Is there any interest in a library which facilitates the implementation and interconnection of objects using Boost.Signals?
Yes, much interest.
For example, in a video processing scenario, one might be using the following objects:
* frame_rate - generates a void() signal at a consistent frame rate * video_generator - upon receiving a void() signal, produces a signal containing an image (e.g., a frame grabbed from a camera or read from a file) * differencer - upon receiving an image signal, outputs the pixel-difference between the image and the previous image received * flipper - upon receiving an image signal, outputs the horizontally flipped image * analysis - upon receiving an image signal, performs some sort of analysis and outputs a feature vector signal * database - upon receiving a feature vector signal, outputs an image from the database based on some relationship * display1, display2 - upon receiving an image, displays it in a window
It would be nice to be able to easily connect these objects via intuitive signal flow "diagrams":
// perform the whole video analysis and display the results frame_rate >>= video_generator >>= differencer >>= flipper >>= analysis >>= database >>= display1;
// also display the video input video_generator >>= display2;
... or, to specify the entire signal flow in one shot using something like this: frame_rate
= video_generator >= (differencer >>= flipper >>= analysis >>= database >>= display1) >= display2;
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. Regards, Paolo