diff --git a/src/libcollections/binary_heap.rs b/src/libcollections/binary_heap.rs
index efa96ca468e01..a28578e305b42 100644
--- a/src/libcollections/binary_heap.rs
+++ b/src/libcollections/binary_heap.rs
@@ -941,7 +941,7 @@ impl<'a, T> Hole<'a, T> {
     /// Unsafe because index must be within the data slice and not equal to pos.
     #[inline]
     unsafe fn get(&self, index: usize) -> &T {
-        debug_assert!(index != self.pos);
+        debug_assert_ne!(index, self.pos);
         debug_assert!(index < self.data.len());
         self.data.get_unchecked(index)
     }
@@ -951,7 +951,7 @@ impl<'a, T> Hole<'a, T> {
     /// Unsafe because index must be within the data slice and not equal to pos.
     #[inline]
     unsafe fn move_to(&mut self, index: usize) {
-        debug_assert!(index != self.pos);
+        debug_assert_ne!(index, self.pos);
         debug_assert!(index < self.data.len());
         let index_ptr: *const _ = self.data.get_unchecked(index);
         let hole_ptr = self.data.get_unchecked_mut(self.pos);
@@ -1194,8 +1194,8 @@ impl<T: Ord, I: IntoIterator<Item = T>> SpecExtend<I> for BinaryHeap<T> {
 }
 
 impl<T: Ord> SpecExtend<BinaryHeap<T>> for BinaryHeap<T> {
-    fn spec_extend(&mut self, ref mut other: BinaryHeap<T>) {
-        self.append(other);
+    fn spec_extend(&mut self, mut other: BinaryHeap<T>) {
+        self.append(&mut other);
     }
 }
 
diff --git a/src/libcollections/borrow.rs b/src/libcollections/borrow.rs
index 65056121f05a0..d625a94fe072d 100644
--- a/src/libcollections/borrow.rs
+++ b/src/libcollections/borrow.rs
@@ -254,7 +254,7 @@ impl<'a, B: ?Sized> fmt::Debug for Cow<'a, B>
 {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            Borrowed(ref b) => fmt::Debug::fmt(b, f),
+            Borrowed(b) => fmt::Debug::fmt(b, f),
             Owned(ref o) => fmt::Debug::fmt(o, f),
         }
     }
@@ -267,7 +267,7 @@ impl<'a, B: ?Sized> fmt::Display for Cow<'a, B>
 {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            Borrowed(ref b) => fmt::Display::fmt(b, f),
+            Borrowed(b) => fmt::Display::fmt(b, f),
             Owned(ref o) => fmt::Display::fmt(o, f),
         }
     }
diff --git a/src/libcollections/btree/map.rs b/src/libcollections/btree/map.rs
index dcacef4f0f0d5..f95bc2dc60dee 100644
--- a/src/libcollections/btree/map.rs
+++ b/src/libcollections/btree/map.rs
@@ -262,7 +262,7 @@ impl<K, Q: ?Sized> super::Recover<Q> for BTreeMap<K, ()>
     }
 }
 
-/// An iterator over a BTreeMap's entries.
+/// An iterator over a `BTreeMap`'s entries.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Iter<'a, K: 'a, V: 'a> {
     range: Range<'a, K, V>,
@@ -276,7 +276,7 @@ impl<'a, K: 'a + fmt::Debug, V: 'a + fmt::Debug> fmt::Debug for Iter<'a, K, V> {
     }
 }
 
-/// A mutable iterator over a BTreeMap's entries.
+/// A mutable iterator over a `BTreeMap`'s entries.
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Debug)]
 pub struct IterMut<'a, K: 'a, V: 'a> {
@@ -284,7 +284,7 @@ pub struct IterMut<'a, K: 'a, V: 'a> {
     length: usize,
 }
 
-/// An owning iterator over a BTreeMap's entries.
+/// An owning iterator over a `BTreeMap`'s entries.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct IntoIter<K, V> {
     front: Handle<NodeRef<marker::Owned, K, V, marker::Leaf>, marker::Edge>,
@@ -303,7 +303,7 @@ impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for IntoIter<K, V> {
     }
 }
 
-/// An iterator over a BTreeMap's keys.
+/// An iterator over a `BTreeMap`'s keys.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Keys<'a, K: 'a, V: 'a> {
     inner: Iter<'a, K, V>,
@@ -316,7 +316,7 @@ impl<'a, K: 'a + fmt::Debug, V: 'a + fmt::Debug> fmt::Debug for Keys<'a, K, V> {
     }
 }
 
-/// An iterator over a BTreeMap's values.
+/// An iterator over a `BTreeMap`'s values.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Values<'a, K: 'a, V: 'a> {
     inner: Iter<'a, K, V>,
@@ -329,14 +329,14 @@ impl<'a, K: 'a + fmt::Debug, V: 'a + fmt::Debug> fmt::Debug for Values<'a, K, V>
     }
 }
 
-/// A mutable iterator over a BTreeMap's values.
+/// A mutable iterator over a `BTreeMap`'s values.
 #[stable(feature = "map_values_mut", since = "1.10.0")]
 #[derive(Debug)]
 pub struct ValuesMut<'a, K: 'a, V: 'a> {
     inner: IterMut<'a, K, V>,
 }
 
-/// An iterator over a sub-range of BTreeMap's entries.
+/// An iterator over a sub-range of `BTreeMap`'s entries.
 #[stable(feature = "btree_range", since = "1.17.0")]
 pub struct Range<'a, K: 'a, V: 'a> {
     front: Handle<NodeRef<marker::Immut<'a>, K, V, marker::Leaf>, marker::Edge>,
@@ -350,7 +350,7 @@ impl<'a, K: 'a + fmt::Debug, V: 'a + fmt::Debug> fmt::Debug for Range<'a, K, V>
     }
 }
 
-/// A mutable iterator over a sub-range of BTreeMap's entries.
+/// A mutable iterator over a sub-range of `BTreeMap`'s entries.
 #[stable(feature = "btree_range", since = "1.17.0")]
 pub struct RangeMut<'a, K: 'a, V: 'a> {
     front: Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::Edge>,
@@ -685,12 +685,12 @@ impl<K: Ord, V> BTreeMap<K, V> {
     #[stable(feature = "btree_append", since = "1.11.0")]
     pub fn append(&mut self, other: &mut Self) {
         // Do we have to append anything at all?
-        if other.len() == 0 {
+        if other.is_empty() {
             return;
         }
 
