virtual

https://www.cnblogs.com/dirichlet/p/3226484.html

 

 

#include "iostream"
#include "string"
#include <typeinfo>
using namespace std;


class Base1
{
public:
    Base1(): x(1){}
    virtual void QueryInterface() { }
    virtual void AddRef(){}
    virtual void Release(){}

private:
    int x;
};

class Base2
{
public:
    Base2(): y(2){}
    virtual void GetIdsOfNames() { }
    virtual void Invoke(){}

private:
    int y;
};

class Base3
{
public:
    Base3(): z(3){}
    virtual void GetMembers() { }
    virtual void ToString(){}

private:
    int z;
};

class Derived : public Base1, public Base2, public Base3
{
public:
    Derived(): w(4){}
private:
    int w;
};

int main()
{
    Derived * pd = new Derived;
    return 1;
}