Fix some clippy::complexity

compiler/rustc_data_structures/src/graph/implementation/mod.rs

@@ -206,17 +206,11 @@ impl<N: Debug, E: Debug> Graph<N, E> {
         AdjacentEdges { graph: self, direction, next: first_edge }
     }
 
-    pub fn successor_nodes<'a>(
-        &'a self,
-        source: NodeIndex,
-    ) -> impl Iterator<Item = NodeIndex> + 'a {
+    pub fn successor_nodes(&self, source: NodeIndex) -> impl Iterator<Item = NodeIndex> + '_ {
         self.outgoing_edges(source).targets()
     }
 
-    pub fn predecessor_nodes<'a>(
-        &'a self,
-        target: NodeIndex,
-    ) -> impl Iterator<Item = NodeIndex> + 'a {
+    pub fn predecessor_nodes(&self, target: NodeIndex) -> impl Iterator<Item = NodeIndex> + '_ {
         self.incoming_edges(target).sources()
     }
 

compiler/rustc_data_structures/src/memmap.rs

@@ -40,7 +40,7 @@ impl Deref for Mmap {
 
 impl AsRef<[u8]> for Mmap {
     fn as_ref(&self) -> &[u8] {
-        &*self.0
+        &self.0
     }
 }
 

compiler/rustc_data_structures/src/stable_hasher.rs

@@ -312,14 +312,14 @@ impl<CTX> HashStable<CTX> for ::std::num::NonZeroUsize {
 
 impl<CTX> HashStable<CTX> for f32 {
     fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
-        let val: u32 = unsafe { ::std::mem::transmute(*self) };
+        let val: u32 = self.to_bits();
         val.hash_stable(ctx, hasher);
     }
 }
 
 impl<CTX> HashStable<CTX> for f64 {
     fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
-        let val: u64 = unsafe { ::std::mem::transmute(*self) };
+        let val: u64 = self.to_bits();
         val.hash_stable(ctx, hasher);
     }
 }

compiler/rustc_data_structures/src/stack.rs

@@ -5,7 +5,7 @@ const RED_ZONE: usize = 100 * 1024; // 100k
 
 // Only the first stack that is pushed, grows exponentially (2^n * STACK_PER_RECURSION) from then
 // on. This flag has performance relevant characteristics. Don't set it too high.
-const STACK_PER_RECURSION: usize = 1 * 1024 * 1024; // 1MB
+const STACK_PER_RECURSION: usize = 1024 * 1024; // 1MB
 
 /// Grows the stack on demand to prevent stack overflow. Call this in strategic locations
 /// to "break up" recursive calls. E.g. almost any call to `visit_expr` or equivalent can benefit

compiler/rustc_data_structures/src/sync/vec.rs

@@ -84,7 +84,7 @@ impl<T: Copy> AppendOnlyVec<T> {
     }
 
     pub fn iter(&self) -> impl Iterator<Item = T> + '_ {
-        (0..).map(|i| self.get(i)).take_while(|o| o.is_some()).filter_map(|o| o)
+        (0..).map(|i| self.get(i)).take_while(|o| o.is_some()).flatten()
     }
 }
 

compiler/rustc_data_structures/src/unord.rs

@@ -224,7 +224,7 @@ impl<V: Eq + Hash> UnordSet<V> {
     }
 
     #[inline]
-    pub fn items<'a>(&'a self) -> UnordItems<&'a V, impl Iterator<Item = &'a V>> {
+    pub fn items(&self) -> UnordItems<&V, impl Iterator<Item = &V>> {
         UnordItems(self.inner.iter())
     }
 
@@ -415,7 +415,7 @@ impl<K: Eq + Hash, V> UnordMap<K, V> {
     }
 
     #[inline]
-    pub fn items<'a>(&'a self) -> UnordItems<(&'a K, &'a V), impl Iterator<Item = (&'a K, &'a V)>> {
+    pub fn items(&self) -> UnordItems<(&K, &V), impl Iterator<Item = (&K, &V)>> {
         UnordItems(self.inner.iter())
     }