         // We can just swap `self` and `other` if `self` is empty.
-        if self.len() == 0 {
+        if self.is_empty() {
             mem::swap(self, other);
             return;
         }
@@ -1894,7 +1894,7 @@ impl<K, V> BTreeMap<K, V> {
     /// assert_eq!(keys, [1, 2]);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn keys<'a>(&'a self) -> Keys<'a, K, V> {
+    pub fn keys(&self) -> Keys<K, V> {
         Keys { inner: self.iter() }
     }
 
@@ -1915,7 +1915,7 @@ impl<K, V> BTreeMap<K, V> {
     /// assert_eq!(values, ["hello", "goodbye"]);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn values<'a>(&'a self) -> Values<'a, K, V> {
+    pub fn values(&self) -> Values<K, V> {
         Values { inner: self.iter() }
     }
 
@@ -2354,8 +2354,8 @@ enum UnderflowResult<'a, K, V> {
     Stole(NodeRef<marker::Mut<'a>, K, V, marker::Internal>),
 }
 
-fn handle_underfull_node<'a, K, V>(node: NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>)
-                                   -> UnderflowResult<'a, K, V> {
+fn handle_underfull_node<K, V>(node: NodeRef<marker::Mut, K, V, marker::LeafOrInternal>)
+                               -> UnderflowResult<K, V> {
     let parent = if let Ok(parent) = node.ascend() {
         parent
     } else {
diff --git a/src/libcollections/btree/node.rs b/src/libcollections/btree/node.rs
index e9bc29118d508..e4cee815315fc 100644
--- a/src/libcollections/btree/node.rs
+++ b/src/libcollections/btree/node.rs
@@ -347,7 +347,7 @@ impl<BorrowType, K, V, Type> NodeRef<BorrowType, K, V, Type> {
     }
 
     /// Temporarily takes out another, immutable reference to the same node.
-    fn reborrow<'a>(&'a self) -> NodeRef<marker::Immut<'a>, K, V, Type> {
+    fn reborrow(&self) -> NodeRef<marker::Immut, K, V, Type> {
         NodeRef {
             height: self.height,
             node: self.node,
@@ -964,7 +964,7 @@ impl<'a, K, V> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Internal>, marker::
     fn insert_fit(&mut self, key: K, val: V, edge: Root<K, V>) {
         // Necessary for correctness, but in an internal module
         debug_assert!(self.node.len() < CAPACITY);
-        debug_assert!(edge.height == self.node.height - 1);
+        debug_assert_eq!(edge.height, self.node.height - 1);
 
         unsafe {
             // This cast is a lie, but it allows us to reuse the key/value insertion logic.
@@ -992,7 +992,7 @@ impl<'a, K, V> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Internal>, marker::
             -> InsertResult<'a, K, V, marker::Internal> {
 
         // Necessary for correctness, but this is an internal module
-        debug_assert!(edge.height == self.node.height - 1);
+        debug_assert_eq!(edge.height, self.node.height - 1);
 
         if self.node.len() < CAPACITY {
             self.insert_fit(key, val, edge);
@@ -1488,8 +1488,8 @@ impl<'a, K, V> Handle<NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>, ma
             let right_new_len = left_node.len() - left_new_len;
             let mut right_node = right.reborrow_mut();
 
-            debug_assert!(right_node.len() == 0);
-            debug_assert!(left_node.height == right_node.height);
+            debug_assert_eq!(right_node.len(), 0);
+            debug_assert_eq!(left_node.height, right_node.height);
 
             let left_kv = left_node.reborrow_mut().into_kv_pointers_mut();
             let right_kv = right_node.reborrow_mut().into_kv_pointers_mut();
diff --git a/src/libcollections/btree/set.rs b/src/libcollections/btree/set.rs
index 9dbb61379379e..acb38ccec0fc7 100644
--- a/src/libcollections/btree/set.rs
+++ b/src/libcollections/btree/set.rs
@@ -1053,7 +1053,7 @@ impl<'a, T: Ord> Iterator for Intersection<'a, T> {
     fn next(&mut self) -> Option<&'a T> {
         loop {
             let o_cmp = match (self.a.peek(), self.b.peek()) {
-                (None, _) => None,
+                (None, _) |
                 (_, None) => None,
                 (Some(a1), Some(b1)) => Some(a1.cmp(b1)),
             };
diff --git a/src/libcollections/enum_set.rs b/src/libcollections/enum_set.rs
index e56b94b2e1ea2..ebee75d1a1a64 100644
--- a/src/libcollections/enum_set.rs
+++ b/src/libcollections/enum_set.rs
@@ -215,7 +215,7 @@ impl<E: CLike> BitXor for EnumSet<E> {
     }
 }
 
-/// An iterator over an EnumSet
+/// An iterator over an `EnumSet`
 pub struct Iter<E> {
     index: usize,
     bits: usize,
diff --git a/src/libcollections/lib.rs b/src/libcollections/lib.rs
index 00448b6abb2cf..c55e63a5b2f04 100644
--- a/src/libcollections/lib.rs
+++ b/src/libcollections/lib.rs
@@ -10,7 +10,7 @@
 
 //! Collection types.
 //!
-//! See [std::collections](../std/collections/index.html) for a detailed discussion of
+//! See [`std::collections`](../std/collections/index.html) for a detailed discussion of
 //! collections in Rust.
 
