---
# System prepended metadata

title: Libs-API Meeting 2021-12-01
tags: [Minutes, Libs Meetings]

---

# Libs-API Meeting 2021-12-01

###### tags: `Libs Meetings` `Minutes`

**Meeting Link**: https://meet.jit.si/rust-libs-meeting-crxoz2at8hiccp7b3ixf89qgxfymlbwr
**Attendees**: ...

## Agenda

- [Open action items](https://hackmd.io/ovrbJj6CRduRgSA0Wzg2zg)
- Triage
- Anything else?

## Triage

### FCPs

20 open T-libs-api FCPs:
<details><summary><a href="https://github.com/rust-lang/rfcs/issues?q=is%3Aopen+label%3AT-libs-api+label%3Aproposed-final-comment-period">1 <code>rust-lang/rfcs</code> FCPs</a></summary>

  - [[merge 3184](https://github.com/rust-lang/rfcs/issues/3184#issuecomment-946682561)] *Thread local Cell methods.* - (2 checkboxes left)
</details>
<details><summary><a href="https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-libs-api+label%3Aproposed-final-comment-period">19 <code>rust-lang/rust</code> FCPs</a></summary>

  - [[merge 84640](https://github.com/rust-lang/rust/issues/84640#issuecomment-829631948)] *Implement \`TryFrom\<char\>\` for \`u8\`* - (0 checkboxes left)
  - [[close 87228](https://github.com/rust-lang/rust/issues/87228#issuecomment-930052007)] *Decide whether \`asm!\` and/or \`global\_asm!\` should be exported from the prelude. * - (2 checkboxes left)
  - [[close 56167](https://github.com/rust-lang/rust/issues/56167#issuecomment-910742041)] *Tracking issue for HashMap::raw\_entry* - (3 checkboxes left)
  - [[merge 89621](https://github.com/rust-lang/rust/issues/89621#issuecomment-939180524)] *doc: guarantee call order for sort\_by\_cached\_key* - (2 checkboxes left)
  - [[merge 89238](https://github.com/rust-lang/rust/issues/89238#issuecomment-927177703)] *deprecate f{32,64}::DIGITS* - (2 checkboxes left)
  - [[merge 86369](https://github.com/rust-lang/rust/issues/86369#issuecomment-934899667)] *Tracking Issue for \`io::Cursor::{remaining\_slice, is\_empty}\`* - (3 checkboxes left)
  - [[merge 87096](https://github.com/rust-lang/rust/issues/87096#issuecomment-950842917)] *Tracking Issue for \`Stdin::lines\`, \`Stdin::split\` forwarder methods* - (3 checkboxes left)
  - [[merge 86845](https://github.com/rust-lang/rust/issues/86845#issuecomment-950843091)] *Tracking Issue for owned locked stdio handles* - (5 checkboxes left)
  - [[merge 86941](https://github.com/rust-lang/rust/issues/86941#issuecomment-951378107)] *Stabilise std::is\_aarch64\_feature\_detected* - (2 checkboxes left)
  - [[merge 90345](https://github.com/rust-lang/rust/issues/90345#issuecomment-955598351)] *Stabilise entry\_insert* - (4 checkboxes left)
  - [[merge 90291](https://github.com/rust-lang/rust/issues/90291#issuecomment-955599591)] *Loosen the bound on the Debug implementation of Weak.* - (3 checkboxes left)
  - [[merge 89926](https://github.com/rust-lang/rust/issues/89926#issuecomment-965742934)] *make \`Instant::{duration\_since, elapsed, sub}\` saturating and remove workarounds* - (4 checkboxes left)
  - [[merge 90955](https://github.com/rust-lang/rust/issues/90955#issuecomment-971978699)] *windows: Map \`ERROR\_INVALID\_NAME\` as \`InvalidInput\`* - (3 checkboxes left)
  - [[merge 91000](https://github.com/rust-lang/rust/issues/91000#issuecomment-973359991)] *Make ptr range iterable* - (4 checkboxes left)
  - [[merge 90343](https://github.com/rust-lang/rust/issues/90343#issuecomment-973371391)] *Tracking Issue for constify\-ing CStr::from\_bytes\_with\_nul\_unchecked* - (3 checkboxes left)
  - [[merge 91086](https://github.com/rust-lang/rust/issues/91086#issuecomment-974732834)] *Implement \`TryFrom\<&'\_ mut \[T\]\>\` for \`\[T; N\]\`* - (3 checkboxes left)
  - [[merge 90972](https://github.com/rust-lang/rust/issues/90972#issuecomment-974997818)] *Tracking Issue for NEON intrinsics* - (3 checkboxes left)
  - [[merge 91091](https://github.com/rust-lang/rust/issues/91091#issuecomment-980451815)] *Stabilize \`ControlFlow::{is\_break, is\_continue}\`* - (3 checkboxes left)
  - [[merge 90666](https://github.com/rust-lang/rust/issues/90666#issuecomment-980456610)] *Stabilize arc\_new\_cyclic* - (5 checkboxes left)
</details>
<p></p>

