async Rust functions are compiled down to a finite state machine. A stackless coroutine I think it can be called. I suspect that C#/.NET does something similar

async Rust functions are compiled down to a finite state machine. A stackless coroutine I think it can be called. I suspect that C#/.NET does something similar though I am just speculating here. The difference between async-std and tokio would then be explained by a lower overhead runtime per task in tokio.