make MaybeUnsafeCell<T> Send when T: Sync

maniwani · maniwani · commit 6a664b978df5 · 2022-08-05T16:57:22.000-07:00
diff --git a/crates/bevy_ptr/src/lib.rs b/crates/bevy_ptr/src/lib.rs
@@ -349,3 +349,7 @@ impl<T> Clone for MaybeUnsafeCell<'_, T> {
         *self
     }
 }
+
+// SAFETY: If `T` is `Sync`, `&T` is `Send` and while `&UnsafeCell<T>` is !Sync, users of
+// `MaybeUnsafeCell<T>` are already responsible for ensuring mutable access is unique.
+unsafe impl<T: Sync> Send for MaybeUnsafeCell<'_, T> {}

Original file line number	Diff line number	Diff line change
`@@ -349,3 +349,7 @@ impl<T> Clone for MaybeUnsafeCell<'_, T> {`
`349`	`349`	`*self`
`350`	`350`	`}`
`351`	`351`	`}`
	`352`	`+`
	`353`	+// SAFETY: If `T` is `Sync`, `&T` is `Send` and while `&UnsafeCell<T>` is !Sync, users of
	`354`	+// `MaybeUnsafeCell<T>` are already responsible for ensuring mutable access is unique.
	`355`	`+unsafe impl<T: Sync> Send for MaybeUnsafeCell<'_, T> {}`