Auto merge of #34778 - GuillaumeGomez:rollup, r=GuillaumeGomez

Rollup of 7 pull requests

- Successful merges: #34736, #34737, #34740, #34742, #34749, #34750, #34770
- Failed merges: #33951

7 files changed, 357 insertions, 19 deletions

diff --git a/src/doc/book/closures.md b/src/doc/book/closures.md
index e8c88b7db06..666d0946ecc 100644
--- a/src/doc/book/closures.md
+++ b/src/doc/book/closures.md
@@ -336,7 +336,7 @@ could annotate it on the function declaration:
 
 ```rust,ignore
 fn call_with_ref<'a, F>(some_closure:F) -> i32
-    where F: Fn(&'a 32) -> i32 {
+    where F: Fn(&'a i32) -> i32 {
 ```
 
 However this presents a problem with in our case. When you specify the explicit
@@ -350,7 +350,7 @@ of the closure we can use Higher-Ranked Trait Bounds with the `for<...>` syntax:
 
 ```ignore
 fn call_with_ref<F>(some_closure:F) -> i32
-    where F: for<'a> Fn(&'a 32) -> i32 {
+    where F: for<'a> Fn(&'a i32) -> i32 {
 ```
 
 This lets the Rust compiler find the minimum lifetime to invoke our closure and
diff --git a/src/doc/reference.md b/src/doc/reference.md
index 59dbffd6e28..b3073f5e526 100644
--- a/src/doc/reference.md
+++ b/src/doc/reference.md
@@ -2633,7 +2633,7 @@ comma:
 
