-Wunused-variable warning

Question

I am implementing the singleton design pattern in a school assignment, and this is my class header file:

class Scheduler {
public:
    static Scheduler * instanc         


        

Answer 1

Your static singleton instance pointer should be a class member. Currently it is just a free pointer.

class Scheduler {
// as before
private:
    Scheduler();
    static Scheduler* _singleton; // declare it in the class
};

and in the implementation file:

Scheduler * Scheduler::_singleton = 0;