6 files changed, 19 insertions, 3 deletions
diff --git a/library/alloc/src/boxed.rs b/library/alloc/src/boxed.rs
index cfaf533088a..7c3fa2312e5 100644
--- a/library/alloc/src/boxed.rs
+++ b/library/alloc/src/boxed.rs
@@ -161,7 +161,7 @@ use core::marker::Unsize;
 use core::mem::{self, SizedTypeProperties};
 use core::ops::{AsyncFn, AsyncFnMut, AsyncFnOnce};
 use core::ops::{
-    CoerceUnsized, Coroutine, CoroutineState, Deref, DerefMut, DispatchFromDyn, Receiver,
+    CoerceUnsized, Coroutine, CoroutineState, Deref, DerefMut, DerefPure, DispatchFromDyn, Receiver,
 };
 use core::pin::Pin;
 use core::ptr::{self, addr_of_mut, NonNull, Unique};
@@ -1939,6 +1939,9 @@ impl<T: ?Sized, A: Allocator> DerefMut for Box<T, A> {
     }
 }
 
+#[unstable(feature = "deref_pure_trait", issue = "87121")]
+unsafe impl<T: ?Sized, A: Allocator> DerefPure for Box<T, A> {}
+
 #[unstable(feature = "receiver_trait", issue = "none")]
 impl<T: ?Sized, A: Allocator> Receiver for Box<T, A> {}
 
diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index 02d155aaf12..ebc30c08910 100644
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -122,6 +122,7 @@
 #![feature(const_waker)]
 #![feature(core_intrinsics)]
 #![feature(deprecated_suggestion)]
+#![feature(deref_pure_trait)]
 #![feature(dispatch_from_dyn)]
 #![feature(error_generic_member_access)]
 #![feature(error_in_core)]
diff --git a/library/alloc/src/rc.rs b/library/alloc/src/rc.rs
index facfc9d208e..569db54b137 100644
--- a/library/alloc/src/rc.rs
+++ b/library/alloc/src/rc.rs
@@ -260,7 +260,7 @@ use core::marker::{PhantomData, Unsize};
 #[cfg(not(no_global_oom_handling))]
 use core::mem::size_of_val;
 use core::mem::{self, align_of_val_raw, forget, ManuallyDrop};
-use core::ops::{CoerceUnsized, Deref, DerefMut, DispatchFromDyn, Receiver};
+use core::ops::{CoerceUnsized, Deref, DerefMut, DerefPure, DispatchFromDyn, Receiver};
 use core::panic::{RefUnwindSafe, UnwindSafe};
 #[cfg(not(no_global_oom_handling))]
 use core::pin::Pin;
@@ -2126,6 +2126,9 @@ impl<T: ?Sized, A: Allocator> Deref for Rc<T, A> {
     }
 }
 
+#[unstable(feature = "deref_pure_trait", issue = "87121")]
+unsafe impl<T: ?Sized, A: Allocator> DerefPure for Rc<T, A> {}
+
 #[unstable(feature = "receiver_trait", issue = "none")]
 impl<T: ?Sized> Receiver for Rc<T> {}
 
diff --git a/library/alloc/src/string.rs b/library/alloc/src/string.rs
index 7dba5b4e1f9..7464df268cc 100644
--- a/library/alloc/src/string.rs
+++ b/library/alloc/src/string.rs
@@ -2479,6 +2479,9 @@ impl ops::Deref for String {
     }
 }
 
+#[unstable(feature = "deref_pure_trait", issue = "87121")]
+unsafe impl ops::DerefPure for String {}
+
 #[stable(feature = "derefmut_for_string", since = "1.3.0")]
 impl ops::DerefMut for String {
     #[inline]
diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs
index 7e3e2fb38b1..4dea27221b7 100644
--- a/library/alloc/src/sync.rs
+++ b/library/alloc/src/sync.rs
@@ -21,7 +21,7 @@ use core::marker::{PhantomData, Unsize};
 #[cfg(not(no_global_oom_handling))]
 use core::mem::size_of_val;
 use core::mem::{self, align_of_val_raw};
-use core::ops::{CoerceUnsized, Deref, DispatchFromDyn, Receiver};
+use core::ops::{CoerceUnsized, Deref, DerefPure, DispatchFromDyn, Receiver};
 use core::panic::{RefUnwindSafe, UnwindSafe};
 use core::pin::Pin;
 use core::ptr::{self, NonNull};
@@ -2107,6 +2107,9 @@ impl<T: ?Sized, A: Allocator> Deref for Arc<T, A> {
     }
 }
 
+#[unstable(feature = "deref_pure_trait", issue = "87121")]
+unsafe impl<T: ?Sized, A: Allocator> DerefPure for Arc<T, A> {}
+
 #[unstable(feature = "receiver_trait", issue = "none")]
 impl<T: ?Sized> Receiver for Arc<T> {}
 
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index 94bed825bb2..3062f8664b7 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -2772,6 +2772,9 @@ impl<T, A: Allocator> ops::DerefMut for Vec<T, A> {
     }
 }
 
+#[unstable(feature = "deref_pure_trait", issue = "87121")]
+unsafe impl<T, A: Allocator> ops::DerefPure for Vec<T, A> {}
+
 #[cfg(not(no_global_oom_handling))]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Clone, A: Allocator + Clone> Clone for Vec<T, A> {