Properly deal with GATs when looking for method chains to point at #121912
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| | ^ `Base::Base` is `<T as Base>::Base<_>` here | ||
| ... | ||
| LL | input.fmap(f1).fmap(f2) | ||
| | -------- `Base::Base` remains `_` here |
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We can likely just check for _ and avoid the label then, as a quick change.
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I can either change the select_where_possible a few lines below my changes to select_all_or_error which would make this note go away or instead add an is_ty_var check.
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Can you check if select_all_or_error will result in any currently "good" note going away too?
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I'll make CI do the dirty work...
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I can either change the
select_where_possiblea few lines below my changes toselect_all_or_errorwhich would make this note go away or instead add anis_ty_varcheck.
Went with is_ty_var since select_all_or_error turned out to be too strict.
| --> $DIR/method-chain-gats.rs:13:29 | ||
| | | ||
| LL | fn fmap2<T, A, B, C>(input: T, f1: impl Fn(A) -> B, f2: impl Fn(B) -> C) -> T::Base<C> | ||
| | ^ `Base::Base` is `<T as Base>::Base<_>` here |
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wrong location I suppose?
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I think the location is "right", because the logic is looking for the root element of the method chain (even accounting for let bindings and fn arguments), so this is trying to say that <Base>::Base<_> = <T as Base>::Base<_>, which is somewhat useless information.
I do have to say that the test code makes my head spin, even without accounting for the error message 😬
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I think the only thing left to do is to improve this label to better account for GATs, but that shouldn't happen in this PR.
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@bors r=compiler-errors,estebank |
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…piler-errors,estebank Properly deal with GATs when looking for method chains to point at Fixes rust-lang#121898. ~~While it prevents an ICE and the structured suggestion is correct, the method chain diagnostic notes are weird / useless / incorrect judging by a quick look. I guess I should improve that in this PR.~~ Sufficiently taken care of. r? estebank or compiler-errors (rust-lang#105332, rust-lang#105674).
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…iaskrgr Rollup of 3 pull requests Successful merges: - rust-lang#121130 (Suggest moving definition if non-found macro_rules! is defined later) - rust-lang#121912 (Properly deal with GATs when looking for method chains to point at) - rust-lang#121927 (Add a proper `with_no_queries` to printing) r? `@ghost` `@rustbot` modify labels: rollup
Rollup merge of rust-lang#121912 - fmease:diag-method-chains-gat, r=compiler-errors,estebank Properly deal with GATs when looking for method chains to point at Fixes rust-lang#121898. ~~While it prevents an ICE and the structured suggestion is correct, the method chain diagnostic notes are weird / useless / incorrect judging by a quick look. I guess I should improve that in this PR.~~ Sufficiently taken care of. r? estebank or compiler-errors (rust-lang#105332, rust-lang#105674).
Fixes #121898.
While it prevents an ICE and the structured suggestion is correct, the method chain diagnostic notes are weird / useless / incorrect judging by a quick look. I guess I should improve that in this PR.Sufficiently taken care of.r? estebank or compiler-errors (#105332, #105674).