#include <iostream>
#include <string>

using namespace std;

class  Singleton {
   public:
      static Singleton & Instance() {
          static Singleton instance;
          return instance;
      }

      void Print() {
          printCalls ++;
          cout << "This is the " << printCalls << " time Print has been called"
               << endl;
      }

      int GetVar() const {
         return avar;
      }

      void SetVar(int i) {
         avar = i; 
      }


   private:
      int cCalls {0};
      int printCalls{0};
      int avar{-99999};

      Singleton() {
         cCalls ++;
         cout << "The singleton constructor was called " << endl;
         cout << "This has happened a total of " << cCalls << " times " << endl;
      }

      ~Singleton() {
         cout << "The singleton distructor was called " << endl;
      }
};

void DoSomething();

int main() {
    Singleton & theSingleton {Singleton::Instance()};

    cout << endl;

    theSingleton.Print();
    theSingleton.SetVar(100000);

    DoSomething();

    theSingleton.Print();
    cout << "The var is now " << theSingleton.GetVar() << endl;

    cout << endl;
    return 0;
}

void DoSomething() {
    Singleton & aSingleton {Singleton::Instance()};

    cout << endl << "In Do Something " << endl;
    aSingleton.Print();
    cout << "The var is " << aSingleton.GetVar() << endl;
    aSingleton.SetVar(42);
    aSingleton.Print();
    cout << "Out of Do Something " << endl << endl;

    return;
}