 #![crate_name = "collections"]
diff --git a/src/libcollections/linked_list.rs b/src/libcollections/linked_list.rs
index 8f0488f69369e..4b5d5510fdf25 100644
--- a/src/libcollections/linked_list.rs
+++ b/src/libcollections/linked_list.rs
@@ -95,7 +95,7 @@ pub struct IterMut<'a, T: 'a> {
 impl<'a, T: 'a + fmt::Debug> fmt::Debug for IterMut<'a, T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_tuple("IterMut")
-         .field(self.clone())
+         .field(self)
          .finish()
     }
 }
@@ -111,7 +111,7 @@ pub struct IntoIter<T> {
 impl<T: fmt::Debug> fmt::Debug for IntoIter<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_tuple("IntoIter")
-         .field(self.clone())
+         .field(self)
          .finish()
     }
 }
@@ -1020,8 +1020,8 @@ impl<I: IntoIterator> SpecExtend<I> for LinkedList<I::Item> {
 }
 
 impl<T> SpecExtend<LinkedList<T>> for LinkedList<T> {
-    fn spec_extend(&mut self, ref mut other: LinkedList<T>) {
-        self.append(other);
+    fn spec_extend(&mut self, mut other: LinkedList<T>) {
+        self.append(&mut other);
     }
 }
 
@@ -1110,7 +1110,7 @@ pub struct FrontPlace<'a, T: 'a> {
 impl<'a, T: 'a + fmt::Debug> fmt::Debug for FrontPlace<'a, T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_tuple("FrontPlace")
-         .field(self.clone())
+         .field(self)
          .finish()
     }
 }
@@ -1165,7 +1165,7 @@ pub struct BackPlace<'a, T: 'a> {
 impl<'a, T: 'a + fmt::Debug> fmt::Debug for BackPlace<'a, T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_tuple("BackPlace")
-         .field(self.clone())
+         .field(self)
          .finish()
     }
 }
diff --git a/src/libcollections/range.rs b/src/libcollections/range.rs
index 06d89a6a70b4a..48d208f6efa8d 100644
--- a/src/libcollections/range.rs
+++ b/src/libcollections/range.rs
@@ -17,7 +17,7 @@
 use core::ops::{RangeFull, Range, RangeTo, RangeFrom, RangeInclusive, RangeToInclusive};
 use Bound::{self, Excluded, Included, Unbounded};
 
-/// **RangeArgument** is implemented by Rust's built-in range types, produced
+/// **`RangeArgument`** is implemented by Rust's built-in range types, produced
 /// by range syntax like `..`, `a..`, `..b` or `c..d`.
 pub trait RangeArgument<T: ?Sized> {
     /// Start index bound.
diff --git a/src/libcollections/slice.rs b/src/libcollections/slice.rs
index 6f8843c2374bc..cdfdd6cf78c35 100644
--- a/src/libcollections/slice.rs
+++ b/src/libcollections/slice.rs
@@ -1651,7 +1651,7 @@ unsafe fn merge<T, F>(v: &mut [T], mid: usize, buf: *mut T, is_less: &mut F)
     }
 }
 
-/// This merge sort borrows some (but not all) ideas from TimSort, which is described in detail
+/// This merge sort borrows some (but not all) ideas from `TimSort`, which is described in detail
 /// [here](http://svn.python.org/projects/python/trunk/Objects/listsort.txt).
 ///
 /// The algorithm identifies strictly descending and non-descending subsequences, which are called
diff --git a/src/libcollections/str.rs b/src/libcollections/str.rs
index 72db452093fc2..5f19b1fe8650a 100644
--- a/src/libcollections/str.rs
+++ b/src/libcollections/str.rs
@@ -133,9 +133,15 @@ impl<S: Borrow<str>> SliceConcatExt<str> for [S] {
     }
 }
 
-/// External iterator for a string's UTF-16 code units.
+/// An iterator of [`u16`] over the string encoded as UTF-16.
 ///
-/// For use with the `std::iter` module.
+/// [`u16`]: ../../std/primitive.u16.html
+///
+/// This struct is created by the [`encode_utf16`] method on [`str`].
+/// See its documentation for more.
+///
+/// [`encode_utf16`]: ../../std/primitive.str.html#method.encode_utf16
+/// [`str`]: ../../std/primitive.str.html
 #[derive(Clone)]
 #[stable(feature = "encode_utf16", since = "1.8.0")]
 pub struct EncodeUtf16<'a> {
@@ -1829,7 +1835,7 @@ impl str {
         fn map_uppercase_sigma(from: &str, i: usize, to: &mut String) {
             // See http://www.unicode.org/versions/Unicode7.0.0/ch03.pdf#G33992
             // for the definition of `Final_Sigma`.
-            debug_assert!('Σ'.len_utf8() == 2);
+            debug_assert_eq!('Σ'.len_utf8(), 2);
             let is_word_final = case_ignoreable_then_cased(from[..i].chars().rev()) &&
                                 !case_ignoreable_then_cased(from[i + 2..].chars());
             to.push_str(if is_word_final { "ς" } else { "σ" });
@@ -1876,7 +1882,7 @@ impl str {
     pub fn to_uppercase(&self) -> String {
         let mut s = String::with_capacity(self.len());
         s.extend(self.chars().flat_map(|c| c.to_uppercase()));
-        return s;
+        s
     }
 
