When we want use template that inheriting custom class we get following error:
there are no arguments to 'aa' that depend on a template parameter, so a declaration of 'aa' must be available

class A{ 
  int aa(){return 42;}
};
template <int x ,typename t> class B : t{
  int bb(){aa()+x;}
};
int main(){
  B <4,A> z;
}