C++ Code Example: Singleton Class (Ex:2)

Sphere: Related Content #include <iostream>
using namespace std;
class Singleton
{
   private:
      static bool instanceFlag;
      static Singleton *single;
      Singleton()
      {
         //private constructor
      cout << "Calling private constructor" << endl;
      }
   public:
      static Singleton* getInstance();
      void method();
      ~Singleton()
      {
         instanceFlag = false;
      }
};
bool Singleton::instanceFlag = false;
Singleton* Singleton::single = NULL;
Singleton* Singleton::getInstance()
{
      //if(! instanceFlag)
      //{
      single = new Singleton();
      //instanceFlag = true;
      return single;
      //}
      /*
      else
      {
         return single;
      }
      */
}
void Singleton::method()
{
      cout << "Method of the singleton class" << endl;
}
int main()
{
      Singleton *sc1,*sc2;
      sc1 = Singleton::getInstance();
      sc1->method();
      sc2 = Singleton::getInstance();
      sc2->method();
      sc2 = Singleton::getInstance();
      sc2->method();
      return 0;
}