Remove needless lifetimes

src/liballoc/collections/btree/map.rs

@@ -2004,7 +2004,7 @@ impl<K, V> BTreeMap<K, V> {
     /// assert_eq!(keys, [1, 2]);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn keys<'a>(&'a self) -> Keys<'a, K, V> {
+    pub fn keys(&self) -> Keys<'_, K, V> {
         Keys { inner: self.iter() }
     }
 
@@ -2025,7 +2025,7 @@ impl<K, V> BTreeMap<K, V> {
     /// assert_eq!(values, ["hello", "goodbye"]);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn values<'a>(&'a self) -> Values<'a, K, V> {
+    pub fn values(&self) -> Values<'_, K, V> {
         Values { inner: self.iter() }
     }
 
@@ -2529,8 +2529,8 @@ enum UnderflowResult<'a, K, V> {
     Stole(NodeRef<marker::Mut<'a>, K, V, marker::Internal>),
 }
 
-fn handle_underfull_node<'a, K, V>(node: NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>)
-                                   -> UnderflowResult<'a, K, V> {
+fn handle_underfull_node<K, V>(node: NodeRef<marker::Mut<'_>, K, V, marker::LeafOrInternal>)
+                               -> UnderflowResult<'_, K, V> {
     let parent = if let Ok(parent) = node.ascend() {
         parent
     } else {

src/liballoc/collections/btree/node.rs

@@ -394,7 +394,7 @@ impl<BorrowType, K, V, Type> NodeRef<BorrowType, K, V, Type> {
     }
 
     /// Temporarily takes out another, immutable reference to the same node.
-    fn reborrow<'a>(&'a self) -> NodeRef<marker::Immut<'a>, K, V, Type> {
+    fn reborrow(&self) -> NodeRef<marker::Immut<'_>, K, V, Type> {
         NodeRef {
             height: self.height,
             node: self.node,

src/liballoc/string.rs

@@ -552,7 +552,7 @@ impl String {
     /// assert_eq!("Hello <20>World", output);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn from_utf8_lossy<'a>(v: &'a [u8]) -> Cow<'a, str> {
+    pub fn from_utf8_lossy(v: &[u8]) -> Cow<'_, str> {
         let mut iter = lossy::Utf8Lossy::from_bytes(v).chunks();
 
         let (first_valid, first_broken) = if let Some(chunk) = iter.next() {

src/libcore/marker.rs

@@ -498,7 +498,7 @@ macro_rules! impls{
 /// #     end: *const T,
 /// #     phantom: PhantomData<&'a T>,
 /// # }
-/// fn borrow_vec<'a, T>(vec: &'a Vec<T>) -> Slice<'a, T> {
+/// fn borrow_vec<T>(vec: &Vec<T>) -> Slice<T> {
 ///     let ptr = vec.as_ptr();
 ///     Slice {
 ///         start: ptr,

src/libcore/ops/index.rs

@@ -105,7 +105,7 @@ pub trait Index<Idx: ?Sized> {
 /// impl Index<Side> for Balance {
 ///     type Output = Weight;
 ///
-///     fn index<'a>(&'a self, index: Side) -> &'a Self::Output {
+///     fn index(&self, index: Side) -> &Self::Output {
 ///         println!("Accessing {:?}-side of balance immutably", index);
 ///         match index {
 ///             Side::Left => &self.left,
@@ -115,7 +115,7 @@ pub trait Index<Idx: ?Sized> {
 /// }
 ///
 /// impl IndexMut<Side> for Balance {
-///     fn index_mut<'a>(&'a mut self, index: Side) -> &'a mut Self::Output {
+///     fn index_mut(&mut self, index: Side) -> &mut Self::Output {
 ///         println!("Accessing {:?}-side of balance mutably", index);
 ///         match index {
 ///             Side::Left => &mut self.left,

src/libproc_macro/bridge/scoped_cell.rs

@@ -74,7 +74,7 @@ impl<T: LambdaL> ScopedCell<T> {
     }
 
     /// Sets the value in `self` to `value` while running `f`.
-    pub fn set<'a, R>(&self, value: <T as ApplyL<'a>>::Out, f: impl FnOnce() -> R) -> R {
+    pub fn set<R>(&self, value: <T as ApplyL<'_>>::Out, f: impl FnOnce() -> R) -> R {
         self.replace(value, |_| f())
     }
 }

src/libstd/sync/mpsc/sync.rs

@@ -140,7 +140,7 @@ fn wait_timeout_receiver<'a, 'b, T>(lock: &'a Mutex<State<T>>,
     new_guard
 }
 
