virtual解决菱形继承中多份拷贝问题

    我一直都知道菱形继承的时候，虚继承就能解决一个基类多份拷贝的问题。但是，已经忘了virtual应该添在哪里了，俗话说得好啊，好记性不如烂笔头，还是记下来吧。纯属笔记，读者请略过。

#include<iostream>using namespace std;class A{public:A(){ cout << "A()" << endl;}~A(){ cout << "~A()" << endl;}};class B: virtual public A{public:B(){ cout << "B()" << endl;}~B(){ cout << "~B()" << endl;}};class C:virtual public A{public:C(){ cout << "C()" << endl;}~C(){ cout << "~C()" << endl;}};class D: public B, C {public:D(){ cout << "D()" << endl;}~D(){ cout << "~D()" << endl;}};int main(){D d;return 0;}