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Correct detection of elided lifetimes in impl-trait. #106501

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Merged
merged 1 commit into from
Jan 6, 2023
+9 −2
Merged

Correct detection of elided lifetimes in impl-trait. #106501

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6 changes: 4 additions & 2 deletions compiler/rustc_hir_analysis/src/collect/lifetimes.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1195,8 +1195,10 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
// Fresh lifetimes in APIT used to be allowed in async fns and forbidden in
// regular fns.
if let Some(hir::PredicateOrigin::ImplTrait) = where_bound_origin
&& let hir::LifetimeName::Param(_) = lifetime_ref.res
&& lifetime_ref.is_anonymous()
&& let hir::LifetimeName::Param(param_id) = lifetime_ref.res
&& let Some(generics) = self.tcx.hir().get_generics(self.tcx.local_parent(param_id))
&& let Some(param) = generics.params.iter().find(|p| p.def_id == param_id)
&& param.is_elided_lifetime()
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@pnkfelix pnkfelix Jan 5, 2023

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With this PR, the error message still reads as ""anonymous lifetimes in impl Trait are unstable"

should it change to "elided lifetimes" instead of "anonymous lifetimes"?

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@pnkfelix pnkfelix Jan 5, 2023

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(this feedback need not block the landing of this PR. It was just something I noticed while looking it over)

&& let hir::IsAsync::NotAsync = self.tcx.asyncness(lifetime_ref.hir_id.owner.def_id)
&& !self.tcx.features().anonymous_lifetime_in_impl_trait
{
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5 changes: 5 additions & 0 deletions src/test/ui/suggestions/impl-trait-missing-lifetime-gated.rs
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Expand Up @@ -60,4 +60,9 @@ mod in_path {
//~| ERROR missing lifetime specifier
}

// This must not err, as the `&` actually resolves to `'a`.
fn resolved_anonymous<'a, T>(f: impl Fn(&'a str) -> &T) {
f("f")
}

fn main() {}