libcore: deny warnings in doctests

14 files changed, 48 insertions, 10 deletions

diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index 9fcc2b3412a..59b05c21d80 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -76,6 +76,7 @@
 //! a trait method that was originally defined to take `&self`.
 //!
 //! ```
+//! # #![allow(dead_code)]
 //! use std::cell::RefCell;
 //!
 //! struct Graph {
@@ -125,6 +126,7 @@
 //! }
 //!
 //! struct RcBox<T> {
+//! # #[allow(dead_code)]
 //!     value: T,
 //!     refcount: Cell<usize>
 //! }
@@ -776,6 +778,7 @@ impl<'b, T: ?Sized> DerefMut for RefMut<'b, T> {
 /// use std::cell::UnsafeCell;
 /// use std::marker::Sync;
 ///
+/// # #[allow(dead_code)]
 /// struct NotThreadSafe<T> {
 ///     value: UnsafeCell<T>,
 /// }
diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index 302c9d0c369..5458a7b9c38 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -140,8 +140,6 @@ impl Ordering {
     /// This method can be used to reverse a comparison:
     ///
     /// ```
-    /// use std::cmp::Ordering;
-    ///
     /// let mut data: &mut [_] = &mut [2, 10, 5, 8];
     ///
     /// // sort the array from largest to smallest.
@@ -263,8 +261,6 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
     /// # Examples
     ///
     /// ```
-    /// use std::cmp::Ordering;
-    ///
     /// let result = 1.0 < 2.0;
     /// assert_eq!(result, true);
     ///
diff --git a/src/libcore/default.rs b/src/libcore/default.rs
index cbad72eae3d..12c4a5ca200 100644
--- a/src/libcore/default.rs
+++ b/src/libcore/default.rs
@@ -15,6 +15,7 @@
 //! that define a set of options:
 //!
 //! ```
+//! # #[allow(dead_code)]
 //! struct SomeOptions {
 //!     foo: i32,
 //!     bar: f32,
@@ -24,6 +25,7 @@
 //! How can we define some default values? You can use `Default`:
 //!
 //! ```
+//! # #[allow(dead_code)]
 //! #[derive(Default)]
 //! struct SomeOptions {
 //!     foo: i32,
@@ -40,6 +42,7 @@
 //! If you have your own type, you need to implement `Default` yourself:
 //!
 //! ```
+//! # #![allow(dead_code)]
 //! enum Kind {
 //!     A,
 //!     B,
@@ -66,6 +69,7 @@
 //! If you want to override a particular option, but still retain the other defaults:
 //!
 //! ```
+//! # #[allow(dead_code)]
 //! # #[derive(Default)]
 //! # struct SomeOptions {
 //! #     foo: i32,
@@ -88,6 +92,7 @@ use marker::Sized;
 /// # Examples
 ///
 /// ```
+/// # #[allow(dead_code)]
 /// #[derive(Default)]
 /// struct SomeOptions {
 ///     foo: i32,
@@ -114,6 +119,7 @@ pub trait Default: Sized {
     /// Making your own:
     ///
     /// ```
+    /// # #[allow(dead_code)]
     /// enum Kind {
     ///     A,
     ///     B,
diff --git a/src/libcore/hash/mod.rs b/src/libcore/hash/mod.rs
index 4e038f455e1..0899dc28848 100644
--- a/src/libcore/hash/mod.rs
+++ b/src/libcore/hash/mod.rs
@@ -45,6 +45,7 @@
 //!
