Jules Bertholet

> There may be a simpler way. If I remember correctly, at some point all heap code in the standard library will be generic over the heap, although default that...

Another way to limit future breakage could be to use the [semver trick](https://github.com/dtolnay/semver-trick).

Discussion of `?Aligned` added to the RFC. As stated there, I don't think we should add `?Aligned` to the current edition, it would just be redundant and cause even more...

Another factor in this discussion is that new opt-out traits might be added in the future (like `DynSized`). That's why I don't think we should make decisions about syntax in...

Added note about `offset_of`: if Rust ever gets structs with multiple unsized fields, these could be `Aligned` but not fully support `offset_of`.

Currently, this RFC leaves adding `Aligned` to a future edition's prelude as a future possibility. But `Aligned` has no associated methods or items, so I think adding it to every...

I've proposed that `Aligned` be added to the prelude immediately.

@nikomatsakis I've added a link to [unsized-vec](https://crates.io/crates/unsized-vec), which is the crate that originally motivated me to write this RFC. `unsized-vec` provides `UnsizedVec`, which is essentially equivalent to `Vec`, except that...

> I do not know of any fat pointers where the pointee has fields, please let me know if you know any ```rust struct Foo { a: i32, b: dyn...

I think, if Rust adds a new syntax to indicate explicit dyn-safety, that should also be an opportunity to re-evalutate the object safety rules in a backward-compatible way. There are...