[RossBencina]

> Is async/await a good idea for an OS kernel, even a toy one?

You might want to look at Joe Duffy's posts about Microsoft's Midori OS. In particular the post "Asynchronous Everything":

http://joeduffyblog.com/2015/11/03/blogging-about-midori/

Their findings sound pretty compelling to me. Personally I'm convinced that eventually we'll see much more system-level use of async/await style mechanisms. Perhaps with Rust, perhaps with C++ once coroutines land in C++20.

[pjmlp]

You can already use C++ coroutines with C++/Winrt, if feeling like having a go at them.