Now using use along with enums, as per https://github.com/rust-lang/rust/pull/18973.

src/header/common/connection.rs

@@ -3,6 +3,8 @@ use std::fmt::{mod, Show};
 use std::str::FromStr;
 use super::util::{from_comma_delimited, fmt_comma_delimited};
 
+use self::ConnectionOption::{KeepAlive, Close, ConnectionHeader};
+
 /// The `Connection` header.
 #[deriving(Clone, PartialEq, Show)]
 pub struct Connection(pub Vec<ConnectionOption>);

src/header/common/transfer_encoding.rs

@@ -3,6 +3,8 @@ use std::fmt;
 use std::str::FromStr;
 use super::util::{from_comma_delimited, fmt_comma_delimited};
 
+use self::Encoding::{Chunked, Gzip, Deflate, Compress, EncodingExt};
+
 /// The `Transfer-Encoding` header.
 ///
 /// This header describes the encoding of the message body. It can be
@@ -32,7 +34,6 @@ pub struct TransferEncoding(pub Vec<Encoding>);
 pub enum Encoding {
     /// The `chunked` encoding.
     Chunked,
-
     /// The `gzip` encoding.
     Gzip,
     /// The `deflate` encoding.

src/header/common/upgrade.rs

@@ -3,6 +3,8 @@ use std::fmt::{mod, Show};
 use std::str::FromStr;
 use super::util::{from_comma_delimited, fmt_comma_delimited};
 
+use self::Protocol::{WebSocket, ProtocolExt};
+
 /// The `Upgrade` header.
 #[deriving(Clone, PartialEq, Show)]
 pub struct Upgrade(Vec<Protocol>);