初始化列表中基类构造函数调用派生类函数

#include <iostream>



using std::cout;

using std::endl;



class Base

{

public:

    Base(int para)

    {

        a = para;

        cout << "Base::a = " << a << endl;

    }

private:

    int a;

};



class Derive : public Base

{

public:

    int foo()

    { 

        cout << "Derived::foo() return 0" << endl;

        return 0;

    }

    Derive() : Base(foo()) {}

};



class Derive2 : public Base

{

public:

    int foo()

    { 

        cout << "Derive2::foo() return " << a << endl;

        return a;

    }

    Derive2() : a(0), Base(foo()) {}

private:

    int a;

};



int main(void)

{

    Derive cld;

    Derive2 cld2;

    //Base *bptr = new Derive;      

    //bptr->foo();        //error: Base has no member named foo





    return 0;

}