diff --git a/benches/client.rs b/benches/client.rs
index 060c53ab54..1582a02d8e 100644
--- a/benches/client.rs
+++ b/benches/client.rs
@@ -1,4 +1,4 @@
-#![feature(core, io, test)]
+#![feature(core, old_io, test)]
 extern crate hyper;
 
 extern crate test;
diff --git a/benches/client_mock_tcp.rs b/benches/client_mock_tcp.rs
index 5caae756e5..370e73b942 100644
--- a/benches/client_mock_tcp.rs
+++ b/benches/client_mock_tcp.rs
@@ -1,4 +1,4 @@
-#![feature(collections, io, test)]
+#![feature(collections, old_io, test)]
 extern crate hyper;
 
 extern crate test;
diff --git a/benches/server.rs b/benches/server.rs
index 2ffcd75ff9..57db9935a7 100644
--- a/benches/server.rs
+++ b/benches/server.rs
@@ -1,4 +1,4 @@
-#![feature(io, test)]
+#![feature(old_io, test)]
 extern crate hyper;
 extern crate test;
 
diff --git a/examples/client.rs b/examples/client.rs
index 70edf87162..ea29965ac6 100644
--- a/examples/client.rs
+++ b/examples/client.rs
@@ -1,4 +1,4 @@
-#![feature(env, io)]
+#![feature(env, old_io)]
 extern crate hyper;
 
 use std::env;
diff --git a/examples/hello.rs b/examples/hello.rs
index 8ed34e2bdd..188f93b084 100644
--- a/examples/hello.rs
+++ b/examples/hello.rs
@@ -1,4 +1,4 @@
-#![feature(io)]
+#![feature(old_io)]
 extern crate hyper;
 
 use std::old_io::net::ip::Ipv4Addr;
diff --git a/examples/server.rs b/examples/server.rs
index 17c580bc84..3f7606ef19 100644
--- a/examples/server.rs
+++ b/examples/server.rs
@@ -1,4 +1,4 @@
-#![feature(io)]
+#![feature(old_io)]
 extern crate hyper;
 #[macro_use] extern crate log;
 
@@ -21,7 +21,7 @@ macro_rules! try_return(
 
 fn echo(mut req: Request, mut res: Response) {
     match req.uri {
-        AbsolutePath(ref path) => match (&req.method, &path[]) {
+        AbsolutePath(ref path) => match (&req.method, &path[..]) {
             (&Get, "/") | (&Get, "/echo") => {
                 let out = b"Try POST /echo";
 
diff --git a/src/client/mod.rs b/src/client/mod.rs
index 64a875105e..81fa9a6a79 100644
--- a/src/client/mod.rs
+++ b/src/client/mod.rs
@@ -197,7 +197,7 @@ impl<'a, U: IntoUrl, C: NetworkConnector> RequestBuilder<'a, U, C> {
                 // punching borrowck here
                 let loc = match res.headers.get::<Location>() {
                     Some(&Location(ref loc)) => {
-                        Some(UrlParser::new().base_url(&url).parse(&loc[]))
+                        Some(UrlParser::new().base_url(&url).parse(&loc[..]))
                     }
                     None => {
                         debug!("no Location header");
@@ -394,7 +394,7 @@ mod tests {
     #[test]
     fn test_redirect_followif() {
         fn follow_if(url: &Url) -> bool {
-            !url.serialize()[].contains("127.0.0.3")
+            !url.serialize().contains("127.0.0.3")
         }
         let mut client = Client::with_connector(MockRedirectPolicy);
         client.set_redirect_policy(RedirectPolicy::FollowIf(follow_if));
diff --git a/src/client/request.rs b/src/client/request.rs
index 2a5c2ff72b..9862aeae66 100644
--- a/src/client/request.rs
+++ b/src/client/request.rs
@@ -1,5 +1,6 @@
 //! Client Requests
 use std::old_io::{BufferedWriter, IoResult};
+use std::marker::PhantomData;
 
 use url::Url;
 
@@ -25,6 +26,8 @@ pub struct Request<W> {
     body: HttpWriter<BufferedWriter<Box<NetworkStream + Send>>>,
     headers: Headers,
     method: method::Method,
+
+    _marker: PhantomData<W>,
 }
 
 impl<W> Request<W> {
@@ -66,7 +69,8 @@ impl Request<Fresh> {
             headers: headers,
             url: url,
             version: version::HttpVersion::Http11,
-            body: stream
+            body: stream,
+            _marker: PhantomData,
         })
     }
 
@@ -77,7 +81,7 @@ impl Request<Fresh> {
         //TODO: this needs a test
         if let Some(ref q) = self.url.query {
             uri.push('?');
-            uri.push_str(&q[]);
+            uri.push_str(&q[..]);
         }
 
         debug!("writing head: {:?} {:?} {:?}", self.method, uri, self.version);
@@ -136,7 +140,8 @@ impl Request<Fresh> {
             headers: self.headers,
             url: self.url,
             version: self.version,
-            body: stream
+            body: stream,
+            _marker: PhantomData,
         })
     }
 
