---
title: WG-async triage meeting 2024-10-03
tags: ["WG-async", "triage-meeting", "minutes"]
date: 2024-10-03
discussion: https://rust-lang.zulipchat.com/#narrow/stream/187312-wg-async/topic/Meeting.202024-10-03
url: https://hackmd.io/Wztkip1ETQyBcLi4H6LYBw
---

# WG-async meeting agenda

- Meeting date: 2024-10-03

## Attendance

- People: TC, eholk, yosh

## Meeting roles

- Minutes:

## Scheduled meetings

None.

Update these [here](https://github.com/orgs/rust-lang/projects/40/views/1).

## Proposed meetings

None.

Update these [here](https://github.com/orgs/rust-lang/projects/40/views/1).

## Announcements or custom items

(Meeting attendees, feel free to add items here!)

## Untriaged issues

### "#[inline(never)] does not work for async functions" rust#129347

**Link:** https://github.com/rust-lang/rust/issues/129347

eholk: Perhaps file this under "reasons why `async fn` was a mistake?"

eholk: Maybe we should pick a reasonable default and then say you can desugar manually to control what the attribute applies to.
This approach means we'd have to allow `#[inline]` on `async { }`.

// for maximum control, you should be allowed to add either attribute at your option

#[inline(never)]
fn foo() -> impl Future<Output = ()> {
    #[inline(never)]
    async {
        ()
    }
}

- Probably want this to apply to both the function and to `poll`.
- Probably want people to desugar if they need better control than that.

### "async code fails to compile with `-Znext-solver`" rust#129865

**Link:** https://github.com/rust-lang/rust/issues/129865

We replied to the submitter asking for a self-standing reproduction.

### "Bogus "implementation of `<whatever trait you want>` is not general enough" with RPITIT + async" rust#130113

**Link:** https://github.com/rust-lang/rust/issues/130113

We're replying with the tracking issues that lists all of these duplicates and near-duplicates.

### "Outlives requirements are not implied in the return type of `async fn`, and generally for RPIT" rust#130935

**Link:** https://github.com/rust-lang/rust/issues/130935

fn f<'a, T>() -> impl Future<Output = &'a T> {
    async { loop {} }
    //~^ ERROR the parameter type `T` may not live long enough
}

This is OK:

fn f<'a, T: 'a>() -> impl Future<Output = &'a T> {
    async { loop {} }
}

This is also OK:

fn f<'a, T>() -> &'a T {
    loop {}
}

But this is not OK:

async fn f<'a, T>() -> &'a T {
    //~^ ERROR the parameter type `T` may not live long enough
    loop {}
}

This is about the behavior of implied bounds.

### "ICE: index out of bounds, instrument coverage" rust#131190

**Link:** https://github.com/rust-lang/rust/issues/131190

Interesting!

## Interesting aside

Bonus points for explaining why this is true...

struct S;
impl From<Box<()>> for S {
    fn from(_: Box<()>) -> Self { S }
}

fn main() {
    let x: Box<_> = loop {};
    //let _: S = x.into(); //~ ERROR type annotations needed
    // Receivers:
    // - Box<_>
    // - &Box<_>
    // - &mut Box<_>
    // - _ (?0) // <--- ERROR
    // - &?0
    // - &mut ?0
    let _: S = <_>::into(x); //~ OK
}

## Nominated RFCs, PRs, and issues

### "Generic Futures" rfcs#3434

**Link:** https://github.com/rust-lang/rfcs/pull/3434

### "Tracking Issue for `task::Waker::noop`" rust#98286

**Link:** https://github.com/rust-lang/rust/issues/98286

### "Rename `AsyncIterator` back to `Stream`, introduce an AFIT-based `AsyncIterator` trait" rust#119550

**Link:** https://github.com/rust-lang/rust/pull/119550

### "Clarification needed on what happens when `Future::poll` wakes an old waker" rust#119698

**Link:** https://github.com/rust-lang/rust/issues/119698

### "Overly conservative async capture analysis when values are borrowed" rust#129325

**Link:** https://github.com/rust-lang/rust/issues/129325

### "Context reactor hook" libs-team#347

**Link:** https://github.com/rust-lang/libs-team/issues/347

## WG RFCs, PRs, and issues nominated for T-lang/T-types

None.

## Pending PRs on the WG-async repo

None.

## `S-waiting-on-team`

### "Rename `AsyncIterator` back to `Stream`, introduce an AFIT-based `AsyncIterator` trait" rust#119550

**Link:** https://github.com/rust-lang/rust/pull/119550

## Proposed FCPs

**Check your boxes!**

None.

## Active FCPs

None.

## P-critical issues

None.

## WG-async work project board

https://github.com/orgs/rust-lang/projects/29/views1/d