core: use assoc types in `Deref[Mut]`

2 files changed, 11 insertions, 5 deletions

diff --git a/src/libstd/sync/mutex.rs b/src/libstd/sync/mutex.rs
index 52004bb4a8f..08980eb01c6 100644
--- a/src/libstd/sync/mutex.rs
+++ b/src/libstd/sync/mutex.rs
@@ -288,12 +288,14 @@ impl<'mutex, T> MutexGuard<'mutex, T> {
     }
 }
 
-impl<'mutex, T> Deref<T> for MutexGuard<'mutex, T> {
+impl<'mutex, T> Deref for MutexGuard<'mutex, T> {
+    type Target = T;
+
     fn deref<'a>(&'a self) -> &'a T {
         unsafe { &*self.__data.get() }
     }
 }
-impl<'mutex, T> DerefMut<T> for MutexGuard<'mutex, T> {
+impl<'mutex, T> DerefMut for MutexGuard<'mutex, T> {
     fn deref_mut<'a>(&'a mut self) -> &'a mut T {
         unsafe { &mut *self.__data.get() }
     }
diff --git a/src/libstd/sync/rwlock.rs b/src/libstd/sync/rwlock.rs
index 7f3c77c97ad..7478e903355 100644
--- a/src/libstd/sync/rwlock.rs
+++ b/src/libstd/sync/rwlock.rs
@@ -326,13 +326,17 @@ impl<'rwlock, T> RWLockWriteGuard<'rwlock, T> {
     }
 }
 
-impl<'rwlock, T> Deref<T> for RWLockReadGuard<'rwlock, T> {
+impl<'rwlock, T> Deref for RWLockReadGuard<'rwlock, T> {
+    type Target = T;
+
     fn deref(&self) -> &T { unsafe { &*self.__data.get() } }
 }
-impl<'rwlock, T> Deref<T> for RWLockWriteGuard<'rwlock, T> {
+impl<'rwlock, T> Deref for RWLockWriteGuard<'rwlock, T> {
+    type Target = T;
+
     fn deref(&self) -> &T { unsafe { &*self.__data.get() } }
 }
-impl<'rwlock, T> DerefMut<T> for RWLockWriteGuard<'rwlock, T> {
+impl<'rwlock, T> DerefMut for RWLockWriteGuard<'rwlock, T> {
     fn deref_mut(&mut self) -> &mut T {
         unsafe { &mut *self.__data.get() }
     }