I've just noticed that the official Swift language guide has been updated. It now includes a number of additional topics on concurrency. There's still a long way to go here, but this is good progress!

I think the migration guide is still useful, and goes into a lot more depth in many areas. But, I'm very glad to see this is being filled in.

(However, I'm not glad to see "split isolation" used in an example: a type with different isolation than its members. The language supports this, sure, and it does have uses, but is a mistake 99% of the time.)

There's quite a lot of background required to even begin to understand this feature completely. However, the documentation here is to-the-point and definitely useful. I like this quite a lot because it also shows how to use the migration feature, which is cool and pretty much essential if you want to adopt this in an existing project.

Could also be quite eye-opening if you have been using concurrency with the compiler feedback disabled.

(This whole per-diagnostic/feature documentation effort is just great too.)