 There are several forms of struct expressions. A _struct expression_
 consists of the [path](#paths) of a [struct item](#structs), followed by
-a brace-enclosed list of one or more comma-separated name-value pairs,
+a brace-enclosed list of zero or more comma-separated name-value pairs,
 providing the field values of a new instance of the struct. A field name
 can be any identifier, and is separated from its value expression by a colon.
 The location denoted by a struct field is mutable if and only if the
@@ -2652,10 +2652,12 @@ The following are examples of struct expressions:
 
 ```
 # struct Point { x: f64, y: f64 }
+# struct NothingInMe { }
 # struct TuplePoint(f64, f64);
 # mod game { pub struct User<'a> { pub name: &'a str, pub age: u32, pub score: usize } }
 # struct Cookie; fn some_fn<T>(t: T) {}
 Point {x: 10.0, y: 20.0};
+NothingInMe {};
 TuplePoint(10.0, 20.0);
 let u = game::User {name: "Joe", age: 35, score: 100_000};
 some_fn::<Cookie>(Cookie);
diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index 51523ca8dc6..7ba5ca30941 100644
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -249,6 +249,14 @@ impl<T: ?Sized> Box<T> {
     /// This function is unsafe because improper use may lead to
     /// memory problems. For example, a double-free may occur if the
     /// function is called twice on the same raw pointer.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let x = Box::new(5);
+    /// let ptr = Box::into_raw(x);
+    /// let x = unsafe { Box::from_raw(ptr) };
+    /// ```
     #[stable(feature = "box_raw", since = "1.4.0")]
     #[inline]
     pub unsafe fn from_raw(raw: *mut T) -> Self {
@@ -266,9 +274,8 @@ impl<T: ?Sized> Box<T> {
     /// # Examples
     ///
     /// ```
-    /// let seventeen = Box::new(17);
-    /// let raw = Box::into_raw(seventeen);
-    /// let boxed_again = unsafe { Box::from_raw(raw) };
+    /// let x = Box::new(5);
+    /// let ptr = Box::into_raw(x);
     /// ```
     #[stable(feature = "box_raw", since = "1.4.0")]
     #[inline]
@@ -399,6 +406,24 @@ impl Box<Any> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     /// Attempt to downcast the box to a concrete type.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::any::Any;
+    ///
+    /// fn print_if_string(value: Box<Any>) {
+    ///     if let Ok(string) = value.downcast::<String>() {
+    ///         println!("String ({}): {}", string.len(), string);
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     let my_string = "Hello World".to_string();
+    ///     print_if_string(Box::new(my_string));
+    ///     print_if_string(Box::new(0i8));
+    /// }
+    /// ```
     pub fn downcast<T: Any>(self) -> Result<Box<T>, Box<Any>> {
         if self.is::<T>() {
             unsafe {
@@ -419,6 +444,24 @@ impl Box<Any + Send> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     /// Attempt to downcast the box to a concrete type.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::any::Any;
+    ///
+    /// fn print_if_string(value: Box<Any + Send>) {
+    ///     if let Ok(string) = value.downcast::<String>() {
+    ///         println!("String ({}): {}", string.len(), string);
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     let my_string = "Hello World".to_string();
+    ///     print_if_string(Box::new(my_string));
+    ///     print_if_string(Box::new(0i8));
+    /// }
+    /// ```
     pub fn downcast<T: Any>(self) -> Result<Box<T>, Box<Any + Send>> {
         <Box<Any>>::downcast(self).map_err(|s| unsafe {
             // reapply the Send marker
diff --git a/src/libcore/any.rs b/src/libcore/any.rs
index 49304b1f3bf..a452be2565b 100644
--- a/src/libcore/any.rs
+++ b/src/libcore/any.rs
@@ -92,6 +92,23 @@ use marker::{Reflect, Sized};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Any: Reflect + 'static {
     /// Gets the `TypeId` of `self`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(get_type_id)]
+    ///
+    /// use std::any::{Any, TypeId};
+    ///
+    /// fn is_string(s: &Any) -> bool {
+    ///     TypeId::of::<String>() == s.get_type_id()
+    /// }
+    ///
+    /// fn main() {
+    ///     assert_eq!(is_string(&0), false);
+    ///     assert_eq!(is_string(&"cookie monster".to_owned()), true);
+    /// }
+    /// ```
     #[unstable(feature = "get_type_id",
                reason = "this method will likely be replaced by an associated static",
                issue = "27745")]
@@ -125,7 +142,26 @@ impl fmt::Debug for Any + Send {
 }
 
 impl Any {
-    /// Returns true if the boxed type is the same as `T`
+    /// Returns true if the boxed type is the same as `T`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::any::Any;
+    ///
+    /// fn is_string(s: &Any) {
+    ///     if s.is::<String>() {
+    ///         println!("It's a string!");
+    ///     } else {
+    ///         println!("Not a string...");
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     is_string(&0);
+    ///     is_string(&"cookie monster".to_owned());
+    /// }
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn is<T: Any>(&self) -> bool {
@@ -141,6 +177,25 @@ impl Any {
 
     /// Returns some reference to the boxed value if it is of type `T`, or
     /// `None` if it isn't.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::any::Any;
+    ///
+    /// fn print_if_string(s: &Any) {
+    ///     if let Some(string) = s.downcast_ref::<String>() {
+    ///         println!("It's a string({}): '{}'", string.len(), string);
+    ///     } else {
+    ///         println!("Not a string...");
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     print_if_string(&0);
+    ///     print_if_string(&"cookie monster".to_owned());
+    /// }
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn downcast_ref<T: Any>(&self) -> Option<&T> {
