Suggest `[const] Trait` bounds in more places by oli-obk · Pull Request #155861 · rust-lang/rust

oli-obk · 2026-04-27T07:18:12Z

Right now we have some special logic in the const checker for emitting [const] Trait suggestions, but I'm trying to handle that similarly to how it is handled for normal Trait clauses. This is just a small step in how it will look on the UX side, which should make my follow-up PRs affect tests less and just be a refactoring

rustbot · 2026-04-27T07:18:17Z

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jdonszelmann · 2026-04-28T10:20:28Z

            if field_ty.has_param() {
-                // FIXME: suggest adding `[const] Destruct` by teaching
-                // `suggest_restricting_param_bound` about const traits.
+                let destruct_def_id = tcx.lang_items().destruct_trait();


why is this variable assignment outside the inner if? if you put it lower you can merge the two ifs

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jdonszelmann

r=me otherwise

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jdonszelmann · 2026-04-28T10:48:20Z

oh, and fix ci
@rustbot review

jdonszelmann · 2026-04-28T10:48:27Z

@rustbot author
I mean

rustbot · 2026-04-28T10:48:32Z

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

…g satisfied

rustbot · 2026-04-28T10:56:23Z

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.

oli-obk · 2026-04-29T05:25:06Z

@bors r=jdonszelmann

The CI failure was just a network issue

rust-bors · 2026-04-29T05:25:10Z

📌 Commit 61e876f has been approved by jdonszelmann

It is now in the queue for this repository.

…r=jdonszelmann Suggest `[const] Trait` bounds in more places Right now we have some special logic in the const checker for emitting `[const] Trait` suggestions, but I'm trying to handle that similarly to how it is handled for normal `Trait` clauses. This is just a small step in how it will look on the UX side, which should make my follow-up PRs affect tests less and just be a refactoring

Rollup of 9 pull requests Successful merges: - #151742 (Remove redundant information in `rustc_abi::Variants`) - #155856 (std_detect: support detecting more features on aarch64 Windows) - #155861 (Suggest `[const] Trait` bounds in more places) - #155899 (`dlltool`: Set the working directory to workaround `--temp-prefix` bug) - #155916 (Update with new LLVM 22 target for `wasm32-wali-linux-musl` target) - #155935 (remap OUT_DIR paths to fix build script path leakage in crate metadata. ) - #155950 (use the new `//@ needs-asm-mnemonic: ret` more) - #155949 (Update `opt_ast_lowering_delayed_lints` query to allow "stealing" lints, allowing to use `FnOnce` instead of `Fn`) - #155951 (Make `FlatMapInPlaceVec` an unsafe trait.)

…r=jdonszelmann Suggest `[const] Trait` bounds in more places Right now we have some special logic in the const checker for emitting `[const] Trait` suggestions, but I'm trying to handle that similarly to how it is handled for normal `Trait` clauses. This is just a small step in how it will look on the UX side, which should make my follow-up PRs affect tests less and just be a refactoring

…uwer Rollup of 12 pull requests Successful merges: - #155189 (simd_reduce_min/max: remove float support) - #155721 (When archive format is wrong produce an error instead of ICE) - #155794 (privacy: share effective visibility initialization) - #155856 (std_detect: support detecting more features on aarch64 Windows) - #155861 (Suggest `[const] Trait` bounds in more places) - #155899 (`dlltool`: Set the working directory to workaround `--temp-prefix` bug) - #155916 (Update with new LLVM 22 target for `wasm32-wali-linux-musl` target) - #155935 (remap OUT_DIR paths to fix build script path leakage in crate metadata. ) - #155950 (use the new `//@ needs-asm-mnemonic: ret` more) - #155958 (ci(free-disk-space): remove more tools and fix warnings) - #155949 (Update `opt_ast_lowering_delayed_lints` query to allow "stealing" lints, allowing to use `FnOnce` instead of `Fn`) - #155951 (Make `FlatMapInPlaceVec` an unsafe trait.)

