Implement 'Responder' for 'Status'.

This commit obviates the following removed types:

  * response::Failure
  * response::status::NoContent
  * response::status::Reset

Closes #489.

core/lib/src/response/failure.rs

@@ -1,20 +0,0 @@
-use request::Request;
-use response::{Response, Responder};
-use http::Status;
-
-/// A failing response; simply forwards to the catcher for the given
-/// `Status`.
-#[derive(Debug)]
-pub struct Failure(pub Status);
-
-impl Responder<'static> for Failure {
-    fn respond_to(self, _: &Request) -> Result<Response<'static>, Status> {
-        Err(self.0)
-    }
-}
-
-impl From<Status> for Failure {
-    fn from(status: Status) -> Self {
-        Failure(status)
-    }
-}

core/lib/src/response/mod.rs

@@ -25,7 +25,6 @@ mod redirect;
 mod named_file;
 mod stream;
 mod response;
-mod failure;
 
 crate mod flash;
 
@@ -38,7 +37,6 @@ pub use self::redirect::Redirect;
 pub use self::flash::Flash;
 pub use self::named_file::NamedFile;
 pub use self::stream::Stream;
-pub use self::failure::Failure;
 #[doc(inline)] pub use self::content::Content;
 
 /// Type alias for the `Result` of a `Responder::respond` call.

core/lib/src/response/responder.rs

@@ -2,7 +2,7 @@ use std::fs::File;
 use std::io::{Cursor, BufReader};
 use std::fmt;
 
-use http::{Status, ContentType};
+use http::{Status, ContentType, StatusClass};
 use response::{self, Response, Body};
 use request::Request;
 
@@ -290,3 +290,36 @@ impl<'r, R: Responder<'r>, E: Responder<'r> + fmt::Debug> Responder<'r> for Resu
         }
     }
 }
+
+/// The response generated by `Status` depends on the status code itself. The
+/// table below summarizes the functionality:
+///
+/// | Status Code Range | Response                              |
+/// |-------------------|---------------------------------------|
+/// | [400, 599]        | Forwards to catcher for given status. |
+/// | 100, [200, 205]   | Empty with status of `self`.          |
+/// | All others.       | Invalid. Errors to `500` catcher.     |
+///
+/// In short, a client or server error status codes will forward to the
+/// corresponding error catcher, a successful status code less than `206` or
+/// `100` responds with any empty body and the given status code, and all other
+/// status code emit an error message and forward to the `500` (internal server
+/// error) catcher.
+impl<'r> Responder<'r> for Status {
+    fn respond_to(self, _: &Request) -> response::Result<'r> {
+        match self.class() {
+            StatusClass::ClientError | StatusClass::ServerError => Err(self),
+            StatusClass::Success if self.code < 206 => {
+                Response::build().status(self).ok()
+            }
+            StatusClass::Informational if self.code == 100 => {
+                Response::build().status(self).ok()
+            }
+            _ => {
+                error_!("Invalid status used as responder: {}.", self);
+                warn_!("Fowarding to 500 (Internal Server Error) catcher.");
+                Err(Status::InternalServerError)
+            }
+        }
+    }
+}

core/lib/src/response/status.rs

@@ -111,50 +111,6 @@ impl<'r, R: Responder<'r>> Responder<'r> for Accepted<R> {
     }
 }
 
-/// Sets the status of the response to 204 (No Content).
-///
-/// # Example
-///
-/// ```rust
-/// use rocket::response::status;
-///
-/// # #[allow(unused_variables)]
-/// let response = status::NoContent;
-/// ```
-// TODO: This would benefit from Header support.
-#[derive(Debug, Clone, PartialEq)]
-pub struct NoContent;
-
-/// Sets the status code of the response to 204 No Content. The body of the
-/// response will be empty.
-impl<'r> Responder<'r> for NoContent {
-    fn respond_to(self, _: &Request) -> Result<Response<'r>, Status> {
-        Response::build().status(Status::NoContent).ok()
-    }
-}
-
-
-/// Sets the status of the response to 205 (Reset Content).
-///
-/// # Example
-///
-/// ```rust
-/// use rocket::response::status;
-///
-/// # #[allow(unused_variables)]
-/// let response = status::Reset;
-/// ```
-#[derive(Debug, Copy, Clone, PartialEq)]
-pub struct Reset;
-
-/// Sets the status code of the response to 205 Reset Content. The body of the
-/// response will be empty.
-impl Responder<'static> for Reset {
-    fn respond_to(self, _: &Request) -> Result<Response<'static>, Status> {
-        Response::build().status(Status::ResetContent).ok()
-    }
-}
-
 /// Sets the status of the response to 400 (Bad Request).
 ///
 /// If a responder is supplied, the remainder of the response is delegated to

core/lib/tests/head_handling.rs

@@ -2,11 +2,11 @@
 
 #[macro_use] extern crate rocket;
 
-use rocket::response::{status, content};
+use rocket::{http::Status, response::content};
 
 #[get("/empty")]
-fn empty() -> status::NoContent {
-    status::NoContent
+fn empty() -> Status {
+    Status::NoContent
 }
 
 #[get("/")]

site/guide/5-responses.md

@@ -78,20 +78,34 @@ return an HTML page with the status code and description. If there is no catcher
 for a custom status code, Rocket uses the **500** error catcher to return a
 response.
 
+### Status
+
 While not encouraged, you can also forward a request to a catcher manually by
-using the [`Failure`](@api/rocket/response/struct.Failure.html)
-type. For instance, to forward to the catcher for **406 - Not Acceptable**, you
-would write:
+returning a [`Status`] directly. For instance, to forward to the catcher for
+**406: Not Acceptable**, you would write:
 
 ```rust
-use rocket::response::Failure;
+use rocket::http::Status;
 
 #[get("/")]
-fn just_fail() -> Failure {
-    Failure(Status::NotAcceptable)
+fn just_fail() -> Status {
+    Status::NotAcceptable
 }
 ```
 
+The response generated by `Status` depends on the status code itself. As
+indicated above, for error status codes (in range [400, 599]), `Status` forwards
+to the corresponding error catcher. The table below summarizes responses
+generated by `Status` for these and other codes:
+
+| Status Code Range | Response                              |
+|-------------------|---------------------------------------|
+| [400, 599]        | Forwards to catcher for given status. |
+| 100, [200, 205]   | Empty with given status.              |
+| All others.       | Invalid. Errors to `500` catcher.     |
+
+[`Status`]: https://api.rocket.rs/v0.4/rocket/http/struct.Status.html
+
 ## Custom Responders
 
 The [`Responder`] trait documentation details how to implement your own custom