c++ 结构型模式-享元(Flyweight)

 1 #include <iostream>
 2 #include <list>
 3 class  Flyweight
 4 {
 5 public:
 6     Flyweight() {}
 7     virtual ~Flyweight() {}
 8     virtual std::string getKey() { return ""; }
 9     virtual void  Operation(std::string extrinsicStr) = 0;
10 };
11 class  ConcreteFlyweight : public Flyweight
12 {
13 public:
14     ConcreteFlyweight() {}
15     ConcreteFlyweight(std::string str):m_inState(str) {}
16     virtual ~ConcreteFlyweight() {}
17     virtual std::string getKey() 
18     {
19         return m_inState;
20     }
21     virtual void  Operation(std::string extrinsicStr)
22     {
23         std::cout << extrinsicStr.c_str() << std::endl;
24         std::cout << m_inState.c_str() << std::endl;
25     }
26 private:
27     std::string m_inState;
28 };
29 class FlyweightFactory
30 {
31 public:
32     FlyweightFactory() {}
33     virtual ~FlyweightFactory() {}
34     Flyweight* GetFlyweight(std::string key)
35     {
36         std::list<Flyweight*>::iterator it = m_listFly.begin();
37         for (; it != m_listFly.end(); ++it)
38         {
39             if ((*it)->getKey() == key)
40             {
41                 return (*it);
42             }
43         }
44         Flyweight* ptr = new ConcreteFlyweight(key);
45         m_listFly.push_back(ptr);
46         return ptr;
47     }
48 private:
49     std::list<Flyweight*> m_listFly;
50 };
51 
52  int main()
53  {
54      FlyweightFactory* factory = new FlyweightFactory();
55      Flyweight* fly = factory->GetFlyweight("hello");
56      fly->Operation("World");
57      system("pause");
58  }