Hacker News Reader

It was removed from that standard library because std is built on nightly (which had const generics a while ago). Now that const generics are stable, crates can take advantage of this too. Previously they were using macros to generate the 32 array implementations.

View on HN

I was bit by this yesterday. I had a 32 array, but the implementations only went up to 31 (with 0, so 32 in total). Found that quite amusing. 1 day away, 1 array element away.

32 seems so normal that it made me question why the default was 33, to include 0-32, but whatever heh. Glad to see this!

> It was removed from that standard library because std is built on nightly

IIRC std and the compiler are built with the previous stable version of the compiler but with some special flag that allow using unstable features for bootstrapping.

IIRC it goes further than that.

Previous stable (0) compiles current source (1) into a temporary new stable (2), then (2) is used to compile (1) into the actual release version (3).

Could be wrong though, it has been a long time since I stumbled over a description of the release process.

Reply on news.ycombinator.com