zlacker

>>lukast+(OP)
When writing some IO bound application, async Rust is great. Less great for libraries that want to support both async and sync without having to make an async runtime a dependency if you just want the sync interface. Mutually exclusive features are taboo unfortunately. One thing I really love about Haskell is you can make any function run in a green thread by simply composing it with the 'async' function. There's nothing special about it. This works much better than say Go, because Haskell is immutable.

>>xedrac+zh
I'm not sure it's worth it even for most IO bound applications. The first couple of IO bound examples that come to mind (an app doing bulk disk or network IO, eg sequential file access or bulk data transfer) would logically seem to work just as well without async since the bottleneck is the disk or network card or connection.

I'd guess it could be an advantage for high concurrency applications that are CPU bound, but could be made IO bound by optimizing the userspace code. But OS threads are pretty efficient and you can have zillions of them, so the async upside is quite bounded, so this niche would seem smallish.