diff options
Diffstat (limited to 'library/alloc/src/boxed.rs')
| -rw-r--r-- | library/alloc/src/boxed.rs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/library/alloc/src/boxed.rs b/library/alloc/src/boxed.rs index b202d9250d5..2736e5ee6c5 100644 --- a/library/alloc/src/boxed.rs +++ b/library/alloc/src/boxed.rs @@ -2062,6 +2062,9 @@ impl<Args: Tuple, F: AsyncFn<Args> + ?Sized, A: Allocator> AsyncFn<Args> for Box #[unstable(feature = "coerce_unsized", issue = "18598")] impl<T: ?Sized + Unsize<U>, U: ?Sized, A: Allocator> CoerceUnsized<Box<U, A>> for Box<T, A> {} +// It is quite crucial that we only allow the `Global` allocator here. +// Handling arbitrary custom allocators (which can affect the `Box` layout heavily!) +// would need a lot of codegen and interpreter adjustments. #[unstable(feature = "dispatch_from_dyn", issue = "none")] impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Box<U>> for Box<T, Global> {} |