Any #Rust programmers working on #Win32 know of a reusable thing for waking up the Ui thread from a non-UI thread, and possibly sending a value back? Seems like that could be a tiny, reusable crate. Yes, yes, people will grouse about the proliferation of small dependencies, but that approach has its advantages, and Rust makes it pretty natural, so I'm inclined to not fight it.
@matt had a use case for something like this recently. I'd love to see something cross platform though.