // 强制转换为父类指针
    int extractedField = parentPtr->getField(); // 提取字段

    return 0;
}