虚基的例子

//若不是虚基类，则每次都会调用Basic（）

#include <iostream>
using namespace std;
class Basic{
public:
    Basic(){
        cout<<"Basic"<<endl;
    }
};
class child1:virtual public Basic{
public:
    child1(){
        cout<<"child1"<<endl;
    }
};
class child2:virtual public Basic{
public:
    child2(){
        cout<<"child2"<<endl;
    }
};
class child3:public Basic{
public:
    child3(){

        cout<<"child3"<<endl;
    }
};
class grachild:public child1,public child2,public child3{
public:
    grachild(){
        cout<<"grachild"<<endl;
    }
};
int main()
{
    grachild test;
    return 0;
}