@@ -185,7 +190,7 @@ mod tests {
         let stream = *req.body.end().unwrap()
             .into_inner().downcast::<MockStream>().ok().unwrap();
         let bytes = stream.write.into_inner();
-        let s = from_utf8(&bytes[]).unwrap();
+        let s = from_utf8(&bytes[..]).unwrap();
         assert!(!s.contains("Content-Length:"));
         assert!(!s.contains("Transfer-Encoding:"));
     }
@@ -199,7 +204,7 @@ mod tests {
         let stream = *req.body.end().unwrap()
             .into_inner().downcast::<MockStream>().ok().unwrap();
         let bytes = stream.write.into_inner();
-        let s = from_utf8(&bytes[]).unwrap();
+        let s = from_utf8(&bytes[..]).unwrap();
         assert!(!s.contains("Content-Length:"));
         assert!(!s.contains("Transfer-Encoding:"));
     }
diff --git a/src/client/response.rs b/src/client/response.rs
index 763f36cd2c..5ded928ef3 100644
--- a/src/client/response.rs
+++ b/src/client/response.rs
@@ -1,6 +1,7 @@
 //! Client Responses
 use std::num::FromPrimitive;
 use std::old_io::{BufferedReader, IoResult};
+use std::marker::PhantomData;
 
 use header;
 use header::{ContentLength, TransferEncoding};
@@ -23,6 +24,8 @@ pub struct Response<S = HttpStream> {
     pub version: version::HttpVersion,
     status_raw: RawStatus,
     body: HttpReader<BufferedReader<Box<NetworkStream + Send>>>,
+
+    _marker: PhantomData<S>,
 }
 
 impl Response {
@@ -72,6 +75,7 @@ impl Response {
             headers: headers,
             body: body,
             status_raw: raw_status,
+            _marker: PhantomData,
         })
     }
 
@@ -98,6 +102,7 @@ mod tests {
     use std::borrow::Cow::Borrowed;
     use std::boxed::BoxAny;
     use std::old_io::BufferedReader;
+    use std::marker::PhantomData;
 
     use header::Headers;
     use header::TransferEncoding;
@@ -119,7 +124,8 @@ mod tests {
             headers: Headers::new(),
             version: version::HttpVersion::Http11,
             body: EofReader(BufferedReader::new(box MockStream::new() as Box<NetworkStream + Send>)),
-            status_raw: RawStatus(200, Borrowed("OK"))
+            status_raw: RawStatus(200, Borrowed("OK")),
+            _marker: PhantomData,
         };
 
         let b = res.into_inner().downcast::<MockStream>().ok().unwrap();
diff --git a/src/header/common/access_control/allow_origin.rs b/src/header/common/access_control/allow_origin.rs
index 893b522b47..b7bde04d0e 100644
--- a/src/header/common/access_control/allow_origin.rs
+++ b/src/header/common/access_control/allow_origin.rs
@@ -29,7 +29,7 @@ impl header::Header for AccessControlAllowOrigin {
 
     fn parse_header(raw: &[Vec<u8>]) -> Option<AccessControlAllowOrigin> {
         if raw.len() == 1 {
-            match str::from_utf8(unsafe { &raw[].get_unchecked(0)[] }) {
+            match str::from_utf8(unsafe { &raw.get_unchecked(0)[..] }) {
                 Ok(s) => {
                     if s == "*" {
                         Some(AccessControlAllowOrigin::AllowStar)
diff --git a/src/header/common/authorization.rs b/src/header/common/authorization.rs
index 9999089e4f..b36183d7bc 100644
--- a/src/header/common/authorization.rs
+++ b/src/header/common/authorization.rs
@@ -22,14 +22,14 @@ impl<S: Scheme> DerefMut for Authorization<S> {
     }
 }
 
-impl<S: Scheme> Header for Authorization<S> {
+impl<S: Scheme + 'static> Header for Authorization<S> where <S as FromStr>::Err: 'static {
     fn header_name() -> &'static str {
         "Authorization"
     }
 
     fn parse_header(raw: &[Vec<u8>]) -> Option<Authorization<S>> {
         if raw.len() == 1 {
-            match (from_utf8(unsafe { &raw[].get_unchecked(0)[] }), Scheme::scheme(None::<S>)) {
+            match (from_utf8(unsafe { &raw.get_unchecked(0)[..] }), Scheme::scheme(None::<S>)) {
                 (Ok(header), Some(scheme))
                     if header.starts_with(scheme) && header.len() > scheme.len() + 1 => {
                     header[scheme.len() + 1..].parse::<S>().map(|s| Authorization(s)).ok()
@@ -43,7 +43,7 @@ impl<S: Scheme> Header for Authorization<S> {
     }
 }
 
