check_match: refactor + improve non-exhaustive diagnostics for default binding modes #64271
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| LL | | None, | ||
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| | |_- `Opt` defined here |
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E0005 seem to not be pointing at the uncovered variants. This should also have at least a note about if let. I'll take a look at the code tomorrow.
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Yes, I wondered if that was by-design or not. If not, this would actually simplify the code and I think I know how to fix it. There's a good argument for why it should be by-design without full or-patterns but we will have those on nightly soon so that argument is probably invalid now.
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I think it should be ok to unify both, maybe with some extra help about how to write or-patterns (only if all variants have the currently covered field types), otherwise talk about if let. But this could be done as follow up work.
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I've unified them a bit but I'd like to punt on the extra help or referring to if let. A follow up issue might be good to file however.
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| LL | | } | ||
| | |_- `Opt` defined here |
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I think it should be ok to unify both, maybe with some extra help about how to write or-patterns (only if all variants have the currently covered field types), otherwise talk about if let. But this could be done as follow up work.
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@bors r+ |
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📌 Commit 20a2605 has been approved by |
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check_match: refactor + improve non-exhaustive diagnostics for default binding modes
Refactor `check_match` a bit with more code-reuse and improve the diagnostics for a non-exhaustive pattern match by peeling off any references from the scrutinee type so that the "defined here" label is added in more cases. For example:
```rust
error[E0004]: non-exhaustive patterns: `&mut &B` not covered
--> foo.rs:4:11
|
1 | enum E { A, B }
| ---------------
| | |
| | not covered
| `E` defined here
...
4 | match x {
| ^ pattern `&mut &B` not covered
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
```
Moreover, wrt. "defined here", we give irrefutable pattern matching (i.e. in `let`, `for`, and `fn` parameters) a more consistent treatment in line with `match`.
r? @estebank
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☀️ Test successful - checks-azure |
Tested on commit rust-lang/rust@f0b58fc. Direct link to PR: <rust-lang/rust#64271> 🎉 rls on linux: test-fail → test-pass (cc @Xanewok, @rust-lang/infra).
Refactor
check_matcha bit with more code-reuse and improve the diagnostics for a non-exhaustive pattern match by peeling off any references from the scrutinee type so that the "defined here" label is added in more cases. For example:Moreover, wrt. "defined here", we give irrefutable pattern matching (i.e. in
let,for, andfnparameters) a more consistent treatment in line withmatch.r? @estebank