Move the Host extractor to axum-extra (#2956)

axum-extra/src/extract/rejection.rs

@@ -0,0 +1,23 @@
+//! Rejection response types.
+
+use axum_core::{
+    __composite_rejection as composite_rejection, __define_rejection as define_rejection,
+};
+
+define_rejection! {
+    #[status = BAD_REQUEST]
+    #[body = "No host found in request"]
+    /// Rejection type used if the [`Host`](super::Host) extractor is unable to
+    /// resolve a host.
+    pub struct FailedToResolveHost;
+}
+
+composite_rejection! {
+    /// Rejection used for [`Host`](super::Host).
+    ///
+    /// Contains one variant for each way the [`Host`](super::Host) extractor
+    /// can fail.
+    pub enum HostRejection {
+        FailedToResolveHost,
+    }
+}