What happened to feature const_ops on nightly?

help
1

I have a build action that uses the latest nightly to build. I was using nightly toolchain version 2023-03-12 and everything was working. Then I noticed my GitHub action started failing the build and complaining about the feature const_ops not existing. I understand this is part of working with nightly, I'm not complaining about it breaking, just wondering what happened to the feature const_ops? Did it get renamed to something else or removed entirely?

Edit: I forgot to add that I checked Github and saw that the issue was closed, then reopened and that someone added the label const_trait_impl to it. I don't know if that means that const_trait_impl is supposed to enable const_ops. I know it doesn't as adding the feature does not enable const_ops. I have edited the code snippet to demonstrate this. Also, this code is pulled from an actual code base and was modified for simplicity, I realize that as is this is a completely silly and pointless function.

Example code to reproduce the issue.
Compiles with nightly-2023-03-12-{arch}

#![feature(const_ops, const_slice_index, const_trait_impl)]

#[must_use]
pub const fn get_data_length(msg: &[u8]) -> usize {
    msg[1..msg.len() - 1].len()
}

fn main() {
    let msg = [0x01, 0x02, 0x03];
    let _ = get_data_length(msg.as_slice());
}

Fails to compile on nightly-2023-04-19-{arch}

cargo b
   Compiling const_ops_question v0.1.0 (/Users/pittengermdp/development/const_ops_question)
error[E0635]: unknown feature `const_ops`
 --> src/main.rs:1:12
  |
1 | #![feature(const_ops)]
  |            ^^^^^^^^^

For more information about this error, try `rustc --explain E0635`.
error: could not compile `const_ops_question` (bin "const_ops_question") due to previous error
2

Looks like it has been removed five days ago, together with a lot of other unstable const Trait related items:

See this zulip threat for the reason why (apparently const Trait and ~const are completely broken). The PR with the changes was this one:

1 Like
3

Thanks. I didn't know about zulip.

4

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