[Cs3] Forward Class Template Declaration

[Mikhail Nesterenko]

>      From my understanding, forward declaring a templated friend function
> from a class protects the friend function from accessing data that it
> shouldn't. However, I do not understand how that actually works.Can you
> elaborate on that?

Look at this example:

http://antares.cs.kent.edu/~mikhail/classes/cs3/Examples/TemplateIntro/friendGeneralProblem.cpp

It has a general definition of a friend function "equal" (friend is a frient
of all instantiations) commented out.

This allows "malicous" implementation of "equal" that accesses private
members of unrelated global object ob2.b_

The commentted in specific definition of the friend function avoid
this problem and leads to compiler error.

Tbanks,
--
Mikhail