【C++ 单例模式】

正确的析构 静态实例和回收类
SingletonMode.cpp

#include <iostream>
#include <pthread.h>class Singleton
{private:Singleton(){std::cout << "构造" << std::endl;};~Singleton(){std::cout << "析构" << std::endl;}public:static Singleton *getInstance(){static Singleton local_instance;return &local_instance;}};class SingletonPattern
{private:SingletonPattern(){std::cout << "创建单例模式对象！\n";}SingletonPattern(const SingletonPattern& other);~SingletonPattern(){}
private:static SingletonPattern* m_Instance;static pthread_once_t ponce_;static void init(){m_Instance = new SingletonPattern();}public:static SingletonPattern* GetInstance(){pthread_once(&ponce_, &SingletonPattern::init);return m_Instance;}void display(){std::cout << "使用单例模式！\n" ;}
private:class CGabor{public:~CGabor(){if (SingletonPattern::m_Instance){delete SingletonPattern::m_Instance;SingletonPattern::m_Instance = NULL;std::cout << "SingletonPattern 析构" << std::endl;}}};static CGabor m_Gabor;
};SingletonPattern* SingletonPattern:: m_Instance = nullptr;
SingletonPattern::CGabor SingletonPattern::m_Gabor;
pthread_once_t SingletonPattern::ponce_ = PTHREAD_ONCE_INIT;// g++ SingletonMode.cpp -o SingletonMode -std=c++11 -lpthread
int main()
{Singleton *a = Singleton::getInstance();Singleton *b = Singleton::getInstance();if(a==b){std::cout<< "a==b" <<'\n';}SingletonPattern* m_Test = SingletonPattern::GetInstance();m_Test->display();return 0;
}