resolved conflict with upstream commit

20 files changed, 376 insertions, 238 deletions

diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index c91aa06609d..13e838773a5 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -106,6 +106,8 @@ use self::Ordering::*;
 /// ```
 #[lang = "eq"]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[doc(alias = "==")]
+#[doc(alias = "!=")]
 #[rustc_on_unimplemented = "can't compare `{Self}` with `{Rhs}`"]
 pub trait PartialEq<Rhs: ?Sized = Self> {
     /// This method tests for `self` and `other` values to be equal, and is used
@@ -160,6 +162,8 @@ pub trait PartialEq<Rhs: ?Sized = Self> {
 /// }
 /// impl Eq for Book {}
 /// ```
+#[doc(alias = "==")]
+#[doc(alias = "!=")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Eq: PartialEq<Self> {
     // this method is used solely by #[deriving] to assert
@@ -428,6 +432,10 @@ impl<T: Ord> Ord for Reverse<T> {
 /// }
 /// ```
 #[lang = "ord"]
+#[doc(alias = "<")]
+#[doc(alias = ">")]
+#[doc(alias = "<=")]
+#[doc(alias = ">=")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Ord: Eq + PartialOrd<Self> {
     /// This method returns an `Ordering` between `self` and `other`.
@@ -599,6 +607,10 @@ impl PartialOrd for Ordering {
 /// ```
 #[lang = "partial_ord"]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[doc(alias = ">")]
+#[doc(alias = "<")]
+#[doc(alias = "<=")]
+#[doc(alias = ">=")]
 #[rustc_on_unimplemented = "can't compare `{Self}` with `{Rhs}`"]
 pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
     /// This method returns an ordering between `self` and `other` values if one exists.
diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs
index a8430f14410..5820fe58932 100644
--- a/src/libcore/fmt/mod.rs
+++ b/src/libcore/fmt/mod.rs
@@ -542,11 +542,12 @@ impl<'a> Display for Arguments<'a> {
 /// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented(
-    on(crate_local, label="`{Self}` cannot be formatted using `:?`; \
-                            add `#[derive(Debug)]` or manually implement `{Debug}`"),
+    on(crate_local, label="`{Self}` cannot be formatted using `{{:?}}`",
+                    note="add `#[derive(Debug)]` or manually implement `{Debug}`"),
     message="`{Self}` doesn't implement `{Debug}`",
-    label="`{Self}` cannot be formatted using `:?` because it doesn't implement `{Debug}`",
+    label="`{Self}` cannot be formatted using `{{:?}}` because it doesn't implement `{Debug}`",
 )]
+#[doc(alias = "{:?}")]
 #[lang = "debug_trait"]
 pub trait Debug {
     /// Formats the value using the given formatter.
@@ -609,9 +610,11 @@ pub trait Debug {
 /// ```
 #[rustc_on_unimplemented(
     message="`{Self}` doesn't implement `{Display}`",
-    label="`{Self}` cannot be formatted with the default formatter; \
-           try using `:?` instead if you are using a format string",
+    label="`{Self}` cannot be formatted with the default formatter",
+    note="in format strings you may be able to use `{{:?}}` \
+          (or {{:#?}} for pretty-print) instead",
 )]
+#[doc(alias = "{}")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Display {
     /// Formats the value using the given formatter.
diff --git a/src/libcore/iter/iterator.rs b/src/libcore/iter/iterator.rs
index 6a77de2c986..b27bd3142e1 100644
--- a/src/libcore/iter/iterator.rs
+++ b/src/libcore/iter/iterator.rs
@@ -1094,6 +1094,8 @@ pub trait Iterator {
     /// `flatten()` a three-dimensional array the result will be
     /// two-dimensional and not one-dimensional. To get a one-dimensional
     /// structure, you have to `flatten()` again.
+    ///
+    /// [`flat_map()`]: #method.flat_map
     #[inline]
     #[unstable(feature = "iterator_flatten", issue = "48213")]
     fn flatten(self) -> Flatten<Self>
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 0e21a3327fd..54f35d17974 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -50,6 +50,15 @@
 
 // Since libcore defines many fundamental lang items, all tests live in a
 // separate crate, libcoretest, to avoid bizarre issues.
+//
+// Here we explicitly #[cfg]-out this whole crate when testing. If we don't do
+// this, both the generated test artifact and the linked libtest (which
+// transitively includes libcore) will both define the same set of lang items,
+// and this will cause the E0152 "duplicate lang item found" error. See
+// discussion in #50466 for details.
+//
+// This cfg won't affect doc tests.
+#![cfg(not(test))]
 
 #![stable(feature = "core", since = "1.6.0")]
 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
@@ -76,7 +85,6 @@
 #![feature(doc_cfg)]
 #![feature(doc_spotlight)]
 #![feature(extern_types)]
-#![feature(fn_must_use)]
 #![feature(fundamental)]
 #![feature(intrinsics)]
 #![feature(iterator_flatten)]
@@ -103,6 +111,7 @@
 #![feature(untagged_unions)]
 #![feature(unwind_attributes)]
 #![feature(doc_alias)]
+#![feature(inclusive_range_methods)]
 
 #![cfg_attr(not(stage0), feature(mmx_target_feature))]
 #![cfg_attr(not(stage0), feature(tbm_target_feature))]
@@ -114,6 +123,7 @@
 
 #![cfg_attr(stage0, feature(target_feature))]
 #![cfg_attr(stage0, feature(cfg_target_feature))]
+#![cfg_attr(stage0, feature(fn_must_use))]
 
