Rollup of 19 pull requests

src/doc/book/bibliography.md

@@ -80,3 +80,4 @@ Language](http://www.cs.indiana.edu/~eholk/papers/hips2013.pdf). Early GPU work
   Rust](http://munksgaard.me/papers/laumann-munksgaard-larsen.pdf). Philip
   Munksgaard's master's thesis. Research for Servo.
 * [Ownership is Theft: Experiences Building an Embedded OS in Rust - Amit Levy, et. al.](http://amitlevy.com/papers/tock-plos2015.pdf)
+* [You can't spell trust without Rust](https://raw.githubusercontent.com/Gankro/thesis/master/thesis.pdf). Alexis Beingessner's master's thesis.

src/doc/book/error-handling.md

@@ -351,11 +351,28 @@ fn file_name(file_path: &str) -> Option<&str> {
 ```
 
 You might think that we could use the `map` combinator to reduce the case
-analysis, but its type doesn't quite fit. Namely, `map` takes a function that
-does something only with the inner value. The result of that function is then
-*always* [rewrapped with `Some`](#code-option-map). Instead, we need something
-like `map`, but which allows the caller to return another `Option`. Its generic
-implementation is even simpler than `map`:
+analysis, but its type doesn't quite fit...
+
+```rust
+fn file_path_ext(file_path: &str) -> Option<&str> {
+    file_name(file_path).map(|x| extension(x)) //Compilation error
+}
+```
+
+The `map` function here wraps the value returned by the `extension` function
+inside an `Option<_>` and since the `extension` function itself returns an
+`Option<&str>` the expression `file_name(file_path).map(|x| extension(x))`
+actually returns an `Option<Option<&str>>`.
+
+But since `file_path_ext` just returns `Option<&str>` (and not
+`Option<Option<&str>>`) we get a compilation error.
+
+The result of the function taken by map as input is *always* [rewrapped with
+`Some`](#code-option-map). Instead, we need something like `map`, but which
+allows the caller to return a `Option<_>` directly without wrapping it in
+another `Option<_>`.
+
+Its generic implementation is even simpler than `map`:
 
 ```rust
 fn and_then<F, T, A>(option: Option<T>, f: F) -> Option<A>
@@ -377,6 +394,10 @@ fn file_path_ext(file_path: &str) -> Option<&str> {
 }
 ```
 
+Side note: Since `and_then` essentially works like `map` but returns an
+`Option<_>` instead of an `Option<Option<_>>` it is known as `flatmap` in some
+other languages.
+
 The `Option` type has many other combinators [defined in the standard
 library][5]. It is a good idea to skim this list and familiarize
 yourself with what's available—they can often reduce case analysis

src/doc/book/getting-started.md

@@ -111,7 +111,7 @@ If we're on Linux or a Mac, all we need to do is open a terminal and type this:
 $ curl -sSf https://static.rust-lang.org/rustup.sh | sh
 ```
 
-This will download a script, and stat the installation. If it all goes well,
+This will download a script, and start the installation. If it all goes well,
 you’ll see this appear:
 
 ```text

src/doc/book/guessing-game.md

@@ -908,6 +908,7 @@ let guess: u32 = match guess.trim().parse() {
 ```
 
 This is how you generally move from ‘crash on error’ to ‘actually handle the
+error’, by switching from `expect()` to a `match` statement. The `Result`
 returned by `parse()` is an `enum`  like `Ordering`, but in this case, each
 variant has some data associated with it: `Ok` is a success, and `Err` is a
 failure. Each contains more information: the successfully parsed integer, or an

src/doc/book/no-stdlib.md

@@ -77,10 +77,11 @@ The compiler currently makes a few assumptions about symbols which are available
 in the executable to call. Normally these functions are provided by the standard
 library, but without it you must define your own.
 
