Allow trailing `self` in more contexts by mu001999 · Pull Request #155137 · rust-lang/rust

mu001999 · 2026-04-11T03:13:45Z

Reference PR:

Document trailing self in paths reference#2237

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As a follow-up PR to #152996, after this PR:

Trailing self can appear in paths
E0429 will be no longer emitted, use ...::self [as target]; will be equivalent to use ...::{self [as target]};

r? petrochenkov

mu001999 · 2026-04-13T13:38:55Z

@rustbot review

petrochenkov · 2026-04-13T14:07:47Z

@mu001999 could you write a change description for lang team for this PR, like in the previous PRs?
I'll nominate it once it's written and the other comments are addressed.
@rustbot author

rustbot · 2026-04-13T14:07:52Z

Reminder, once the PR becomes ready for a review, use @rustbot ready.

mu001999 · 2026-04-13T15:46:15Z

Description for lang team

This PR implements the last part of the lang team guidance from #146972 (comment).
It relaxes the rules to allow trailing self in more context.

Concretely, after this PR

use foo::self [as bar]; would be accepted and is resolved the same way as use foo::{self [as bar]};, instead of being rejected with E0429.
In non-import paths, trailing self would be accepted as well. This will make things like type E = path::to::Enum::self; and pub(in path::to::Mod::self) accepted.

And technically, this PR will not break existing code.

mu001999 · 2026-04-13T15:47:21Z

@rustbot review

traviscross · 2026-04-15T15:45:54Z

Makes sense to me. Thanks @mu001999 for pushing this along. Let's propose to do it.

@rfcbot fcp merge lang

rust-rfcbot · 2026-04-15T15:45:57Z

Team member @traviscross has proposed to merge this. The next step is review by the rest of the tagged team members:

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
See this document for info about what commands tagged team members can give me.

tmandry · 2026-04-15T15:46:12Z

@rfcbot reviewed

nikomatsakis · 2026-04-15T15:47:35Z

@rfcbot reviewed

joshtriplett · 2026-04-15T15:47:42Z

@rfcbot reviewed

rust-rfcbot · 2026-04-15T15:47:57Z

🔔 This is now entering its final comment period, as per the review above. 🔔

The Reference says that `self` can only appear as the first segment of a path. Further, the `use` chapter describes `{self}` brace syntax as the way to bind the parent entity of a `use` path under its own name. In rust-lang/rust#155137, we're relaxing these restrictions: `self` may now also appear as the last segment of a path (preceded by `::`) as long as the preceding path resolves to a module, enumeration, or trait. In a `use` path, `use P::self [as name]` is equivalent to `use P::{self [as name]}`. In non-`use` paths, forms such as `type Ty = P::self` and `pub(in P::self)` are now accepted. Let's update the Reference to reflect this.

traviscross · 2026-04-20T04:00:50Z

Reference PR:

Document trailing self in paths reference#2237

cc @rust-lang/lang-docs @rust-lang/fls

rustbot · 2026-04-21T11:20:28Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

rustbot assigned petrochenkov Apr 11, 2026

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Apr 11, 2026

petrochenkov reviewed Apr 13, 2026

View reviewed changes

Comment thread compiler/rustc_resolve/src/build_reduced_graph.rs

Comment thread compiler/rustc_resolve/src/ident.rs Outdated

petrochenkov added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Apr 13, 2026

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Apr 13, 2026

rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Apr 13, 2026

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Apr 13, 2026

petrochenkov added S-waiting-on-t-lang Status: Awaiting decision from T-lang I-lang-nominated Nominated for discussion during a lang team meeting. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Apr 14, 2026

traviscross added P-lang-drag-1 Lang team prioritization drag level 1. https://rust-lang.zulipchat.com/#narrow/channel/410516-t-lang T-lang Relevant to the language team labels Apr 15, 2026

rust-rfcbot added proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. disposition-merge This issue / PR is in PFCP or FCP with a disposition to merge it. labels Apr 15, 2026

rust-rfcbot added final-comment-period In the final comment period and will be merged soon unless new substantive objections are raised. and removed proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. labels Apr 15, 2026