     /// Escapes each char in `s` with `char::escape_debug`.
diff --git a/src/libcollections/string.rs b/src/libcollections/string.rs
index 0ee4c8b8e95a6..fdc5dd5e4a394 100644
--- a/src/libcollections/string.rs
+++ b/src/libcollections/string.rs
@@ -533,7 +533,7 @@ impl String {
     /// assert_eq!("Hello �World", output);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn from_utf8_lossy<'a>(v: &'a [u8]) -> Cow<'a, str> {
+    pub fn from_utf8_lossy(v: &[u8]) -> Cow<str> {
         let mut i;
         match str::from_utf8(v) {
             Ok(s) => return Cow::Borrowed(s),
@@ -591,9 +591,9 @@ impl String {
                     }
                     3 => {
                         match (byte, safe_get(v, i, total)) {
-                            (0xE0, 0xA0...0xBF) => (),
-                            (0xE1...0xEC, 0x80...0xBF) => (),
-                            (0xED, 0x80...0x9F) => (),
+                            (0xE0, 0xA0...0xBF) |
+                            (0xE1...0xEC, 0x80...0xBF) |
+                            (0xED, 0x80...0x9F) |
                             (0xEE...0xEF, 0x80...0xBF) => (),
                             _ => {
                                 error!();
@@ -609,8 +609,8 @@ impl String {
                     }
                     4 => {
                         match (byte, safe_get(v, i, total)) {
-                            (0xF0, 0x90...0xBF) => (),
-                            (0xF1...0xF3, 0x80...0xBF) => (),
+                            (0xF0, 0x90...0xBF) |
+                            (0xF1...0xF3, 0x80...0xBF) |
                             (0xF4, 0x80...0x8F) => (),
                             _ => {
                                 error!();
diff --git a/src/libcollections/vec.rs b/src/libcollections/vec.rs
index 56b60a3e00341..b2ea35a6b61a3 100644
--- a/src/libcollections/vec.rs
+++ b/src/libcollections/vec.rs
@@ -2052,21 +2052,19 @@ impl<T> Iterator for IntoIter<T> {
         unsafe {
             if self.ptr as *const _ == self.end {
                 None
+            } else if mem::size_of::<T>() == 0 {
+                // purposefully don't use 'ptr.offset' because for
+                // vectors with 0-size elements this would return the
+                // same pointer.
+                self.ptr = arith_offset(self.ptr as *const i8, 1) as *mut T;
+
+                // Use a non-null pointer value
+                Some(ptr::read(EMPTY as *mut T))
             } else {
-                if mem::size_of::<T>() == 0 {
-                    // purposefully don't use 'ptr.offset' because for
-                    // vectors with 0-size elements this would return the
-                    // same pointer.
-                    self.ptr = arith_offset(self.ptr as *const i8, 1) as *mut T;
-
-                    // Use a non-null pointer value
-                    Some(ptr::read(EMPTY as *mut T))
-                } else {
-                    let old = self.ptr;
-                    self.ptr = self.ptr.offset(1);
-
-                    Some(ptr::read(old))
-                }
+                let old = self.ptr;
+                self.ptr = self.ptr.offset(1);
+
+                Some(ptr::read(old))
             }
         }
     }
@@ -2097,18 +2095,16 @@ impl<T> DoubleEndedIterator for IntoIter<T> {
         unsafe {
             if self.end == self.ptr {
                 None
-            } else {
-                if mem::size_of::<T>() == 0 {
-                    // See above for why 'ptr.offset' isn't used
-                    self.end = arith_offset(self.end as *const i8, -1) as *mut T;
+            } else if mem::size_of::<T>() == 0 {
+                // See above for why 'ptr.offset' isn't used
+                self.end = arith_offset(self.end as *const i8, -1) as *mut T;
 
-                    // Use a non-null pointer value
-                    Some(ptr::read(EMPTY as *mut T))
-                } else {
-                    self.end = self.end.offset(-1);
+                // Use a non-null pointer value
+                Some(ptr::read(EMPTY as *mut T))
+            } else {
+                self.end = self.end.offset(-1);
 
-                    Some(ptr::read(self.end))
-                }
+                Some(ptr::read(self.end))
             }
         }
     }
diff --git a/src/libcollections/vec_deque.rs b/src/libcollections/vec_deque.rs
index cb92236ec736c..40bb4ced36660 100644
--- a/src/libcollections/vec_deque.rs
+++ b/src/libcollections/vec_deque.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-//! VecDeque is a double-ended queue, which is implemented with the help of a
+//! `VecDeque` is a double-ended queue, which is implemented with the help of a
 //! growing ring buffer.
 //!
 //! This queue has `O(1)` amortized inserts and removals from both ends of the
@@ -357,7 +357,7 @@ impl<T> VecDeque<T> {
         }
         debug_assert!(self.head < self.cap());
         debug_assert!(self.tail < self.cap());
-        debug_assert!(self.cap().count_ones() == 1);
+        debug_assert_eq!(self.cap().count_ones(), 1);
     }
 }
 
@@ -631,7 +631,7 @@ impl<T> VecDeque<T> {
 
             debug_assert!(self.head < self.cap());
             debug_assert!(self.tail < self.cap());
-            debug_assert!(self.cap().count_ones() == 1);
+            debug_assert_eq!(self.cap().count_ones(), 1);
         }
     }
 
@@ -1614,7 +1614,7 @@ impl<T> VecDeque<T> {
             }
         }
 
-        return elem;
+        elem
     }
 
     /// Splits the collection into two at the given index.
@@ -1847,7 +1847,7 @@ fn wrap_index(index: usize, size: usize) -> usize {
     index & (size - 1)
 }
 
-/// Returns the two slices that cover the VecDeque's valid range
+/// Returns the two slices that cover the `VecDeque`'s valid range
 trait RingSlices: Sized {
     fn slice(self, from: usize, to: usize) -> Self;
     fn split_at(self, i: usize) -> (Self, Self);
@@ -1983,7 +1983,7 @@ pub struct IterMut<'a, T: 'a> {
 impl<'a, T: 'a + fmt::Debug> fmt::Debug for IterMut<'a, T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_tuple("IterMut")
-         .field(&self.clone())
+         .field(&self)
          .finish()
     }
 }
@@ -2047,7 +2047,7 @@ impl<'a, T> ExactSizeIterator for IterMut<'a, T> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<'a, T> FusedIterator for IterMut<'a, T> {}
 
-/// A by-value VecDeque iterator
+/// A by-value `VecDeque` iterator
 #[derive(Clone)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct IntoIter<T> {
@@ -2058,7 +2058,7 @@ pub struct IntoIter<T> {
 impl<T: fmt::Debug> fmt::Debug for IntoIter<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_tuple("IntoIter")
-         .field(&self.clone())
+         .field(&self)
          .finish()
     }
 }
@@ -2097,7 +2097,7 @@ impl<T> ExactSizeIterator for IntoIter<T> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<T> FusedIterator for IntoIter<T> {}
 
