How to force a static member to be initialized?

Question

Consider this example code:

template
char register_(){
    return D::get_dummy(); // static function
}

template
struct Foo{
           


        

Answer 1

Consider:

template struct value { };

template
struct HasStatics {
  static int a; // we force this to be initialized
  typedef value value_user;
};

template
int HasStatics::a = /* whatever side-effect you want */ 0;

It's also possible without introducing any member:

template struct var { enum { value }; };
typedef char user;

template
struct HasStatics {
  static int a; // we force this to be initialized
  static int b; // and this

  // hope you like the syntax!
  user :var::value,
       :var::value;
};

template
int HasStatics::a = /* whatever side-effect you want */ 0;

template
int HasStatics::b = /* whatever side-effect you want */ 0;