 //! struct Person {
 //!     id: u32,
+//! # #[allow(dead_code)]
 //!     name: String,
 //!     phone: u64,
 //! }
diff --git a/src/libcore/intrinsics.rs b/src/libcore/intrinsics.rs
index ea4792bb495..a094bcd0192 100644
--- a/src/libcore/intrinsics.rs
+++ b/src/libcore/intrinsics.rs
@@ -334,6 +334,7 @@ extern "rust-intrinsic" {
     /// use std::mem;
     /// use std::ptr;
     ///
+    /// # #[allow(dead_code)]
     /// fn swap<T>(x: &mut T, y: &mut T) {
     ///     unsafe {
     ///         // Give ourselves some scratch space to work with
@@ -372,6 +373,7 @@ extern "rust-intrinsic" {
     /// ```
     /// use std::ptr;
     ///
+    /// # #[allow(dead_code)]
     /// unsafe fn from_buf_raw<T>(ptr: *const T, elts: usize) -> Vec<T> {
     ///     let mut dst = Vec::with_capacity(elts);
     ///     dst.set_len(elts);
diff --git a/src/libcore/iter.rs b/src/libcore/iter.rs
index f8c6e3cfdd7..8558927e4ac 100644
--- a/src/libcore/iter.rs
+++ b/src/libcore/iter.rs
@@ -241,6 +241,7 @@
 //! method calls a closure on each element it iterates over:
 //!
 //! ```
+//! # #![allow(unused_must_use)]
 //! let v = vec![1, 2, 3, 4, 5];
 //! v.iter().map(|x| println!("{}", x));
 //! ```
@@ -419,7 +420,7 @@ pub trait Iterator {
     ///
     /// ```
     /// // an infinite iterator has no upper bound
-    /// let iter = (0..);
+    /// let iter = 0..;
     ///
     /// assert_eq!((0, None), iter.size_hint());
     /// ```
@@ -709,6 +710,7 @@ pub trait Iterator {
     /// If you're doing some sort of side effect, prefer [`for`] to `map()`:
     ///
     /// ```
+    /// # #![allow(unused_must_use)]
     /// // don't do this:
     /// (0..5).map(|x| println!("{}", x));
     ///
@@ -2695,7 +2697,7 @@ impl<'a, I: DoubleEndedIterator + ?Sized> DoubleEndedIterator for &'a mut I {
 ///
 /// ```
 /// // a finite range knows exactly how many times it will iterate
-/// let five = (0..5);
+/// let five = 0..5;
 ///
 /// assert_eq!(5, five.len());
 /// ```
@@ -2761,7 +2763,7 @@ pub trait ExactSizeIterator: Iterator {
     ///
     /// ```
     /// // a finite range knows exactly how many times it will iterate
-    /// let five = (0..5);
+    /// let five = 0..5;
     ///
     /// assert_eq!(5, five.len());
     /// ```
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 94408072932..df7b7c437c3 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -60,7 +60,7 @@
        html_root_url = "https://doc.rust-lang.org/nightly/",
        html_playground_url = "https://play.rust-lang.org/",
        issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/")]
-#![doc(test(no_crate_inject))]
+#![doc(test(no_crate_inject, attr(allow(unused_variables), deny(warnings))))]
 
 #![no_core]
 #![allow(raw_pointer_derive)]
diff --git a/src/libcore/macros.rs b/src/libcore/macros.rs
index 579232e5a5d..ad78ab307a0 100644
--- a/src/libcore/macros.rs
+++ b/src/libcore/macros.rs
@@ -247,6 +247,7 @@ macro_rules! writeln {
 /// Match arms:
 ///
 /// ```
+/// # #[allow(dead_code)]
 /// fn foo(x: Option<i32>) {
 ///     match x {
 ///         Some(n) if n >= 0 => println!("Some(Non-negative)"),
@@ -260,6 +261,7 @@ macro_rules! writeln {
 /// Iterators:
 ///
 /// ```
+/// # #[allow(dead_code)]
 /// fn divide_by_three(x: u32) -> u32 { // one of the poorest implementations of x/3
 ///     for i in 0.. {
 ///         if 3*i < i { panic!("u32 overflow"); }
diff --git a/src/libcore/marker.rs b/src/libcore/marker.rs
index 2f2dcc41a1c..6e6ae618527 100644
--- a/src/libcore/marker.rs
+++ b/src/libcore/marker.rs
@@ -42,6 +42,7 @@ impl<T> !Send for *mut T { }
 /// `?Sized` can be used to remove this bound if it is not appropriate.