-The first of these two functions, `eh_personality`, is used by the
-failure mechanisms of the compiler. This is often mapped to GCC's
-personality function (see the
-[libstd implementation](../std/rt/unwind/index.html) for more
-information), but crates which do not trigger a panic can be assured
-that this function is never called. The second function, `panic_fmt`, is
-also used by the failure mechanisms of the compiler.
+The first of these two functions, `eh_personality`, is used by the failure
+mechanisms of the compiler. This is often mapped to GCC's personality function
+(see the [libstd implementation][unwind] for more information), but crates
+which do not trigger a panic can be assured that this function is never
+called. The second function, `panic_fmt`, is also used by the failure
+mechanisms of the compiler.
+
+[unwind]: https://github.com/rust-lang/rust/blob/master/src/libstd/sys/common/unwind/gcc.rs

src/doc/book/traits.md

@@ -277,16 +277,22 @@ This will compile without error.
 This means that even if someone does something bad like add methods to `i32`,
 it won’t affect you, unless you `use` that trait.
 
-There’s one more restriction on implementing traits: either the trait, or the
-type you’re writing the `impl` for, must be defined by you. So, we could
-implement the `HasArea` type for `i32`, because `HasArea` is in our code. But
-if we tried to implement `ToString`, a trait provided by Rust, for `i32`, we could
-not, because neither the trait nor the type are in our code.
+There’s one more restriction on implementing traits: either the trait
+or the type you’re implementing it for must be defined by you. Or more
+precisely, one of them must be defined in the same crate as the `impl`
+you're writing. For more on Rust's module and package system, see the
+chapter on [crates and modules][cm].
+
+So, we could implement the `HasArea` type for `i32`, because we defined
+`HasArea` in our code. But if we tried to implement `ToString`, a trait
+provided by Rust, for `i32`, we could not, because neither the trait nor
+the type are defined in our crate.
 
 One last thing about traits: generic functions with a trait bound use
 ‘monomorphization’ (mono: one, morph: form), so they are statically dispatched.
 What’s that mean? Check out the chapter on [trait objects][to] for more details.
 
+[cm]: crates-and-modules.html
 [to]: trait-objects.html
 
 # Multiple trait bounds

src/doc/version_info.html.template

@@ -1,5 +1,5 @@
 <div id="versioninfo">
-  <img src="https://www.rust-lang.org/logos/rust-logo-32x32-blk.png" width="32" height="32" alt><br>
+  <img src="https://www.rust-lang.org/logos/rust-logo-32x32-blk.png" width="32" height="32" alt="Rust logo"><br>
   <span class="white-sticker"><a href="https://www.rust-lang.org">Rust</a> VERSION</span><br>
   <a href="https://github.com/rust-lang/rust/commit/STAMP"
     class="hash white-sticker">SHORT_HASH</a>

src/libcollections/btree/map.rs

@@ -1194,17 +1194,17 @@ unsafe fn unwrap_unchecked<T>(val: Option<T>) -> T {
 }
 
 impl<K, V> BTreeMap<K, V> {
-    /// Gets an iterator over the entries of the map.
+    /// Gets an iterator over the entries of the map, sorted by key.
     ///
     /// # Examples
     ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
     /// let mut map = BTreeMap::new();
-    /// map.insert(1, "a");
-    /// map.insert(2, "b");
     /// map.insert(3, "c");
+    /// map.insert(2, "b");
+    /// map.insert(1, "a");
     ///
     /// for (key, value) in map.iter() {
     ///     println!("{}: {}", key, value);
@@ -1224,7 +1224,7 @@ impl<K, V> BTreeMap<K, V> {
         }
     }
 
-    /// Gets a mutable iterator over the entries of the map.
+    /// Gets a mutable iterator over the entries of the map, sorted by key.
     ///
     /// # Examples
     ///
@@ -1257,16 +1257,16 @@ impl<K, V> BTreeMap<K, V> {
         }
     }
 
