---
title: WG-async triage meeting 2024-08-08
tags: ["WG-async", "triage-meeting", "minutes"]
date: 2024-08-08
discussion: https://rust-lang.zulipchat.com/#narrow/stream/187312-wg-async/topic/Meeting.202024-08-08
url: https://hackmd.io/qbe18CS-SWmsJHzdZWWzhQ
---

# WG-async meeting agenda

- Meeting date: 2024-08-08

## Attendance

- People: TC, eholk, Yosh, tmandry

## 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

### "Weirdness around async function with error "implementation of FnOnce is not general enough"" rust#114177

**Link:** https://github.com/rust-lang/rust/issues/114177

errs note: el classico `Send` bound problem, not fixable

Tracking issue:
https://github.com/rust-lang/rust/issues/110338

### "rustc fails to prove `Send`ness for an `async` block where a `!Send` value is dropped before an `.await` point" rust#128095

**Link:** https://github.com/rust-lang/rust/issues/128095

errs note: i'm planning on rebasing and FCPing the PR i linked at the bottom of that

### "Add LocalWaker support" libs-team#191

**Link:** https://github.com/rust-lang/libs-team/issues/191

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

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

## Nominated RFCs, PRs, and issues

### "Add a method for constructing a `Waker` from a `Fn()`" libs-team#415

**Link:** https://github.com/rust-lang/libs-team/issues/415

use std::{sync::Arc, task::Wake};

struct S;
impl Wake for S {
    fn wake(self: Arc<Self>) {
        todo!()
    }
}
let foo = S;

Anonymous trait impl:

let foo = impl Wake {    
    fn wake(self: Arc<Self>) {
        todo!()
    }
};

`wake_fn`:

let foo = alloc::task::wake_fn(|| todo!());

No captures:

let foo = Waker::from_fn(|| todo!());

After discussion, we agreed that `wake_fn` is well motivated, and we were separately open to a `core::task::Waker::from_fn` that didn't use `Arc`. Summary is here:

https://github.com/rust-lang/libs-team/issues/415#issuecomment-2276596757

### "Generic Futures" rfcs#3434

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

### Misc

It'd be nice if the `Into*` traits around futures could work like this:

trait IntoFuture {
    type Output;
    
    async fn into_future(self) -> Self::Output;
}

// or similar for IntoAsyncGen
trait IntoAsyncGen {
    type Item;
    
    async gen fn into_async_gen(self) -> Self::Item;
}

The trait as it exists today:

pub trait IntoFuture {
    type Output;
    type IntoFuture: Future<Output = Self::Output>;
    fn into_future(self) -> Self::IntoFuture;
}

Inferred associated types handle this without modifying the trait:

impl T for IntoFuture {
    type Output = ();
    async fn into_future(self) -> Self::Output { .. }
    fn into_future(self) -> impl Future<Output = Self::Output> { .. }
}

What you can write today with ATPIT:

impl T for IntoFuture {
    type Output = ();
    type IntoFuture = impl Future<Output = Self::Output>;
    async fn into_future(self) -> Self::Output { .. }
    fn into_future(self) -> Self::IntoFuture { .. }
}

### "Tracking Issue for `waker_getters`" rust#96992

**Link:** https://github.com/rust-lang/rust/issues/96992

### "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

### "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`

### "Initial support for auto traits with default bounds" rust#120706

**Link:** https://github.com/rust-lang/rust/pull/120706

### "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

### "Tracking Issue for `Ready::into_inner()`" rust#101196

**Link:** https://github.com/rust-lang/rust/issues/101196

## P-critical issues

None.

## WG-async work project board

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