diff options
| -rw-r--r-- | library/alloc/src/vec/mod.rs | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs index 2863da05932..fffdc2c3ac0 100644 --- a/library/alloc/src/vec/mod.rs +++ b/library/alloc/src/vec/mod.rs @@ -2141,12 +2141,17 @@ impl<T, A: Allocator> Vec<T, A> { unsafe fn split_at_spare_mut_with_len( &mut self, ) -> (&mut [T], &mut [MaybeUninit<T>], &mut usize) { - let Range { start: ptr, end: spare_ptr } = self.as_mut_ptr_range(); + let ptr = self.as_mut_ptr(); + // SAFETY: + // - `ptr` is guaranteed to be valid for `self.len` elements + // - but the allocation extends out to `self.buf.capacity()` elements, possibly + // uninitialized + let spare_ptr = unsafe { ptr.add(self.len) }; let spare_ptr = spare_ptr.cast::<MaybeUninit<T>>(); let spare_len = self.buf.capacity() - self.len; // SAFETY: - // - `ptr` is guaranteed to be valid for `len` elements + // - `ptr` is guaranteed to be valid for `self.len` elements // - `spare_ptr` is pointing one element past the buffer, so it doesn't overlap with `initialized` unsafe { let initialized = slice::from_raw_parts_mut(ptr, self.len); |