On Wed Mar 26, 2025 at 11:09 PM CET, Tamir Duberstein wrote: > On Wed, Mar 26, 2025 at 5:09 PM Benno Lossin <benno.los...@proton.me> wrote: >> On Wed Mar 26, 2025 at 8:06 PM CET, Tamir Duberstein wrote: >> > On Wed, Mar 26, 2025 at 1:36 PM Benno Lossin <benno.los...@proton.me> >> > wrote: >> >> On Wed Mar 26, 2025 at 5:57 PM CET, Tamir Duberstein wrote: >> >> > >> >> > 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