-fn abort_selection<'a, T>(guard: &mut MutexGuard<'a , State<T>>) -> bool {
+fn abort_selection<T>(guard: &mut MutexGuard<'_, State<T>>) -> bool {
     match mem::replace(&mut guard.blocker, NoneBlocked) {
         NoneBlocked => true,
         BlockedSender(token) => {

src/libstd/sys/redox/ext/net.rs

@@ -673,7 +673,7 @@ impl UnixListener {
     /// }
     /// ```
     #[stable(feature = "unix_socket_redox", since = "1.29.0")]
-    pub fn incoming<'a>(&'a self) -> Incoming<'a> {
+    pub fn incoming(&self) -> Incoming {
         Incoming { listener: self }
     }
 }

src/libstd/sys/unix/ext/net.rs

@@ -894,7 +894,7 @@ impl UnixListener {
     /// }
     /// ```
     #[stable(feature = "unix_socket", since = "1.10.0")]
-    pub fn incoming<'a>(&'a self) -> Incoming<'a> {
+    pub fn incoming(&self) -> Incoming<'_> {
         Incoming { listener: self }
     }
 }

src/libstd/sys/windows/mod.rs

@@ -195,7 +195,7 @@ fn wide_char_to_multi_byte(code_page: u32,
     }
 }
 
-pub fn truncate_utf16_at_nul<'a>(v: &'a [u16]) -> &'a [u16] {
+pub fn truncate_utf16_at_nul(v: &[u16]) -> &[u16] {
     match v.iter().position(|c| *c == 0) {
         // don't include the 0
         Some(i) => &v[..i],

src/libstd/sys/windows/path.rs

@@ -19,7 +19,7 @@ pub fn is_verbatim_sep(b: u8) -> bool {
     b == b'\\'
 }
 
-pub fn parse_prefix<'a>(path: &'a OsStr) -> Option<Prefix<'a>> {
+pub fn parse_prefix(path: &OsStr) -> Option<Prefix> {
     use crate::path::Prefix::*;
     unsafe {
         // The unsafety here stems from converting between &OsStr and &[u8]

src/libstd/sys_common/io.rs

@@ -16,7 +16,7 @@ pub mod test {
             p.join(path)
         }
 
-        pub fn path<'a>(&'a self) -> &'a Path {
+        pub fn path(&self) -> &Path {
             let TempDir(ref p) = *self;
             p
         }

src/libsyntax/attr/mod.rs

@@ -440,12 +440,12 @@ pub fn contains_name(attrs: &[Attribute], name: Symbol) -> bool {
     })
 }
 
-pub fn find_by_name<'a>(attrs: &'a [Attribute], name: Symbol) -> Option<&'a Attribute> {
+pub fn find_by_name(attrs: &[Attribute], name: Symbol) -> Option<&Attribute> {
     attrs.iter().find(|attr| attr.check_name(name))
 }
 
-pub fn filter_by_name<'a>(attrs: &'a [Attribute], name: Symbol)
-    -> impl Iterator<Item = &'a Attribute> {
+pub fn filter_by_name(attrs: &[Attribute], name: Symbol)
+                      -> impl Iterator<Item=&Attribute> {
     attrs.iter().filter(move |attr| attr.check_name(name))
 }
 

src/libsyntax/ext/tt/macro_parser.rs

@@ -901,7 +901,7 @@ fn may_begin_with(token: &Token, name: Name) -> bool {
 /// # Returns
 ///
 /// The parsed non-terminal.
-fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: Symbol) -> Nonterminal {
+fn parse_nt(p: &mut Parser<'_>, sp: Span, name: Symbol) -> Nonterminal {
     if name == sym::tt {
         return token::NtTT(p.parse_token_tree());
     }

src/libsyntax/util/parser_testing.rs

@@ -20,7 +20,7 @@ pub fn string_to_stream(source_str: String) -> TokenStream {
 }
 
 /// Map string to parser (via tts)
-pub fn string_to_parser<'a>(ps: &'a ParseSess, source_str: String) -> Parser<'a> {
+pub fn string_to_parser(ps: &ParseSess, source_str: String) -> Parser {
     new_parser_from_source_str(ps, PathBuf::from("bogofile").into(), source_str)
 }