Rust doesn’t apply TBAA, and there aren’t any concrete plans to land it (with @nikomatsakis notably being quite unhappy with TBAA in general). That said, it wouldn’t be the worst to leave TBAA on the table.
Would there be any problem with using the standard conversion traits for this sort of thing? Seems like a classic case for from/into/as_ref/whatev.
let data: &[u8] = u32_slice.into();
Not super readable, I guess.