/*********************************
*设计模式--享元模式实现
*C++语言
*Author：WangYong
*Blog:http://www.cnblogs.com/newwy
********************************/
#include <iostream>
#include <cassert>
#include <vector>
#include <string>
using namespace std;
class Flyweight
{public:virtual ~Flyweight(){}virtual void Operation(const string & extrinsicState){}string GetIntrinsicState(){return this->_intrinsicState;}protected:Flyweight(string intrinsicState){this->_intrinsicState = _intrinsicState;}private:string _intrinsicState;
};
class ConcreteFlyweight:public Flyweight
{public:ConcreteFlyweight(string intrinsicState):Flyweight(intrinsicState){cout<<"ConcreteFlyweight Build ...."<<intrinsicState<<endl;}~ConcreteFlyweight(){}void Operation(const string & extrinsicState){cout<<"ConcreteFlyweight:内蕴"<<this->GetIntrinsicState()<<"ConcreteFlyweight:外蕴"<<extrinsicState<<endl;}
};
class FlyweightFactory
{public:FlyweightFactory(){}~FlyweightFactory(){}Flyweight * GetFlyweight(const string &key){vector<Flyweight *>::iterator it = _fly.begin();for(;it != _fly.end(); it++){if( (*it)->GetIntrinsicState() == key)cout<<"already created by users..."<<endl;return *it;}Flyweight *fn = new ConcreteFlyweight(key);_fly.push_back(fn);return fn;    }private:vector<Flyweight*> _fly;
};
int main()
{FlyweightFactory *fc = new FlyweightFactory();Flyweight * fw1 = fc->GetFlyweight("hello");Flyweight * fw2 = fc->GetFlyweight("world!");Flyweight * fw3 = fc->GetFlyweight("hello");
}