-impl<S: Scheme> HeaderFormat for Authorization<S> {
+impl<S: Scheme + 'static> HeaderFormat for Authorization<S> where <S as FromStr>::Err: 'static {
     fn fmt_header(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         match Scheme::scheme(None::<S>) {
             Some(scheme) => try!(write!(fmt, "{} ", scheme)),
@@ -96,7 +96,7 @@ impl Scheme for Basic {
         let mut text = self.username.clone();
         text.push(':');
         if let Some(ref pass) = self.password {
-            text.push_str(&pass[]);
+            text.push_str(&pass[..]);
         }
         write!(f, "{}", text.as_bytes().to_base64(Config {
             char_set: Standard,
@@ -113,7 +113,7 @@ impl FromStr for Basic {
         match s.from_base64() {
             Ok(decoded) => match String::from_utf8(decoded) {
                 Ok(text) => {
-                    let mut parts = &mut text[].split(':');
+                    let mut parts = &mut text.split(':');
                     let user = match parts.next() {
                         Some(part) => part.to_string(),
                         None => return Err(())
@@ -160,7 +160,7 @@ mod tests {
     #[test]
     fn test_raw_auth_parse() {
         let headers = Headers::from_raw(&mut mem("Authorization: foo bar baz\r\n\r\n")).unwrap();
-        assert_eq!(&headers.get::<Authorization<String>>().unwrap().0[], "foo bar baz");
+        assert_eq!(&headers.get::<Authorization<String>>().unwrap().0[..], "foo bar baz");
     }
 
     #[test]
@@ -181,7 +181,7 @@ mod tests {
     fn test_basic_auth_parse() {
         let headers = Headers::from_raw(&mut mem("Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==\r\n\r\n")).unwrap();
         let auth = headers.get::<Authorization<Basic>>().unwrap();
-        assert_eq!(&auth.0.username[], "Aladdin");
+        assert_eq!(&auth.0.username[..], "Aladdin");
         assert_eq!(auth.0.password, Some("open sesame".to_string()));
     }
 
diff --git a/src/header/common/cache_control.rs b/src/header/common/cache_control.rs
index 50e4a4af4c..f1def9e112 100644
--- a/src/header/common/cache_control.rs
+++ b/src/header/common/cache_control.rs
@@ -16,7 +16,7 @@ impl Header for CacheControl {
 
     fn parse_header(raw: &[Vec<u8>]) -> Option<CacheControl> {
         let directives = raw.iter()
-            .filter_map(|line| from_one_comma_delimited(&line[]))
+            .filter_map(|line| from_one_comma_delimited(&line[..]))
             .collect::<Vec<Vec<CacheDirective>>>()
             .concat();
         if directives.len() > 0 {
@@ -29,7 +29,7 @@ impl Header for CacheControl {
 
 impl HeaderFormat for CacheControl {
     fn fmt_header(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        fmt_comma_delimited(fmt, &self[])
+        fmt_comma_delimited(fmt, &self[..])
     }
 }
 
@@ -88,7 +88,7 @@ impl fmt::Display for CacheDirective {
             ProxyRevalidate => "proxy-revalidate",
             SMaxAge(secs) => return write!(f, "s-maxage={}", secs),
 
-            Extension(ref name, None) => &name[],
+            Extension(ref name, None) => &name[..],
             Extension(ref name, Some(ref arg)) => return write!(f, "{}={}", name, arg),
 
         }, f)
diff --git a/src/header/common/connection.rs b/src/header/common/connection.rs
index 3c1dd88dd2..981c30a8db 100644
--- a/src/header/common/connection.rs
+++ b/src/header/common/connection.rs
@@ -64,7 +64,7 @@ impl Header for Connection {
 impl HeaderFormat for Connection {
     fn fmt_header(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         let Connection(ref parts) = *self;
-        fmt_comma_delimited(fmt, &parts[])
+        fmt_comma_delimited(fmt, &parts[..])
     }
 }
 
diff --git a/src/header/common/cookie.rs b/src/header/common/cookie.rs
index fa68ab2d18..16df67e5de 100644
--- a/src/header/common/cookie.rs
+++ b/src/header/common/cookie.rs
@@ -26,7 +26,7 @@ impl Header for Cookie {
     fn parse_header(raw: &[Vec<u8>]) -> Option<Cookie> {
         let mut cookies = Vec::with_capacity(raw.len());
         for cookies_raw in raw.iter() {
-            match from_utf8(&cookies_raw[]) {
+            match from_utf8(&cookies_raw[..]) {
                 Ok(cookies_str) => {
                     for cookie_str in cookies_str.split(';') {
                         match cookie_str.trim().parse() {
@@ -82,7 +82,7 @@ impl Cookie {
 
 #[test]
 fn test_parse() {
-    let h = Header::parse_header(&[b"foo=bar; baz=quux".to_vec()][]);
+    let h = Header::parse_header(&[b"foo=bar; baz=quux".to_vec()][..]);
     let c1 = CookiePair::new("foo".to_string(), "bar".to_string());
     let c2 = CookiePair::new("baz".to_string(), "quux".to_string());
     assert_eq!(h, Some(Cookie(vec![c1, c2])));
@@ -99,7 +99,7 @@ fn test_fmt() {
     let mut headers = Headers::new();
     headers.set(cookie_header);
 
-    assert_eq!(&headers.to_string()[], "Cookie: foo=bar; baz=quux\r\n");
+    assert_eq!(&headers.to_string()[..], "Cookie: foo=bar; baz=quux\r\n");
 }
 