@@ -159,6 +214,29 @@ impl Any {
 
     /// Returns some mutable reference to the boxed value if it is of type `T`, or
     /// `None` if it isn't.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::any::Any;
+    ///
+    /// fn modify_if_u32(s: &mut Any) {
+    ///     if let Some(num) = s.downcast_mut::<u32>() {
+    ///         *num = 42;
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     let mut x = 10u32;
+    ///     let mut s = "starlord".to_owned();
+    ///
+    ///     modify_if_u32(&mut x);
+    ///     modify_if_u32(&mut s);
+    ///
+    ///     assert_eq!(x, 42);
+    ///     assert_eq!(&s, "starlord");
+    /// }
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn downcast_mut<T: Any>(&mut self) -> Option<&mut T> {
@@ -178,6 +256,25 @@ impl Any {
 
 impl Any+Send {
     /// Forwards to the method defined on the type `Any`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::any::Any;
+    ///
+    /// fn is_string(s: &(Any + Send)) {
+    ///     if s.is::<String>() {
+    ///         println!("It's a string!");
+    ///     } else {
+    ///         println!("Not a string...");
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     is_string(&0);
+    ///     is_string(&"cookie monster".to_owned());
+    /// }
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn is<T: Any>(&self) -> bool {
@@ -185,6 +282,25 @@ impl Any+Send {
     }
 
     /// Forwards to the method defined on the type `Any`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::any::Any;
+    ///
+    /// fn print_if_string(s: &(Any + Send)) {
+    ///     if let Some(string) = s.downcast_ref::<String>() {
+    ///         println!("It's a string({}): '{}'", string.len(), string);
+    ///     } else {
+    ///         println!("Not a string...");
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     print_if_string(&0);
+    ///     print_if_string(&"cookie monster".to_owned());
+    /// }
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn downcast_ref<T: Any>(&self) -> Option<&T> {
@@ -192,6 +308,29 @@ impl Any+Send {
     }
 
     /// Forwards to the method defined on the type `Any`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::any::Any;
+    ///
+    /// fn modify_if_u32(s: &mut (Any+ Send)) {
+    ///     if let Some(num) = s.downcast_mut::<u32>() {
+    ///         *num = 42;
+    ///     }
+    /// }
+    ///
+    /// fn main() {
+    ///     let mut x = 10u32;
+    ///     let mut s = "starlord".to_owned();
+    ///
+    ///     modify_if_u32(&mut x);
+    ///     modify_if_u32(&mut s);
+    ///
+    ///     assert_eq!(x, 42);
+    ///     assert_eq!(&s, "starlord");
+    /// }
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn downcast_mut<T: Any>(&mut self) -> Option<&mut T> {
@@ -220,7 +359,24 @@ pub struct TypeId {
 
 impl TypeId {
     /// Returns the `TypeId` of the type this generic function has been
-    /// instantiated with
+    /// instantiated with.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(get_type_id)]
+    ///
+    /// use std::any::{Any, TypeId};
+    ///
+    /// fn is_string(s: &Any) -> bool {
+    ///     TypeId::of::<String>() == s.get_type_id()
+    /// }
+    ///
+    /// fn main() {
+    ///     assert_eq!(is_string(&0), false);
+    ///     assert_eq!(is_string(&"cookie monster".to_owned()), true);
+    /// }
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn of<T: ?Sized + Reflect + 'static>() -> TypeId {
         TypeId {
diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index 9435be3b012..65cb1aaaff6 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -237,6 +237,17 @@ impl<T:Copy> Cell<T> {
     ///
     /// This call borrows `Cell` mutably (at compile-time) which guarantees
     /// that we possess the only reference.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::cell::Cell;
+    ///
+    /// let mut c = Cell::new(5);
+    /// *c.get_mut() += 1;
+    ///
+    /// assert_eq!(c.get(), 6);
+    /// ```
     #[inline]
     #[stable(feature = "cell_get_mut", since = "1.11.0")]
     pub fn get_mut(&mut self) -> &mut T {
@@ -388,6 +399,22 @@ impl<T: ?Sized> RefCell<T> {
     ///
     /// The returned value can be dispatched on to determine if a call to
     /// `borrow` or `borrow_mut` would succeed.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(borrow_state)]
+    ///
+    /// use std::cell::{BorrowState, RefCell};
+    ///
+    /// let c = RefCell::new(5);
+    ///
+    /// match c.borrow_state() {
+    ///     BorrowState::Writing => println!("Cannot be borrowed"),
+    ///     BorrowState::Reading => println!("Cannot be borrowed mutably"),
+    ///     BorrowState::Unused => println!("Can be borrowed (mutably as well)"),
+    /// }
+    /// ```
     #[unstable(feature = "borrow_state", issue = "27733")]
     #[inline]
     pub fn borrow_state(&self) -> BorrowState {
@@ -498,6 +525,17 @@ impl<T: ?Sized> RefCell<T> {
     /// This can be used to circumvent `RefCell`'s safety checks.
     ///
     /// This function is `unsafe` because `UnsafeCell`'s field is public.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(as_unsafe_cell)]
+    ///
+    /// use std::cell::RefCell;
+    ///
+    /// let c = RefCell::new(5);
+    /// let c = unsafe { c.as_unsafe_cell() };
+    /// ```
     #[inline]
     #[unstable(feature = "as_unsafe_cell", issue = "27708")]
     pub unsafe fn as_unsafe_cell(&self) -> &UnsafeCell<T> {
@@ -508,6 +546,17 @@ impl<T: ?Sized> RefCell<T> {
     ///
     /// This call borrows `RefCell` mutably (at compile-time) so there is no
     /// need for dynamic checks.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::cell::RefCell;
+    ///
+    /// let mut c = RefCell::new(5);
+    /// *c.get_mut() += 1;
+    ///