[joshtriplett (13)](https://rfcbot.rs/fcp/joshtriplett), [BurntSushi (14)](https://rfcbot.rs/fcp/BurntSushi), [m-ou-se (12)](https://rfcbot.rs/fcp/m-ou-se), [Amanieu (7)](https://rfcbot.rs/fcp/Amanieu), [dtolnay (4)](https://rfcbot.rs/fcp/dtolnay), [yaahc (9)](https://rfcbot.rs/fcp/yaahc)

### Prioritization Requested

- [1 `rust-lang/rust` `T-libs-api` `I-prioritize` items](https://github.com/rust-lang/rust/issues?q=label:T-libs-api+label:I-prioritize+is:open)
  - [[90904](https://github.com/rust-lang/rust/issues/90904)] *Presence of \`std::simd\` sometimes breaks type inference on nightly*
      - Jubilee joined to discuss this.
      - We have operator impls like `f32x4 + f32`
      - Josh: Maybe temporarily remove it?
      - Jubilee: Another type interference algorithm may be able to resolve this. But that's not what we currently have.
      - Let's wait for the beta crater run for input.
          - dtolnay: The crater run won't determine whether we *should* revert (it'll likely show we should), but it'll advise implementation strategies
      - Jubilee to handle the reply/comment.

### Nominated

- [3 `rust-lang/rust` `T-libs-api` `I-libs-api-nominated` items](https://github.com/rust-lang/rust/issues?q=label:T-libs-api+label:I-libs-api-nominated+is:open)
  - [[26179](https://github.com/rust-lang/rust/issues/26179)] *Implement likely/unlikely intrinsic (tracking issue for RFC 1131)*
      - Looks like the llvm intrinsics are not working right now.
      - Amanieu: This should be attributes (e.g. on a match) instead of functions. They only work when the result is directly used for a branch.
        - Now responsibility of lang.
        - Attribute might be complicated for `else if`.
  - [[87021](https://github.com/rust-lang/rust/issues/87021)] *Feature: Provide getters of data and vtable pointer for \`RawWaker\`?*
      - Looks fine. PR welcome to add them as unstable.
  - [[90830](https://github.com/rust-lang/rust/pull/90830)] *Deprecate set\_var and remove\_var in 1.58.0*
     - Much code that sets RUST_LOG before initializing env logger afterwards.
        - Clippy could lint for this pattern.
     - Deprecate before we have a replacement?
       - Doesn't seem effective.
     - Provide a way to control RUST_BACKTRACE from within the program.
     - There's already a comment in the documentation on set_var.
- [2 `rust-lang/rfcs` `T-libs-api` `I-libs-api-nominated` items](https://github.com/rust-lang/rfcs/issues?q=label:T-libs-api+label:I-libs-api-nominated+is:open)
  - [[3184](https://github.com/rust-lang/rfcs/pull/3184)] *Thread local Cell methods.*
      - Already discussed. Need to follow up on that and resolve the concern.
  - [[3192](https://github.com/rust-lang/rfcs/pull/3192)] *Add provide\_any module to core*

### Waiting on team

None

### Needs decision

- [3 `rust-lang/rust` `T-libs-api` `I-needs-decision` items](https://github.com/rust-lang/rust/issues?q=label:T-libs-api+label:I-needs-decision+is:open)
  - [[87228](https://github.com/rust-lang/rust/issues/87228)] *Decide whether \`asm!\` and/or \`global\_asm!\` should be exported from the prelude.*
  - [[87620](https://github.com/rust-lang/rust/pull/87620)] *io: Add the Peek trait*
  - [[88967](https://github.com/rust-lang/rust/issues/88967)] *Stabilizing Iterator::intersperse breaks a large number of crates*
     - cfg-accessible could also help here.

### Stalled Tracking Issues

- [30 `rust-lang/rust` `T-libs-api` `C-tracking-issue` items](https://github.com/rust-lang/rust/issues?q=label:T-libs-api+label:C-tracking-issue+is:open+sort:updated-asc)
  - [[62370](https://github.com/rust-lang/rust/issues/62370)] *Tracking issue for Box::into\_pin (feature \`box\_into\_pin\`)*
  - [[64888](https://github.com/rust-lang/rust/issues/64888)] *Tracking issue for \`report\-time\`*
  - [[74217](https://github.com/rust-lang/rust/issues/74217)] *Tracking Issue for deque\_range*
  - [[71213](https://github.com/rust-lang/rust/issues/71213)] *Tracking Issue for \`wasi\_ext\`*
  - [[69099](https://github.com/rust-lang/rust/issues/69099)] *Tracking Issue for \`std::cell::{Ref, RefMut}::leak\`*

## Actions

- [ ] Reply to all issues/PRs discussed in this meeting, or add them to the [open action items](https://hackmd.io/ovrbJj6CRduRgSA0Wzg2zg).

_Generated by [fully-automatic-rust-libs-team-triage-meeting-agenda-generator](https://github.com/rust-lang/libs-team/tree/main/tools/agenda-generator)_
