diff --git a/compiler/rustc_resolve/src/late/lifetimes.rs b/compiler/rustc_resolve/src/late/lifetimes.rs index 8fa6160d436..c18d5d06d64 100644 --- a/compiler/rustc_resolve/src/late/lifetimes.rs +++ b/compiler/rustc_resolve/src/late/lifetimes.rs @@ -1333,12 +1333,41 @@ fn resolve_lifetime_ref( && let hir::IsAsync::NotAsync = self.tcx.asyncness(lifetime_ref.hir_id.owner.def_id) && !self.tcx.features().anonymous_lifetime_in_impl_trait { - rustc_session::parse::feature_err( + let mut diag = rustc_session::parse::feature_err( &self.tcx.sess.parse_sess, sym::anonymous_lifetime_in_impl_trait, lifetime_ref.span, "anonymous lifetimes in `impl Trait` are unstable", - ).emit(); + ); + + match self.tcx.hir().get_generics(lifetime_ref.hir_id.owner.def_id) { + Some(generics) => { + + let new_param_sugg_tuple; + + new_param_sugg_tuple = match generics.span_for_param_suggestion() { + Some(_) => { + Some((self.tcx.sess.source_map().span_through_char(generics.span, '<').shrink_to_hi(), "'a, ".to_owned())) + }, + None => Some((generics.span, "<'a>".to_owned())) + }; + + let mut multi_sugg_vec = vec![(lifetime_ref.span.shrink_to_hi(), "'a ".to_owned())]; + + if let Some(new_tuple) = new_param_sugg_tuple{ + multi_sugg_vec.push(new_tuple); + } + + diag.span_label(lifetime_ref.span, "expected named lifetime parameter"); + diag.multipart_suggestion("consider introducing a named lifetime parameter", + multi_sugg_vec, + rustc_errors::Applicability::MaybeIncorrect); + + }, + None => { } + } + + diag.emit(); return; } scope = s; diff --git a/src/test/ui/suggestions/impl-trait-missing-lifetime-gated.stderr b/src/test/ui/suggestions/impl-trait-missing-lifetime-gated.stderr index e82a6f769e0..9833da13ffc 100644 --- a/src/test/ui/suggestions/impl-trait-missing-lifetime-gated.stderr +++ b/src/test/ui/suggestions/impl-trait-missing-lifetime-gated.stderr @@ -26,17 +26,25 @@ error[E0658]: anonymous lifetimes in `impl Trait` are unstable --> $DIR/impl-trait-missing-lifetime-gated.rs:5:31 | LL | fn f(_: impl Iterator) {} - | ^^ + | ^^ expected named lifetime parameter | = help: add `#![feature(anonymous_lifetime_in_impl_trait)]` to the crate attributes to enable +help: consider introducing a named lifetime parameter + | +LL | fn f<'a>(_: impl Iterator) {} + | ++++ ++ error[E0658]: anonymous lifetimes in `impl Trait` are unstable --> $DIR/impl-trait-missing-lifetime-gated.rs:8:31 | LL | fn g(x: impl Iterator) -> Option<&'_ ()> { x.next() } - | ^^ + | ^^ expected named lifetime parameter | = help: add `#![feature(anonymous_lifetime_in_impl_trait)]` to the crate attributes to enable +help: consider introducing a named lifetime parameter + | +LL | fn g<'a>(x: impl Iterator) -> Option<&'_ ()> { x.next() } + | ++++ ++ error: aborting due to 4 previous errors