[C++知识库]C++ design pattern -- decorator

#include <string>
#include <iostream>

class Head{
public :
  std::string description = "Head";
  virtual std::string get_description(  ){return description;}
};

class Decorator:public Head{
public:
  virtual std::string get_description()=0;

};

class Hair:public Decorator
{
public :
  Head *base;
  std::string get_description(){return "Hair, " + base->get_description();};
  Hair(Head* h):base(h){};
};

class Noise:public Decorator
{
public:
  Head *base;
  Noise(Head* h):base(h){};
  std::string get_description(){return "Noise, " + base->get_description();}
};


int main(){
  Head *head = new Head();
  head = new Hair(head);
  head = new Noise(head);
  std::cout << head->get_description() << std::endl;

  return 0;
}