From 141833850c93feb9cf635d0d200565578cfb1475 Mon Sep 17 00:00:00 2001
From: Chayim Refael Friedman <chayimfr@gmail.com>
Date: Sun, 22 Sep 2024 06:17:33 +0300
Subject: [PATCH] Consider lifetime GATs object unsafe

---
 crates/hir-ty/src/object_safety.rs       |  2 +-
 crates/hir-ty/src/object_safety/tests.rs | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/crates/hir-ty/src/object_safety.rs b/crates/hir-ty/src/object_safety.rs
index 89bf3619a0..a4c6626855 100644
--- a/crates/hir-ty/src/object_safety.rs
+++ b/crates/hir-ty/src/object_safety.rs
@@ -349,7 +349,7 @@ where
                 ControlFlow::Continue(())
             } else {
                 let generic_params = db.generic_params(item.into());
-                if generic_params.len_type_or_consts() > 0 {
+                if !generic_params.is_empty() {
                     cb(ObjectSafetyViolation::GAT(it))
                 } else {
                     ControlFlow::Continue(())
diff --git a/crates/hir-ty/src/object_safety/tests.rs b/crates/hir-ty/src/object_safety/tests.rs
index 3dc08c4619..c2a9117c5b 100644
--- a/crates/hir-ty/src/object_safety/tests.rs
+++ b/crates/hir-ty/src/object_safety/tests.rs
@@ -378,3 +378,16 @@ pub trait Error: core::fmt::Debug + core::fmt::Display {
         [("Error", vec![])],
     );
 }
+
+#[test]
+fn lifetime_gat_is_object_unsafe() {
+    check_object_safety(
+        r#"
+//- minicore: dispatch_from_dyn
+trait Foo {
+    type Bar<'a>;
+}
+"#,
+        [("Foo", vec![ObjectSafetyViolationKind::GAT])],
+    );
+}