【C++ 单例模式】

#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;
}