-    /// Gets an iterator over the keys of the map.
+    /// Gets an iterator over the keys of the map, in sorted order.
     ///
     /// # Examples
     ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
     /// let mut a = BTreeMap::new();
-    /// a.insert(1, "a");
     /// a.insert(2, "b");
+    /// a.insert(1, "a");
     ///
     /// let keys: Vec<_> = a.keys().cloned().collect();
     /// assert_eq!(keys, [1, 2]);
@@ -1276,19 +1276,19 @@ impl<K, V> BTreeMap<K, V> {
         Keys { inner: self.iter() }
     }
 
-    /// Gets an iterator over the values of the map.
+    /// Gets an iterator over the values of the map, in order by key.
     ///
     /// # Examples
     ///
     /// ```
     /// use std::collections::BTreeMap;
     ///
     /// let mut a = BTreeMap::new();
-    /// a.insert(1, "a");
-    /// a.insert(2, "b");
+    /// a.insert(1, "hello");
+    /// a.insert(2, "goodbye");
     ///
     /// let values: Vec<&str> = a.values().cloned().collect();
-    /// assert_eq!(values, ["a", "b"]);
+    /// assert_eq!(values, ["hello", "goodbye"]);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn values<'a>(&'a self) -> Values<'a, K, V> {

src/librustc_borrowck/diagnostics.rs

@@ -124,7 +124,7 @@ fn main() {
     let mut x = Rc::new(RefCell::new(MyStruct{ s: 5u32 }));
     let y = x.clone();
     x.borrow_mut().s = 6;
-    println!("{}", x.borrow.s);
+    println!("{}", x.borrow().s);
 }
 ```
 

src/librustc_resolve/diagnostics.rs

@@ -207,7 +207,41 @@ https://doc.rust-lang.org/reference.html#statements
 E0317: r##"
 User-defined types or type parameters cannot shadow the primitive types.
 This error indicates you tried to define a type, struct or enum with the same
-name as an existing primitive type.
+name as an existing primitive type:
+
+```
+struct u8 {
+    // ...
+}
+```
+
+To fix this, simply name it something else.
+
+Such an error may also occur if you define a type parameter which shadows a
+primitive type. An example would be something like:
+
+```
+impl<u8> MyTrait for Option<u8> {
+    // ...
+}
+```
+
+In such a case, if you meant for `u8` to be a generic type parameter (i.e. any
+type can be used in its place), use something like `T` instead:
+
+```
+impl<T> MyTrait for Option<T> {
+    // ...
+}
+```
+
+On the other hand, if you wished to refer to the specific type `u8`, remove it
+from the type parameter list:
+
+```
+impl MyTrait for Option<u8> {
+    // ...
+}
 
 See the Types section of the reference for more information about the primitive
 types:

src/librustc_typeck/collect.rs

@@ -1918,8 +1918,8 @@ fn get_or_create_type_parameter_def<'a,'tcx>(ccx: &CrateCtxt<'a,'tcx>,
                 lint::builtin::INVALID_TYPE_PARAM_DEFAULT,
                 param.id,
                 param.span,
-                format!("defaults for type parameters are only allowed on type definitions, \
-                         like `struct` or `enum`"));
+                format!("defaults for type parameters are only allowed in `struct`, \
+                         `enum`, `type`, or `trait` definitions."));
         }
     }
 

src/librustc_typeck/diagnostics.rs

@@ -2269,6 +2269,8 @@ struct MyType<T>(T);
 impl<T> ForeignTrait for MyType<T> { ... } // Ok
 ```
 
+Please note that a type alias is not sufficient.
+
 For another example of an error, suppose there's another trait defined in `foo`
 named `ForeignTrait2` that takes two type parameters. Then this `impl` results
 in the same rule violation:

src/librustdoc/html/layout.rs

@@ -148,7 +148,7 @@ r##"<!DOCTYPE html>
         "".to_string()
     } else {
         format!("<a href='{}{}/index.html'>\
-                 <img src='{}' alt='' width='100'></a>",
+                 <img src='{}' alt='logo' width='100'></a>",
                 page.root_path, layout.krate,
                 layout.logo)
     },

