1 files changed, 11 insertions, 24 deletions
diff --git a/compiler/rustc_query_system/src/query/caches.rs b/compiler/rustc_query_system/src/query/caches.rs
index 4b3cd16c2..29f6a07e8 100644
--- a/compiler/rustc_query_system/src/query/caches.rs
+++ b/compiler/rustc_query_system/src/query/caches.rs
@@ -16,17 +16,11 @@ pub trait CacheSelector<'tcx, V> {
         V: Copy;
 }
 
-pub trait QueryStorage {
-    type Value: Copy;
-}
-
-pub trait QueryCache: QueryStorage + Sized {
+pub trait QueryCache: Sized {
     type Key: Hash + Eq + Copy + Debug;
+    type Value: Copy;
 
     /// Checks if the query is already computed and in the cache.
-    /// It returns the shard index and a lock guard to the shard,
-    /// which will be used if the query is not in the cache and we need
-    /// to compute it.
     fn lookup(&self, key: &Self::Key) -> Option<(Self::Value, DepNodeIndex)>;
 
     fn complete(&self, key: Self::Key, value: Self::Value, index: DepNodeIndex);
@@ -55,16 +49,13 @@ impl<K, V> Default for DefaultCache<K, V> {
     }
 }
 
-impl<K: Eq + Hash, V: Copy + Debug> QueryStorage for DefaultCache<K, V> {
-    type Value = V;
-}
-
 impl<K, V> QueryCache for DefaultCache<K, V>
 where
     K: Eq + Hash + Copy + Debug,
-    V: Copy + Debug,
+    V: Copy,
 {
     type Key = K;
+    type Value = V;
 
     #[inline(always)]
     fn lookup(&self, key: &K) -> Option<(V, DepNodeIndex)> {
@@ -127,15 +118,12 @@ impl<V> Default for SingleCache<V> {
     }
 }
 
-impl<V: Copy + Debug> QueryStorage for SingleCache<V> {
-    type Value = V;
-}
-
 impl<V> QueryCache for SingleCache<V>
 where
-    V: Copy + Debug,
+    V: Copy,
 {
     type Key = ();
+    type Value = V;
 
     #[inline(always)]
     fn lookup(&self, _key: &()) -> Option<(V, DepNodeIndex)> {
@@ -148,7 +136,9 @@ where
     }
 
     fn iter(&self, f: &mut dyn FnMut(&Self::Key, &Self::Value, DepNodeIndex)) {
-        self.cache.lock().as_ref().map(|value| f(&(), &value.0, value.1));
+        if let Some(value) = self.cache.lock().as_ref() {
+            f(&(), &value.0, value.1)
+        }
     }
 }
 
@@ -173,16 +163,13 @@ impl<K: Idx, V> Default for VecCache<K, V> {
     }
 }
 
-impl<K: Eq + Idx, V: Copy + Debug> QueryStorage for VecCache<K, V> {
-    type Value = V;
-}
-
 impl<K, V> QueryCache for VecCache<K, V>
 where
     K: Eq + Idx + Copy + Debug,
-    V: Copy + Debug,
+    V: Copy,
 {
     type Key = K;
+    type Value = V;
 
     #[inline(always)]
     fn lookup(&self, key: &K) -> Option<(V, DepNodeIndex)> {