-/// A draining VecDeque iterator
+/// A draining `VecDeque` iterator
 #[stable(feature = "drain", since = "1.6.0")]
 pub struct Drain<'a, T: 'a> {
     after_tail: usize,
@@ -2110,7 +2110,7 @@ pub struct Drain<'a, T: 'a> {
 impl<'a, T: 'a + fmt::Debug> fmt::Debug for Drain<'a, T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_tuple("Drain")
-         .field(&self.clone())
+         .field(&self)
          .finish()
     }
 }
@@ -2426,57 +2426,54 @@ impl<T> From<VecDeque<T>> for Vec<T> {
             // Need to move the ring to the front of the buffer, as vec will expect this.
             if other.is_contiguous() {
                 ptr::copy(buf.offset(tail as isize), buf, len);
-            } else {
-                if (tail - head) >= cmp::min((cap - tail), head) {
-                    // There is enough free space in the centre for the shortest block so we can
-                    // do this in at most three copy moves.
-                    if (cap - tail) > head {
-                        // right hand block is the long one; move that enough for the left
-                        ptr::copy(buf.offset(tail as isize),
-                                  buf.offset((tail - head) as isize),
-                                  cap - tail);
-                        // copy left in the end
-                        ptr::copy(buf, buf.offset((cap - head) as isize), head);
-                        // shift the new thing to the start
-                        ptr::copy(buf.offset((tail - head) as isize), buf, len);
-                    } else {
-                        // left hand block is the long one, we can do it in two!
-                        ptr::copy(buf, buf.offset((cap - tail) as isize), head);
-                        ptr::copy(buf.offset(tail as isize), buf, cap - tail);
-                    }
+            } else if (tail - head) >= cmp::min((cap - tail), head) {
+                // There is enough free space in the centre for the shortest block so we can
+                // do this in at most three copy moves.
+                if (cap - tail) > head {
+                    // right hand block is the long one; move that enough for the left
+                    ptr::copy(buf.offset(tail as isize),
+                              buf.offset((tail - head) as isize),
+                              cap - tail);
+                    // copy left in the end
+                    ptr::copy(buf, buf.offset((cap - head) as isize), head);
+                    // shift the new thing to the start
+                    ptr::copy(buf.offset((tail - head) as isize), buf, len);
                 } else {
-                    // Need to use N swaps to move the ring
-                    // We can use the space at the end of the ring as a temp store
-
-                    let mut left_edge: usize = 0;
-                    let mut right_edge: usize = tail;
-
-                    // The general problem looks like this
-                    // GHIJKLM...ABCDEF - before any swaps
-                    // ABCDEFM...GHIJKL - after 1 pass of swaps
-                    // ABCDEFGHIJM...KL - swap until the left edge reaches the temp store
-                    //                  - then restart the algorithm with a new (smaller) store
-                    // Sometimes the temp store is reached when the right edge is at the end
-                    // of the buffer - this means we've hit the right order with fewer swaps!
-                    // E.g
-                    // EF..ABCD
-                    // ABCDEF.. - after four only swaps we've finished
-
-                    while left_edge < len && right_edge != cap {
-                        let mut right_offset = 0;
-                        for i in left_edge..right_edge {
-                            right_offset = (i - left_edge) % (cap - right_edge);
-                            let src: isize = (right_edge + right_offset) as isize;
-                            ptr::swap(buf.offset(i as isize), buf.offset(src));
-                        }
-                        let n_ops = right_edge - left_edge;
-                        left_edge += n_ops;
-                        right_edge += right_offset + 1;
-
+                    // left hand block is the long one, we can do it in two!
+                    ptr::copy(buf, buf.offset((cap - tail) as isize), head);
+                    ptr::copy(buf.offset(tail as isize), buf, cap - tail);
+                }
+            } else {
+                // Need to use N swaps to move the ring
+                // We can use the space at the end of the ring as a temp store
+
+                let mut left_edge: usize = 0;
+                let mut right_edge: usize = tail;
+
+                // The general problem looks like this
+                // GHIJKLM...ABCDEF - before any swaps
+                // ABCDEFM...GHIJKL - after 1 pass of swaps
+                // ABCDEFGHIJM...KL - swap until the left edge reaches the temp store
+                //                  - then restart the algorithm with a new (smaller) store
+                // Sometimes the temp store is reached when the right edge is at the end
+                // of the buffer - this means we've hit the right order with fewer swaps!
+                // E.g
+                // EF..ABCD
+                // ABCDEF.. - after four only swaps we've finished
+
+                while left_edge < len && right_edge != cap {
+                    let mut right_offset = 0;
+                    for i in left_edge..right_edge {
+                        right_offset = (i - left_edge) % (cap - right_edge);
+                        let src: isize = (right_edge + right_offset) as isize;
+                        ptr::swap(buf.offset(i as isize), buf.offset(src));
                     }
+                    let n_ops = right_edge - left_edge;
+                    left_edge += n_ops;
+                    right_edge += right_offset + 1;
                 }
-
             }
+
             let out = Vec::from_raw_parts(buf, len, cap);
             mem::forget(other);
             out
diff --git a/src/libcollectionstest/slice.rs b/src/libcollectionstest/slice.rs
index 00d4dbe9c0458..c3e5304fb2b35 100644
--- a/src/libcollectionstest/slice.rs
+++ b/src/libcollectionstest/slice.rs
@@ -383,9 +383,11 @@ fn test_reverse() {
 
 #[test]
 fn test_sort() {
+    let mut rng = thread_rng();
+
     for len in (2..25).chain(500..510) {
         for _ in 0..100 {
-            let mut v: Vec<_> = thread_rng().gen_iter::<i32>().take(len).collect();
+            let mut v: Vec<_> = rng.gen_iter::<i32>().take(len).collect();
             let mut v1 = v.clone();
 
             v.sort();
@@ -399,6 +401,18 @@ fn test_sort() {
         }
     }
 
+    // Sort using a completely random comparison function.
+    // This will reorder the elements *somehow*, but won't panic.
+    let mut v = [0; 500];
+    for i in 0..v.len() {
+        v[i] = i as i32;
+    }
+    v.sort_by(|_, _| *rng.choose(&[Less, Equal, Greater]).unwrap());
+    v.sort();
+    for i in 0..v.len() {
+        assert_eq!(v[i], i as i32);
+    }
+
     // Should not panic.
     [0i32; 0].sort();
     [(); 10].sort();
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 5056adeaeeec3..f75a1f7ab6e0f 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -369,11 +369,15 @@ impl fmt::Display for Utf8Error {
 Section: Iterators
 */
 