 #[test]
diff --git a/src/header/common/host.rs b/src/header/common/host.rs
index 6e0bb06d3d..c0c08ba568 100644
--- a/src/header/common/host.rs
+++ b/src/header/common/host.rs
@@ -28,7 +28,7 @@ impl Header for Host {
             // FIXME: use rust-url to parse this
             // https://github.com/servo/rust-url/issues/42
             let idx = {
-                let slice = &s[];
+                let slice = &s[..];
                 if slice.char_at(1) == '[' {
                     match slice.rfind(']') {
                         Some(idx) => {
diff --git a/src/header/common/if_match.rs b/src/header/common/if_match.rs
index 30a3a802bf..467ac640a8 100644
--- a/src/header/common/if_match.rs
+++ b/src/header/common/if_match.rs
@@ -25,7 +25,7 @@ impl Header for IfMatch {
 
     fn parse_header(raw: &[Vec<u8>]) -> Option<IfMatch> {
         from_one_raw_str(raw).and_then(|s: String| {
-            let slice = &s[];
+            let slice = &s[..];
             match slice {
                 "" => None,
                 "*" => Some(IfMatch::Any),
@@ -39,7 +39,7 @@ impl HeaderFormat for IfMatch {
     fn fmt_header(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             IfMatch::Any => write!(fmt, "*"),
-            IfMatch::EntityTags(ref fields) => fmt_comma_delimited(fmt, &fields[])
+            IfMatch::EntityTags(ref fields) => fmt_comma_delimited(fmt, &fields[..])
         }
     }
 }
diff --git a/src/header/common/if_none_match.rs b/src/header/common/if_none_match.rs
index ef1211d841..8159ed3495 100644
--- a/src/header/common/if_none_match.rs
+++ b/src/header/common/if_none_match.rs
@@ -33,7 +33,7 @@ impl Header for IfNoneMatch {
 
     fn parse_header(raw: &[Vec<u8>]) -> Option<IfNoneMatch> {
         from_one_raw_str(raw).and_then(|s: String| {
-            let slice = &s[];
+            let slice = &s[..];
             match slice {
                 "" => None,
                 "*" => Some(IfNoneMatch::Any),
@@ -47,7 +47,7 @@ impl HeaderFormat for IfNoneMatch {
     fn fmt_header(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             IfNoneMatch::Any => { write!(fmt, "*") }
-            IfNoneMatch::EntityTags(ref fields) => { fmt_comma_delimited(fmt, &fields[]) }
+            IfNoneMatch::EntityTags(ref fields) => { fmt_comma_delimited(fmt, &fields[..]) }
         }
     }
 }
diff --git a/src/header/common/mod.rs b/src/header/common/mod.rs
index 718361e85a..b2ffa50192 100644
--- a/src/header/common/mod.rs
+++ b/src/header/common/mod.rs
@@ -50,13 +50,13 @@ macro_rules! bench_header(
             fn bench_parse(b: &mut Bencher) {
                 let val = $value;
                 b.iter(|| {
-                    let _: $ty = Header::parse_header(&val[]).unwrap();
+                    let _: $ty = Header::parse_header(&val[..]).unwrap();
                 });
             }
 
             #[bench]
             fn bench_format(b: &mut Bencher) {
-                let val: $ty = Header::parse_header(&$value[]).unwrap();
+                let val: $ty = Header::parse_header(&$value[..]).unwrap();
                 let fmt = HeaderFormatter(&val);
                 b.iter(|| {
                     format!("{}", fmt);
@@ -102,7 +102,7 @@ macro_rules! impl_list_header(
 
         impl $crate::header::HeaderFormat for $from {
             fn fmt_header(&self, fmt: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
-                $crate::header::parsing::fmt_comma_delimited(fmt, &self[])
+                $crate::header::parsing::fmt_comma_delimited(fmt, &self[..])
             }
         }
 
diff --git a/src/header/common/pragma.rs b/src/header/common/pragma.rs
index d9551d9202..b080c412af 100644
--- a/src/header/common/pragma.rs
+++ b/src/header/common/pragma.rs
@@ -31,7 +31,7 @@ impl Header for Pragma {
 
     fn parse_header(raw: &[Vec<u8>]) -> Option<Pragma> {
         parsing::from_one_raw_str(raw).and_then(|s: String| {
-            let slice = &s.to_ascii_lowercase()[];
+            let slice = &s.to_ascii_lowercase()[..];
             match slice {
                 "" => None,
                 "no-cache" => Some(Pragma::NoCache),
diff --git a/src/header/common/set_cookie.rs b/src/header/common/set_cookie.rs
index a0e37bc15f..419e4c8f31 100644
--- a/src/header/common/set_cookie.rs
+++ b/src/header/common/set_cookie.rs
@@ -23,7 +23,7 @@ impl Header for SetCookie {
     fn parse_header(raw: &[Vec<u8>]) -> Option<SetCookie> {
         let mut set_cookies = Vec::with_capacity(raw.len());
         for set_cookies_raw in raw.iter() {
-            match from_utf8(&set_cookies_raw[]) {
+            match from_utf8(&set_cookies_raw[..]) {
                 Ok(s) if !s.is_empty() => {
                     match s.parse() {
                         Ok(cookie) => set_cookies.push(cookie),
@@ -76,7 +76,7 @@ impl SetCookie {
 
 #[test]
 fn test_parse() {
-    let h = Header::parse_header(&[b"foo=bar; HttpOnly".to_vec()][]);
+    let h = Header::parse_header(&[b"foo=bar; HttpOnly".to_vec()][..]);
     let mut c1 = Cookie::new("foo".to_string(), "bar".to_string());
     c1.httponly = true;
 
