I hope the Rust team takes a look at Kotlins coroutines (and all the stuff they managed to build on top of them). I think Kotlin is a good example because it is built ontop of a 1:1 runtime and uses very elegant primitives.

I was pretty disappointed Rust didn't ship with async/await and some form of lightweight thread but it's understandable.

async/await still has the fundamental problem of composability that all the other attempts at sugaring around an event loop have (aka the "functions have colors" problem [1]). It sucks for collaboration, which is one of the most important things for modern software development.

1. http://journal.stuffwithstuff.com/2015/02/01/what-color-is-y...

I don't like that article, because (1) it claims Go is doing something new, while Go is really just threads with a particularly idiosyncratic implementation; (2) it ignores the fact that you can convert async to sync by just blocking and sync to async by proxying out to a thread pool. The "what color is your function" problem really isn't a big deal.

A thread pool is far from "ergonomic", it's accidental complexity with numerous gotchas.