>>>>> "JV" == John M Vreeland <jmvree@infi.net> writes:

JV> But I could not figure out a way to forward declare it.
JV> "template <class T> B<T>;" was rejected.

Then try:

template <class T> class B;

--
Marc Girod                Valimo 1/2         Voice:  +358-9-511 63331
Nokia Telecommunications  P.O. Box 315       Mobile: +358-40-569 7954
NWS/NMS/NMS for Data      00045 NOKIA Group  Fax:    +358-9-511 63310
                          Finland            marc.girod@ntc.nokia.com


[ comp.std.c++ is moderated.  To submit articles, try just posting with ]
[ your news-reader.  If that fails, use mailto:std-c++@ncar.ucar.edu    ]
[              --- Please see the FAQ before posting. ---               ]
[ FAQ: http://reality.sgi.com/austern_mti/std-c++/faq.html              ]

I get different results from different compilers with this one.  I hope
these examples are correct and to-the-point .

**********
//forward dec
class B;

template <class T>
class A {
public:
  T object;
  friend class B;  //tried both of these
  //friend class B<T>;
private:
  struct PrivateStruct{T * something;};
};

template <class T>
class B {
private:
  A::PrivateStruct localCopy;   // <<--Problem here
};

********
This works just fine in the g++ code I have, but chokes when I try to
port it to Borland 5.  Borland claims I do not have access to the
private members of A, so what was the "friend" for?  I know that Borland
occasionally blunders, but the G++ I am using can barely handle
templates, and forget about the standard lib.

"friend B<T>;"  would not work because it had not been forward
declared.  But I could not figure out a way to forward declare it.
"template <class T> B<T>;" was rejected.

Please note that I hate using "friend" for anything but global
operators.  My task is just to port this monster, not re-write it.
Tempting, though.  :-P

-John M. Vreeland
---
[ comp.std.c++ is moderated.  To submit articles, try just posting with ]
[ your news-reader.  If that fails, use mailto:std-c++@ncar.ucar.edu    ]
[              --- Please see the FAQ before posting. ---               ]
[ FAQ: http://reality.sgi.com/austern_mti/std-c++/faq.html              ]

"John M. Vreeland" <jmvree@infi.net> writes:
 [how to forward-declare a template class]

I think the following should work:

    template <class T> class B;

    template <class T> class A {
    public:
 friend class B<T>;
    private:
 struct pip { T* pop;} ;
    };

    template <class T> class B {
 A<T>::pip pup;
    };

and indeed it compiles just fine on MS VC++5.0 SP3.


Alex
--
 ____    Alex Martelli, Bologna, Italia -- email: alex@magenta.com
 \SM/___                                 http://magenta.com/~alex
  \/\bi/     You never know what is enough unless you know what
     \/          is more than enough.
---
[ comp.std.c++ is moderated.  To submit articles, try just posting with ]
[ your news-reader.  If that fails, use mailto:std-c++@ncar.ucar.edu    ]
[              --- Please see the FAQ before posting. ---               ]
[ FAQ: http://reality.sgi.com/austern_mti/std-c++/faq.html              ]