1 files changed, 2 insertions, 4 deletions
diff --git a/compiler/rustc_data_structures/src/functor.rs b/compiler/rustc_data_structures/src/functor.rs
index 920f7b1ed0a..2703af97a1b 100644
--- a/compiler/rustc_data_structures/src/functor.rs
+++ b/compiler/rustc_data_structures/src/functor.rs
@@ -31,11 +31,9 @@ impl<T> IdFunctor for Box<T> {
             let value = raw.read();
             // SAFETY: Converts `Box<T>` to `Box<MaybeUninit<T>>` which is the
             // inverse of `Box::assume_init()` and should be safe.
-            let mut raw: Box<mem::MaybeUninit<T>> = Box::from_raw(raw.cast());
+            let raw: Box<mem::MaybeUninit<T>> = Box::from_raw(raw.cast());
             // SAFETY: Write the mapped value back into the `Box`.
-            raw.write(f(value)?);
-            // SAFETY: We just initialized `raw`.
-            raw.assume_init()
+            Box::write(raw, f(value)?)
         })
     }
 }