Message dispatch problem

[Karel Miklav]

Hello, I need some advice about the following C++ situation: there
are two classes, A and B. A knows nothing about B, but it passes
messages to B, which they both understand. How should I implement
dispatch of these messages in class B? Here are some common but
not good enough solutions:

1. put type enum in messages and implement message as a union
a-la xlib events, dispatch in a loop on type enum
2. make messages polymorphic classes and dispatch on RTTI in a
loop
3. make massages polymorphic classes with common dispatch interface

The third solution looks kind-a nice, but it exposes details of
class B to class A. Is there some well known solution for this
problem?

--

Regards,
Karel Miklav

[Nick Malik [Microsoft]]

http://sern.ucalgary.ca/courses/SENG...serverLib.html

--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
--
"Karel Miklav" <karel@lovetemple.adbloccker.net> wrote in message
news:dfl7mn01gbv@enews1.newsguy.com...
> Hello, I need some advice about the following C++ situation: there
> are two classes, A and B. A knows nothing about B, but it passes
> messages to B, which they both understand. How should I implement
> dispatch of these messages in class B? Here are some common but
> not good enough solutions:
>
> 1. put type enum in messages and implement message as a union
> a-la xlib events, dispatch in a loop on type enum
> 2. make messages polymorphic classes and dispatch on RTTI in a
> loop
> 3. make massages polymorphic classes with common dispatch interface
>
> The third solution looks kind-a nice, but it exposes details of
> class B to class A. Is there some well known solution for this
> problem?
>
> --
>
> Regards,
> Karel Miklav

[Karel Miklav]

Nick Malik [Microsoft] wrote:
> http://sern.ucalgary.ca/courses/SENG...serverLib.html

Hm, it looks more like command pattern to me. But even then I cannot
completely solve the problem of dispatch - I'd like it to be a matter of
virtual function call or two... Thanks nick for pointing me in the righ
direction, I need some more time now.

--

Regards,
Karel Miklav