@@ -94,7 +94,7 @@ fn test_fmt() {
     let mut headers = Headers::new();
     headers.set(cookies);
 
-    assert_eq!(&headers.to_string()[], "Set-Cookie: foo=bar; HttpOnly; Path=/p\r\nSet-Cookie: baz=quux; Path=/\r\n");
+    assert_eq!(&headers.to_string()[..], "Set-Cookie: foo=bar; HttpOnly; Path=/p\r\nSet-Cookie: baz=quux; Path=/\r\n");
 }
 
 #[test]
diff --git a/src/header/common/upgrade.rs b/src/header/common/upgrade.rs
index 9347d3a2da..e6260a37e0 100644
--- a/src/header/common/upgrade.rs
+++ b/src/header/common/upgrade.rs
@@ -55,7 +55,7 @@ impl Header for Upgrade {
 impl HeaderFormat for Upgrade {
     fn fmt_header(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         let Upgrade(ref parts) = *self;
-        fmt_comma_delimited(fmt, &parts[])
+        fmt_comma_delimited(fmt, &parts[..])
     }
 }
 
diff --git a/src/header/common/vary.rs b/src/header/common/vary.rs
index 52482e7359..ff19ec6036 100644
--- a/src/header/common/vary.rs
+++ b/src/header/common/vary.rs
@@ -21,7 +21,7 @@ impl Header for Vary {
 
     fn parse_header(raw: &[Vec<u8>]) -> Option<Vary> {
         from_one_raw_str(raw).and_then(|s: String| {
-            let slice = &s[];
+            let slice = &s[..];
             match slice {
                 "" => None,
                 "*" => Some(Vary::Any),
@@ -35,7 +35,7 @@ impl HeaderFormat for Vary {
     fn fmt_header(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             Vary::Any => { write!(fmt, "*") }
-            Vary::Headers(ref fields) => { fmt_comma_delimited(fmt, &fields[]) }
+            Vary::Headers(ref fields) => { fmt_comma_delimited(fmt, &fields[..]) }
         }
     }
 }
diff --git a/src/header/mod.rs b/src/header/mod.rs
index 2b08a924e3..b846a568d9 100644
--- a/src/header/mod.rs
+++ b/src/header/mod.rs
@@ -9,11 +9,10 @@ use std::borrow::Cow::{Borrowed, Owned};
 use std::fmt;
 use std::raw::TraitObject;
 use std::str::from_utf8;
-use std::string::CowString;
 use std::collections::HashMap;
 use std::collections::hash_map::{Iter, Entry};
-use std::iter::FromIterator;
-use std::borrow::IntoCow;
+use std::iter::{FromIterator, IntoIterator};
+use std::borrow::{Cow, IntoCow};
 use std::{mem, raw};
 
 use uany::{UnsafeAnyExt};
@@ -30,7 +29,7 @@ mod common;
 mod shared;
 pub mod parsing;
 
-type HeaderName = UniCase<CowString<'static>>;
+type HeaderName = UniCase<Cow<'static, str>>;
 
 /// A trait for any object that will represent a header field and value.
 ///
@@ -139,7 +138,7 @@ impl Headers {
         loop {
             match try!(http::read_header(rdr)) {
                 Some((name, value)) => {
-                    debug!("raw header: {:?}={:?}", name, &value[]);
+                    debug!("raw header: {:?}={:?}", name, &value[..]);
                     count += (name.len() + value.len()) as u32;
                     if count > MAX_HEADERS_LENGTH {
                         debug!("Max header size reached, aborting");
@@ -183,14 +182,14 @@ impl Headers {
             .get(&UniCase(Borrowed(unsafe { mem::transmute::<&str, &str>(name) })))
             .and_then(|item| {
                 if let Some(ref raw) = *item.raw {
-                    return Some(&raw[]);
+                    return Some(&raw[..]);
                 }
 
                 let raw = vec![item.typed.as_ref().unwrap().to_string().into_bytes()];
                 item.raw.set(raw);
 
                 let raw = item.raw.as_ref().unwrap();
-                Some(&raw[])
+                Some(&raw[..])
             })
     }
 
@@ -203,7 +202,7 @@ impl Headers {
     /// # let mut headers = Headers::new();
     /// headers.set_raw("content-length", vec![b"5".to_vec()]);
     /// ```
-    pub fn set_raw<K: IntoCow<'static, String, str>>(&mut self, name: K, value: Vec<Vec<u8>>) {
+    pub fn set_raw<K: IntoCow<'static, str>>(&mut self, name: K, value: Vec<Vec<u8>>) {
         self.data.insert(UniCase(name.into_cow()), Item::new_raw(value));
     }
 
