Allow to terminate individual tasks #6
Description
Currently it's only possible to terminate all tasks and it stops the scope from being restarted.
It should be possible to terminate individual tasks and still let the scope be restarted. This would allow to build a multi-race strategy (each task is scheduled multiple times and abort the others of a group when one result is available and still wait for the other groups to finish).
This could be done by wrapping the tasks callables inside a new Tagged object that would hold the callable and a tag value (that could be of any type). And on the continuation a new method would tell the list of tag values to terminate.