To be fair, async (and generators, closures and Iterator) can expand to fairly hairy types with innocuous looking code. A think I do to simplify the output is t

To be fair, async (and generators, closures and Iterator) can expand to fairly hairy types with innocuous looking code. A think I do to simplify the output is to rely on `impl Trait` or `Box<dyn Trait>` to erase the type at strategic points, but that's working around my inability to find a way to make rustc figure out whether the full type is relevant or not right now.