From 6400736142172ea0cd64e742bf43cd119e24f02a Mon Sep 17 00:00:00 2001
From: Josh Stone <jistone@redhat.com>
Date: Mon, 27 Jun 2022 15:49:59 -0700
Subject: [PATCH] Implement `Send` and `Sync` for `ThinBox<T>`

Just like `Box<T>`, `ThinBox<T>` owns its data on the heap, so it should
implement `Send` and `Sync` when `T` does.
---
 library/alloc/src/boxed/thin.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/library/alloc/src/boxed/thin.rs b/library/alloc/src/boxed/thin.rs
index 807c035fdbd0d..203e5dff0c77f 100644
--- a/library/alloc/src/boxed/thin.rs
+++ b/library/alloc/src/boxed/thin.rs
@@ -33,6 +33,14 @@ pub struct ThinBox<T: ?Sized> {
     _marker: PhantomData<T>,
 }
 
+/// `ThinBox<T>` is `Send` if `T` is `Send` because the data is owned.
+#[unstable(feature = "thin_box", issue = "92791")]
+unsafe impl<T: ?Sized + Send> Send for ThinBox<T> {}
+
+/// `ThinBox<T>` is `Sync` if `T` is `Sync` because the data is owned.
+#[unstable(feature = "thin_box", issue = "92791")]
+unsafe impl<T: ?Sized + Sync> Sync for ThinBox<T> {}
+
 #[unstable(feature = "thin_box", issue = "92791")]
 impl<T> ThinBox<T> {
     /// Moves a type to the heap with its `Metadata` stored in the heap allocation instead of on