Idea: DerefPin/DerefCell

[Centril]

Could this be done via some auto-deriving mechanism instead?

I also wonder if it could / should apply to non-reference stuff but arbitrary_self_types cases such as:

Forever immutable owned values

We have the concept of “exclusive” (or mutable) references &mut T in Rust. The only way to create value of that type in safe Rust is to (at some point) have a let mut foo: T = .. and then do &mut foo somewhere else. Owning a value and not marking that mut in let mut foo = make_owned_value(); does not mean that it is not possible to mutate it. All you have to do is to move foo and now you are allowed to mutate the moved foo. You can simply do this with: fn main() { struct Foo; fn make_o…