#include <iostream>
#include <stdio.h>
using namespace std;
struct Base {
  int v1;
  //    private:   //error!
  int v3;

public: // 显示声明public
  int v2;
  virtual void print() { printf("%s\n", "Base"); };
  Base() { cout << "Base construct" << endl; };
  virtual ~Base() { cout << "Base deconstruct" << endl; };
};

struct Derived : Base {

  Derived() { cout << "Derived construct" << endl; };
  virtual ~Derived() { cout << "Derived deconstruct" << endl; };

public:
  int v2;
  void print() { printf("%s\n", "Derived"); };
};

int main() {
  Base *b = new Derived();
  b->print();
  delete b;
  return 0;
}