Its not the same. Anything in the nursery can cause cancellation of all async work. Cancellation is safe to unwind in all workers by scope exit rules.

Completion is just a type of cancellation.

Spawn 10 workers to lookup Dog in 10 different dictionaries, the first one to get the answer wins. This is hard to do with out language/runtime cancellation support.

Note below is a practical lib to get close to this https://blog.labix.org/2011/10/09/death-of-goroutines-under-... .. https://github.com/go-tomb/tomb/tree/v2