A few cleanups for rustc_data_structures

src/librustc_data_structures/base_n.rs

@@ -17,7 +17,7 @@ pub const MAX_BASE: usize = 64;
 pub const ALPHANUMERIC_ONLY: usize = 62;
 pub const CASE_INSENSITIVE: usize = 36;
 
-const BASE_64: &'static [u8; MAX_BASE as usize] =
+const BASE_64: &[u8; MAX_BASE as usize] =
     b"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ@$";
 
 #[inline]
@@ -37,7 +37,8 @@ pub fn push_str(mut n: u128, base: usize, output: &mut String) {
             break;
         }
     }
-    &mut s[0..index].reverse();
+    s[0..index].reverse();
+
     output.push_str(str::from_utf8(&s[0..index]).unwrap());
 }
 

src/librustc_data_structures/bitslice.rs

@@ -75,7 +75,7 @@ fn bit_lookup(bit: usize) -> BitLookup {
     let word = bit / word_bits;
     let bit_in_word = bit % word_bits;
     let bit_mask = 1 << bit_in_word;
-    BitLookup { word: word, bit_in_word: bit_in_word, bit_mask: bit_mask }
+    BitLookup { word, bit_in_word, bit_mask }
 }
 
 pub fn bits_to_string(words: &[Word], bits: usize) -> String {
@@ -105,7 +105,8 @@ pub fn bits_to_string(words: &[Word], bits: usize) -> String {
         sep = '|';
     }
     result.push(']');
-    return result
+
+    result
 }
 
 #[inline]

src/librustc_data_structures/bitvec.rs

@@ -196,7 +196,8 @@ impl<'a, C: Idx> Iterator for BitIter<'a, C> {
         self.current >>= offset;
         self.current >>= 1; // shift otherwise overflows for 0b1000_0000_…_0000
         self.idx += offset + 1;
-        return Some(C::new(self.idx - 1));
+
+        Some(C::new(self.idx - 1))
     }
 
     fn size_hint(&self) -> (usize, Option<usize>) {
@@ -299,7 +300,7 @@ impl<R: Idx, C: Idx> BitMatrix<R, C> {
             let v1 = vector[write_index];
             let v2 = v1 | vector[read_index];
             vector[write_index] = v2;
-            changed = changed | (v1 != v2);
+            changed |= v1 != v2;
         }
         changed
     }

src/librustc_data_structures/flock.rs

@@ -254,8 +254,8 @@ mod imp {
     type ULONG_PTR = usize;
 
     type LPOVERLAPPED = *mut OVERLAPPED;
-    const LOCKFILE_EXCLUSIVE_LOCK: DWORD = 0x00000002;
-    const LOCKFILE_FAIL_IMMEDIATELY: DWORD = 0x00000001;
+    const LOCKFILE_EXCLUSIVE_LOCK: DWORD = 0x0000_0002;
+    const LOCKFILE_FAIL_IMMEDIATELY: DWORD = 0x0000_0001;
 
     const FILE_SHARE_DELETE: DWORD = 0x4;
     const FILE_SHARE_READ: DWORD = 0x1;

src/librustc_data_structures/graph/dominators/mod.rs

@@ -107,7 +107,8 @@ fn intersect<Node: Idx>(
             node2 = immediate_dominators[node2].unwrap();
         }
     }
-    return node1;
+
+    node1
 }
 
 #[derive(Clone, Debug)]

src/librustc_data_structures/graph/implementation/mod.rs

@@ -90,7 +90,7 @@ pub const INCOMING: Direction = Direction { repr: 1 };
 
 impl NodeIndex {
     /// Returns unique id (unique with respect to the graph holding associated node).
-    pub fn node_id(&self) -> usize {
+    pub fn node_id(self) -> usize {
         self.0
     }
 }
@@ -187,7 +187,7 @@ impl<N: Debug, E: Debug> Graph<N, E> {
         self.nodes[source.0].first_edge[OUTGOING.repr] = idx;
         self.nodes[target.0].first_edge[INCOMING.repr] = idx;
 
-        return idx;
+        idx
     }
 
     pub fn edge(&self, idx: EdgeIndex) -> &Edge<E> {
@@ -261,8 +261,8 @@ impl<N: Debug, E: Debug> Graph<N, E> {
         DepthFirstTraversal::with_start_node(self, start, direction)
     }
 
-    pub fn nodes_in_postorder<'a>(
-        &'a self,
+    pub fn nodes_in_postorder(
+        &self,
         direction: Direction,
         entry_node: NodeIndex,
     ) -> Vec<NodeIndex> {

src/librustc_data_structures/indexed_set.rs

@@ -65,6 +65,7 @@ impl<T: Idx> rustc_serialize::Decodable for IdxSetBuf<T> {
 ///
 /// In other words, `T` is the type used to index into the bitslice
 /// this type uses to represent the set of object it holds.
+#[repr(transparent)]
 pub struct IdxSet<T: Idx> {
     _pd: PhantomData<fn(&T)>,
     bits: [Word],

src/librustc_data_structures/obligation_forest/mod.rs

@@ -573,7 +573,7 @@ impl<O: ForestObligation> ObligationForest<O> {
         }
 
         let mut kill_list = vec![];
-        for (predicate, index) in self.waiting_cache.iter_mut() {
+        for (predicate, index) in &mut self.waiting_cache {
             let new_index = node_rewrites[index.get()];
             if new_index >= nodes_len {
                 kill_list.push(predicate.clone());

src/librustc_data_structures/tiny_list.rs

@@ -107,7 +107,8 @@ impl<T: PartialEq> Element<T> {
         };
 
         self.next = new_next;
-        return true
+
+        true
     }
 
     fn len(&self) -> usize {

src/librustc_data_structures/transitive_relation.rs

@@ -77,7 +77,7 @@ impl<T: Clone + Debug + Eq + Hash> TransitiveRelation<T> {
             ..
         } = self;
 
-        map.entry(a.clone())
+        *map.entry(a.clone())
            .or_insert_with(|| {
                elements.push(a);
 
@@ -86,7 +86,6 @@ impl<T: Clone + Debug + Eq + Hash> TransitiveRelation<T> {
 
                Index(elements.len() - 1)
            })
-           .clone()
     }
 
     /// Applies the (partial) function to each edge and returns a new
@@ -98,14 +97,12 @@ impl<T: Clone + Debug + Eq + Hash> TransitiveRelation<T> {
     {
         let mut result = TransitiveRelation::new();
         for edge in &self.edges {
-            let r = f(&self.elements[edge.source.0]).and_then(|source| {
+            f(&self.elements[edge.source.0]).and_then(|source| {
                 f(&self.elements[edge.target.0]).and_then(|target| {
-                    Some(result.add(source, target))
+                    result.add(source, target);
+                    Some(())
                 })
-            });
-            if r.is_none() {
-                return None;
-            }
+            })?;
         }
         Some(result)
     }
@@ -372,7 +369,7 @@ impl<T: Clone + Debug + Eq + Hash> TransitiveRelation<T> {
         let mut changed = true;
         while changed {
             changed = false;
-            for edge in self.edges.iter() {
+            for edge in &self.edges {
                 // add an edge from S -> T
                 changed |= matrix.add(edge.source.0, edge.target.0);