@@ -351,7 +350,7 @@ impl<'a> fmt::Debug for HeaderView<'a> {
 }
 
 impl<'a> Extend<HeaderView<'a>> for Headers {
-    fn extend<I: Iterator<Item=HeaderView<'a>>>(&mut self, iter: I) {
+    fn extend<I: IntoIterator<Item=HeaderView<'a>>>(&mut self, iter: I) {
         for header in iter {
             self.data.insert((*header.0).clone(), (*header.1).clone());
         }
@@ -359,7 +358,7 @@ impl<'a> Extend<HeaderView<'a>> for Headers {
 }
 
 impl<'a> FromIterator<HeaderView<'a>> for Headers {
-    fn from_iter<I: Iterator<Item=HeaderView<'a>>>(iter: I) -> Headers {
+    fn from_iter<I: IntoIterator<Item=HeaderView<'a>>>(iter: I) -> Headers {
         let mut headers = Headers::new();
         headers.extend(iter);
         headers
@@ -451,7 +450,7 @@ fn get_or_parse_mut<H: Header + HeaderFormat>(item: &mut Item) -> Option<&mut It
 
 fn parse<H: Header + HeaderFormat>(item: &Item) {
     match *item.raw {
-        Some(ref raw) => match Header::parse_header(&raw[]) {
+        Some(ref raw) => match Header::parse_header(&raw[..]) {
             Some::<H>(h) => item.typed.set(box h as Box<HeaderFormat + Send + Sync>),
             None => ()
         },
@@ -476,7 +475,7 @@ impl fmt::Display for Item {
             None => match *self.raw {
                 Some(ref raw) => {
                     for part in raw.iter() {
-                        match from_utf8(&part[]) {
+                        match from_utf8(&part[..]) {
                             Ok(s) => try!(fmt.write_str(s)),
                             Err(e) => {
                                 error!("raw header value is not utf8. header={:?}, error={:?}", part, e);
@@ -595,7 +594,7 @@ mod tests {
                 return None;
             }
             // we JUST checked that raw.len() == 1, so raw[0] WILL exist.
-            match from_utf8(unsafe { &raw[].get_unchecked(0)[] }) {
+            match from_utf8(unsafe { &raw.get_unchecked(0)[..] }) {
                 Ok(s) => FromStr::from_str(s).ok(),
                 Err(_) => None
             }.map(|u| CrazyLength(Some(false), u))
@@ -671,7 +670,7 @@ mod tests {
         let mut headers = Headers::new();
         headers.set(ContentLength(10));
         headers.set_raw("content-LENGTH", vec![b"20".to_vec()]);
-        assert_eq!(headers.get_raw("Content-length").unwrap(), &[b"20".to_vec()][]);
+        assert_eq!(headers.get_raw("Content-length").unwrap(), &[b"20".to_vec()][..]);
         assert_eq!(headers.get(), Some(&ContentLength(20)));
     }
 
diff --git a/src/header/parsing.rs b/src/header/parsing.rs
index 16964f261c..5727a2b9cc 100644
--- a/src/header/parsing.rs
+++ b/src/header/parsing.rs
@@ -11,7 +11,7 @@ pub fn from_one_raw_str<T: str::FromStr>(raw: &[Vec<u8>]) -> Option<T> {
         return None;
     }
     // we JUST checked that raw.len() == 1, so raw[0] WILL exist.
-    match str::from_utf8(&raw[0][]) {
+    match str::from_utf8(&raw[0][..]) {
         Ok(s) => str::FromStr::from_str(s).ok(),
         Err(_) => None
     }
@@ -24,7 +24,7 @@ pub fn from_comma_delimited<T: str::FromStr>(raw: &[Vec<u8>]) -> Option<Vec<T>>
         return None;
     }
     // we JUST checked that raw.len() == 1, so raw[0] WILL exist.
-    from_one_comma_delimited(&raw[0][])
+    from_one_comma_delimited(&raw[0][..])
 }
 
 /// Reads a comma-delimited raw string into a Vec.
diff --git a/src/header/shared/entity.rs b/src/header/shared/entity.rs
index 740ba2abab..2388b677d8 100644
--- a/src/header/shared/entity.rs
+++ b/src/header/shared/entity.rs
@@ -42,7 +42,7 @@ impl FromStr for EntityTag {
     type Err = ();
     fn from_str(s: &str) -> Result<EntityTag, ()> {
         let length: usize = s.len();
-        let slice = &s[];
+        let slice = &s[..];
 
         // Early exits:
         // 1. The string is empty, or,
diff --git a/src/header/shared/quality_item.rs b/src/header/shared/quality_item.rs
index a83060d60f..199ef9a72f 100644
--- a/src/header/shared/quality_item.rs
+++ b/src/header/shared/quality_item.rs
@@ -39,7 +39,7 @@ impl<T: fmt::Display> fmt::Display for QualityItem<T> {
             write!(f, "{}", self.item)
         } else {
             write!(f, "{}; q={}", self.item,
-                   format!("{:.3}", self.quality).trim_right_matches(&['0', '.'][]))
+                   format!("{:.3}", self.quality).trim_right_matches(&['0', '.'][..]))
         }
     }
 }
diff --git a/src/http.rs b/src/http.rs
index 2d081bcb43..7affb8bd92 100644
--- a/src/http.rs
+++ b/src/http.rs
@@ -1,11 +1,10 @@
 //! Pieces pertaining to the HTTP message protocol.
-use std::borrow::Cow::{Borrowed, Owned};
+use std::borrow::Cow::{self, Borrowed, Owned};
 use std::borrow::IntoCow;
 use std::cmp::min;
 use std::old_io::{self, Reader, IoResult, BufWriter};
 use std::num::from_u16;
 use std::str;
-use std::string::CowString;
 
 use url::Url;
 use url::ParseError as UrlError;
@@ -395,7 +394,7 @@ pub fn read_method<R: Reader>(stream: &mut R) -> HttpResult<method::Method> {
 
     debug!("maybe_method = {:?}", maybe_method);
 
