// to make a singleton class
//
//   1) start with this file
//   2) replace all the Foo with My_class and 
//   3) break it into my_class.h and my_class.cpp at the -------------
//   4) add real code


// class Foo is a singleton
class Foo
{
    public:
        static Foo *instance();
    private:
        static Foo *m_instance;

        Foo() {};

        // disable default copy constructor and default assignment
        // done as a precaution, they should never be called
        Foo(const Foo &); 
        const Foo &operator=(const Foo &); 

};

---------------------------------------------


/* static */ Foo *Foo::m_instance = 0;

/* static */ Foo *
Foo::instance()
{
    if (m_instance == 0)
        m_instance = new Foo();
    return m_instance;
}