 ///
 /// ```
+/// # #![allow(dead_code)]
 /// struct Foo<T>(T);
 /// struct Bar<T: ?Sized>(T);
 ///
@@ -106,6 +107,7 @@ pub trait Unsize<T: ?Sized> {
 /// `struct` can be `Copy`:
 ///
 /// ```
+/// # #[allow(dead_code)]
 /// struct Point {
 ///    x: i32,
 ///    y: i32,
@@ -115,6 +117,7 @@ pub trait Unsize<T: ?Sized> {
 /// A `struct` can be `Copy`, and `i32` is `Copy`, so therefore, `Point` is eligible to be `Copy`.
 ///
 /// ```
+/// # #![allow(dead_code)]
 /// # struct Point;
 /// struct PointList {
 ///     points: Vec<Point>,
@@ -303,6 +306,7 @@ macro_rules! impls{
 /// ```
 /// use std::marker::PhantomData;
 ///
+/// # #[allow(dead_code)]
 /// struct Slice<'a, T:'a> {
 ///     start: *const T,
 ///     end: *const T,
@@ -323,6 +327,7 @@ macro_rules! impls{
 /// mismatches by enforcing types in the method implementations:
 ///
 /// ```
+/// # #![allow(dead_code)]
 /// # trait ResType { fn foo(&self); }
 /// # struct ParamType;
 /// # mod foreign_lib {
@@ -393,6 +398,8 @@ mod impls {
 /// #![feature(reflect_marker)]
 /// use std::marker::Reflect;
 /// use std::any::Any;
+///
+/// # #[allow(dead_code)]
 /// fn foo<T:Reflect+'static>(x: &T) {
 ///     let any: &Any = x;
 ///     if any.is::<u32>() { println!("u32"); }
diff --git a/src/libcore/mem.rs b/src/libcore/mem.rs
index a87d135e425..2f01ea38340 100644
--- a/src/libcore/mem.rs
+++ b/src/libcore/mem.rs
@@ -92,6 +92,7 @@ pub use intrinsics::transmute;
 /// use std::mem;
 /// use std::ptr;
 ///
+/// # #[allow(dead_code)]
 /// fn swap<T>(x: &mut T, y: &mut T) {
 ///     unsafe {
 ///         // Give ourselves some scratch space to work with
@@ -151,6 +152,7 @@ pub fn size_of_val<T: ?Sized>(val: &T) -> usize {
 /// # Examples
 ///
 /// ```
+/// # #![allow(deprecated)]
 /// use std::mem;
 ///
 /// assert_eq!(4, mem::min_align_of::<i32>());
@@ -167,6 +169,7 @@ pub fn min_align_of<T>() -> usize {
 /// # Examples
 ///
 /// ```
+/// # #![allow(deprecated)]
 /// use std::mem;
 ///
 /// assert_eq!(4, mem::min_align_of_val(&5i32));
@@ -414,6 +417,7 @@ pub fn swap<T>(x: &mut T, y: &mut T) {
 /// `self`, allowing it to be returned:
 ///
 /// ```
+/// # #![allow(dead_code)]
 /// use std::mem;
 /// # struct Buffer<T> { buf: Vec<T> }
 /// impl<T> Buffer<T> {
diff --git a/src/libcore/ops.rs b/src/libcore/ops.rs
index 1bfdafa7133..7ad49eef8f7 100644
--- a/src/libcore/ops.rs
+++ b/src/libcore/ops.rs
@@ -947,6 +947,7 @@ shr_impl_all! { u8 u16 u32 u64 usize i8 i16 i32 i64 isize }
 ///     }
 /// }
 ///
+/// # #[allow(unused_assignments)]
 /// fn main() {
 ///     let mut foo = Foo;
 ///     foo += Foo;
@@ -996,6 +997,7 @@ add_assign_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 }
 ///     }
 /// }
 ///
+/// # #[allow(unused_assignments)]
 /// fn main() {
 ///     let mut foo = Foo;
 ///     foo -= Foo;
@@ -1045,6 +1047,7 @@ sub_assign_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 }
 ///     }
 /// }
 ///
+/// # #[allow(unused_assignments)]
 /// fn main() {
 ///     let mut foo = Foo;
 ///     foo *= Foo;
@@ -1094,6 +1097,7 @@ mul_assign_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 }
 ///     }
 /// }
 ///
+/// # #[allow(unused_assignments)]
 /// fn main() {
 ///     let mut foo = Foo;
 ///     foo /= Foo;