-/// Iterator for the char (representing *Unicode Scalar Values*) of a string.
+/// An iterator over the [`char`]s of a string slice.
 ///
-/// Created with the method [`chars`].
+/// [`char`]: ../../std/primitive.char.html
+///
+/// This struct is created by the [`chars`] method on [`str`].
+/// See its documentation for more.
 ///
 /// [`chars`]: ../../std/primitive.str.html#method.chars
+/// [`str`]: ../../std/primitive.str.html
 #[derive(Clone, Debug)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Chars<'a> {
@@ -553,7 +557,15 @@ impl<'a> Chars<'a> {
     }
 }
 
-/// Iterator for a string's characters and their byte offsets.
+/// An iterator over the [`char`]s of a string slice, and their positions.
+///
+/// [`char`]: ../../std/primitive.char.html
+///
+/// This struct is created by the [`char_indices`] method on [`str`].
+/// See its documentation for more.
+///
+/// [`char_indices`]: ../../std/primitive.str.html#method.char_indices
+/// [`str`]: ../../std/primitive.str.html
 #[derive(Clone, Debug)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct CharIndices<'a> {
@@ -625,12 +637,13 @@ impl<'a> CharIndices<'a> {
     }
 }
 
-/// External iterator for a string's bytes.
-/// Use with the `std::iter` module.
+/// An iterator over the bytes of a string slice.
 ///
-/// Created with the method [`bytes`].
+/// This struct is created by the [`bytes`] method on [`str`].
+/// See its documentation for more.
 ///
 /// [`bytes`]: ../../std/primitive.str.html#method.bytes
+/// [`str`]: ../../std/primitive.str.html
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Clone, Debug)]
 pub struct Bytes<'a>(Cloned<slice::Iter<'a, u8>>);
@@ -1161,9 +1174,13 @@ generate_pattern_iterators! {
     delegate double ended;
 }
 
-/// Created with the method [`lines`].
+/// An iterator over the lines of a string, as string slices.
+///
+/// This struct is created with the [`lines`] method on [`str`].
+/// See its documentation for more.
 ///
 /// [`lines`]: ../../std/primitive.str.html#method.lines
+/// [`str`]: ../../std/primitive.str.html
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Clone, Debug)]
 pub struct Lines<'a>(Map<SplitTerminator<'a, char>, LinesAnyMap>);
diff --git a/src/libcore/sync/atomic.rs b/src/libcore/sync/atomic.rs
index 743e3c41170a3..ae47e6fdfa928 100644
--- a/src/libcore/sync/atomic.rs
+++ b/src/libcore/sync/atomic.rs
@@ -15,27 +15,37 @@
 //! types.
 //!
 //! This module defines atomic versions of a select number of primitive
-//! types, including `AtomicBool`, `AtomicIsize`, and `AtomicUsize`.
+//! types, including [`AtomicBool`], [`AtomicIsize`], and [`AtomicUsize`].
 //! Atomic types present operations that, when used correctly, synchronize
 //! updates between threads.
 //!
-//! Each method takes an `Ordering` which represents the strength of
+//! [`AtomicBool`]: struct.AtomicBool.html
+//! [`AtomicIsize`]: struct.AtomicIsize.html
+//! [`AtomicUsize`]: struct.AtomicUsize.html
+//!
+//! Each method takes an [`Ordering`] which represents the strength of
 //! the memory barrier for that operation. These orderings are the
 //! same as [LLVM atomic orderings][1]. For more information see the [nomicon][2].
 //!
+//! [`Ordering`]: enum.Ordering.html
+//!
 //! [1]: http://llvm.org/docs/LangRef.html#memory-model-for-concurrent-operations
 //! [2]: ../../../nomicon/atomics.html
 //!
-//! Atomic variables are safe to share between threads (they implement `Sync`)
+//! Atomic variables are safe to share between threads (they implement [`Sync`])
 //! but they do not themselves provide the mechanism for sharing and follow the
 //! [threading model](../../../std/thread/index.html#the-threading-model) of rust.
-//! The most common way to share an atomic variable is to put it into an `Arc` (an
+//! The most common way to share an atomic variable is to put it into an [`Arc`][arc] (an
 //! atomically-reference-counted shared pointer).
 //!
+//! [`Sync`]: ../../marker/trait.Sync.html
+//! [arc]: ../../../std/sync/struct.Arc.html
+//!
 //! Most atomic types may be stored in static variables, initialized using
-//! the provided static initializers like `ATOMIC_BOOL_INIT`. Atomic statics
+//! the provided static initializers like [`ATOMIC_BOOL_INIT`]. Atomic statics
 //! are often used for lazy global initialization.
 //!
+//! [`ATOMIC_BOOL_INIT`]: constant.ATOMIC_BOOL_INIT.html
 //!
 //! # Examples
 //!
@@ -148,22 +158,32 @@ unsafe impl<T> Sync for AtomicPtr<T> {}
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Copy, Clone, Debug)]
 pub enum Ordering {
-    /// No ordering constraints, only atomic operations. Corresponds to LLVM's
-    /// `Monotonic` ordering.
+    /// No ordering constraints, only atomic operations.
+    ///
+    /// Corresponds to LLVM's [`Monotonic`] ordering.
+    ///
+    /// [`Monotonic`]: http://llvm.org/docs/Atomics.html#monotonic
     #[stable(feature = "rust1", since = "1.0.0")]
     Relaxed,
     /// When coupled with a store, all previous writes become visible
-    /// to the other threads that perform a load with `Acquire` ordering
+    /// to the other threads that perform a load with [`Acquire`] ordering
     /// on the same value.
+    ///
+    /// [`Acquire`]: http://llvm.org/docs/Atomics.html#acquire
     #[stable(feature = "rust1", since = "1.0.0")]
     Release,
     /// When coupled with a load, all subsequent loads will see data
-    /// written before a store with `Release` ordering on the same value
+    /// written before a store with [`Release`] ordering on the same value
     /// in other threads.
+    ///
+    /// [`Release`]: http://llvm.org/docs/Atomics.html#release
     #[stable(feature = "rust1", since = "1.0.0")]
     Acquire,
-    /// When coupled with a load, uses `Acquire` ordering, and with a store
-    /// `Release` ordering.
+    /// When coupled with a load, uses [`Acquire`] ordering, and with a store
+    /// [`Release`] ordering.
+    ///
+    /// [`Acquire`]: http://llvm.org/docs/Atomics.html#acquire
+    /// [`Release`]: http://llvm.org/docs/Atomics.html#release
     #[stable(feature = "rust1", since = "1.0.0")]
     AcqRel,
     /// Like `AcqRel` with the additional guarantee that all threads see all
@@ -176,7 +196,9 @@ pub enum Ordering {
     __Nonexhaustive,
 }
 
