C++ 虚继承

#include <cstdio>#include <string>#include <iostream>using namespace std;class Root {public:Root(){}virtual void v1(){cout<< "ROOT V1 is "<< endl;}virtual void v2(){cout<< "ROOT V2" << endl; }void over(){cout << "ROOT is show R_AGE is "<< r_age << endl;}protected:int r_age;};class TrunkA: virtual public Root{public:int t_age;TrunkA(){r_age = 1;}/*void v1(){cout << "TrunkA V1 " << endl;}*/void over(){cout<< "TrunkA is show  R_age is " << r_age << endl;}};class TrunkB: virtual public Root{public:TrunkB(){r_age = 2;}/*virtual void v1(){cout<<"TrnkB V1" << endl;}void v2(){cout<< "TrunkB V2 " << endl;}*/void over(){cout << "TrunkB is show R_age is "<< r_age << endl;}};class TrunkC : public Root{public:void over() {cout << "TRUNKC R_AGE is"<< r_age << endl;}};class Leaves :  public TrunkB,  public TrunkA, public TrunkC{public :void over(){cout<< "Leaves is show "<< endl;}};int main(){Leaves L1;//含2个 ROOT 对象 (TrunkA, TrunkB 为虚继承共用一个 ROOT， TrunkC 使用一个ROOT)// 共用的ROOT 的r_age 为 先声明的TrunkA设置的变量值，值为 1；L1.over();//L1.v1();//L1.v2();//Root r1 = (Root)L1; --- errorTrunkB  b = (TrunkB)L1;b.over();b.v1();Root rb = (Root)b; rb.over();TrunkA a = (TrunkA)L1;a.over();a.v1();a.v2();Root ra = (Root)a;ra.over();TrunkC c = (TrunkC)c;c.over();c.v1();c.v2();return 0;};