async-std

I must be dumb, because every time I dive into async/await, I feel like I reach an epiphany about how it works, and how to use it. Then a week later I read about it again and totally lost all understanding. What do I gain if I have code like this [0], which has a bunch of `.await?` in sequence? I know .await != join_thread(), but doesn't execution of the current scope of code halt while it waits for the future we are `.await`-ing to complete? I know this allows the executor to go poll other futures. But if we haven't explicitly spawned more futures concurrently, via something like task::spawn() or thread::spawn(), then there's nothing else the cpu can possible do in our process? [0] https://github.com/async-rs/async-std/blob/master/examples/t...

Note that the implementation of the runtime itself is subject to change. It's currently an unbounded threadpool. https://github.com/async-rs/async-std/pulls?utf8=%E2%9C%93&q...