C++中，虚函数与容器（vector）的巧妙组合

#include <iostream>
#include <vector>
using namespace std;

class base    //纯虚基类
{
public:
 virtual void init() = 0;
 virtual void start() = 0;
 virtual void end() = 0;
};

class other1
{
public:
   void logprint1()
 {
  cout<<"print err1"<<endl;
 };
};

class other2
{
public:
 void logprint2()
 {
  cout<<"print err2"<<endl;
 };
};

class rea1:public other1,public base
{
public:
 void init()
 {
  cout<<"rea1"<<endl;
 };
 void start()
 {
  cout<<"start1"<<endl;
 };
 void end()
 {
  cout<<"end1"<<endl;
  logprint1();
 };
};

class rea2:public other2,public base
{
public:
 void init()
 {
  cout<<"rea2"<<endl;
 };
 void start()
 {
  cout<<"start2"<<endl;
 };
 void end()
 {
  cout<<"end2"<<endl;
  logprint2();
 };
};

int main()
{
 vector<base *>  myvec;
 vector<base *>::iterator itr;

 rea1 crea1;
 rea2 crea2;
 myvec.push_back(&crea1);
    myvec.push_back(&crea2);

 for (itr = myvec.begin(); itr != myvec.end(); itr++)   //打印出来
 {
  (*itr)->init();
  (*itr)->start();
  (*itr)->end();
 }

    return 0;
}