…r=jdonszelmann Suggest `[const] Trait` bounds in more places Right now we have some special logic in the const checker for emitting `[const] Trait` suggestions, but I'm trying to handle that similarly to how it is handled for normal `Trait` clauses. This is just a small step in how it will look on the UX side, which should make my follow-up PRs affect tests less and just be a refactoring

…uwer Rollup of 22 pull requests Successful merges: - #154149 (resolve: Extend `ambiguous_import_visibilities` deprecation lint to glob-vs-glob ambiguities) - #155189 (simd_reduce_min/max: remove float support) - #155453 (apply Cortex-A53 errata 843419 mitigation to the AArch64 Linux targets) - #155562 (Add a missing `GenericTypeVisitable`, and avoid having interner traits for `FnSigKind` and `Abi`) - #155608 (rustc_middle: Implement the `partial_cmp` operation for `DefId`s) - #155721 (When archive format is wrong produce an error instead of ICE) - #155794 (privacy: share effective visibility initialization) - #155832 (c-variadic: more precise compatibility check in const-eval) - #155856 (std_detect: support detecting more features on aarch64 Windows) - #155861 (Suggest `[const] Trait` bounds in more places) - #155899 (`dlltool`: Set the working directory to workaround `--temp-prefix` bug) - #155916 (Update with new LLVM 22 target for `wasm32-wali-linux-musl` target) - #155935 (remap OUT_DIR paths to fix build script path leakage in crate metadata. ) - #155950 (use the new `//@ needs-asm-mnemonic: ret` more) - #155958 (ci(free-disk-space): remove more tools and fix warnings) - #155966 (miri subtree update) - #155711 (bump curl-sys and openssl-sys to support OpenSSL 4.0.x) - #155831 (Add `AcceptContext::expect_key_value`) - #155877 (Avoid misleading return-type note for foreign `Fn` callees) - #155949 (Update `opt_ast_lowering_delayed_lints` query to allow "stealing" lints, allowing to use `FnOnce` instead of `Fn`) - #155951 (Make `FlatMapInPlaceVec` an unsafe trait.) - #155967 (Fix `doc_cfg` feature for extern items)

…uwer Rollup of 21 pull requests Successful merges: - #155966 (miri subtree update) - #154149 (resolve: Extend `ambiguous_import_visibilities` deprecation lint to glob-vs-glob ambiguities) - #155189 (simd_reduce_min/max: remove float support) - #155562 (Add a missing `GenericTypeVisitable`, and avoid having interner traits for `FnSigKind` and `Abi`) - #155608 (rustc_middle: Implement the `partial_cmp` operation for `DefId`s) - #155721 (When archive format is wrong produce an error instead of ICE) - #155794 (privacy: share effective visibility initialization) - #155832 (c-variadic: more precise compatibility check in const-eval) - #155856 (std_detect: support detecting more features on aarch64 Windows) - #155861 (Suggest `[const] Trait` bounds in more places) - #155899 (`dlltool`: Set the working directory to workaround `--temp-prefix` bug) - #155916 (Update with new LLVM 22 target for `wasm32-wali-linux-musl` target) - #155935 (remap OUT_DIR paths to fix build script path leakage in crate metadata. ) - #155950 (use the new `//@ needs-asm-mnemonic: ret` more) - #155958 (ci(free-disk-space): remove more tools and fix warnings) - #155711 (bump curl-sys and openssl-sys to support OpenSSL 4.0.x) - #155831 (Add `AcceptContext::expect_key_value`) - #155877 (Avoid misleading return-type note for foreign `Fn` callees) - #155949 (Update `opt_ast_lowering_delayed_lints` query to allow "stealing" lints, allowing to use `FnOnce` instead of `Fn`) - #155951 (Make `FlatMapInPlaceVec` an unsafe trait.) - #155967 (Fix `doc_cfg` feature for extern items)

