What is the recommended way to transform an Incoming hyper::Error into http::Response on the server?

[zacknewman]

When reading the body of http::Request<hyper::body::Incoming>, you have to rely on Incoming::poll_frame which can return hyper::Error. Is there a better way to transform such an error into an http::Response that doesn't always assume http::StatusCode::BAD_REQUEST is the appropriate status code? Is the best one can do is rely on the bool methods of Error? If so, what StatusCode should be used for each of those methods?

Presumably Error::is_timeout should mean StatusCode::REQUEST_TIMEOUT is sent, but is that even possible if one doesn't set a timer via Builder::timer? What about the others? Error::is_parse_too_large seems to imply either StatusCode::PAYLOAD_TOO_LARGE or StatusCode::URI_TOO_LONG. I'm guessing that since Request::uri returns &Uri that it must be StatusCode::PAYLOAD_TOO_LARGE since the Request wouldn't have been able to be constructed if it were StatusCode::URI_TOO_LONG.

Does it make sense to add a status_code method to Error that returns Option<StatusCode>? It would only return Some when it make sense (e.g., when returned from Incoming::poll_frame on the server).