Implement ResponseError for Infallible (#2769)

Author: SabrinaJewson

actix-web/CHANGES.md

@@ -5,6 +5,7 @@
 - Add `ServiceRequest::extract()` to make it easier to use extractors when writing middlewares. [#2647]
 - Add `Route::wrap()` to allow individual routes to use middleware. [#2725]
 - Add `ServiceConfig::default_service()`. [#2338] [#2743]
+- Implement `ResponseError` for `std::convert::Infallible`
 
 ### Fixed
 - Clear connection-level data on `HttpRequest` drop. [#2742]

actix-web/src/error/error.rs

@@ -51,12 +51,6 @@ impl StdError for Error {
     }
 }
 
-impl From<std::convert::Infallible> for Error {
-    fn from(val: std::convert::Infallible) -> Self {
-        match val {}
-    }
-}
-
 /// `Error` for any error that implements `ResponseError`
 impl<T: ResponseError + 'static> From<T> for Error {
     fn from(err: T) -> Error {

actix-web/src/error/response_error.rs

@@ -1,6 +1,7 @@
 //! `ResponseError` trait and foreign impls.
 
 use std::{
+    convert::Infallible,
     error::Error as StdError,
     fmt,
     io::{self, Write as _},
@@ -54,6 +55,15 @@ downcast_dyn!(ResponseError);
 
 impl ResponseError for Box<dyn StdError + 'static> {}
 
+impl ResponseError for Infallible {
+    fn status_code(&self) -> StatusCode {
+        match *self {}
+    }
+    fn error_response(&self) -> HttpResponse<BoxBody> {
+        match *self {}
+    }
+}
+
 #[cfg(feature = "openssl")]
 impl ResponseError for actix_tls::accept::openssl::reexports::Error {}