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Fix suggestions for nested refs and muts

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This commit is contained in:
Yuki Okushi 2025-10-11 21:17:17 +09:00
parent 0eaa3366f9
commit dbc7327748
4 changed files with 47 additions and 2 deletions
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24
compiler/rustc_hir_typeck/src/method/suggest.rs
View file

@ -2577,10 +2577,32 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
&& matches!(parent_pat.kind, hir::PatKind::Ref(..)) =>
{
err.span_label(span, "you must specify a type for this binding");
let mut ref_muts = Vec::new();
let mut current_node = parent_node;
while let Node::Pat(parent_pat) = current_node {
if let hir::PatKind::Ref(_, mutability) = parent_pat.kind {
ref_muts.push(mutability);
current_node = self.tcx.parent_hir_node(parent_pat.hir_id);
} else {
break;
}
}
let mut type_annotation = String::new();
for mutability in ref_muts.iter().rev() {
match mutability {
hir::Mutability::Mut => type_annotation.push_str("&mut "),
hir::Mutability::Not => type_annotation.push('&'),
}
}
type_annotation.push_str(&concrete_type);
err.span_suggestion_verbose(
pat.span.shrink_to_hi(),
"specify the type in the closure argument list",
format!(": &{concrete_type}"),
format!(": {type_annotation}"),
Applicability::MaybeIncorrect,
);
}

5
tests/ui/inference/ambiguous-numeric-in-closure-ref.fixed
View file

@ -6,4 +6,9 @@ fn main() {
let _ = (0..10).filter(|&v: &i32| v.pow(2) > 0);
//~^ ERROR can't call method `pow` on ambiguous numeric type `{integer}`
//~| SUGGESTION &i32
let v = vec![0, 1, 2];
let _ = v.iter().filter(|&&v: &&i32| v.pow(2) > 0);
//~^ ERROR can't call method `pow` on ambiguous numeric type `{integer}`
//~| SUGGESTION &&i32
}

5
tests/ui/inference/ambiguous-numeric-in-closure-ref.rs
View file

@ -6,4 +6,9 @@ fn main() {
let _ = (0..10).filter(|&v| v.pow(2) > 0);
//~^ ERROR can't call method `pow` on ambiguous numeric type `{integer}`
//~| SUGGESTION &i32
let v = vec![0, 1, 2];
let _ = v.iter().filter(|&&v| v.pow(2) > 0);
//~^ ERROR can't call method `pow` on ambiguous numeric type `{integer}`
//~| SUGGESTION &&i32
}

15
tests/ui/inference/ambiguous-numeric-in-closure-ref.stderr
View file

@ -11,6 +11,19 @@ help: specify the type in the closure argument list
LL | let _ = (0..10).filter(|&v: &i32| v.pow(2) > 0);
| ++++++
error: aborting due to 1 previous error
error[E0689]: can't call method `pow` on ambiguous numeric type `{integer}`
--> $DIR/ambiguous-numeric-in-closure-ref.rs:11:37
|
LL | let _ = v.iter().filter(|&&v| v.pow(2) > 0);
| - ^^^
| |
| you must specify a type for this binding
|
help: specify the type in the closure argument list
|
LL | let _ = v.iter().filter(|&&v: &&i32| v.pow(2) > 0);
| +++++++
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0689`.