Auto merge of #37896 - GuillaumeGomez:rollup, r=GuillaumeGomez

Rollup of 8 pull requests

- Successful merges: #37835, #37840, #37841, #37848, #37876, #37880, #37881, #37882
- Failed merges:

src/doc/book/lifetimes.md

@@ -352,7 +352,7 @@ to it.
 Rust supports powerful local type inference in the bodies of functions but not in their item signatures. 
 It's forbidden to allow reasoning about types based on the item signature alone. 
 However, for ergonomic reasons, a very restricted secondary inference algorithm called 
-“lifetime elision” does apply when judging lifetimes. Lifetime elision is concerned solely to infer 
+“lifetime elision” does apply when judging lifetimes. Lifetime elision is concerned solely with inferring 
 lifetime parameters using three easily memorizable and unambiguous rules. This means lifetime elision 
 acts as a shorthand for writing an item signature, while not hiding
 away the actual types involved as full local inference would if applied to it.

src/doc/reference.md

@@ -2474,18 +2474,19 @@ The currently implemented features of the reference compiler are:
                               internally without imposing on callers
                               (i.e. making them behave like function calls in
                               terms of encapsulation).
-* - `default_type_parameter_fallback` - Allows type parameter defaults to
-                                        influence type inference.
 
-* - `stmt_expr_attributes` - Allows attributes on expressions.
+* `default_type_parameter_fallback` - Allows type parameter defaults to
+                                      influence type inference.
 
-* - `type_ascription` - Allows type ascription expressions `expr: Type`.
+* `stmt_expr_attributes` - Allows attributes on expressions.
 
-* - `abi_vectorcall` - Allows the usage of the vectorcall calling convention
-                             (e.g. `extern "vectorcall" func fn_();`)
+* `type_ascription` - Allows type ascription expressions `expr: Type`.
 
-* - `abi_sysv64` - Allows the usage of the system V AMD64 calling convention
-                             (e.g. `extern "sysv64" func fn_();`)
+* `abi_vectorcall` - Allows the usage of the vectorcall calling convention
+                     (e.g. `extern "vectorcall" func fn_();`)
+
+* `abi_sysv64` - Allows the usage of the system V AMD64 calling convention
+                 (e.g. `extern "sysv64" func fn_();`)
 
 If a feature is promoted to a language feature, then all existing programs will
 start to receive compilation warnings about `#![feature]` directives which enabled

src/libcollectionstest/str.rs

@@ -814,6 +814,14 @@ fn test_iterator_clone() {
     assert!(it.clone().zip(it).all(|(x,y)| x == y));
 }
 
+#[test]
+fn test_iterator_last() {
+    let s = "ศไทย中华Việt Nam";
+    let mut it = s.chars();
+    it.next();
+    assert_eq!(it.last(), Some('m'));
+}
+
 #[test]
 fn test_bytesator() {
     let s = "ศไทย中华Việt Nam";
@@ -911,6 +919,14 @@ fn test_char_indices_revator() {
     assert_eq!(pos, p.len());
 }
 
+#[test]
+fn test_char_indices_last() {
+    let s = "ศไทย中华Việt Nam";
+    let mut it = s.char_indices();
+    it.next();
+    assert_eq!(it.last(), Some((27, 'm')));
+}
+
 #[test]
 fn test_splitn_char_iterator() {
     let data = "\nMäry häd ä little lämb\nLittle lämb\n";

src/libcore/str/mod.rs

@@ -432,6 +432,12 @@ impl<'a> Iterator for Chars<'a> {
         // `isize::MAX` (that's well below `usize::MAX`).
         ((len + 3) / 4, Some(len))
     }
+
+    #[inline]
+    fn last(mut self) -> Option<char> {
+        // No need to go through the entire string.
+        self.next_back()
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -505,6 +511,12 @@ impl<'a> Iterator for CharIndices<'a> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
+
+    #[inline]
+    fn last(mut self) -> Option<(usize, char)> {
+        // No need to go through the entire string.
+        self.next_back()
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]

src/librustc_data_structures/unify/mod.rs

@@ -344,7 +344,7 @@ impl<'tcx, K, V> UnificationTable<K>
     }
 
     pub fn probe(&mut self, a_id: K) -> Option<V> {
-        self.get(a_id).value.clone()
+        self.get(a_id).value
     }
 
     pub fn unsolved_variables(&mut self) -> Vec<K> {

src/librustc_typeck/check/mod.rs

@@ -4436,19 +4436,20 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         let lifetime_defs = segment.map_or(&[][..], |(_, generics)| &generics.regions);
         if lifetimes.len() > lifetime_defs.len() {
             let span = lifetimes[lifetime_defs.len()].span;
-            span_err!(self.tcx.sess, span, E0088,
-                      "too many lifetime parameters provided: \
-                       expected {}, found {}",
-                      count(lifetime_defs.len()),
-                      count(lifetimes.len()));
-        } else if lifetimes.len() > 0 && lifetimes.len() < lifetime_defs.len() {
-            span_err!(self.tcx.sess, span, E0090,
-                      "too few lifetime parameters provided: \
-                       expected {}, found {}",
-                      count(lifetime_defs.len()),
-                      count(lifetimes.len()));
+            struct_span_err!(self.tcx.sess, span, E0088,
+                             "too many lifetime parameters provided: \
+                              expected {}, found {}",
+                              count(lifetime_defs.len()),
+                              count(lifetimes.len()))
+                .span_label(span, &format!("unexpected lifetime parameter{}",
+                                           match lifetimes.len() { 1 => "", _ => "s" }))
+                .emit();
         }
 