@@ -1143,6 +1147,7 @@ div_assign_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 }
 ///     }
 /// }
 ///
+/// # #[allow(unused_assignments)]
 /// fn main() {
 ///     let mut foo = Foo;
 ///     foo %= Foo;
@@ -1192,6 +1197,7 @@ rem_assign_impl! { usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 }
 ///     }
 /// }
 ///
+/// # #[allow(unused_assignments)]
 /// fn main() {
 ///     let mut foo = Foo;
 ///     foo &= Foo;
@@ -1241,6 +1247,7 @@ bitand_assign_impl! { bool usize u8 u16 u32 u64 isize i8 i16 i32 i64 }
 ///     }
 /// }
 ///
+/// # #[allow(unused_assignments)]
 /// fn main() {
 ///     let mut foo = Foo;
 ///     foo |= Foo;
@@ -1290,6 +1297,7 @@ bitor_assign_impl! { bool usize u8 u16 u32 u64 isize i8 i16 i32 i64 }
 ///     }
 /// }
 ///
+/// # #[allow(unused_assignments)]
 /// fn main() {
 ///     let mut foo = Foo;
 ///     foo ^= Foo;
@@ -1339,6 +1347,7 @@ bitxor_assign_impl! { bool usize u8 u16 u32 u64 isize i8 i16 i32 i64 }
 ///     }
 /// }
 ///
+/// # #[allow(unused_assignments)]
 /// fn main() {
 ///     let mut foo = Foo;
 ///     foo <<= Foo;
@@ -1407,6 +1416,7 @@ shl_assign_impl_all! { u8 u16 u32 u64 usize i8 i16 i32 i64 isize }
 ///     }
 /// }
 ///
+/// # #[allow(unused_assignments)]
 /// fn main() {
 ///     let mut foo = Foo;
 ///     foo >>= Foo;
diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 26e00867d84..7a3b83f68d0 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -275,6 +275,7 @@ impl<T> Option<T> {
     ///
     /// ```
     /// #![feature(as_slice)]
+    /// # #![allow(deprecated)]
     ///
     /// let mut x = Some("Diamonds");
     /// {
diff --git a/src/libcore/result.rs b/src/libcore/result.rs
index c111ea8dce6..d547a17e8b7 100644
--- a/src/libcore/result.rs
+++ b/src/libcore/result.rs
@@ -16,6 +16,7 @@
 //! and containing an error value.
 //!
 //! ```
+//! # #[allow(dead_code)]
 //! enum Result<T, E> {
 //!    Ok(T),
 //!    Err(E)
@@ -104,6 +105,7 @@
 //! something like this:
 //!
 //! ```no_run
+//! # #![allow(unused_must_use)] // \o/
 //! use std::fs::File;
 //! use std::io::prelude::*;
 //!
@@ -143,6 +145,7 @@
 //! # use std::fs::File;
 //! # use std::io::prelude::*;
 //! # use std::io;
+//! # #[allow(dead_code)]
 //! fn write_message() -> io::Result<()> {
 //!     let mut file = try!(File::create("valuable_data.txt"));
 //!     try!(file.write_all(b"important message"));
@@ -160,6 +163,7 @@
 //! It replaces this:
 //!
 //! ```
+//! # #![allow(dead_code)]
 //! use std::fs::File;
 //! use std::io::prelude::*;
 //! use std::io;
@@ -189,6 +193,7 @@
 //! With this:
 //!
 //! ```
+//! # #![allow(dead_code)]
 //! use std::fs::File;
 //! use std::io::prelude::*;
 //! use std::io;
@@ -422,6 +427,7 @@ impl<T, E> Result<T, E> {
     ///
     /// ```
     /// #![feature(as_slice)]
+    /// # #![allow(deprecated)]
     ///
     /// let mut x: Result<&str, u32> = Ok("Gold");
     /// {
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 18334ba91c6..7954bc3a0bf 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -142,8 +142,6 @@ impl Utf8Error {
     /// Basic usage:
     ///
     /// ```
-    /// #![feature(utf8_error)]
-    ///
     /// use std::str;
     ///
     /// // some invalid bytes, in a vector