-/// An `AtomicBool` initialized to `false`.
+/// An [`AtomicBool`] initialized to `false`.
+///
+/// [`AtomicBool`]: struct.AtomicBool.html
 #[cfg(target_has_atomic = "8")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub const ATOMIC_BOOL_INIT: AtomicBool = AtomicBool::new(false);
@@ -250,7 +272,7 @@ impl AtomicBool {
     ///
     /// [`Ordering`]: enum.Ordering.html
     /// [`Release`]: enum.Ordering.html#variant.Release
-    /// [`AcqRel`]: enum.Ordering.html#variant.Release
+    /// [`AcqRel`]: enum.Ordering.html#variant.AcqRel
     ///
     /// # Examples
     ///
@@ -287,7 +309,10 @@ impl AtomicBool {
     ///
     /// # Panics
     ///
-    /// Panics if `order` is `Acquire` or `AcqRel`.
+    /// Panics if `order` is [`Acquire`] or [`AcqRel`].
+    ///
+    /// [`Acquire`]: enum.Ordering.html#variant.Acquire
+    /// [`AcqRel`]: enum.Ordering.html#variant.AcqRel
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn store(&self, val: bool, order: Ordering) {
@@ -404,7 +429,7 @@ impl AtomicBool {
 
     /// Stores a value into the `bool` if the current value is the same as the `current` value.
     ///
-    /// Unlike `compare_exchange`, this function is allowed to spuriously fail even when the
+    /// Unlike [`compare_exchange`], this function is allowed to spuriously fail even when the
     /// comparison succeeds, which can result in more efficient code on some platforms. The
     /// return value is a result indicating whether the new value was written and containing the
     /// previous value.
@@ -415,6 +440,7 @@ impl AtomicBool {
     /// failure ordering can't be [`Release`] or [`AcqRel`] and must be equivalent or
     /// weaker than the success ordering.
     ///
+    /// [`compare_exchange`]: #method.compare_exchange
     /// [`Ordering`]: enum.Ordering.html
     /// [`Release`]: enum.Ordering.html#variant.Release
     /// [`AcqRel`]: enum.Ordering.html#variant.Release
@@ -694,7 +720,10 @@ impl<T> AtomicPtr<T> {
     ///
     /// # Panics
     ///
-    /// Panics if `order` is `Acquire` or `AcqRel`.
+    /// Panics if `order` is [`Acquire`] or [`AcqRel`].
+    ///
+    /// [`Acquire`]: enum.Ordering.html#variant.Acquire
+    /// [`AcqRel`]: enum.Ordering.html#variant.AcqRel
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn store(&self, ptr: *mut T, order: Ordering) {
@@ -1008,7 +1037,10 @@ macro_rules! atomic_int {
             ///
             /// # Panics
             ///
-            /// Panics if `order` is `Acquire` or `AcqRel`.
+            /// Panics if `order` is [`Acquire`] or [`AcqRel`].
+            ///
+            /// [`Acquire`]: enum.Ordering.html#variant.Acquire
+            /// [`AcqRel`]: enum.Ordering.html#variant.AcqRel
             #[inline]
             #[$stable]
             pub fn store(&self, val: $int_type, order: Ordering) {
diff --git a/src/libcoretest/slice.rs b/src/libcoretest/slice.rs
index 89bd3be08519c..ec38345030fa5 100644
--- a/src/libcoretest/slice.rs
+++ b/src/libcoretest/slice.rs
@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use core::cmp::Ordering::{Equal, Greater, Less};
 use core::slice::heapsort;
 use core::result::Result::{Ok, Err};
 use rand::{Rng, XorShiftRng};
@@ -268,6 +269,17 @@ fn sort_unstable() {
         }
     }
 
