Accessing external function from a class defined in the same file
===

If I have a class definition

    class myClass
    {
      void x(); 
    };


    void myClass::x()
    {
       hello(); // error: ‘hello’ was not declared in this scope
    }

    void hello()
    {
       cout << "Hello\n" << endl;
    }

How can I call a function defined outside the scope of a class and located in the same file ? I know that I can use `Namespace::function` but I am not sure in this case what I should use for `Namespace`