Rollup merge of #27326 - steveklabnik:doc_show_use, r=Gankro

In spirit with https://internals.rust-lang.org/t/should-we-keep-including-obvious-imports-in-code-examples/2217, show the feature flags we're using in examples.

(also one instance of 'use')

9 files changed, 42 insertions, 21 deletions

diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index 2c4ebeafc0b..c443270d5f4 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -221,7 +221,8 @@ impl<T:Copy> Cell<T> {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(as_unsafe_cell)]
+    /// #![feature(as_unsafe_cell)]
+    ///
     /// use std::cell::Cell;
     ///
     /// let c = Cell::new(5);
@@ -589,7 +590,8 @@ impl<'b, T: ?Sized> Ref<'b, T> {
     /// # Example
     ///
     /// ```
-    /// # #![feature(cell_extras)]
+    /// #![feature(cell_extras)]
+    ///
     /// use std::cell::{RefCell, Ref};
     ///
     /// let c = RefCell::new((5, 'b'));
diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index 93542185eab..9d151abea78 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -383,7 +383,8 @@ pub fn max<T: Ord>(v1: T, v2: T) -> T {
 /// # Examples
 ///
 /// ```
-/// # #![feature(cmp_partial)]
+/// #![feature(cmp_partial)]
+///
 /// use std::cmp;
 ///
 /// assert_eq!(Some(1), cmp::partial_min(1, 2));
@@ -393,7 +394,8 @@ pub fn max<T: Ord>(v1: T, v2: T) -> T {
 /// When comparison is impossible:
 ///
 /// ```
-/// # #![feature(cmp_partial)]
+/// #![feature(cmp_partial)]
+///
 /// use std::cmp;
 ///
 /// let result = cmp::partial_min(std::f64::NAN, 1.0);
@@ -417,7 +419,8 @@ pub fn partial_min<T: PartialOrd>(v1: T, v2: T) -> Option<T> {
 /// # Examples
 ///
 /// ```
-/// # #![feature(cmp_partial)]
+/// #![feature(cmp_partial)]
+///
 /// use std::cmp;
 ///
 /// assert_eq!(Some(2), cmp::partial_max(1, 2));
@@ -427,7 +430,8 @@ pub fn partial_min<T: PartialOrd>(v1: T, v2: T) -> Option<T> {
 /// When comparison is impossible:
 ///
 /// ```
-/// # #![feature(cmp_partial)]
+/// #![feature(cmp_partial)]
+///
 /// use std::cmp;
 ///
 /// let result = cmp::partial_max(std::f64::NAN, 1.0);
diff --git a/src/libcore/fmt/num.rs b/src/libcore/fmt/num.rs
index 8141916dd60..7cacc6af575 100644
--- a/src/libcore/fmt/num.rs
+++ b/src/libcore/fmt/num.rs
@@ -167,7 +167,8 @@ pub struct RadixFmt<T, R>(T, R);
 /// # Examples
 ///
 /// ```
-/// # #![feature(fmt_radix)]
+/// #![feature(fmt_radix)]
+///
 /// use std::fmt::radix;
 /// assert_eq!(format!("{}", radix(55, 36)), "1j".to_string());
 /// ```
diff --git a/src/libcore/hash/mod.rs b/src/libcore/hash/mod.rs
index a660cf0cf2d..75b7208d66b 100644
--- a/src/libcore/hash/mod.rs
+++ b/src/libcore/hash/mod.rs
@@ -16,7 +16,8 @@
 //! # Examples
 //!
 //! ```rust
-//! # #![feature(hash_default)]
+//! #![feature(hash_default)]
+//!
 //! use std::hash::{hash, Hash, SipHasher};
 //!
 //! #[derive(Hash)]
@@ -36,7 +37,8 @@
 //! the trait `Hash`:
 //!
 //! ```rust
-//! # #![feature(hash_default)]
+//! #![feature(hash_default)]
+//!
 //! use std::hash::{hash, Hash, Hasher, SipHasher};
 //!
 //! struct Person {
diff --git a/src/libcore/iter.rs b/src/libcore/iter.rs
index 4d8de0c85b6..2968d634544 100644
--- a/src/libcore/iter.rs
+++ b/src/libcore/iter.rs
@@ -824,7 +824,8 @@ pub trait Iterator {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(iter_min_max)]
+    /// #![feature(iter_min_max)]
+    ///
