Auto merge of #40867 - alexcrichton:rollup, r=alexcrichton

Rollup of 19 pull requests

- Successful merges: #40317, #40516, #40524, #40606, #40683, #40751, #40778, #40813, #40818, #40819, #40824, #40828, #40832, #40833, #40837, #40849, #40852, #40853, #40865
- Failed merges:

4 files changed, 10 insertions, 10 deletions

diff --git a/src/librustc_data_structures/accumulate_vec.rs b/src/librustc_data_structures/accumulate_vec.rs
index d4bd9e707fd..c03c2890ba3 100644
--- a/src/librustc_data_structures/accumulate_vec.rs
+++ b/src/librustc_data_structures/accumulate_vec.rs
@@ -91,8 +91,8 @@ impl<A: Array> Deref for AccumulateVec<A> {
     type Target = [A::Element];
     fn deref(&self) -> &Self::Target {
         match *self {
-            AccumulateVec::Array(ref v) => &v[..],
-            AccumulateVec::Heap(ref v) => &v[..],
+            AccumulateVec::Array(ref v) => v,
+            AccumulateVec::Heap(ref v) => v,
         }
     }
 }
@@ -100,8 +100,8 @@ impl<A: Array> Deref for AccumulateVec<A> {
 impl<A: Array> DerefMut for AccumulateVec<A> {
     fn deref_mut(&mut self) -> &mut [A::Element] {
         match *self {
-            AccumulateVec::Array(ref mut v) => &mut v[..],
-            AccumulateVec::Heap(ref mut v) => &mut v[..],
+            AccumulateVec::Array(ref mut v) => v,
+            AccumulateVec::Heap(ref mut v) => v,
         }
     }
 }
diff --git a/src/librustc_data_structures/base_n.rs b/src/librustc_data_structures/base_n.rs
index 4359581a897..cf54229fa7f 100644
--- a/src/librustc_data_structures/base_n.rs
+++ b/src/librustc_data_structures/base_n.rs
@@ -48,7 +48,7 @@ pub fn encode(n: u64, base: u64) -> String {
 #[test]
 fn test_encode() {
     fn test(n: u64, base: u64) {
-        assert_eq!(Ok(n), u64::from_str_radix(&encode(n, base)[..], base as u32));
+        assert_eq!(Ok(n), u64::from_str_radix(&encode(n, base), base as u32));
     }
 
     for base in 2..37 {
diff --git a/src/librustc_data_structures/blake2b.rs b/src/librustc_data_structures/blake2b.rs
index 31492e26219..9d97a83f693 100644
--- a/src/librustc_data_structures/blake2b.rs
+++ b/src/librustc_data_structures/blake2b.rs
@@ -35,7 +35,7 @@ pub struct Blake2bCtx {
 impl ::std::fmt::Debug for Blake2bCtx {
     fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
         try!(write!(fmt, "hash: "));
-        for v in &self.h[..] {
+        for v in &self.h {
             try!(write!(fmt, "{:x}", v));
         }
         Ok(())
diff --git a/src/librustc_data_structures/indexed_set.rs b/src/librustc_data_structures/indexed_set.rs
index 2e9e054e97e..572ce98d3ae 100644
--- a/src/librustc_data_structures/indexed_set.rs
+++ b/src/librustc_data_structures/indexed_set.rs
@@ -91,13 +91,13 @@ impl<T: Idx> IdxSet<T> {
 impl<T: Idx> Deref for IdxSetBuf<T> {
     type Target = IdxSet<T>;
     fn deref(&self) -> &IdxSet<T> {
-        unsafe { IdxSet::from_slice(&self.bits[..]) }
+        unsafe { IdxSet::from_slice(&self.bits) }
     }
 }
 
 impl<T: Idx> DerefMut for IdxSetBuf<T> {
     fn deref_mut(&mut self) -> &mut IdxSet<T> {
-        unsafe { IdxSet::from_slice_mut(&mut self.bits[..]) }
+        unsafe { IdxSet::from_slice_mut(&mut self.bits) }
     }
 }
 
@@ -135,11 +135,11 @@ impl<T: Idx> IdxSet<T> {
     }
 
     pub fn words(&self) -> &[Word] {
-        &self.bits[..]
+        &self.bits
     }
 
     pub fn words_mut(&mut self) -> &mut [Word] {
-        &mut self.bits[..]
+        &mut self.bits
     }
 
     pub fn clone_from(&mut self, other: &IdxSet<T>) {