设计模式总篇-单例模式

#define __CRT_SECURE_NO_WARNINGS
#include<string>
#include<vector>
#include<iostream>

#include<vld.h>


//using namespace std;
/*
@作者：莫忘输赢
@时间：
2020/02/22 22:09
@版本：v1

@单例模式
@作用：
提供全局单一访问对象
*/


class Singleton
{
private:
	Singleton(){ }
	static Singleton* single;
public:
	static Singleton* GetInstance()
	{
		if (single == NULL)
		{
			single = new Singleton();
		}
		return single;
	}
	static void FreeInstance()
	{
		if (single != NULL)
		{
			delete single;
			single = NULL;
		}
	}
};
Singleton* Singleton::single = NULL;//静态变量初始化

int main()
{
	Singleton *s1 = Singleton::GetInstance();
	Singleton *s2 = Singleton::GetInstance();

	if (s1 == s2)
	{
		std::cout << "相等"<<std::endl;
	}
	else
	{
		std::cout << "不相等" << std::endl;
	}

	//delete s2;
	//delete s1;
	Singleton::FreeInstance();


	return 0;
}