On Wed Mar 26, 2025 at 11:09 PM CET, Tamir Duberstein wrote:

On Wed, Mar 26, 2025 at 5:09 PM Benno Lossin [off-list ref] wrote:

quoted

On Wed Mar 26, 2025 at 8:06 PM CET, Tamir Duberstein wrote:

quoted

On Wed, Mar 26, 2025 at 1:36 PM Benno Lossin [off-list ref] wrote:

quoted

On Wed Mar 26, 2025 at 5:57 PM CET, Tamir Duberstein wrote:

quoted

Yeah, we should do this - but again: not relevant in this discussion.

I think it's pretty relevant.

It's not relevant because we're no longer talking about transmuting
pointer to pointer. The two options are:
1. transmute reference to reference.
2. coerce reference to pointer, `as` cast pointer to pointer (triggers
`ptr_as_ptr`), reborrow pointer to reference.

If anyone can help me understand why (2) is better than (1), I'd
certainly appreciate it.

I am very confident that (2) is correct. With (1) I'm not sure (see
above), so that's why I mentioned it.

Can you help me understand why you're confident about (2) but not (1)?

My explanation from above explains why I'm not confident about (1):

    For ptr-to-int transmutes, I know that they will probably remove
    provenance, hence I am a bit cautious about using them for ptr-to-ptr or
    ref-to-ref.

The reason I'm confident about (2) is that that is the canonical way to
cast the type of a reference pointing to an `!Sized` value.

---
Cheers,
Benno