復制基類和派生類的構造函數

Question

我有這兩個班

///////////BASE CLASS

    class Base{
    public:
     Base(int = 0);
     ~Base();
     Base(Base&);
     Base(Derived&);   ////<-may be problem here?, note: I tried without this function
     int valueOfBase();
    protected:
     int protectedData;
    private:
     int baseData;
    };

    /////////////DERIVED CLASS
    class Derived: public Base{
    public:
     Derived(int);
     //Derived(Derived&);
     ~Derived();
    private:
     int derivedData;
    };

and here my main

    int main(){
     Base base(1);
     Derived derived = base;
    return 0;
    }

我讀過如果我的派生類沒有副本c'tor copy c'tor of the base will be called但每次我收到conversion from Base to non-scalar type Derived requested誰是錯的？ 我的編譯器或我的書，或者我剛剛被誤解了？ 提前致謝

Answer 1

只是一個提示。

以下代碼是否會出現相同的錯誤？

class base{};
class derived: public base{};

int main()
{
      derived d= base();
}

是？ 為什么？ 因為沒有從基類到派生類的轉換。 如果希望編譯代碼，則應定義此轉換。

如何將它添加到派生類？

derived(const base &b){} 

有道理，對吧？