Crystal Durham

Procedural note: should wait on #126152 to merge and rebase to explicitly include that guarantee.

I'm fully on board with cargo adopting build-rs directly. I've put a small amount of effort into trying to figure out what that'd look like but hadn't really gotten anywhere...

Well, we do actually expose *a* concept of "the stack's memory" via the thread builder's [stack size](https://doc.rust-lang.org/stable/std/thread/index.html#stack-size) configuration. So the reference refers to locals being in stack in that concept...

If only `std` is used, it's *fine* if std's `str contains` shows up in `help str`, but imo it should be indicated that one is different (e.g. by showing with...

Note that at least in the OP example, one is available as `str contains` and one as `std str contains`. If there were two commands in scope called `"str contains"`...

Note: `&raw` is currently unstable, but is in FCP for stabilization at https://github.com/rust-lang/rust/pull/127679.

- https://github.com/rust-lang/reference/pull/1387 It not being UB at the pointer dereference is what allows `addr_of!(*ptr)` to be valid. In theory, taking reference of a place *could've* required the place to be...

> Is there nomenclature already defined whose meaning matches what I'm aiming for here? The language to address each unsize kind separately exists (we differentiate between pointer casts that adjust...

For a newtype `MySlice(SliceWithHeader)`, you can soundly cast between `Box` and `Box` if `MySlice` is `#[repr(transparent)]`[^1]. If you want to forward the trait impls as well, those currently need to...

The intent of the ACP as-written is to introduce no new language semantics, and be implementable solely in terms of today's `feature(ptr_metadata)` APIs/features. In that light, I think this *could*...