 #[prelude_import]
 #[allow(unused)]
diff --git a/src/libcore/macros.rs b/src/libcore/macros.rs
index f9371ed0575..c830c22ee5f 100644
--- a/src/libcore/macros.rs
+++ b/src/libcore/macros.rs
@@ -606,8 +606,8 @@ mod builtin {
     #[macro_export]
     #[cfg(dox)]
     macro_rules! concat_idents {
-        ($($e:ident),*) => ({ /* compiler built-in */ });
-        ($($e:ident,)*) => ({ /* compiler built-in */ });
+        ($($e:ident),+) => ({ /* compiler built-in */ });
+        ($($e:ident,)+) => ({ /* compiler built-in */ });
     }
 
     /// Concatenates literals into a static string slice.
diff --git a/src/libcore/marker.rs b/src/libcore/marker.rs
index feb689dbc1f..c074adfd570 100644
--- a/src/libcore/marker.rs
+++ b/src/libcore/marker.rs
@@ -602,6 +602,8 @@ unsafe impl<'a, T: ?Sized> Freeze for &'a mut T {}
 /// `Pin` pointer.
 ///
 /// This trait is automatically implemented for almost every type.
+///
+/// [`Pin`]: ../mem/struct.Pin.html
 #[unstable(feature = "pin", issue = "49150")]
 pub unsafe auto trait Unpin {}
 
diff --git a/src/libcore/ops/arith.rs b/src/libcore/ops/arith.rs
index a1f6030428f..a1bc5463f73 100644
--- a/src/libcore/ops/arith.rs
+++ b/src/libcore/ops/arith.rs
@@ -94,6 +94,7 @@ pub trait Add<RHS=Self> {
     type Output;
 
     /// Performs the `+` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn add(self, rhs: RHS) -> Self::Output;
 }
@@ -191,6 +192,7 @@ pub trait Sub<RHS=Self> {
     type Output;
 
     /// Performs the `-` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn sub(self, rhs: RHS) -> Self::Output;
 }
@@ -310,6 +312,7 @@ pub trait Mul<RHS=Self> {
     type Output;
 
     /// Performs the `*` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn mul(self, rhs: RHS) -> Self::Output;
 }
@@ -433,6 +436,7 @@ pub trait Div<RHS=Self> {
     type Output;
 
     /// Performs the `/` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn div(self, rhs: RHS) -> Self::Output;
 }
@@ -517,6 +521,7 @@ pub trait Rem<RHS=Self> {
     type Output = Self;
 
     /// Performs the `%` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn rem(self, rhs: RHS) -> Self::Output;
 }
@@ -601,6 +606,7 @@ pub trait Neg {
     type Output;
 
     /// Performs the unary `-` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn neg(self) -> Self::Output;
 }
diff --git a/src/libcore/ops/bit.rs b/src/libcore/ops/bit.rs
index 81c4455cef4..3900f365b0a 100644
--- a/src/libcore/ops/bit.rs
+++ b/src/libcore/ops/bit.rs
@@ -46,6 +46,7 @@ pub trait Not {
     type Output;
 
     /// Performs the unary `!` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn not(self) -> Self::Output;
 }
@@ -119,6 +120,7 @@ not_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// assert_eq!(bv1 & bv2, expected);
 /// ```
 #[lang = "bitand"]
+#[doc(alias = "&")]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented(message="no implementation for `{Self} & {RHS}`",
                          label="no implementation for `{Self} & {RHS}`")]
@@ -128,6 +130,7 @@ pub trait BitAnd<RHS=Self> {
     type Output;
 
     /// Performs the `&` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn bitand(self, rhs: RHS) -> Self::Output;
 }
@@ -201,6 +204,7 @@ bitand_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// assert_eq!(bv1 | bv2, expected);
 /// ```
 #[lang = "bitor"]
+#[doc(alias = "|")]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented(message="no implementation for `{Self} | {RHS}`",
                          label="no implementation for `{Self} | {RHS}`")]
@@ -210,6 +214,7 @@ pub trait BitOr<RHS=Self> {
     type Output;
 
     /// Performs the `|` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn bitor(self, rhs: RHS) -> Self::Output;
 }
@@ -286,6 +291,7 @@ bitor_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// assert_eq!(bv1 ^ bv2, expected);
 /// ```
 #[lang = "bitxor"]
+#[doc(alias = "^")]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented(message="no implementation for `{Self} ^ {RHS}`",
                          label="no implementation for `{Self} ^ {RHS}`")]
@@ -295,6 +301,7 @@ pub trait BitXor<RHS=Self> {
     type Output;
 
     /// Performs the `^` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn bitxor(self, rhs: RHS) -> Self::Output;
 }
@@ -372,6 +379,7 @@ bitxor_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 ///            SpinVector { vec: vec![2, 3, 4, 0, 1] });
 /// ```
 #[lang = "shl"]
+#[doc(alias = "<<")]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented(message="no implementation for `{Self} << {RHS}`",
                          label="no implementation for `{Self} << {RHS}`")]
@@ -381,6 +389,7 @@ pub trait Shl<RHS=Self> {
     type Output;
 
     /// Performs the `<<` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn shl(self, rhs: RHS) -> Self::Output;
 }
@@ -479,6 +488,7 @@ shl_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 isize i128 }
 ///            SpinVector { vec: vec![3, 4, 0, 1, 2] });
 /// ```
 #[lang = "shr"]
+#[doc(alias = ">>")]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented(message="no implementation for `{Self} >> {RHS}`",
                          label="no implementation for `{Self} >> {RHS}`")]
@@ -488,6 +498,7 @@ pub trait Shr<RHS=Self> {
     type Output;
 
