The key idea was also mentioned in an older thread about generic field projection. History that I know of:
- this prior internals post: [Idea] Pointer to Field
- lead to this RFC: Generic Pointer to Field by RustyYato · Pull Request #2708 · rust-lang/rfcs · GitHub
- that lead to this prototype: GitHub - RustyYato/generic-field-projection: This crate was created to implement the ideas in this RFC #rust-lang/rfcs/2708
- which was recently touched upon in unsafe-guidelines: Should raw pointer deref/projections have to be in-bounds? · Issue #319 · rust-lang/unsafe-code-guidelines · GitHub
I believe the last point at least touches on the subject mentioned for closing the RFC. If outstanding semantic difficulties of pointer offsetting could be solved by field-projection then that's seems like a clear case for moving from a library to a language feature.