Constifying traits in a nightly branch or feature gate it? (with #[const_trait])

[marioirossi]

Re-opening [https://github.com//issues/283].

Stabilization of Rust's const trait and T: [const] U features seems to be in its final stages. I've been working on a const-from-scratch num-traits-like crate for a while, but at this point, it makes more sense to contribute these efforts to num-traits. Is there a group already working on this? Are there any ideas on the approach to take (parallel const traits vs potentially breaking changes to the current ones)? It would be very positive for the community to have a constified num-traits version as soon as stable Rust allows it.

[boozook]

Could be awesome 👍🏻