Suggest `impl Iterator` when possible for `_` return type#106172

estebank · 2022-12-27T02:22:56Z

rustbot · 2022-12-27T02:23:02Z

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rustbot · 2022-12-27T02:23:05Z

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If this PR contains changes to any rust-lang/rust public library APIs then please comment with @rustbot label +T-libs-api -T-libs to tag it appropriately. If this PR contains changes to any unstable APIs please edit the PR description to add a link to the relevant API Change Proposal or create one if you haven't already. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary.

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compiler-errors

r=me with nits or not

compiler/rustc_hir_analysis/src/collect.rs

compiler-errors · 2022-12-27T03:23:29Z

compiler/rustc_hir_analysis/src/collect.rs

+    let ty_var = infcx.next_ty_var(origin);
+    let projection = ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::Projection(
+        ty::ProjectionPredicate {
+            projection_ty: tcx.mk_alias_ty(iterator_item, tcx.mk_substs([ret_ty.into()].iter())),
+            term: ty_var.into(),
+        },
+    )));
+    // Add `<ret_ty as Iterator>::Item = _` obligation.
+    ocx.register_obligation(crate::traits::Obligation::misc(
+        tcx,
+        span,
+        hir_id,
+        tcx.param_env(def_id),
+        projection,
+    ));


I think you can just construct a projection type then pass it to ocx.normalize instead, should make the code a lot simpler

I guess I'll fix this in a follow-up PR

I tried making that change, but I must have done it incorrectly and it didn't work. Let's land this and clean it up soon.

Don't worry about it at all, I got it working on a local branch in any case. I do wonder what was wrong, though.

compiler/rustc_hir_analysis/src/collect.rs

src/test/ui/typeck/typeck_type_placeholder_item.stderr

estebank · 2022-12-27T22:14:43Z

@bors r=compiler-errors

bors · 2022-12-27T22:14:45Z

📌 Commit 96f37aff124d77c6b0355157cbddb0f6d36a3371 has been approved by compiler-errors

It is now in the queue for this repository.

compiler-errors · 2022-12-27T22:53:57Z

@bors r-

tests needs bless 😸

estebank · 2022-12-27T23:36:30Z

@bors r=compiler-errors

bors · 2022-12-27T23:36:32Z

📌 Commit b400bde has been approved by compiler-errors

It is now in the queue for this repository.

…piler-errors Suggest `impl Iterator` when possible for `_` return type Address rust-lang#106096.

…iaskrgr Rollup of 6 pull requests Successful merges: - rust-lang#106028 (docs/test: add UI test and long-form error docs for `E0461`) - rust-lang#106172 (Suggest `impl Iterator` when possible for `_` return type) - rust-lang#106173 (Deduplicate `op` methods) - rust-lang#106176 (Recover `fn` keyword as `Fn` trait in bounds) - rust-lang#106194 (rustdoc: combine common sidebar background color CSS rules) - rust-lang#106199 (Silence knock-down errors on `[type error]` bindings) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup

…, r=estebank Suggest `impl Fn*` and `impl Future` in `-> _` return suggestions Follow-up to rust-lang#106172, only the last commit is relevant. Can rebase once that PR is landed for easier review. Suggests `impl Future` and `impl Fn{,Mut,Once}` in `-> _` return suggestions. r? `@estebank`

Suggest impl Iterator when possible for _ return type

1b341fe

Address rust-lang#106096.

rustbot assigned spastorino Dec 27, 2022

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. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Dec 27, 2022

compiler-errors reviewed Dec 27, 2022

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scottmcm reviewed Dec 27, 2022

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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 Dec 27, 2022

bors 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-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Dec 27, 2022

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b400bde

estebank force-pushed the suggest-impl-trait branch from 96f37af to b400bde Compare December 27, 2022 23:36

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-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Dec 27, 2022

matthiaskrgr added a commit to matthiaskrgr/rust that referenced this pull request Dec 28, 2022

Rollup merge of rust-lang#106172 - estebank:suggest-impl-trait, r=com…

8d2c93e

…piler-errors Suggest `impl Iterator` when possible for `_` return type Address rust-lang#106096.

matthiaskrgr mentioned this pull request Dec 28, 2022

Rollup of 8 pull requests #106198

Closed

compiler-errors mentioned this pull request Dec 28, 2022

Suggest impl Fn* and impl Future in -> _ return suggestions #106200

Merged

matthiaskrgr added a commit to matthiaskrgr/rust that referenced this pull request Dec 28, 2022

Rollup merge of rust-lang#106172 - estebank:suggest-impl-trait, r=com…

d40f16e

…piler-errors Suggest `impl Iterator` when possible for `_` return type Address rust-lang#106096.

matthiaskrgr mentioned this pull request Dec 28, 2022

Rollup of 7 pull requests #106214

Closed

matthiaskrgr mentioned this pull request Dec 28, 2022

Rollup of 6 pull requests #106215

Merged

bors merged commit 31f5e75 into rust-lang:master Dec 28, 2022

rustbot added this to the 1.68.0 milestone Dec 28, 2022

estebank deleted the suggest-impl-trait branch November 9, 2023 05:14

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