style(all): Address suggestions made by rust-clippy

src/header/common/authorization.rs

@@ -60,13 +60,13 @@ pub struct Authorization<S: Scheme>(pub S);
 impl<S: Scheme> Deref for Authorization<S> {
     type Target = S;
 
-    fn deref<'a>(&'a self) -> &'a S {
+    fn deref(&self) -> &S {
         &self.0
     }
 }
 
 impl<S: Scheme> DerefMut for Authorization<S> {
-    fn deref_mut<'a>(&'a mut self) -> &'a mut S {
+    fn deref_mut(&mut self) -> &mut S {
         &mut self.0
     }
 }
@@ -81,7 +81,7 @@ impl<S: Scheme + Any> Header for Authorization<S> where <S as FromStr>::Err: 'st
             return Err(::Error::Header);
         }
         let header = try!(from_utf8(unsafe { &raw.get_unchecked(0)[..] }));
-        return if let Some(scheme) = <S as Scheme>::scheme() {
+        if let Some(scheme) = <S as Scheme>::scheme() {
             if header.starts_with(scheme) && header.len() > scheme.len() + 1 {
                 match header[scheme.len() + 1..].parse::<S>().map(Authorization) {
                     Ok(h) => Ok(h),

src/header/common/content_disposition.rs

@@ -160,9 +160,9 @@ impl fmt::Display for ContentDisposition {
             DispositionType::Attachment => try!(write!(f, "attachment")),
             DispositionType::Ext(ref s) => try!(write!(f, "{}", s)),
         }
-        for param in self.parameters.iter() {
-            match param {
-                &DispositionParam::Filename(ref charset, ref opt_lang, ref bytes) => {
+        for param in &self.parameters {
+            match *param {
+                DispositionParam::Filename(ref charset, ref opt_lang, ref bytes) => {
                     let mut use_simple_format: bool = false;
                     if opt_lang.is_none() {
                         if let Charset::Ext(ref ext) = *charset {
@@ -188,7 +188,7 @@ impl fmt::Display for ContentDisposition {
                                 bytes, percent_encoding::HTTP_VALUE_ENCODE_SET)))
                     }
                 },
-                &DispositionParam::Ext(ref k, ref v) => try!(write!(f, "; {}=\"{}\"", k, v)),
+                DispositionParam::Ext(ref k, ref v) => try!(write!(f, "; {}=\"{}\"", k, v)),
             }
         }
         Ok(())

src/header/common/content_range.rs

@@ -31,8 +31,8 @@ header! {
         test_header!(test_unregistered,
             vec![b"seconds 1-2"],
             Some(ContentRange(ContentRangeSpec::Unregistered {
-                unit: "seconds".to_string(),
-                resp: "1-2".to_string()
+                unit: "seconds".to_owned(),
+                resp: "1-2".to_owned()
             })));
 
         test_header!(test_no_len,
@@ -108,7 +108,7 @@ pub enum ContentRangeSpec {
     }
 }
 
-fn split_in_two<'a>(s: &'a str, separator: char) -> Option<(&'a str, &'a str)> {
+fn split_in_two(s: &str, separator: char) -> Option<(&str, &str)> {
     let mut iter = s.splitn(2, separator);
     match (iter.next(), iter.next()) {
         (Some(a), Some(b)) => Some((a, b)),
@@ -149,8 +149,8 @@ impl FromStr for ContentRangeSpec {
             }
             Some((unit, resp)) => {
                 ContentRangeSpec::Unregistered {
-                    unit: unit.to_string(),
-                    resp: resp.to_string()
+                    unit: unit.to_owned(),
+                    resp: resp.to_owned()
                 }
             }
             _ => return Err(::Error::Header)

src/header/common/if_range.rs

@@ -72,9 +72,9 @@ impl Header for IfRange {
 
 impl HeaderFormat for IfRange {
     fn fmt_header(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
-        match self {
-            &IfRange::EntityTag(ref x) => Display::fmt(x, f),
-            &IfRange::Date(ref x) => Display::fmt(x, f),
+        match *self {
+            IfRange::EntityTag(ref x) => Display::fmt(x, f),
+            IfRange::Date(ref x) => Display::fmt(x, f),
         }
     }
 }

src/header/common/mod.rs

@@ -91,13 +91,13 @@ macro_rules! __hyper__deref {
         impl ::std::ops::Deref for $from {
             type Target = $to;
 
-            fn deref<'a>(&'a self) -> &'a $to {
+            fn deref(&self) -> &$to {
                 &self.0
             }
         }
 
         impl ::std::ops::DerefMut for $from {
-            fn deref_mut<'a>(&'a mut self) -> &'a mut $to {
+            fn deref_mut(&mut self) -> &mut $to {
                 &mut self.0
             }
         }
@@ -297,7 +297,7 @@ macro_rules! header {
                         return Ok($id::Any)
                     }
                 }
-                $crate::header::parsing::from_comma_delimited(raw).map(|vec| $id::Items(vec))
+                $crate::header::parsing::from_comma_delimited(raw).map($id::Items)
             }
         }
         impl $crate::header::HeaderFormat for $id {

src/header/common/range.rs

@@ -157,10 +157,10 @@ impl FromStr for ByteRangeSpec {
 
         match (parts.next(), parts.next()) {
             (Some(""), Some(end)) => {
-                end.parse().or(Err(::Error::Header)).map(|end| ByteRangeSpec::Last(end))
+                end.parse().or(Err(::Error::Header)).map(ByteRangeSpec::Last)
             },
             (Some(start), Some("")) => {
-                start.parse().or(Err(::Error::Header)).map(|start| ByteRangeSpec::AllFrom(start))
+                start.parse().or(Err(::Error::Header)).map(ByteRangeSpec::AllFrom)
             },
             (Some(start), Some(end)) => {
                 match (start.parse(), end.parse()) {