Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Support default-body trait functions with return-position impl Trait in traits #101679

Merged
merged 5 commits into from
Oct 13, 2022
Merged

Support default-body trait functions with return-position impl Trait in traits #101679

merged 5 commits into from
Oct 13, 2022

Conversation

compiler-errors
Copy link
Member

Introduce a new Trait candidate kind for the ImplTraitInTrait projection candidate, which just projects an RPITIT down to its opaque type form.

This is a hack until we lower RPITITs to regular associated types, after which we will need to rework how these default bodies are type-checked, so comments are left in a few places for us to clean up later.

Fixes #101665

@rustbot rustbot added the T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. label Sep 11, 2022
@rust-highfive
Copy link
Collaborator

r? @jackh726

(rust-highfive has picked a reviewer for you, use r? to override)

@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Sep 11, 2022
@rust-log-analyzer

This comment has been minimized.

Sign in to view
@rust-log-analyzer

This comment has been minimized.

Sign in to view
@compiler-errors compiler-errors mentioned this pull request Sep 11, 2022
Merged
bors added a commit to rust-lang-ci/rust that referenced this pull request Sep 11, 2022
@bors
Auto merge of rust-lang#101682 - compiler-errors:rpitit-encode, r=fee…
17a627f 
…1-dead

Only encode return-position `impl Trait` in trait when parent function has a default body

Semi-blocked on rust-lang#101679, because I can't currently write a test for when we _should_ encode the type of the return-position `impl Trait` in trait, which is when a trait has a default function body, like so:

```rust
trait Foo {
  fn bar() -> impl Sized { }
}
```

Though this can land even without rust-lang#101679, since it does prevent ICEs from occuring any time you use `#![feature(return_position_impl_trait_in_trait)]` in a library, which is kind annoying.
@compiler-errors compiler-errors added the F-return_position_impl_trait_in_trait `#![feature(return_position_impl_trait_in_trait)]` label Sep 12, 2022
@bors
Copy link
Contributor

bors commented Sep 24, 2022

☔ The latest upstream changes (presumably #102223) made this pull request unmergeable. Please resolve the merge conflicts.

@compiler-errors compiler-errors mentioned this pull request Sep 26, 2022
Closed
@nikomatsakis
Copy link
Contributor

r=me, but needs rebase

@bors
Copy link
Contributor

bors commented Oct 3, 2022

☔ The latest upstream changes (presumably #102627) made this pull request unmergeable. Please resolve the merge conflicts.

@compiler-errors compiler-errors mentioned this pull request Oct 5, 2022
Closed
@compiler-errors
Copy link
Member Author

compiler-errors commented Oct 5, 2022 •
edited
Loading

  1. I added 7a1f25e0569c6ca5fb3d3c8fa05aa3202235d36d which actually makes sure the default body satisfies the RPIT bounds, and doesn't normalize unless there's a default body.
  2. I added a test for default-body async fn in trait with impl Trait return fails to compile #102688 which fails to compile even with this PR. That requires #![feature(return_position_impl_trait_in_trait)], so I still want to land this since it fixes the AFIT case which we're more likely to stabilize sooner.

This was referenced Oct 9, 2022
Closed
Closed
@nikomatsakis
Copy link
Contributor

@bors r+

@bors
Copy link
Contributor

bors commented Oct 12, 2022

📌 Commit 0eeeea9 has been approved by nikomatsakis

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Oct 12, 2022
@bors
Copy link
Contributor

bors commented Oct 12, 2022

⌛ Testing commit 0eeeea9 with merge 0938e16...

@bors
Copy link
Contributor

bors commented Oct 13, 2022

☀️ Test successful - checks-actions
Approved by: nikomatsakis
Pushing 0938e16 to master...

@bors bors added the merged-by-bors This PR was explicitly merged by bors. label Oct 13, 2022
@bors bors merged commit 0938e16 into rust-lang:master Oct 13, 2022
@rustbot rustbot added this to the 1.66.0 milestone Oct 13, 2022
@bors bors mentioned this pull request Oct 13, 2022
Closed
@rust-timer
Copy link
Collaborator

Finished benchmarking commit (0938e16): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

mean1 range count2
Regressions ❌
(primary)		 - - 0
Regressions ❌
(secondary)		 - - 0
Improvements ✅
(primary)		 -0.7% [-0.9%, -0.6%] 6
Improvements ✅
(secondary)		 -0.6% [-0.8%, -0.3%] 3
All ❌✅ (primary) -0.7% [-0.9%, -0.6%] 6

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

mean1 range count2
Regressions ❌
(primary)		 - - 0
Regressions ❌
(secondary)		 - - 0
Improvements ✅
(primary)		 -2.5% [-2.5%, -2.5%] 1
Improvements ✅
(secondary)		 - - 0
All ❌✅ (primary) -2.5% [-2.5%, -2.5%] 1

Footnotes

  1. the arithmetic mean of the percent change ↩ ↩2

  2. number of relevant changes ↩ ↩2

@Mark-Simulacrum
Copy link
Member

Improvements look to be at least mostly driven by diesel, which is in its (new) noise range. Can likely be ignored.

@tmandry tmandry mentioned this pull request Nov 1, 2022
Closed
7 tasks
@compiler-errors compiler-errors deleted the rpitit-default-body branch November 2, 2022 02:58
Aaron1011 pushed a commit to Aaron1011/rust that referenced this pull request Jan 6, 2023
@bors
Auto merge of rust-lang#101679 - compiler-errors:rpitit-default-body,…
823485f 
… r=nikomatsakis

Support default-body trait functions with return-position `impl Trait` in traits

Introduce a new `Trait` candidate kind for the `ImplTraitInTrait` projection candidate, which just projects an RPITIT down to its opaque type form.

This is a hack until we lower RPITITs to regular associated types, after which we will need to rework how these default bodies are type-checked, so comments are left in a few places for us to clean up later.

Fixes rust-lang#101665
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers

@nikomatsakis nikomatsakis nikomatsakis approved these changes

Assignees

@jackh726 jackh726

Labels
F-return_position_impl_trait_in_trait `#![feature(return_position_impl_trait_in_trait)]` merged-by-bors This PR was explicitly merged by bors. S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.
Projects
None yet
Milestone
1.66.0
Development

Successfully merging this pull request may close these issues.

ICE in RPITIT trait methods with default bodies
9 participants
@compiler-errors @rust-highfive @rust-log-analyzer @bors @nikomatsakis @rust-timer @Mark-Simulacrum @jackh726 @rustbot