// Ivan Novick
// Dec-23, 2007
// Meyers singleton pattern

#include <iostream>

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

    void hello()
    {
        std::cout << "Hello World address is " << this << std::endl;
    }

protected:
    // prevent users from calling any of these
    Singleton() {}
    Singleton(Singleton&);
    Singleton& operator=(const Singleton&);
};

int main(int argc, char** argv)
{
    // should be 3 references to same object
    Singleton& s1 = Singleton::Instance();
    Singleton& s2 = Singleton::Instance();
    Singleton& s3 = Singleton::Instance();

    // should print out the same memory address 3 times
    s1.hello();
    s2.hello();
    s3.hello();

    return 0;
}