Re: [boost] interest in a "signal flow" library?

From: Stjepan Rajko (stipe_at_[hidden])
Date: 2007-02-21 17:15:10

> From: Paolo Coletta <paolo_at_[hidden]>
> Subject: Re: [boost] interest in a "signal flow" library?
> > Is there any interest in a library which facilitates the
> > implementation and interconnection of objects using Boost.Signals?
>
> Yes, much interest.
> [snip]
> I didn't look at the library yet, however, in a similar context I had the
> requirement to perform some operations in parallel. Thus, I wonder if this
> could be supported by the syntax, e.g.,
>
> video_generator >>= ( effect1 && effect2 ) >>= image_sum >>= display
>
> where effect1 and effect2 are executed in parallel (for example, by
> different threads of a thread_group); image_sum (which expects two
> arguments) is executed only when both effect1 and effect2 are completed.

That would be a good addition - right now you would have to do something like:

video_generator >>= effect1 >>= image_sum >>= display;
video_generator >>= effect2 >>= image_sum;

(or)

video_generator
  >= (effect1 >>= image_sum >>= display);
  >= (effect2 >>= image_sum);

 - both of which are more awkward than video_generator >>= ( effect1
&& effect2 ) >>= image_sum >>= display.  Also, image_sum would have to
take care of receiving the two signals separately (which would
probably require a use of slot_selector in the end) and combining them
together after both are received.

I'll think about this and try to add it in.

Thanks!

Stjepan