Report more detailed reason why Index impl is not satisfied
#110432
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| if let Some((_, index_ty, element_ty)) = | ||
| self.find_and_report_unsatisfied_index_impl(expr.hir_id, base, base_t) | ||
| { | ||
| self.demand_coerce(idx, idx_t, index_ty, None, AllowTwoPhase::No); |
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Why are we registering a coercion? To avoid ambiguities later?
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Mostly just copying the confirmation logic from the happy path. Leaving it unconstrained probably isn't great, but I haven't thought much about creating additional spurious errors from this.
| let errors = ocx.select_where_possible(); | ||
| // There should be at least one error reported. If not, we | ||
| // will still delay a span bug in `report_fulfillment_errors`. | ||
| Ok::<_, NoSolution>(( |
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If we are emitting an error, why are we committing inference constraints?
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Because otherwise we wouldn't be able to return a useful return type here for later typechecking to use. I guess we could return ty::Error here or something, but I prefer recoveries to be as accurate as possible for downstream typechecking.
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Hey! It looks like you've submitted a new PR for the library teams! If this PR contains changes to any Examples of
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@cjgillot, I messed with the test a bit to justify what the index ty coercion and that |
| @@ -0,0 +1,27 @@ | |||
| use std::hash::Hash; | |||
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I would've marked this as // run-rustfix but I cannot due to overlapping suggestion spans. I'll fix that in a different PR.
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Thanks! |
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…iaskrgr Rollup of 7 pull requests Successful merges: - rust-lang#110432 (Report more detailed reason why `Index` impl is not satisfied) - rust-lang#110451 (Minor changes to `IndexVec::ensure_contains_elem` & related methods) - rust-lang#110476 (Delay a good path bug on drop for `TypeErrCtxt` (instead of a regular delayed bug)) - rust-lang#110498 (Switch to `EarlyBinder` for `collect_return_position_impl_trait_in_trait_tys`) - rust-lang#110507 (boostrap: print output during building tools) - rust-lang#110510 (Fix ICE for transmutability in candidate assembly) - rust-lang#110513 (make `non_upper_case_globals` lint not report trait impls) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup
… r=cjgillot Tweak borrow suggestion span Avoids a `span_to_snippet` call when we don't need to surround the expression in parentheses. The fact that the suggestion was using the whole span of the expression rather than just appending a `&` was prevented me from using `// run-rustfix` in another PR (rust-lang#110432 (comment)). Also some drive-by renames of functions that have been annoying me for a bit.
… r=cjgillot Tweak borrow suggestion span Avoids a `span_to_snippet` call when we don't need to surround the expression in parentheses. The fact that the suggestion was using the whole span of the expression rather than just appending a `&` was prevented me from using `// run-rustfix` in another PR (rust-lang#110432 (comment)). Also some drive-by renames of functions that have been annoying me for a bit.
… r=cjgillot Tweak borrow suggestion span Avoids a `span_to_snippet` call when we don't need to surround the expression in parentheses. The fact that the suggestion was using the whole span of the expression rather than just appending a `&` was prevented me from using `// run-rustfix` in another PR (rust-lang#110432 (comment)). Also some drive-by renames of functions that have been annoying me for a bit.
… r=cjgillot Tweak borrow suggestion span Avoids a `span_to_snippet` call when we don't need to surround the expression in parentheses. The fact that the suggestion was using the whole span of the expression rather than just appending a `&` was prevented me from using `// run-rustfix` in another PR (rust-lang#110432 (comment)). Also some drive-by renames of functions that have been annoying me for a bit.
Fixes #110373