+    // Sort using a completely random comparison function.
+    // This will reorder the elements *somehow*, but won't panic.
+    for i in 0..v.len() {
+        v[i] = i as i32;
+    }
+    v.sort_unstable_by(|_, _| *rng.choose(&[Less, Equal, Greater]).unwrap());
+    v.sort_unstable();
+    for i in 0..v.len() {
+        assert_eq!(v[i], i as i32);
+    }
+
     // Should not panic.
     [0i32; 0].sort_unstable();
     [(); 10].sort_unstable();
diff --git a/src/librustc_lint/lib.rs b/src/librustc_lint/lib.rs
index 05dbbc0987025..8d759d89135ac 100644
--- a/src/librustc_lint/lib.rs
+++ b/src/librustc_lint/lib.rs
@@ -196,10 +196,6 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
             id: LintId::of(SUPER_OR_SELF_IN_GLOBAL_PATH),
             reference: "issue #36888 <https://github.com/rust-lang/rust/issues/36888>",
         },
-        FutureIncompatibleInfo {
-            id: LintId::of(OVERLAPPING_INHERENT_IMPLS),
-            reference: "issue #36889 <https://github.com/rust-lang/rust/issues/36889>",
-        },
         FutureIncompatibleInfo {
             id: LintId::of(ILLEGAL_FLOATING_POINT_CONSTANT_PATTERN),
             reference: "issue #36890 <https://github.com/rust-lang/rust/issues/36890>",
@@ -263,4 +259,5 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
     store.register_removed("drop_with_repr_extern", "drop flags have been removed");
     store.register_removed("transmute_from_fn_item_types",
         "always cast functions before transmuting them");
+    store.register_removed("overlapping_inherent_impls", "converted into hard error, see #36889");
 }
diff --git a/src/librustc_typeck/coherence/inherent_impls.rs b/src/librustc_typeck/coherence/inherent_impls.rs
index 3a39df505eb07..dc4bd7733fc21 100644
--- a/src/librustc_typeck/coherence/inherent_impls.rs
+++ b/src/librustc_typeck/coherence/inherent_impls.rs
@@ -322,4 +322,3 @@ impl<'a, 'tcx> InherentCollect<'a, 'tcx> {
         }
     }
 }
-
diff --git a/src/librustc_typeck/diagnostics.rs b/src/librustc_typeck/diagnostics.rs
index bd6129eb5bee3..fb951fd20e564 100644
--- a/src/librustc_typeck/diagnostics.rs
+++ b/src/librustc_typeck/diagnostics.rs
@@ -4212,4 +4212,5 @@ register_diagnostics! {
            // but `{}` was found in the type `{}`
     E0567, // auto traits can not have type parameters
     E0568, // auto-traits can not have predicates,
+    E0592, // duplicate definitions with name `{}`
 }
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index 5b628d51d1513..8ebc5c0a8fe2d 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -145,6 +145,18 @@
 //! # }
 //! ```
 //!
+//! Note that you cannot use the `?` operator in functions that do not return
+//! a `Result<T, E>` (e.g. `main`). Instead, you can call `.unwrap()` or `match`
+//! on the return value to catch any possible errors:
+//!
+//! ```
+//! use std::io;
+//!
+//! let mut input = String::new();
+//!
+//! io::stdin().read_line(&mut input).unwrap();
+//! ```
+//!
 //! And a very common source of output is standard output:
 //!
 //! ```
diff --git a/src/libstd/primitive_docs.rs b/src/libstd/primitive_docs.rs
index c738dc9440614..5b2053e929a10 100644
--- a/src/libstd/primitive_docs.rs
+++ b/src/libstd/primitive_docs.rs
@@ -183,9 +183,9 @@ mod prim_unit { }
 /// Working with raw pointers in Rust is uncommon,
 /// typically limited to a few patterns.
 ///
-/// Use the `null` function to create null pointers, and the `is_null` method
+/// Use the [`null`] function to create null pointers, and the [`is_null`] method
 /// of the `*const T` type  to check for null. The `*const T` type also defines
-/// the `offset` method, for pointer math.
+/// the [`offset`] method, for pointer math.
 ///
 /// # Common ways to create raw pointers
 ///
@@ -213,7 +213,7 @@ mod prim_unit { }
 ///
 /// ## 2. Consume a box (`Box<T>`).
 ///
-/// The `into_raw` function consumes a box and returns
+/// The [`into_raw`] function consumes a box and returns
 /// the raw pointer. It doesn't destroy `T` or deallocate any memory.
 ///
 /// ```
@@ -227,7 +227,7 @@ mod prim_unit { }
 /// }
 /// ```
 ///
-/// Note that here the call to `drop` is for clarity - it indicates
+/// Note that here the call to [`drop`] is for clarity - it indicates
 /// that we are done with the given value and it should be destroyed.
 ///
 /// ## 3. Get it from C.
@@ -255,6 +255,11 @@ mod prim_unit { }
 ///
 /// *[See also the `std::ptr` module](ptr/index.html).*
 ///
+/// [`null`]: ../std/ptr/fn.null.html
+/// [`is_null`]: ../std/primitive.pointer.html#method.is_null
+/// [`offset`]: ../std/primitive.pointer.html#method.offset
+/// [`into_raw`]: ../std/boxed/struct.Box.html#method.into_raw
+/// [`drop`]: ../std/mem/fn.drop.html
 #[stable(feature = "rust1", since = "1.0.0")]
 mod prim_pointer { }
 
diff --git a/src/libstd_unicode/u_str.rs b/src/libstd_unicode/u_str.rs
index 3c02ea82d2a11..770b67acd49ef 100644
--- a/src/libstd_unicode/u_str.rs
+++ b/src/libstd_unicode/u_str.rs
@@ -19,6 +19,12 @@ use core::str::Split;
 
 /// An iterator over the non-whitespace substrings of a string,
 /// separated by any amount of whitespace.
+///
+/// This struct is created by the [`split_whitespace`] method on [`str`].
+/// See its documentation for more.
+///
+/// [`split_whitespace`]: ../../std/primitive.str.html#method.split_whitespace
+/// [`str`]: ../../std/primitive.str.html
 #[stable(feature = "split_whitespace", since = "1.1.0")]
 pub struct SplitWhitespace<'a> {
     inner: Filter<Split<'a, fn(char) -> bool>, fn(&&str) -> bool>,
diff --git a/src/test/compile-fail/coherence-overlapping-inherent-impl-trait.rs b/src/test/compile-fail/coherence-overlapping-inherent-impl-trait.rs
index 08e8605e91773..158d3606104a9 100644
--- a/src/test/compile-fail/coherence-overlapping-inherent-impl-trait.rs
+++ b/src/test/compile-fail/coherence-overlapping-inherent-impl-trait.rs
@@ -9,10 +9,8 @@
 // except according to those terms.
 
 #![allow(dead_code)]
-#![deny(overlapping_inherent_impls)]
 
 trait C {}
 impl C { fn f() {} } //~ ERROR duplicate definitions with name `f`
-//~^ WARN: this was previously accepted
 impl C { fn f() {} }
 fn main() { }
diff --git a/src/test/compile-fail/inherent-overlap.rs b/src/test/compile-fail/inherent-overlap.rs
index 00d41244639f5..18e77ddfd2c5b 100644
--- a/src/test/compile-fail/inherent-overlap.rs
+++ b/src/test/compile-fail/inherent-overlap.rs
@@ -17,7 +17,6 @@ struct Foo;
 
 impl Foo {
     fn id() {} //~ ERROR duplicate definitions
-    //~^ WARN previously accepted
 }
 
 impl Foo {
@@ -28,7 +27,6 @@ struct Bar<T>(T);
 
 impl<T> Bar<T> {
     fn bar(&self) {} //~ ERROR duplicate definitions
-    //~^ WARN previously accepted
 }
 
 impl Bar<u32> {
@@ -39,7 +37,6 @@ struct Baz<T>(T);
 
 impl<T: Copy> Baz<T> {
     fn baz(&self) {} //~ ERROR duplicate definitions
-    //~^ WARN previously accepted
 }
 
 impl<T> Baz<Vec<T>> {