-    match (maybe_method, &buf[]) {
+    match (maybe_method, &buf[..]) {
         (Some(method), _) => Ok(method),
         (None, ext) => {
             // We already checked that the buffer is ASCII
@@ -587,7 +586,7 @@ pub type StatusLine = (HttpVersion, RawStatus);
 
 /// The raw status code and reason-phrase.
 #[derive(PartialEq, Debug)]
-pub struct RawStatus(pub u16, pub CowString<'static>);
+pub struct RawStatus(pub u16, pub Cow<'static, str>);
 
 impl Clone for RawStatus {
     fn clone(&self) -> RawStatus {
@@ -664,7 +663,7 @@ pub fn read_status<R: Reader>(stream: &mut R) -> HttpResult<RawStatus> {
         }
     }
 
-    let reason = match str::from_utf8(&buf[]) {
+    let reason = match str::from_utf8(&buf[..]) {
         Ok(s) => s.trim(),
         Err(_) => return Err(HttpStatusError)
     };
diff --git a/src/lib.rs b/src/lib.rs
index 4af33e7d07..cc71b61108 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,5 @@
-#![feature(core, collections, hash, io, os, path, std_misc,
-           slicing_syntax, box_syntax, unsafe_destructor)]
+#![feature(core, collections, hash, io, old_io, os, old_path,
+           std_misc, box_syntax, unsafe_destructor)]
 #![deny(missing_docs)]
 #![cfg_attr(test, deny(warnings))]
 #![cfg_attr(test, feature(alloc, test))]
diff --git a/src/net.rs b/src/net.rs
index b11abfa327..f7ff2554f6 100644
--- a/src/net.rs
+++ b/src/net.rs
@@ -58,7 +58,7 @@ pub trait NetworkAcceptor: Clone + Send {
 }
 
 /// An iterator wrapper over a NetworkAcceptor.
-pub struct NetworkConnections<'a, N: NetworkAcceptor>(&'a mut N);
+pub struct NetworkConnections<'a, N: NetworkAcceptor + 'a>(&'a mut N);
 
 impl<'a, N: NetworkAcceptor> Iterator for NetworkConnections<'a, N> {
     type Item = IoResult<N::Stream>;
diff --git a/src/server/acceptor.rs b/src/server/acceptor.rs
index 3c0e0b5e15..38e0652d9b 100644
--- a/src/server/acceptor.rs
+++ b/src/server/acceptor.rs
@@ -1,13 +1,13 @@
-use std::thread::{Thread, JoinGuard};
-use std::sync::Arc;
+use std::thread::{self, JoinGuard};
 use std::sync::mpsc;
+use std::collections::VecMap;
 use net::NetworkAcceptor;
 
 pub struct AcceptorPool<A: NetworkAcceptor> {
     acceptor: A
 }
 
-impl<A: NetworkAcceptor> AcceptorPool<A> {
+impl<'a, A: NetworkAcceptor + 'a> AcceptorPool<A> {
     /// Create a thread pool to manage the acceptor.
     pub fn new(acceptor: A) -> AcceptorPool<A> {
         AcceptorPool { acceptor: acceptor }
@@ -18,34 +18,39 @@ impl<A: NetworkAcceptor> AcceptorPool<A> {
     /// ## Panics
     ///
     /// Panics if threads == 0.
-    pub fn accept<F: Fn(A::Stream) + Send + Sync>(self,
-                                                  work: F,
-                                                  threads: usize) -> JoinGuard<'static, ()> {
+    pub fn accept<F>(self, work: F, threads: usize)
+        where F: Fn(A::Stream) + Send + Sync + 'a {
         assert!(threads != 0, "Can't accept on 0 threads.");
 
-        // Replace with &F when Send changes land.
-        let work = Arc::new(work);
-
         let (super_tx, supervisor_rx) = mpsc::channel();
 
-        let spawn =
-            move || spawn_with(super_tx.clone(), work.clone(), self.acceptor.clone());
+        let counter = &mut 0;
+        let work = &work;
+        let mut spawn = move || {
+            let id = *counter;
+            let guard = spawn_with(super_tx.clone(), work, self.acceptor.clone(), id);
+            *counter += 1;
+            (id, guard)
+        };
 
         // Go
-        for _ in 0..threads { spawn() }
+        let mut guards: VecMap<_> = (0..threads).map(|_| spawn()).collect();
 
-        // Spawn the supervisor
-        Thread::scoped(move || for () in supervisor_rx.iter() { spawn() })
+        for id in supervisor_rx.iter() {
+            guards.remove(&id);
+            let (id, guard) = spawn();
+            guards.insert(id, guard);
+        }
     }
 }
 
