单例模式懒汉式示例

#include <iostream>

class Singleton

{

public: ~Singleton()

{

std::cout<<"destructor called!"<<std::endl;

}

Singleton(const Singleton&)=delete;

Singleton& operator=(const Singleton&)=delete;

static Singleton& get_instance()

{

static Singleton instance;

return instance;

}

private:

Singleton()

{

std::cout<<"constructor called!"<<std::endl;

}

};

 

int main(int argc, char *argv[])

{

Singleton& instance_1 = Singleton::get_instance();

Singleton& instance_2 = Singleton::get_instance();

return 0;

}