设计模式——享元模式（C++实现）

 #include <iostream>
 #include <string>
 #include <map>
 #include <vector>
 #include <iterator>
 #include <algorithm>

 using namespace std;

 class User
 {
 public:
         User(string strName): m_strName(strName)
         {

         }

         string GetName() const
         {
                 return m_strName;
         }

 private:
         string m_strName;
 };

 class WebSite
 {
 public:
         virtual void Use(const User* stUser) = ;

 };

 class ConcreteWebSite: public WebSite
 {
 public:
         ConcreteWebSite(string strName): m_strName(strName)
         {

         }

         virtual void Use(const User* stUser)
         {
                 cout<< "网站分类："<< m_strName<< "\t 用户："<< stUser->GetName()<< endl;
         }

 private:
         string m_strName;

 };

 class WebSiteFactory
 {

 public:
         WebSite* GetWebSiteCategory(string strKey)
         {
                 if (mapFlyWeights.find(strKey) != mapFlyWeights.end())
                 {
                         return mapFlyWeights[strKey];
                 }
                 else
                 {
                         mapFlyWeights.insert(pair<string, WebSite*>(strKey, new ConcreteWebSite(strKey)));
                         return mapFlyWeights[strKey];
                 }
         }

 private:
         map<string, WebSite*> mapFlyWeights;
 };

 int main(int argc, char* argv[])
 {
         WebSiteFactory* f = new WebSiteFactory();

         WebSite* fx = f->GetWebSiteCategory("产品展示");
         fx->Use(new User("小菜"));

         WebSite* fy = f->GetWebSiteCategory("产品展示");
         fy->Use(new User("大鸟"));

         WebSite* fz = f->GetWebSiteCategory("博客");
         fz->Use(new User("xxxxx"));

         WebSite* fm = f->GetWebSiteCategory("博客");
         fm->Use(new User("OOOOOO"));

         return ;
 }

 [root@ ~/learn_code/design_pattern/22_fly_weight]$ ./flyWeight
 网站分类：产品展示       用户：小菜
 网站分类：产品展示       用户：大鸟
 网站分类：博客   用户：xxxxx
 网站分类：博客   用户：OOOOOO