1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
#![feature(negative_impls)] #[lang = "sized"] pub trait Sized {} pub trait Deref {} pub trait DerefMut: Deref { type Target; /// Mutably dereferences the value. #[stable(feature = "rust1", since = "1.0.0")] fn deref_mut(&mut self) -> &mut Self::Target; } impl<T: ?Sized> !DerefMut for &T {}