+    /// assert_eq!(c, RefCell::new(6));
+    /// ```
     #[inline]
     #[stable(feature = "cell_get_mut", since = "1.11.0")]
     pub fn get_mut(&mut self) -> &mut T {
diff --git a/src/libstd/error.rs b/src/libstd/error.rs
index 2a2d41112ff..1459420cdc0 100644
--- a/src/libstd/error.rs
+++ b/src/libstd/error.rs
@@ -66,10 +66,80 @@ pub trait Error: Debug + Display + Reflect {
     /// The description should not contain newlines or sentence-ending
     /// punctuation, to facilitate embedding in larger user-facing
     /// strings.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::error::Error;
+    ///
+    /// match "xc".parse::<u32>() {
+    ///     Err(e) => {
+    ///         println!("Error: {}", e.description());
+    ///     }
+    ///     _ => println!("No error"),
+    /// }
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     fn description(&self) -> &str;
 
     /// The lower-level cause of this error, if any.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::error::Error;
+    /// use std::fmt;
+    ///
+    /// #[derive(Debug)]
+    /// struct SuperError {
+    ///     side: SuperErrorSideKick,
+    /// }
+    ///
+    /// impl fmt::Display for SuperError {
+    ///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    ///         write!(f, "SuperError is here!")
+    ///     }
+    /// }
+    ///
+    /// impl Error for SuperError {
+    ///     fn description(&self) -> &str {
+    ///         "I'm the superhero of errors!"
+    ///     }
+    ///
+    ///     fn cause(&self) -> Option<&Error> {
+    ///         Some(&self.side)
+    ///     }
+    /// }
+    ///
+    /// #[derive(Debug)]
+    /// struct SuperErrorSideKick;
+    ///
+    /// impl fmt::Display for SuperErrorSideKick {
+    ///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    ///         write!(f, "SuperErrorSideKick is here!")
+    ///     }
+    /// }
+    ///
+    /// impl Error for SuperErrorSideKick {
+    ///     fn description(&self) -> &str {
+    ///         "I'm SuperError side kick!"
+    ///     }
+    /// }
+    ///
+    /// fn get_super_error() -> Result<(), SuperError> {
+    ///     Err(SuperError { side: SuperErrorSideKick })
+    /// }
+    ///
+    /// fn main() {
+    ///     match get_super_error() {
+    ///         Err(e) => {
+    ///             println!("Error: {}", e.description());
+    ///             println!("Caused by: {}", e.cause().unwrap());
+    ///         }
+    ///         _ => println!("No error"),
+    ///     }
+    /// }
+    /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     fn cause(&self) -> Option<&Error> { None }
 
diff --git a/src/libstd/process.rs b/src/libstd/process.rs
index 2edd1a30638..16bc81de78e 100644
--- a/src/libstd/process.rs
+++ b/src/libstd/process.rs
@@ -27,8 +27,9 @@ use sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 /// Representation of a running or exited child process.
 ///
 /// This structure is used to represent and manage child processes. A child
-/// process is created via the `Command` struct, which configures the spawning
-/// process and can itself be constructed using a builder-style interface.
+/// process is created via the [`Command`] struct, which configures the
+/// spawning process and can itself be constructed using a builder-style
+/// interface.
 ///
 /// # Examples
 ///
@@ -48,13 +49,18 @@ use sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 ///
 /// # Note
 ///
-/// Take note that there is no implementation of
-/// [`Drop`](../../core/ops/trait.Drop.html) for child processes, so if you
-/// do not ensure the `Child` has exited then it will continue to run, even
-/// after the `Child` handle to the child process has gone out of scope.
+/// Take note that there is no implementation of [`Drop`] for child processes,
+/// so if you do not ensure the `Child` has exited then it will continue to
+/// run, even after the `Child` handle to the child process has gone out of
+/// scope.
 ///
-/// Calling `wait` (or other functions that wrap around it) will make the
-/// parent process wait until the child has actually exited before continuing.
+/// Calling [`wait`][`wait`] (or other functions that wrap around it) will make
+/// the parent process wait until the child has actually exited before
+/// continuing.
+///
+/// [`Command`]: struct.Command.html
+/// [`Drop`]: ../../core/ops/trait.Drop.html
+/// [`wait`]: #method.wait
 #[stable(feature = "process", since = "1.0.0")]
 pub struct Child {
     handle: imp::Process,
@@ -91,7 +97,11 @@ impl IntoInner<imp::Process> for Child {
     fn into_inner(self) -> imp::Process { self.handle }
 }
 
-/// A handle to a child process's stdin
+/// A handle to a child process's stdin. This struct is used in the [`stdin`]
+/// field on [`Child`].
+///
+/// [`Child`]: struct.Child.html
+/// [`stdin`]: struct.Child.html#structfield.stdin
 #[stable(feature = "process", since = "1.0.0")]
 pub struct ChildStdin {
     inner: AnonPipe
@@ -122,7 +132,11 @@ impl FromInner<AnonPipe> for ChildStdin {
     }
 }
 
-/// A handle to a child process's stdout
+/// A handle to a child process's stdout. This struct is used in the [`stdout`]
+/// field on [`Child`].
+///
+/// [`Child`]: struct.Child.html
+/// [`stdout`]: struct.Child.html#structfield.stdout
 #[stable(feature = "process", since = "1.0.0")]
 pub struct ChildStdout {
     inner: AnonPipe
@@ -152,7 +166,11 @@ impl FromInner<AnonPipe> for ChildStdout {
     }
 }
 
-/// A handle to a child process's stderr
+/// A handle to a child process's stderr. This struct is used in the [`stderr`]
+/// field on [`Child`].
+///
+/// [`Child`]: struct.Child.html
+/// [`stderr`]: struct.Child.html#structfield.stderr
 #[stable(feature = "process", since = "1.0.0")]
 pub struct ChildStderr {
     inner: AnonPipe