     /// Performs the `>>` operation.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn shr(self, rhs: RHS) -> Self::Output;
 }
@@ -593,6 +604,7 @@ shr_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize }
 /// assert_eq!(bv, expected);
 /// ```
 #[lang = "bitand_assign"]
+#[doc(alias = "&=")]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
 #[rustc_on_unimplemented(message="no implementation for `{Self} &= {Rhs}`",
                          label="no implementation for `{Self} &= {Rhs}`")]
@@ -641,6 +653,7 @@ bitand_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// assert_eq!(prefs, PersonalPreferences { likes_cats: true, likes_dogs: true });
 /// ```
 #[lang = "bitor_assign"]
+#[doc(alias = "|=")]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
 #[rustc_on_unimplemented(message="no implementation for `{Self} |= {Rhs}`",
                          label="no implementation for `{Self} |= {Rhs}`")]
@@ -689,6 +702,7 @@ bitor_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// assert_eq!(personality, Personality { has_soul: true, likes_knitting: false});
 /// ```
 #[lang = "bitxor_assign"]
+#[doc(alias = "^=")]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
 #[rustc_on_unimplemented(message="no implementation for `{Self} ^= {Rhs}`",
                          label="no implementation for `{Self} ^= {Rhs}`")]
@@ -735,6 +749,7 @@ bitxor_assign_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 /// assert_eq!(scalar, Scalar(16));
 /// ```
 #[lang = "shl_assign"]
+#[doc(alias = "<<=")]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
 #[rustc_on_unimplemented(message="no implementation for `{Self} <<= {Rhs}`",
                          label="no implementation for `{Self} <<= {Rhs}`")]
@@ -802,6 +817,7 @@ shl_assign_impl_all! { u8 u16 u32 u64 u128 usize i8 i16 i32 i64 i128 isize }
 /// assert_eq!(scalar, Scalar(4));
 /// ```
 #[lang = "shr_assign"]
+#[doc(alias = ">>=")]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
 #[rustc_on_unimplemented(message="no implementation for `{Self} >>= {Rhs}`",
                          label="no implementation for `{Self} >>= {Rhs}`")]
diff --git a/src/libcore/ops/deref.rs b/src/libcore/ops/deref.rs
index 4ce0740130b..54eecc82e19 100644
--- a/src/libcore/ops/deref.rs
+++ b/src/libcore/ops/deref.rs
@@ -68,6 +68,8 @@
 /// assert_eq!('a', *x);
 /// ```
 #[lang = "deref"]
+#[doc(alias = "*")]
+#[doc(alias = "&*")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Deref {
     /// The resulting type after dereferencing.
@@ -75,6 +77,7 @@ pub trait Deref {
     type Target: ?Sized;
 
     /// Dereferences the value.
+    #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     fn deref(&self) -> &Self::Target;
 }
@@ -162,6 +165,7 @@ impl<'a, T: ?Sized> Deref for &'a mut T {
 /// assert_eq!('b', *x);
 /// ```
 #[lang = "deref_mut"]
+#[doc(alias = "*")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait DerefMut: Deref {
     /// Mutably dereferences the value.
diff --git a/src/libcore/ops/range.rs b/src/libcore/ops/range.rs
index 6f3e3b50885..b01a769eda7 100644
--- a/src/libcore/ops/range.rs
+++ b/src/libcore/ops/range.rs
@@ -45,6 +45,7 @@ use fmt;
 /// [`IntoIterator`]: ../iter/trait.Iterator.html
 /// [`Iterator`]: ../iter/trait.IntoIterator.html
 /// [slicing index]: ../slice/trait.SliceIndex.html
+#[doc(alias = "..")]
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct RangeFull;
@@ -74,6 +75,7 @@ impl fmt::Debug for RangeFull {
 /// assert_eq!(arr[1.. ], [     'b', 'c', 'd']);
 /// assert_eq!(arr[1..3], [     'b', 'c'     ]);  // Range
 /// ```
+#[doc(alias = "..")]
 #[derive(Clone, PartialEq, Eq, Hash)]  // not Copy -- see #27186
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Range<Idx> {
@@ -175,6 +177,7 @@ impl<Idx: PartialOrd<Idx>> Range<Idx> {
 /// ```
 ///
 /// [`Iterator`]: ../iter/trait.IntoIterator.html
+#[doc(alias = "..")]
 #[derive(Clone, PartialEq, Eq, Hash)]  // not Copy -- see #27186
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct RangeFrom<Idx> {
@@ -256,6 +259,7 @@ impl<Idx: PartialOrd<Idx>> RangeFrom<Idx> {
 /// [`IntoIterator`]: ../iter/trait.Iterator.html
 /// [`Iterator`]: ../iter/trait.IntoIterator.html
 /// [slicing index]: ../slice/trait.SliceIndex.html
+#[doc(alias = "..")]
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct RangeTo<Idx> {
@@ -314,26 +318,101 @@ impl<Idx: PartialOrd<Idx>> RangeTo<Idx> {
 /// # Examples
 ///
 /// ```
-/// #![feature(inclusive_range_fields)]
+/// #![feature(inclusive_range_methods)]
 ///
-/// assert_eq!((3..=5), std::ops::RangeInclusive { start: 3, end: 5 });
+/// assert_eq!((3..=5), std::ops::RangeInclusive::new(3, 5));
 /// assert_eq!(3 + 4 + 5, (3..=5).sum());
 ///
 /// let arr = [0, 1, 2, 3];
 /// assert_eq!(arr[ ..=2], [0,1,2  ]);
 /// assert_eq!(arr[1..=2], [  1,2  ]);  // RangeInclusive
 /// ```
+#[doc(alias = "..=")]
 #[derive(Clone, PartialEq, Eq, Hash)]  // not Copy -- see #27186
 #[stable(feature = "inclusive_range", since = "1.26.0")]
 pub struct RangeInclusive<Idx> {
+    // FIXME: The current representation follows RFC 1980,
+    // but it is known that LLVM is not able to optimize loops following that RFC.
+    // Consider adding an extra `bool` field to indicate emptiness of the range.
+    // See #45222 for performance test cases.
+    #[cfg(not(stage0))]
+    pub(crate) start: Idx,
+    #[cfg(not(stage0))]
+    pub(crate) end: Idx,
     /// The lower bound of the range (inclusive).
+    #[cfg(stage0)]
     #[unstable(feature = "inclusive_range_fields", issue = "49022")]
     pub start: Idx,
     /// The upper bound of the range (inclusive).
+    #[cfg(stage0)]
     #[unstable(feature = "inclusive_range_fields", issue = "49022")]
     pub end: Idx,
 }
 
