TITLE: nested friend template classes and functions

(Newsgroups: comp.std.c++)

PROBLEM: Bernd Anhaeupl <anhaeupl@late.e-technik.uni-erlangen.de>

Look at 14.12 of the (public) draft. There is an explicit example of
friend templates:

	class A {
		template <class T> friend B;      //ok
		template <class T> friend void f(T);   //ok

		template <class T> friend BB { /* ... */ } // error
		template <class T> friend void ff(T) { /* ... */ } // error
	};

So you can declare a friend template of a class but you must not define
it inside the class.


RESPONSE: jason@cygnus.com (Jason Merrill), 13 Jun 96

That has changed in the current (May) draft:

2 A friend template may be declared  within  a  non-template  class.   A
  friend  function  template may be defined within a non-template class.
  In these cases, all specializations of the class or function  template
  are friends of the class granting friendship.  [Example:
          class A {
                  template<class T> friend class B; // ok
                  template<class T> friend void f(T){ /* ... */ } // ok
          };
   --end example]