c++开发模式，享元模式

享元模式，个人理解，就是应用共享技术来减少类的对象创建，节省计算机资源消耗，而且能够减少维护成本

#include <iostream>
#include <string>
#include <vector>using namespace std;class Flyweight {
public:Flyweight(string state):_state(state) {}virtual void Operation(const string&state) { }string GetState()const { return _state; }virtual ~Flyweight() { }
private:string _state;
};class ConcreteFlyweight :public Flyweight {
public:ConcreteFlyweight(string state):Flyweight(state) {cout << "ConcreteFlyweight Build..." << state << endl;}void Operation(const string& state) {cout << "ConcreteFlyweight " << GetState() << " \\ " << state << endl;}
};class FlyweightFactory {
public:Flyweight *GetFlyweight(std::string key) {for (auto fly : _flys) {if (fly->GetState() == key) {cout << "already created by users..." << endl;return fly;}}Flyweight *fn = new ConcreteFlyweight(key);_flys.push_back(fn);return fn;}
private:std::vector<Flyweight*> _flys;
};int main() {FlyweightFactory *fc = new FlyweightFactory();Flyweight *fw1 = fc->GetFlyweight("hello");Flyweight *fw2 = fc->GetFlyweight("world");Flyweight *fw3 = fc->GetFlyweight("hello");delete fw1;delete fw2;//delete fw3;delete fc;return 0;
}