---
# System prepended metadata

title: Libs-API Meeting 2022-10-11
tags: [Minutes, Libs Meetings]

---

# Libs-API Meeting 2022-10-11

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

**Meeting Link**: https://meet.jit.si/rust-libs-meeting-crxoz2at8hiccp7b3ixf89qgxfymlbwr
**Attendees**: Amanieu, David, Mara, The 8472, Chris Denton, thomcc

## Agenda

- Triage
- Anything else?

## Triage

### FCPs

16 rust-lang/rust T-libs-api FCPs
[Amanieu (1)](https://rfcbot.rs/fcp/Amanieu), [dtolnay (4)](https://rfcbot.rs/fcp/dtolnay), [m-ou-se (6)](https://rfcbot.rs/fcp/m-ou-se), [yaahc (11)](https://rfcbot.rs/fcp/yaahc), [joshtriplett (5)](https://rfcbot.rs/fcp/joshtriplett), [BurntSushi (13)](https://rfcbot.rs/fcp/BurntSushi)

### Nominated

- [7 `rust-lang/rust` `I-libs-api-nominated` items](https://github.com/rust-lang/rust/issues?q=label:I-libs-api-nominated+is:open)
  - rust.tf/99385 *Removal of exact capacity guarantee for \`Vec::with\_capacity()\` is a breaking change*
    - Relevant open pr: https://github.com/rust-lang/rust/pull/99790
      - with_capacity(5) can give a capacity of 8, but deallocating that as an array of 5 should be accepted by the allocator.
  - rust.tf/101263 *Add default trait implementations for "c\-unwind" ABI function pointers*
    - Seems fine. At some point it would be cool to not have to make this as repetitive.
  - rust.tf/101698 *Constify \`TypeId\` ordering impls*
    - Still nominated for t-compiler.
  - rust.tf/101899 *#95295 causes unsoundness in multiple existing crates*
    - Discussed last time.
  - rust.tf/101991 *Stabilize proc\_macro Span::source\_text*
    - Discussed last time. FCP in progress.
  - rust.tf/102225 *Allow const iterator implementations*
    - Discussed last time. Waiting for derive_const. Removed label.
  - rust.tf/102737 *poll\_fn and Unpin: fix pinning*
    - Technically fine? Fine with the pin and pin_mut macros, but breaks if someone does Pin::unchecked_new for a local of the surrounding function.
    - Let's ask for an example of something this breaks and something that this enabels.
- [1 `rust-lang/rfcs` `I-libs-api-nominated` items](https://github.com/rust-lang/rfcs/issues?q=label:I-libs-api-nominated+is:open)
  - rust.tf/rfc3271 *RFC: Add more support for fallible allocations in Vec*
    - Separate type seems better.
      - Also allows for e.g. not implementing FromIterator for it.
    - Most of the methods that don't need to change are part of Deref to slice, not of Vec, anyway.
    - Could be done in an external crate (for now) using a repr transparent wrapper around Vec.
    - Mara to comment.

### Waiting on team

- [2 `rust-lang/rust` `T-libs-api` `S-waiting-on-team` items](https://github.com/rust-lang/rust/issues?q=label:T-libs-api+label:S-waiting-on-team+is:open)
  - rust.tf/99032 *Disable unwinding for \`catch\_unwind\` error payloads.*
  - rust.tf/102445 *Add \`is\_empty()\` method to \`core::ffi::CStr\`.*
    - Looks fine. Approved.

### Needs decision

None

### 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)