Rollup merge of #138998 - rperier:donot_suggest_to_use_impl_trait_in_closure_params, r=Noratrieb

Don't suggest the use of  `impl Trait` in closure parameter

Fixes #138932

1 files changed, 17 insertions, 6 deletions

diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
index 3583bc8ad8f..b963e4a2c7c 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
@@ -3018,12 +3018,23 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                                 [] => span_bug!(ty.span, "trait object with no traits: {ty:?}"),
                             };
                             let needs_parens = traits.len() != 1;
-                            err.span_suggestion_verbose(
-                                span,
-                                "you can use `impl Trait` as the argument type",
-                                "impl ",
-                                Applicability::MaybeIncorrect,
-                            );
+                            // Don't recommend impl Trait as a closure argument
+                            if let Some(hir_id) = hir_id
+                                && matches!(
+                                    self.tcx.parent_hir_node(hir_id),
+                                    hir::Node::Item(hir::Item {
+                                        kind: hir::ItemKind::Fn { .. },
+                                        ..
+                                    })
+                                )
+                            {
+                                err.span_suggestion_verbose(
+                                    span,
+                                    "you can use `impl Trait` as the argument type",
+                                    "impl ",
+                                    Applicability::MaybeIncorrect,
+                                );
+                            }
                             let sugg = if !needs_parens {
                                 vec![(span.shrink_to_lo(), format!("&{kw}"))]
                             } else {