-fn spawn_with<A, F>(supervisor: mpsc::Sender<()>, work: Arc<F>, mut acceptor: A)
-where A: NetworkAcceptor,
-      F: Fn(<A as NetworkAcceptor>::Stream) + Send + Sync {
+fn spawn_with<'a, A, F>(supervisor: mpsc::Sender<usize>, work: &'a F, mut acceptor: A, id: usize) -> JoinGuard<'a, ()>
+where A: NetworkAcceptor + 'a,
+      F: Fn(<A as NetworkAcceptor>::Stream) + Send + Sync + 'a {
     use std::old_io::EndOfFile;
 
-    Thread::spawn(move || {
-        let sentinel = Sentinel::new(supervisor, ());
+    thread::scoped(move || {
+        let sentinel = Sentinel::new(supervisor, id);
 
         loop {
             match acceptor.accept() {
@@ -61,7 +66,7 @@ where A: NetworkAcceptor,
                 }
             }
         }
-    });
+    })
 }
 
 struct Sentinel<T: Send> {
@@ -83,7 +88,7 @@ impl<T: Send> Sentinel<T> {
 }
 
 #[unsafe_destructor]
-impl<T: Send> Drop for Sentinel<T> {
+impl<T: Send + 'static> Drop for Sentinel<T> {
     fn drop(&mut self) {
         // If we were cancelled, get out of here.
         if !self.active { return; }
diff --git a/src/server/mod.rs b/src/server/mod.rs
index 01fa9184bd..169979d4a4 100644
--- a/src/server/mod.rs
+++ b/src/server/mod.rs
@@ -2,7 +2,7 @@
 use std::old_io::{Listener, BufferedReader, BufferedWriter};
 use std::old_io::net::ip::{IpAddr, Port, SocketAddr};
 use std::os;
-use std::thread::JoinGuard;
+use std::thread::{self, JoinGuard};
 
 pub use self::request::Request;
 pub use self::response::Response;
@@ -56,7 +56,7 @@ impl Server<HttpListener> {
 
 impl<
 L: NetworkListener<Acceptor=A> + Send,
-A: NetworkAcceptor<Stream=S> + Send,
+A: NetworkAcceptor<Stream=S> + Send + 'static,
 S: NetworkStream + Clone + Send> Server<L> {
     /// Creates a new server that will handle `HttpStream`s.
     pub fn with_listener(ip: IpAddr, port: Port, listener: L) -> Server<L> {
@@ -68,7 +68,7 @@ S: NetworkStream + Clone + Send> Server<L> {
     }
 
     /// Binds to a socket, and starts handling connections using a task pool.
-    pub fn listen_threads<H: Handler>(mut self, handler: H, threads: usize) -> HttpResult<Listening<L::Acceptor>> {
+    pub fn listen_threads<H: Handler + 'static>(mut self, handler: H, threads: usize) -> HttpResult<Listening<L::Acceptor>> {
         debug!("binding to {:?}:{:?}", self.ip, self.port);
         let acceptor = try!(self.listener.listen((self.ip, self.port)));
         let socket = try!(acceptor.socket_name());
@@ -77,15 +77,17 @@ S: NetworkStream + Clone + Send> Server<L> {
         let pool = AcceptorPool::new(acceptor.clone());
         let work = move |stream| handle_connection(stream, &handler);
 
+        let guard = thread::scoped(move || pool.accept(work, threads));
+
         Ok(Listening {
-            _guard: pool.accept(work, threads),
+            _guard: guard,
             socket: socket,
             acceptor: acceptor
         })
     }
 
     /// Binds to a socket and starts handling connections.
-    pub fn listen<H: Handler>(self, handler: H) -> HttpResult<Listening<L::Acceptor>> {
+    pub fn listen<H: Handler + 'static>(self, handler: H) -> HttpResult<Listening<L::Acceptor>> {
         self.listen_threads(handler, os::num_cpus() * 5 / 4)
     }
 
diff --git a/src/server/response.rs b/src/server/response.rs
index 1e3604b0e7..e6fbb9cf99 100644
--- a/src/server/response.rs
+++ b/src/server/response.rs
@@ -3,6 +3,7 @@
 //! These are responses sent by a `hyper::Server` to clients, after
 //! receiving a request.
 use std::old_io::IoResult;
+use std::marker::PhantomData;
 
 use time::now_utc;
 
@@ -22,7 +23,9 @@ pub struct Response<'a, W = Fresh> {
     // The status code for the request.
     status: status::StatusCode,
     // The outgoing headers on this response.
-    headers: header::Headers
+    headers: header::Headers,
+
+    _marker: PhantomData<W>
 }
 
 impl<'a, W> Response<'a, W> {
@@ -42,7 +45,8 @@ impl<'a, W> Response<'a, W> {
             status: status,
             version: version,
             body: body,
-            headers: headers
+            headers: headers,
+            _marker: PhantomData,
         }
     }
 
@@ -60,7 +64,8 @@ impl<'a> Response<'a, Fresh> {
             status: status::StatusCode::Ok,
             version: version::HttpVersion::Http11,
             headers: header::Headers::new(),
-            body: ThroughWriter(stream)
+            body: ThroughWriter(stream),
+            _marker: PhantomData,
         }
     }
 
@@ -119,7 +124,8 @@ impl<'a> Response<'a, Fresh> {
             version: self.version,
             body: stream,
             status: self.status,
-            headers: self.headers
+            headers: self.headers,
+            _marker: PhantomData,
         })
     }