How to think about `async`/`await` in Rust

HN discussion with some salient points. As to the post itself:

CAUTION: There’s a proposal to make code generic on whether or not it’s being used async, so that the same code could produce both a simple function and a Future. In this case you’d have to make sure to think about correctness in all possible ways your code could be used. I am suspicious, and I hope after reading this section, you are too.

I was suspicious before, but couldn't put in words why. Now I know. :-/