implement Responder for Option<()> and Result<(), E: Error>

actix-web/CHANGES.md

@@ -5,6 +5,7 @@
 - On Windows, an error is now returned from `HttpServer::bind()` (or TLS variants) when binding to a socket that's already in use.
 - Update `brotli` dependency to `7`.
 - Minimum supported Rust version (MSRV) is now 1.75.
+- Implemented responder for `Option<()>` and `Result<(), E: Error> to respond with `204 No Content`
 
 ## 4.9.0
 

actix-web/src/response/responder.rs

@@ -116,6 +116,17 @@ impl<R: Responder> Responder for Option<R> {
     }
 }
 
+//Note see https://github.com/actix/actix-web/issues/1108 on why Responder is not implemented for ()
+impl Responder for Option<()> {
+    type Body = BoxBody;
+    fn respond_to(self, _req: &HttpRequest) -> HttpResponse {
+        match self {
+            Some(()) => HttpResponse::NoContent().finish(),
+            None => HttpResponse::NotFound().finish(),
+        }
+    }
+}
+
 impl<R, E> Responder for Result<R, E>
 where
     R: Responder,
@@ -131,6 +142,18 @@ where
     }
 }
 
+//Note see https://github.com/actix/actix-web/issues/1108 on why Responder is not implemented for ()
+impl<E: Into<Error>> Responder for Result<(), E> {
+    type Body = BoxBody;
+
+    fn respond_to(self, _req: &HttpRequest) -> HttpResponse {
+        match self {
+            Ok(()) => HttpResponse::new(StatusCode::NO_CONTENT),
+            Err(e) => HttpResponse::from_error(e.into()),
+        }
+    }
+}
+
 impl<R: Responder> Responder for (R, StatusCode) {
     type Body = R::Body;