Document that RightmostForwarded requires "forwarded-header" feature, closes #42

Author: imbolc

README.md

@@ -35,6 +35,8 @@ separate extractors for each proxy / source header.
 | [`XRealIp`]                          | `X-Real-Ip`                 | Nginx                                                   |
 | [`ConnectInfo`]                      | N/A (uses socket address)   | No proxy, e.g. listening directly to 80 port            |
 
+[`RightmostForwarded`] requires enabling the `forwarded-header` feature.
+
 ## Configurable extractor
 
 The configurable extractor assumes initializing [`ClientIpSource`] at runtime

src/lib.rs

@@ -1,3 +1,4 @@
+#![cfg_attr(docsrs, feature(doc_cfg))]
 #![doc = include_str!("../README.md")]
 #[cfg(feature = "connect-info")]
 use std::net::SocketAddr;
@@ -70,6 +71,9 @@ define_extractor!(
 #[cfg(feature = "forwarded-header")]
 define_extractor!(
     /// Extracts the rightmost IP from `Forwarded` header
+    ///
+    /// Requires the `forwarded-header` feature.
+    #[cfg_attr(docsrs, doc(cfg(feature = "forwarded-header")))]
     RightmostForwarded,
     client_ip::rightmost_forwarded
 );
@@ -125,7 +129,10 @@ pub enum ClientIpSource {
     /// IP from the `Fly-Client-IP` header
     FlyClientIp,
     #[cfg(feature = "forwarded-header")]
-    /// Rightmost IP from the `Forwarded` header
+    /// Rightmost IP from the `Forwarded` header.
+    ///
+    /// Requires the `forwarded-header` feature.
+    #[cfg_attr(docsrs, doc(cfg(feature = "forwarded-header")))]
     RightmostForwarded,
     /// Rightmost IP from the `X-Forwarded-For` header
     RightmostXForwardedFor,