Last I checked when I tried to the library last the blocker on stable was packed_simd, which provides vector instructions in Rust. I can imagine the arrow/datafusion-guy isn't too keen on dropping vectorized instructions as that would be letting up a huge advantage and I'm imagine it's used liberally throughout the code.

As for stablizing packed_simd, It's completely unclear to me when that will land in stable rust. I recently had a project where I just ended up calling out to C code to handle vectorization.

EDIT: According to, https://github.com/rust-lang/lang-team/issues/29, the effort looks abandonded/deprioritized, so it may be a long time before it sees stable rust