+        // The case where there is not enough lifetime parameters is not checked,
+        // because this is not possible - a function never takes lifetime parameters.
+        // See discussion for Pull Request 36208.
+
         // Check provided type parameters.
         let type_defs = segment.map_or(&[][..], |(_, generics)| {
             if generics.parent.is_none() {

src/librustdoc/html/render.rs

@@ -2437,7 +2437,6 @@ fn item_enum(w: &mut fmt::Formatter, cx: &Context, it: &clean::Item,
         write!(w, "}}")?;
     }
     write!(w, "</pre>")?;
-    render_stability_since_raw(w, it.stable_since(), None)?;
 
     document(w, cx, it)?;
     if !e.variants.is_empty() {
@@ -3053,7 +3052,6 @@ fn item_macro(w: &mut fmt::Formatter, cx: &Context, it: &clean::Item,
                                                      Some("macro"),
                                                      None,
                                                      None))?;
-    render_stability_since_raw(w, it.stable_since(), None)?;
     document(w, cx, it)
 }
 

src/libstd/net/addr.rs

@@ -31,7 +31,7 @@ pub enum SocketAddr {
     /// An IPv4 socket address which is a (ip, port) combination.
     #[stable(feature = "rust1", since = "1.0.0")]
     V4(#[stable(feature = "rust1", since = "1.0.0")] SocketAddrV4),
-    /// An IPv6 socket address
+    /// An IPv6 socket address.
     #[stable(feature = "rust1", since = "1.0.0")]
     V6(#[stable(feature = "rust1", since = "1.0.0")] SocketAddrV6),
 }
@@ -48,6 +48,16 @@ pub struct SocketAddrV6 { inner: c::sockaddr_in6 }
 
 impl SocketAddr {
     /// Creates a new socket address from the (ip, port) pair.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+    ///
+    /// let socket = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080);
+    /// assert_eq!(socket.ip(), IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)));
+    /// assert_eq!(socket.port(), 8080);
+    /// ```
     #[stable(feature = "ip_addr", since = "1.7.0")]
     pub fn new(ip: IpAddr, port: u16) -> SocketAddr {
         match ip {
@@ -57,6 +67,15 @@ impl SocketAddr {
     }
 
     /// Returns the IP address associated with this socket address.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+    ///
+    /// let socket = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080);
+    /// assert_eq!(socket.ip(), IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)));
+    /// ```
     #[stable(feature = "ip_addr", since = "1.7.0")]
     pub fn ip(&self) -> IpAddr {
         match *self {
@@ -66,6 +85,16 @@ impl SocketAddr {
     }
 
     /// Change the IP address associated with this socket address.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+    ///
+    /// let mut socket = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080);
+    /// socket.set_ip(IpAddr::V4(Ipv4Addr::new(10, 10, 0, 1)));
+    /// assert_eq!(socket.ip(), IpAddr::V4(Ipv4Addr::new(10, 10, 0, 1)));
+    /// ```
     #[stable(feature = "sockaddr_setters", since = "1.9.0")]
     pub fn set_ip(&mut self, new_ip: IpAddr) {
         // `match (*self, new_ip)` would have us mutate a copy of self only to throw it away.
@@ -77,6 +106,15 @@ impl SocketAddr {
     }
 
     /// Returns the port number associated with this socket address.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+    ///
+    /// let socket = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080);
+    /// assert_eq!(socket.port(), 8080);
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn port(&self) -> u16 {
         match *self {
@@ -86,6 +124,16 @@ impl SocketAddr {
     }
 
     /// Change the port number associated with this socket address.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+    ///
+    /// let mut socket = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080);
+    /// socket.set_port(1025);
+    /// assert_eq!(socket.port(), 1025);
+    /// ```
     #[stable(feature = "sockaddr_setters", since = "1.9.0")]
     pub fn set_port(&mut self, new_port: u16) {
         match *self {
@@ -96,6 +144,20 @@ impl SocketAddr {
 
     /// Returns true if the IP in this `SocketAddr` is a valid IPv4 address,
     /// false if it's a valid IPv6 address.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(sockaddr_checker)]
+    ///
+    /// use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+    ///
+    /// fn main() {
+    ///     let socket = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080);
+    ///     assert_eq!(socket.is_ipv4(), true);
+    ///     assert_eq!(socket.is_ipv6(), false);
+    /// }
+    /// ```
     #[unstable(feature = "sockaddr_checker", issue = "36949")]
     pub fn is_ipv4(&self) -> bool {
         match *self {
@@ -106,6 +168,21 @@ impl SocketAddr {
 
     /// Returns true if the IP in this `SocketAddr` is a valid IPv6 address,
     /// false if it's a valid IPv4 address.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(sockaddr_checker)]
+    ///
+    /// use std::net::{IpAddr, Ipv6Addr, SocketAddr};
+    ///
+    /// fn main() {
+    ///     let socket = SocketAddr::new(
+    ///                      IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 65535, 0, 1)), 8080);
+    ///     assert_eq!(socket.is_ipv4(), false);
+    ///     assert_eq!(socket.is_ipv6(), true);
+    /// }
+    /// ```
     #[unstable(feature = "sockaddr_checker", issue = "36949")]
     pub fn is_ipv6(&self) -> bool {
         match *self {

src/test/compile-fail/E0088.rs

@@ -9,7 +9,12 @@
 // except according to those terms.
 
 fn f() {}
+fn g<'a>() {}
 
 fn main() {
     f::<'static>(); //~ ERROR E0088
+    //~^ unexpected lifetime parameter
+
+    g::<'static, 'static>(); //~ ERROR E0088
+    //~^ unexpected lifetime parameters
 }