From: Dejan Dimic <dejan.dimic@...>
Date: 2007-12-03T02:35:01+09:00
Subject: Re: Friend functions or classes

On Dec 2, 11:02 am, SunRaySon <sunray...@gmail.com> wrote:
> Note:  parts of this message were removed by the gateway to make it a legal Usenet post.
>
> Hi,
>
> I would like to simulate something like friend class or method in Ruby; From
> the pickaxe documentation I could not figure out if there is one directly
> available or not.
>
> I do understand that having friend classes and functions is not good
> practice.
>
> Regards,
> Kiran.

Friend Functions and Friend Classes are often useful for one class to
see the private variables of another class, even though these
variables should probably not be made part of the public interface
that the class supports.

Friend function or friend classes are one of most dangerous
construction. From my experience mostly because programmers tend to
misuse it. I do not want to make this an academic issue so to make
this short: my advice is do not use friend class as a construction in
you code especially if you try to port some C++ algorithm even if that
seams to look like an easy thing to do.

Depending on particular reason, why do you think you have to use the
friend class, I will most probably consider using observer and/or
visitor pattern in stand.