Libs-API Meeting 2022-10-11

# 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)