Rollup merge of #155861 - oli-obk:effect-bound-suggestions, r=jdonszelmann Suggest `[const] Trait` bounds in more places Right now we have some special logic in the const checker for emitting `[const] Trait` suggestions, but I'm trying to handle that similarly to how it is handled for normal `Trait` clauses. This is just a small step in how it will look on the UX side, which should make my follow-up PRs affect tests less and just be a refactoring

…uwer Rollup of 21 pull requests Successful merges: - rust-lang/rust#155966 (miri subtree update) - rust-lang/rust#154149 (resolve: Extend `ambiguous_import_visibilities` deprecation lint to glob-vs-glob ambiguities) - rust-lang/rust#155189 (simd_reduce_min/max: remove float support) - rust-lang/rust#155562 (Add a missing `GenericTypeVisitable`, and avoid having interner traits for `FnSigKind` and `Abi`) - rust-lang/rust#155608 (rustc_middle: Implement the `partial_cmp` operation for `DefId`s) - rust-lang/rust#155721 (When archive format is wrong produce an error instead of ICE) - rust-lang/rust#155794 (privacy: share effective visibility initialization) - rust-lang/rust#155832 (c-variadic: more precise compatibility check in const-eval) - rust-lang/rust#155856 (std_detect: support detecting more features on aarch64 Windows) - rust-lang/rust#155861 (Suggest `[const] Trait` bounds in more places) - rust-lang/rust#155899 (`dlltool`: Set the working directory to workaround `--temp-prefix` bug) - rust-lang/rust#155916 (Update with new LLVM 22 target for `wasm32-wali-linux-musl` target) - rust-lang/rust#155935 (remap OUT_DIR paths to fix build script path leakage in crate metadata. ) - rust-lang/rust#155950 (use the new `//@ needs-asm-mnemonic: ret` more) - rust-lang/rust#155958 (ci(free-disk-space): remove more tools and fix warnings) - rust-lang/rust#155711 (bump curl-sys and openssl-sys to support OpenSSL 4.0.x) - rust-lang/rust#155831 (Add `AcceptContext::expect_key_value`) - rust-lang/rust#155877 (Avoid misleading return-type note for foreign `Fn` callees) - rust-lang/rust#155949 (Update `opt_ast_lowering_delayed_lints` query to allow "stealing" lints, allowing to use `FnOnce` instead of `Fn`) - rust-lang/rust#155951 (Make `FlatMapInPlaceVec` an unsafe trait.) - rust-lang/rust#155967 (Fix `doc_cfg` feature for extern items)

rustbot assigned jdonszelmann Apr 27, 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 27, 2026

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oli-obk force-pushed the effect-bound-suggestions branch from d698994 to 1f31c57 Compare April 27, 2026 15:52

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fmease added the PG-const-traits Project group: Const traits label Apr 27, 2026

jdonszelmann reviewed Apr 28, 2026

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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 28, 2026

oli-obk added 2 commits April 28, 2026 12:54

Suggest const destruct bounds on Drop impls when they are missing

89cfc22

Suggest various missing trait bounds on HostEffect clauses not bein…

61e876f

…g satisfied

oli-obk force-pushed the effect-bound-suggestions branch from 1f31c57 to 61e876f Compare April 28, 2026 10:56

rust-bors Bot 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 Apr 29, 2026

jhpratt mentioned this pull request Apr 29, 2026

Rollup of 7 pull requests #155956

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jhpratt mentioned this pull request Apr 29, 2026

Rollup of 9 pull requests #155960

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JonathanBrouwer mentioned this pull request Apr 29, 2026

Rollup of 12 pull requests #155964

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JonathanBrouwer mentioned this pull request Apr 29, 2026

Rollup of 22 pull requests #155976

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JonathanBrouwer mentioned this pull request Apr 29, 2026

Rollup of 21 pull requests #155979

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rust-bors Bot merged commit a0ef691 into rust-lang:main Apr 30, 2026
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Suggest `[const] Trait` bounds in more places#155861

Suggest `[const] Trait` bounds in more places#155861
rust-bors[bot] merged 2 commits intorust-lang:mainfrom
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