add either extractor (#1788)

src/responder.rs

@@ -332,82 +332,6 @@ impl<T: Responder> Future for CustomResponderFut<T> {
     }
 }
 
-/// Combines two different responder types into a single type
-///
-/// ```rust
-/// use actix_web::{Either, Error, HttpResponse};
-///
-/// type RegisterResult = Either<HttpResponse, Result<HttpResponse, Error>>;
-///
-/// fn index() -> RegisterResult {
-///     if is_a_variant() {
-///         // <- choose left variant
-///         Either::A(HttpResponse::BadRequest().body("Bad data"))
-///     } else {
-///         Either::B(
-///             // <- Right variant
-///             Ok(HttpResponse::Ok()
-///                 .content_type("text/html")
-///                 .body("Hello!"))
-///         )
-///     }
-/// }
-/// # fn is_a_variant() -> bool { true }
-/// # fn main() {}
-/// ```
-#[derive(Debug, PartialEq)]
-pub enum Either<A, B> {
-    /// First branch of the type
-    A(A),
-    /// Second branch of the type
-    B(B),
-}
-
-impl<A, B> Responder for Either<A, B>
-where
-    A: Responder,
-    B: Responder,
-{
-    type Error = Error;
-    type Future = EitherResponder<A, B>;
-
-    fn respond_to(self, req: &HttpRequest) -> Self::Future {
-        match self {
-            Either::A(a) => EitherResponder::A(a.respond_to(req)),
-            Either::B(b) => EitherResponder::B(b.respond_to(req)),
-        }
-    }
-}
-
-#[pin_project(project = EitherResponderProj)]
-pub enum EitherResponder<A, B>
-where
-    A: Responder,
-    B: Responder,
-{
-    A(#[pin] A::Future),
-    B(#[pin] B::Future),
-}
-
-impl<A, B> Future for EitherResponder<A, B>
-where
-    A: Responder,
-    B: Responder,
-{
-    type Output = Result<Response, Error>;
-
-    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        match self.project() {
-            EitherResponderProj::A(fut) => {
-                Poll::Ready(ready!(fut.poll(cx)).map_err(|e| e.into()))
-            }
-            EitherResponderProj::B(fut) => {
-                Poll::Ready(ready!(fut.poll(cx).map_err(|e| e.into())))
-            }
-        }
-    }
-}
-
 impl<T> Responder for InternalError<T>
 where
     T: std::fmt::Debug + std::fmt::Display + 'static,