diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs index 423122a69009..8f7b8efd811f 100644 --- a/src/liballoc/rc.rs +++ b/src/liballoc/rc.rs @@ -592,11 +592,9 @@ impl Rc { pub fn as_ptr(this: &Self) -> *const T { let ptr: *mut RcBox = NonNull::as_ptr(this.ptr); - // SAFETY: This cannot go through Deref::deref. - // Instead, we manually offset the pointer rather than manifesting a reference. - // This is so that the returned pointer retains the same provenance as our pointer. - // This is required so that e.g. `get_mut` can write through the pointer - // after the Rc is recovered through `from_raw`. + // SAFETY: This cannot go through Deref::deref or Rc::inner. + // This is required to retain raw/mut provenance such that e.g. `get_mut` can + // write through the pointer after the Rc is recovered through `from_raw`. unsafe { &raw const (*ptr).value } } diff --git a/src/liballoc/sync.rs b/src/liballoc/sync.rs index 289aea3afcce..27c36f4a5693 100644 --- a/src/liballoc/sync.rs +++ b/src/liballoc/sync.rs @@ -591,11 +591,9 @@ impl Arc { pub fn as_ptr(this: &Self) -> *const T { let ptr: *mut ArcInner = NonNull::as_ptr(this.ptr); - // SAFETY: This cannot go through Deref::deref. - // Instead, we manually offset the pointer rather than manifesting a reference. - // This is so that the returned pointer retains the same provenance as our pointer. - // This is required so that e.g. `get_mut` can write through the pointer - // after the Arc is recovered through `from_raw`. + // SAFETY: This cannot go through Deref::deref or RcBoxPtr::inner. + // This is required to retain raw/mut provenance such that e.g. `get_mut` can + // write through the pointer after the Rc is recovered through `from_raw`. unsafe { &raw const (*ptr).data } }