There’s magic in the Box: ability to partially move content out of it, where any other type with Drop couldn’t handle it. You can implement traits for Box<Foo>

There’s magic in the Box: ability to partially move content out of it, where any other type with Drop couldn’t handle it. You can implement traits for Box<Foo> even when Othertype<Foo> wouldn’t be allowed. But noalias is not very special for Rust. &mut and & have a bunch of limitations too. But there’s no need to give up on them, because Rust has the UnsafeCell wrapper type for doing crimes with pointers. It selectively disables noalias, thread safety, etc. Instead of weakening guarantees of Box in general for all types, just insert UnsafeCell where you need to be clever with pointers.