+impl<Idx> RangeInclusive<Idx> {
+    /// Creates a new inclusive range. Equivalent to writing `start..=end`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(inclusive_range_methods)]
+    /// use std::ops::RangeInclusive;
+    ///
+    /// assert_eq!(3..=5, RangeInclusive::new(3, 5));
+    /// ```
+    #[unstable(feature = "inclusive_range_methods", issue = "49022")]
+    #[inline]
+    pub const fn new(start: Idx, end: Idx) -> Self {
+        Self { start, end }
+    }
+
+    /// Returns the lower bound of the range (inclusive).
+    ///
+    /// When using an inclusive range for iteration, the values of `start()` and
+    /// [`end()`] are unspecified after the iteration ended. To determine
+    /// whether the inclusive range is empty, use the [`is_empty()`] method
+    /// instead of comparing `start() > end()`.
+    ///
+    /// [`end()`]: #method.end
+    /// [`is_empty()`]: #method.is_empty
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(inclusive_range_methods)]
+    ///
+    /// assert_eq!((3..=5).start(), &3);
+    /// ```
+    #[unstable(feature = "inclusive_range_methods", issue = "49022")]
+    #[inline]
+    pub fn start(&self) -> &Idx {
+        &self.start
+    }
+
+    /// Returns the upper bound of the range (inclusive).
+    ///
+    /// When using an inclusive range for iteration, the values of [`start()`]
+    /// and `end()` are unspecified after the iteration ended. To determine
+    /// whether the inclusive range is empty, use the [`is_empty()`] method
+    /// instead of comparing `start() > end()`.
+    ///
+    /// [`start()`]: #method.start
+    /// [`is_empty()`]: #method.is_empty
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(inclusive_range_methods)]
+    ///
+    /// assert_eq!((3..=5).end(), &5);
+    /// ```
+    #[unstable(feature = "inclusive_range_methods", issue = "49022")]
+    #[inline]
+    pub fn end(&self) -> &Idx {
+        &self.end
+    }
+}
+
 #[stable(feature = "inclusive_range", since = "1.26.0")]
 impl<Idx: fmt::Debug> fmt::Debug for RangeInclusive<Idx> {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
@@ -449,6 +528,7 @@ impl<Idx: PartialOrd<Idx>> RangeInclusive<Idx> {
 /// [`IntoIterator`]: ../iter/trait.Iterator.html
 /// [`Iterator`]: ../iter/trait.IntoIterator.html
 /// [slicing index]: ../slice/trait.SliceIndex.html
+#[doc(alias = "..=")]
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 #[stable(feature = "inclusive_range", since = "1.26.0")]
 pub struct RangeToInclusive<Idx> {
diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
index 74bb264cc67..5d0b675e8e4 100644
--- a/src/libcore/ptr.rs
+++ b/src/libcore/ptr.rs
@@ -2513,6 +2513,7 @@ impl<T: ?Sized> PartialOrd for *mut T {
            reason = "use NonNull instead and consider PhantomData<T> \
                      (if you also use #[may_dangle]), Send, and/or Sync")]
 #[allow(deprecated)]
+#[doc(hidden)]
 pub struct Unique<T: ?Sized> {
     pointer: NonZero<*const T>,
     // NOTE: this marker has no consequences for variance, but is necessary
@@ -2551,10 +2552,9 @@ impl<T: Sized> Unique<T> {
     /// This is useful for initializing types which lazily allocate, like
     /// `Vec::new` does.
     // FIXME: rename to dangling() to match NonNull?
-    pub fn empty() -> Self {
+    pub const fn empty() -> Self {
         unsafe {
-            let ptr = mem::align_of::<T>() as *mut T;
-            Unique::new_unchecked(ptr)
+            Unique::new_unchecked(mem::align_of::<T>() as *mut T)
         }
     }
 }
diff --git a/src/libcore/slice/memchr.rs b/src/libcore/slice/memchr.rs
index 69c9cb37dcf..7b62e7b0620 100644
--- a/src/libcore/slice/memchr.rs
+++ b/src/libcore/slice/memchr.rs
@@ -39,21 +39,10 @@ fn repeat_byte(b: u8) -> usize {
     (b as usize) << 8 | b as usize
 }
 
