Question

我试图在c ++中使用转换运算符我有2个类，我试图从一个转换为另一个，我收到错误：

class Cow; //error: forward declaration of 'struct Cow'

class Horse {
public:
    Horse():i(0){}
    Horse(int i):i(i){}
    operator Cow() const { return Cow(i); } // error: invalid use of incomplete type 'struct Cow'
                                            //error : return type 'struct Cow' is incomplete

private:
    int i;
};

class Cow{
public:
    Cow():i(0){}
    Cow(int i):i(i){}
    operator Horse() const { return Horse(i); }
private:
    int i;
};

谁能告诉我我做错了什么？

Answer 1

试试这个：

class Cow;

class Horse {
public:
    Horse():i(0){}
    Horse(int i):i(i){}
    operator Cow() const;                     
private:
    int i;
};

class Cow{
public:
    Cow():i(0){}
    Cow(int i):i(i){}
    operator Horse() const;
private:
    int i;
};

Horse::operator Cow() const { return Cow(i); }                                      
Cow::operator Horse() const { return Horse(i); }

带前向声明的转换运算符

1 个答案: