Note ref expr being cast when encounter NonScalar cast error

Signed-off-by: xizheyin <xizheyin@smail.nju.edu.cn>
2026-05-28 20:16:58 +03:00 · 2025-05-09 15:30:16 +08:00
parent 31ee840000
commit 17352e6937
3 changed files with 14 additions and 0 deletions
@@ -408,6 +408,16 @@ fn report_cast_error(&self, fcx: &FnCtxt<'a, 'tcx>, e: CastError<'tcx>) {
                    self.expr_ty,
                    fcx.ty_to_string(self.cast_ty)
                );
+
+                if let Ok(snippet) = fcx.tcx.sess.source_map().span_to_snippet(self.expr_span)
+                    && matches!(self.expr.kind, ExprKind::AddrOf(..))
+                {
+                    err.note(format!(
+                        "casting reference expression `{}` because `&` binds tighter than `as`",
+                        snippet
+                    ));
+                }
+
                let mut sugg = None;
                let mut sugg_mutref = false;
                if let ty::Ref(reg, cast_ty, mutbl) = *self.cast_ty.kind() {