-#[cfg(target_pointer_width = "32")]
+#[cfg(not(target_pointer_width = "16"))]
 #[inline]
 fn repeat_byte(b: u8) -> usize {
-    let mut rep = (b as usize) << 8 | b as usize;
-    rep = rep << 16 | rep;
-    rep
-}
-
-#[cfg(target_pointer_width = "64")]
-#[inline]
-fn repeat_byte(b: u8) -> usize {
-    let mut rep = (b as usize) << 8 | b as usize;
-    rep = rep << 16 | rep;
-    rep = rep << 32 | rep;
-    rep
+    (b as usize) * (::usize::MAX / 255)
 }
 
 /// Return the first index matching the byte `x` in `text`.
@@ -146,85 +135,3 @@ pub fn memrchr(x: u8, text: &[u8]) -> Option<usize> {
     // find the byte before the point the body loop stopped
     text[..offset].iter().rposition(|elt| *elt == x)
 }
-
-// test fallback implementations on all platforms
-#[test]
-fn matches_one() {
-    assert_eq!(Some(0), memchr(b'a', b"a"));
-}
-
-#[test]
-fn matches_begin() {
-    assert_eq!(Some(0), memchr(b'a', b"aaaa"));
-}
-
-#[test]
-fn matches_end() {
-    assert_eq!(Some(4), memchr(b'z', b"aaaaz"));
-}
-
-#[test]
-fn matches_nul() {
-    assert_eq!(Some(4), memchr(b'\x00', b"aaaa\x00"));
-}
-
-#[test]
-fn matches_past_nul() {
-    assert_eq!(Some(5), memchr(b'z', b"aaaa\x00z"));
-}
-
-#[test]
-fn no_match_empty() {
-    assert_eq!(None, memchr(b'a', b""));
-}
-
-#[test]
-fn no_match() {
-    assert_eq!(None, memchr(b'a', b"xyz"));
-}
-
-#[test]
-fn matches_one_reversed() {
-    assert_eq!(Some(0), memrchr(b'a', b"a"));
-}
-
-#[test]
-fn matches_begin_reversed() {
-    assert_eq!(Some(3), memrchr(b'a', b"aaaa"));
-}
-
-#[test]
-fn matches_end_reversed() {
-    assert_eq!(Some(0), memrchr(b'z', b"zaaaa"));
-}
-
-#[test]
-fn matches_nul_reversed() {
-    assert_eq!(Some(4), memrchr(b'\x00', b"aaaa\x00"));
-}
-
-#[test]
-fn matches_past_nul_reversed() {
-    assert_eq!(Some(0), memrchr(b'z', b"z\x00aaaa"));
-}
-
-#[test]
-fn no_match_empty_reversed() {
-    assert_eq!(None, memrchr(b'a', b""));
-}
-
-#[test]
-fn no_match_reversed() {
-    assert_eq!(None, memrchr(b'a', b"xyz"));
-}
-
-#[test]
-fn each_alignment_reversed() {
-    let mut data = [1u8; 64];
-    let needle = 2;
-    let pos = 40;
-    data[pos] = needle;
-    for start in 0..16 {
-        assert_eq!(Some(pos - start), memrchr(needle, &data[start..]));
-    }
-}
diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs
index cc42acd77ae..83e8a6e4b68 100644
--- a/src/libcore/slice/mod.rs
+++ b/src/libcore/slice/mod.rs
@@ -880,7 +880,6 @@ macro_rules! slice_core_methods { () => {
     #[inline]
     pub fn split_last(&self) -> Option<(&T, &[T])> {
         SliceExt::split_last(self)
-
     }
 
     /// Returns the last and all the rest of the elements of the slice, or `None` if it is empty.
diff --git a/src/libcore/tests/lib.rs b/src/libcore/tests/lib.rs
index 111cf58c2c6..28dac02654b 100644
--- a/src/libcore/tests/lib.rs
+++ b/src/libcore/tests/lib.rs
@@ -44,9 +44,10 @@
 #![feature(exact_chunks)]
 #![cfg_attr(stage0, feature(atomic_nand))]
 #![feature(reverse_bits)]
-#![feature(inclusive_range_fields)]
+#![feature(inclusive_range_methods)]
 #![feature(iterator_find_map)]
 #![feature(inner_deref)]
+#![feature(slice_internals)]
 
 extern crate core;
 extern crate test;
@@ -75,4 +76,5 @@ mod result;
 mod slice;
 mod str;
 mod str_lossy;
+mod time;
 mod tuple;
diff --git a/src/libcore/tests/num/uint_macros.rs b/src/libcore/tests/num/uint_macros.rs
index ca6906f7310..257f6ea20d4 100644
--- a/src/libcore/tests/num/uint_macros.rs
+++ b/src/libcore/tests/num/uint_macros.rs
@@ -98,6 +98,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg(not(stage0))]
     fn test_reverse_bits() {
         assert_eq!(A.reverse_bits().reverse_bits(), A);
         assert_eq!(B.reverse_bits().reverse_bits(), B);
diff --git a/src/libcore/tests/ops.rs b/src/libcore/tests/ops.rs
index bed08f86d72..d66193b1687 100644
--- a/src/libcore/tests/ops.rs
+++ b/src/libcore/tests/ops.rs
@@ -50,21 +50,21 @@ fn test_full_range() {
 
 #[test]
 fn test_range_inclusive() {
-    let mut r = RangeInclusive { start: 1i8, end: 2 };
+    let mut r = RangeInclusive::new(1i8, 2);
     assert_eq!(r.next(), Some(1));
     assert_eq!(r.next(), Some(2));
     assert_eq!(r.next(), None);
 
-    r = RangeInclusive { start: 127i8, end: 127 };
+    r = RangeInclusive::new(127i8, 127);
     assert_eq!(r.next(), Some(127));
     assert_eq!(r.next(), None);
 
-    r = RangeInclusive { start: -128i8, end: -128 };
+    r = RangeInclusive::new(-128i8, -128);
     assert_eq!(r.next_back(), Some(-128));
     assert_eq!(r.next_back(), None);
 
     // degenerate
-    r = RangeInclusive { start: 1, end: -1 };
+    r = RangeInclusive::new(1, -1);
     assert_eq!(r.size_hint(), (0, Some(0)));
     assert_eq!(r.next(), None);
 }
diff --git a/src/libcore/tests/slice.rs b/src/libcore/tests/slice.rs
index 53fdfa06827..c81e5e97cbb 100644
--- a/src/libcore/tests/slice.rs
+++ b/src/libcore/tests/slice.rs
@@ -550,3 +550,89 @@ fn sort_unstable() {
     v.sort_unstable();
     assert!(v == [0xDEADBEEF]);
 }
+
+pub mod memchr {
+    use core::slice::memchr::{memchr, memrchr};
+
+    // test fallback implementations on all platforms
+    #[test]
+    fn matches_one() {
+        assert_eq!(Some(0), memchr(b'a', b"a"));
+    }
+
+    #[test]
+    fn matches_begin() {
+        assert_eq!(Some(0), memchr(b'a', b"aaaa"));
+    }
+
+    #[test]
+    fn matches_end() {
+        assert_eq!(Some(4), memchr(b'z', b"aaaaz"));
+    }
+
+    #[test]
+    fn matches_nul() {
+        assert_eq!(Some(4), memchr(b'\x00', b"aaaa\x00"));
+    }
+
+    #[test]
+    fn matches_past_nul() {
+        assert_eq!(Some(5), memchr(b'z', b"aaaa\x00z"));
+    }
+
+    #[test]
+    fn no_match_empty() {
+        assert_eq!(None, memchr(b'a', b""));
+    }
+
+    #[test]
+    fn no_match() {
+        assert_eq!(None, memchr(b'a', b"xyz"));
+    }
+
+    #[test]
+    fn matches_one_reversed() {
+        assert_eq!(Some(0), memrchr(b'a', b"a"));
+    }
+
+    #[test]
+    fn matches_begin_reversed() {
+        assert_eq!(Some(3), memrchr(b'a', b"aaaa"));
+    }
+
+    #[test]
+    fn matches_end_reversed() {
+        assert_eq!(Some(0), memrchr(b'z', b"zaaaa"));
+    }
+
+    #[test]
+    fn matches_nul_reversed() {
+        assert_eq!(Some(4), memrchr(b'\x00', b"aaaa\x00"));
+    }
+
+    #[test]
+    fn matches_past_nul_reversed() {
+        assert_eq!(Some(0), memrchr(b'z', b"z\x00aaaa"));
+    }
+
+    #[test]
+    fn no_match_empty_reversed() {
+        assert_eq!(None, memrchr(b'a', b""));
+    }
+
+    #[test]
+    fn no_match_reversed() {
+        assert_eq!(None, memrchr(b'a', b"xyz"));
+    }
+
+    #[test]
+    fn each_alignment_reversed() {
+        let mut data = [1u8; 64];
+        let needle = 2;
+        let pos = 40;
+        data[pos] = needle;
+        for start in 0..16 {
+            assert_eq!(Some(pos - start), memrchr(needle, &data[start..]));
+        }
+    }
+}
diff --git a/src/libcore/tests/time.rs b/src/libcore/tests/time.rs
new file mode 100644
index 00000000000..042c523f25f
--- /dev/null
+++ b/src/libcore/tests/time.rs
@@ -0,0 +1,124 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use core::time::Duration;
+
+#[test]
+fn creation() {
+    assert!(Duration::from_secs(1) != Duration::from_secs(0));
+    assert_eq!(Duration::from_secs(1) + Duration::from_secs(2),
+               Duration::from_secs(3));
+    assert_eq!(Duration::from_millis(10) + Duration::from_secs(4),
+               Duration::new(4, 10 * 1_000_000));
+    assert_eq!(Duration::from_millis(4000), Duration::new(4, 0));
+}
+
+#[test]
+fn secs() {
+    assert_eq!(Duration::new(0, 0).as_secs(), 0);
+    assert_eq!(Duration::from_secs(1).as_secs(), 1);
+    assert_eq!(Duration::from_millis(999).as_secs(), 0);
+    assert_eq!(Duration::from_millis(1001).as_secs(), 1);
+}
+
+#[test]
+fn nanos() {
+    assert_eq!(Duration::new(0, 0).subsec_nanos(), 0);
+    assert_eq!(Duration::new(0, 5).subsec_nanos(), 5);
+    assert_eq!(Duration::new(0, 1_000_000_001).subsec_nanos(), 1);
+    assert_eq!(Duration::from_secs(1).subsec_nanos(), 0);
+    assert_eq!(Duration::from_millis(999).subsec_nanos(), 999 * 1_000_000);
+    assert_eq!(Duration::from_millis(1001).subsec_nanos(), 1 * 1_000_000);
+}
+
+#[test]
+fn add() {
+    assert_eq!(Duration::new(0, 0) + Duration::new(0, 1),
+               Duration::new(0, 1));
+    assert_eq!(Duration::new(0, 500_000_000) + Duration::new(0, 500_000_001),
+               Duration::new(1, 1));
+}
+
+#[test]
+fn checked_add() {
+    assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)),
+               Some(Duration::new(0, 1)));
+    assert_eq!(Duration::new(0, 500_000_000).checked_add(Duration::new(0, 500_000_001)),
+               Some(Duration::new(1, 1)));
+    assert_eq!(Duration::new(1, 0).checked_add(Duration::new(::core::u64::MAX, 0)), None);
+}
+
+#[test]
+fn sub() {
+    assert_eq!(Duration::new(0, 1) - Duration::new(0, 0),
+               Duration::new(0, 1));
+    assert_eq!(Duration::new(0, 500_000_001) - Duration::new(0, 500_000_000),
+               Duration::new(0, 1));
+    assert_eq!(Duration::new(1, 0) - Duration::new(0, 1),
+               Duration::new(0, 999_999_999));
+}
+
+#[test]
+fn checked_sub() {
+    let zero = Duration::new(0, 0);
+    let one_nano = Duration::new(0, 1);
+    let one_sec = Duration::new(1, 0);
+    assert_eq!(one_nano.checked_sub(zero), Some(Duration::new(0, 1)));
+    assert_eq!(one_sec.checked_sub(one_nano),
+               Some(Duration::new(0, 999_999_999)));
+    assert_eq!(zero.checked_sub(one_nano), None);
+    assert_eq!(zero.checked_sub(one_sec), None);
+}
+
+#[test]
+#[should_panic]
+fn sub_bad1() {
+    let _ = Duration::new(0, 0) - Duration::new(0, 1);
+}
+
+#[test]
+#[should_panic]
+fn sub_bad2() {
+    let _ = Duration::new(0, 0) - Duration::new(1, 0);
+}
+
+#[test]
+fn mul() {
+    assert_eq!(Duration::new(0, 1) * 2, Duration::new(0, 2));
+    assert_eq!(Duration::new(1, 1) * 3, Duration::new(3, 3));
+    assert_eq!(Duration::new(0, 500_000_001) * 4, Duration::new(2, 4));
+    assert_eq!(Duration::new(0, 500_000_001) * 4000,
+               Duration::new(2000, 4000));
+}
+
+#[test]
+fn checked_mul() {
+    assert_eq!(Duration::new(0, 1).checked_mul(2), Some(Duration::new(0, 2)));
+    assert_eq!(Duration::new(1, 1).checked_mul(3), Some(Duration::new(3, 3)));
+    assert_eq!(Duration::new(0, 500_000_001).checked_mul(4), Some(Duration::new(2, 4)));
+    assert_eq!(Duration::new(0, 500_000_001).checked_mul(4000),
+               Some(Duration::new(2000, 4000)));
+    assert_eq!(Duration::new(::core::u64::MAX - 1, 0).checked_mul(2), None);
+}
+
+#[test]
+fn div() {
+    assert_eq!(Duration::new(0, 1) / 2, Duration::new(0, 0));
+    assert_eq!(Duration::new(1, 1) / 3, Duration::new(0, 333_333_333));
+    assert_eq!(Duration::new(99, 999_999_000) / 100,
+               Duration::new(0, 999_999_990));
+}
+
+#[test]
+fn checked_div() {
+    assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
+    assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
+    assert_eq!(Duration::new(2, 0).checked_div(0), None);
+}
diff --git a/src/libcore/time.rs b/src/libcore/time.rs
index e22fe450bb1..8e8b1691c65 100644
--- a/src/libcore/time.rs
+++ b/src/libcore/time.rs
@@ -481,119 +481,3 @@ impl<'a> Sum<&'a Duration> for Duration {
         iter.fold(Duration::new(0, 0), |a, b| a + *b)
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::Duration;
-
-    #[test]
-    fn creation() {
-        assert!(Duration::from_secs(1) != Duration::from_secs(0));
-        assert_eq!(Duration::from_secs(1) + Duration::from_secs(2),
-                   Duration::from_secs(3));
-        assert_eq!(Duration::from_millis(10) + Duration::from_secs(4),
-                   Duration::new(4, 10 * 1_000_000));
-        assert_eq!(Duration::from_millis(4000), Duration::new(4, 0));
-    }
-
-    #[test]
-    fn secs() {
-        assert_eq!(Duration::new(0, 0).as_secs(), 0);
-        assert_eq!(Duration::from_secs(1).as_secs(), 1);
-        assert_eq!(Duration::from_millis(999).as_secs(), 0);
-        assert_eq!(Duration::from_millis(1001).as_secs(), 1);
-    }
-
-    #[test]
-    fn nanos() {
-        assert_eq!(Duration::new(0, 0).subsec_nanos(), 0);
-        assert_eq!(Duration::new(0, 5).subsec_nanos(), 5);
-        assert_eq!(Duration::new(0, 1_000_000_001).subsec_nanos(), 1);
-        assert_eq!(Duration::from_secs(1).subsec_nanos(), 0);
-        assert_eq!(Duration::from_millis(999).subsec_nanos(), 999 * 1_000_000);
-        assert_eq!(Duration::from_millis(1001).subsec_nanos(), 1 * 1_000_000);
-    }
-
-    #[test]
-    fn add() {
-        assert_eq!(Duration::new(0, 0) + Duration::new(0, 1),
-                   Duration::new(0, 1));
-        assert_eq!(Duration::new(0, 500_000_000) + Duration::new(0, 500_000_001),
-                   Duration::new(1, 1));
-    }
-
-    #[test]