src/librustdoc/html/static/rustdoc.css

@@ -383,7 +383,7 @@ a {
 }
 
 .content span.enum, .content a.enum, .block a.current.enum { color: #5e9766; }
-.content span.struct, .content a.struct, .block a.current.struct { color: #e53700; }
+.content span.struct, .content a.struct, .block a.current.struct { color: #df3600; }
 .content a.type { color: #e57300; }
 .content a.macro { color: #068000; }
 .block a.current.crate { font-weight: 500; }

src/librustdoc/html/static/styles/main.css

@@ -106,14 +106,14 @@ a {
 }
 
 .docblock a, .stability a {
-    color: #4e8bca;
+    color: #3873AD;
 }
 
 a.test-arrow {
     color: #f5f5f5;
 }
 
-.content span.trait, .content a.trait, .block a.current.trait { color: #8866ff; }
+.content span.trait, .content a.trait, .block a.current.trait { color: #7c5af3; }
 
 .search-input {
     color: #555;

src/libstd/collections/hash/map.rs

@@ -272,6 +272,35 @@ fn test_resize_policy() {
 /// }
 /// ```
 ///
+/// `HashMap` also implements an [`Entry API`](#method.entry), which allows
+/// for more complex methods of getting, setting, updating and removing keys and
+/// their values:
+///
+/// ```
+/// use std::collections::HashMap;
+///
+/// // type inference lets us omit an explicit type signature (which
+/// // would be `HashMap<&str, u8>` in this example).
+/// let mut player_stats = HashMap::new();
+///
+/// fn random_stat_buff() -> u8 {
+///   // could actually return some random value here - let's just return
+///   // some fixed value for now
+///   42
+/// }
+///
+/// // insert a key only if it doesn't already exist
+/// player_stats.entry("health").or_insert(100);
+///
+/// // insert a key using a function that provides a new value only if it
+/// // doesn't already exist
+/// player_stats.entry("defence").or_insert_with(random_stat_buff);
+///
+/// // update a key, guarding against the key possibly not being set
+/// let stat = player_stats.entry("attack").or_insert(100);
+/// *stat += random_stat_buff();
+/// ```
+///
 /// The easiest way to use `HashMap` with a custom type as key is to derive `Eq` and `Hash`.
 /// We must also derive `PartialEq`.
 ///

src/libstd/ffi/c_str.rs

@@ -407,16 +407,14 @@ impl CStr {
     /// # fn main() {
     /// use std::ffi::CStr;
     /// use std::os::raw::c_char;
-    /// use std::str;
     ///
     /// extern {
     ///     fn my_string() -> *const c_char;
     /// }
     ///
     /// unsafe {
     ///     let slice = CStr::from_ptr(my_string());
-    ///     println!("string returned: {}",
-    ///              str::from_utf8(slice.to_bytes()).unwrap());
+    ///     println!("string returned: {}", slice.to_str().unwrap());
     /// }
     /// # }
     /// ```

src/libstd/fs.rs

@@ -414,7 +414,7 @@ impl OpenOptions {
     /// This option, when true, will indicate that the file should be
     /// `write`-able if opened.
     ///
-    /// If a file already exist, any write calls on the file will overwrite its
+    /// If the file already exists, any write calls on it will overwrite its
     /// contents, without truncating it.
     ///
     /// # Examples
@@ -487,8 +487,8 @@ impl OpenOptions {
     /// This option indicates whether a new file will be created if the file
     /// does not yet already exist.
     ///
-    /// The file must be opened with write or append access in order to create
-    /// a new file.
+    /// In order for the file to be created, `write` or `append` access must
+    /// be used.
     ///
     /// # Examples
     ///

src/libstd/sync/semaphore.rs

@@ -13,7 +13,7 @@
                       of resources is currently unclear",
             issue = "27798")]
 #![rustc_deprecated(since = "1.7.0",
-                    reason = "easily confused with system sempahores and not \
+                    reason = "easily confused with system semaphores and not \
                               used enough to pull its weight")]
 #![allow(deprecated)]