How do I make main a friend of my class from within a library?

Question

Please see my first attempt at answering this . I neglected to tell the whole story before in an attempt to simplify things. Turns out my example works! Sorry.

The w

Answer 1

@parapura provided a solution, but doesn't explain why you first have to declare main in the global scope.

§7.3.1.2 [namespace.memdef] p3

[...] If a friend declaration in a nonlocal class first declares a class or function the friend class or function is a member of the innermost enclosing namespace. [...]

So with that in mind, your code would look somewhat like this:

namespace MyNamespace
{ // MyNamespace is the innermost enclosing namespace
  // 'main' from the friend declaration is treated
  // as if it was a member of 'MyNamespace'
  int main(int argc, char** argv);

  class ProcessManager
  {
  public:
    friend int main(int argc, char** argv);
  private:
    void test();
  };
};

Now it should be clear why the global main function wasn't your friend.