类和对象(6)：const成员，&/const &重载

void Print()
{
    cout << _year << " " << _month << " " << _day << endl;
}

int main()
{
    const Date d1(2023, 11, 15);
    d1.Print();// error C2662: “void Date::Print(void)”: 不能将“this”指针从“const Date”转换为“Date &”
    return 0;
}

class Date
{
    void Print() const;// ——> void Print(const Date* this)
};

Date* operator&()
{
    return this;
}

const Date* operator&() const
{
    return this;
}