#include
     
      using namespace std;//虚函数和析构函数需要定义，否则//a missing vtable usually means the first //non-inline virtual member function has no definition.class a{    virtual void func(){};public:    virtual ~a()=default;//析构函数需要为public}aObj;class b :public virtual a{    virtual void foo(){};public:    virtual ~b()=default;}bObj;class ax{    virtual void func(){};    char x;public:    virtual ~ax()=default;}axObj;class bx:public virtual ax{    virtual void foo(){};public:    virtual ~bx()=default;}bxObj;class c{    virtual void func(){};public:    virtual ~c()=default;}cObj;class d :public c{    virtual void foo(){};public:    virtual ~d()=default;}dObj;class cx{    virtual void func(){};public:    virtual ~cx()=default;    char x;}cxObj;class dx:public cx{    virtual void foo(){};public:    virtual ~dx()=default;}dxObj;int main(){    cout<<"aObj "<
      
       <