-    fn checked_add() {
-        assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)),
-                   Some(Duration::new(0, 1)));
-        assert_eq!(Duration::new(0, 500_000_000).checked_add(Duration::new(0, 500_000_001)),
-                   Some(Duration::new(1, 1)));
-        assert_eq!(Duration::new(1, 0).checked_add(Duration::new(::u64::MAX, 0)), None);
-    }
-
-    #[test]
-    fn sub() {
-        assert_eq!(Duration::new(0, 1) - Duration::new(0, 0),
-                   Duration::new(0, 1));
-        assert_eq!(Duration::new(0, 500_000_001) - Duration::new(0, 500_000_000),
-                   Duration::new(0, 1));
-        assert_eq!(Duration::new(1, 0) - Duration::new(0, 1),
-                   Duration::new(0, 999_999_999));
-    }
-
-    #[test]
-    fn checked_sub() {
-        let zero = Duration::new(0, 0);
-        let one_nano = Duration::new(0, 1);
-        let one_sec = Duration::new(1, 0);
-        assert_eq!(one_nano.checked_sub(zero), Some(Duration::new(0, 1)));
-        assert_eq!(one_sec.checked_sub(one_nano),
-                   Some(Duration::new(0, 999_999_999)));
-        assert_eq!(zero.checked_sub(one_nano), None);
-        assert_eq!(zero.checked_sub(one_sec), None);
-    }
-
-    #[test] #[should_panic]
-    fn sub_bad1() {
-        Duration::new(0, 0) - Duration::new(0, 1);
-    }
-
-    #[test] #[should_panic]
-    fn sub_bad2() {
-        Duration::new(0, 0) - Duration::new(1, 0);
-    }
-
-    #[test]
-    fn mul() {
-        assert_eq!(Duration::new(0, 1) * 2, Duration::new(0, 2));
-        assert_eq!(Duration::new(1, 1) * 3, Duration::new(3, 3));
-        assert_eq!(Duration::new(0, 500_000_001) * 4, Duration::new(2, 4));
-        assert_eq!(Duration::new(0, 500_000_001) * 4000,
-                   Duration::new(2000, 4000));
-    }
-
-    #[test]
-    fn checked_mul() {
-        assert_eq!(Duration::new(0, 1).checked_mul(2), Some(Duration::new(0, 2)));
-        assert_eq!(Duration::new(1, 1).checked_mul(3), Some(Duration::new(3, 3)));
-        assert_eq!(Duration::new(0, 500_000_001).checked_mul(4), Some(Duration::new(2, 4)));
-        assert_eq!(Duration::new(0, 500_000_001).checked_mul(4000),
-                   Some(Duration::new(2000, 4000)));
-        assert_eq!(Duration::new(::u64::MAX - 1, 0).checked_mul(2), None);
-    }
-
-    #[test]
-    fn div() {
-        assert_eq!(Duration::new(0, 1) / 2, Duration::new(0, 0));
-        assert_eq!(Duration::new(1, 1) / 3, Duration::new(0, 333_333_333));
-        assert_eq!(Duration::new(99, 999_999_000) / 100,
-                   Duration::new(0, 999_999_990));
-    }
-
-    #[test]
-    fn checked_div() {
-        assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
-        assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
-        assert_eq!(Duration::new(2, 0).checked_div(0), None);
-    }
-}
diff --git a/src/libcore/unicode/bool_trie.rs b/src/libcore/unicode/bool_trie.rs
index 3e45b08f399..0e6437fded5 100644
--- a/src/libcore/unicode/bool_trie.rs
+++ b/src/libcore/unicode/bool_trie.rs
@@ -42,15 +42,15 @@ pub struct BoolTrie {
 }
 impl BoolTrie {
     pub fn lookup(&self, c: char) -> bool {
-        let c = c as usize;
+        let c = c as u32;
         if c < 0x800 {
-            trie_range_leaf(c, self.r1[c >> 6])
+            trie_range_leaf(c, self.r1[(c >> 6) as usize])
         } else if c < 0x10000 {
-            let child = self.r2[(c >> 6) - 0x20];
+            let child = self.r2[(c >> 6) as usize - 0x20];
             trie_range_leaf(c, self.r3[child as usize])
         } else {
-            let child = self.r4[(c >> 12) - 0x10];
-            let leaf = self.r5[((child as usize) << 6) + ((c >> 6) & 0x3f)];
+            let child = self.r4[(c >> 12) as usize - 0x10];
+            let leaf = self.r5[((child as usize) << 6) + ((c >> 6) as usize & 0x3f)];
             trie_range_leaf(c, self.r6[leaf as usize])
         }
     }
@@ -63,14 +63,14 @@ pub struct SmallBoolTrie {
 
 impl SmallBoolTrie {
     pub fn lookup(&self, c: char) -> bool {
-        let c = c as usize;
-        match self.r1.get(c >> 6) {
+        let c = c as u32;
+        match self.r1.get((c >> 6) as usize) {
             Some(&child) => trie_range_leaf(c, self.r2[child as usize]),
             None => false,
         }
     }
 }
 
-fn trie_range_leaf(c: usize, bitmap_chunk: u64) -> bool {
+fn trie_range_leaf(c: u32, bitmap_chunk: u64) -> bool {
     ((bitmap_chunk >> (c & 63)) & 1) != 0
 }