     /// use std::iter::MinMaxResult::{NoElements, OneElement, MinMax};
     ///
     /// let a: [i32; 0] = [];
@@ -898,7 +899,8 @@ pub trait Iterator {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(iter_cmp)]
+    /// #![feature(iter_cmp)]
+    ///
     /// let a = [-3_i32, 0, 1, 5, -10];
     /// assert_eq!(*a.iter().max_by(|x| x.abs()).unwrap(), -10);
     /// ```
@@ -926,7 +928,8 @@ pub trait Iterator {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(iter_cmp)]
+    /// #![feature(iter_cmp)]
+    ///
     /// let a = [-3_i32, 0, 1, 5, -10];
     /// assert_eq!(*a.iter().min_by(|x| x.abs()).unwrap(), 0);
     /// ```
@@ -1065,7 +1068,8 @@ pub trait Iterator {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(iter_arith)]
+    /// #![feature(iter_arith)]
+    ///
     /// let a = [1, 2, 3, 4, 5];
     /// let it = a.iter();
     /// assert_eq!(it.sum::<i32>(), 15);
@@ -1083,7 +1087,8 @@ pub trait Iterator {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(iter_arith)]
+    /// #![feature(iter_arith)]
+    ///
     /// fn factorial(n: u32) -> u32 {
     ///     (1..).take_while(|&i| i <= n).product()
     /// }
@@ -1367,7 +1372,8 @@ impl<T: Clone> MinMaxResult<T> {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(iter_min_max)]
+    /// #![feature(iter_min_max)]
+    ///
     /// use std::iter::MinMaxResult::{self, NoElements, OneElement, MinMax};
     ///
     /// let r: MinMaxResult<i32> = NoElements;
@@ -2764,7 +2770,8 @@ impl<A: Step> ops::Range<A> {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(step_by)]
+    /// #![feature(step_by)]
+    ///
     /// for i in (0..10).step_by(2) {
     ///     println!("{}", i);
     /// }
diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 9ccba7ad78d..2235dc4af11 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -274,7 +274,8 @@ impl<T> Option<T> {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(as_slice)]
+    /// #![feature(as_slice)]
+    ///
     /// let mut x = Some("Diamonds");
     /// {
     ///     let v = x.as_mut_slice();
diff --git a/src/libcore/raw.rs b/src/libcore/raw.rs
index 43535ddd1d5..f0bac1bfef3 100644
--- a/src/libcore/raw.rs
+++ b/src/libcore/raw.rs
@@ -49,7 +49,8 @@ use mem;
 /// # Examples
 ///
 /// ```
-/// # #![feature(raw)]
+/// #![feature(raw)]
+///
 /// use std::raw::{self, Repr};
 ///
 /// let slice: &[u16] = &[1, 2, 3, 4];
@@ -98,7 +99,8 @@ impl<T> Clone for Slice<T> {
 /// # Examples
 ///
 /// ```
-/// # #![feature(raw)]
+/// #![feature(raw)]
+///
 /// use std::mem;
 /// use std::raw;
 ///
diff --git a/src/libcore/result.rs b/src/libcore/result.rs
index 2b33b1f83d2..100cf0779b7 100644
--- a/src/libcore/result.rs
+++ b/src/libcore/result.rs
@@ -420,7 +420,8 @@ impl<T, E> Result<T, E> {
     /// Converts from `Result<T, E>` to `&mut [T]` (without copying)
     ///
     /// ```
-    /// # #![feature(as_slice)]
+    /// #![feature(as_slice)]
+    ///
     /// let mut x: Result<&str, u32> = Ok("Gold");
     /// {
     ///     let v = x.as_mut_slice();
diff --git a/src/libcore/simd.rs b/src/libcore/simd.rs
index 7ecd08bea35..d0205fc9b12 100644
--- a/src/libcore/simd.rs
+++ b/src/libcore/simd.rs
@@ -19,7 +19,8 @@
 //! provided beyond this module.
 //!
 //! ```rust
-//! # #![feature(core_simd)]
+//! #![feature(core_simd)]
+//!
 //! fn main() {
 //!     use std::simd::f32x4;
 //!     let a = f32x4(40.0, 41.0, 42.0, 43.0);