#include <iostream>

 #include "test.h"

 #include "testfuc.h"

 using namespace std;

 int main(void)

 {

     a *p=new b();

     p->fuc();

     cout<<"指针p占用空间"<<sizeof(p)<<endl;

     cout<<"类占用空间"<<sizeof(a)<<endl;

     delete p;

     return ;

 }

 #ifndef TEST_H

 #define TEST_H

 class a

 {

 public:

     a();

     ~a();

     void virtual fuc();

 };

 class b:public a

 {

 public:

     b();

     ~b();

     void fuc();

 };

 #endif

 #ifndef testfuc_h

 #define testfuc_h

 #include <iostream>

 using namespace std;

 a::a()

 {

     cout<<"a的构造函数"<<endl;

 }

 a::~a()

 {

     cout<<"a的析构函数"<<endl;

 }

 b::b()

 {

     cout<<"b的构造函数"<<endl;

 }

 b::~b()

 {

     cout<<"b的析构函数"<<endl;

 }

 void a::fuc()

 {

     cout<<"a的函数"<<endl;

 }

 void b::fuc()

 {

     cout<<"b的函数"<<endl;

 }

 #endif