1 files changed, 41 insertions, 0 deletions
diff --git a/tests/ui/impl-trait/impl-generic-mismatch.rs b/tests/ui/impl-trait/impl-generic-mismatch.rs
new file mode 100644
index 000000000..fb8bde0d0
--- /dev/null
+++ b/tests/ui/impl-trait/impl-generic-mismatch.rs
@@ -0,0 +1,41 @@
+use std::fmt::Debug;
+
+trait Foo {
+    fn foo(&self, _: &impl Debug);
+}
+
+impl Foo for () {
+    fn foo<U: Debug>(&self, _: &U) { }
+    //~^ Error method `foo` has incompatible signature for trait
+}
+
+trait Bar {
+    fn bar<U: Debug>(&self, _: &U);
+}
+
+impl Bar for () {
+    fn bar(&self, _: &impl Debug) { }
+    //~^ Error method `bar` has incompatible signature for trait
+}
+
+trait Baz {
+    fn baz<U: Debug, T: Debug>(&self, _: &U, _: &T);
+}
+
+impl Baz for () {
+    fn baz<T: Debug>(&self, _: &impl Debug, _: &T) { }
+    //~^ Error method `baz` has incompatible signature for trait
+}
+
+// With non-local trait (#49841):
+
+use std::hash::{Hash, Hasher};
+
+struct X;
+
+impl Hash for X {
+    fn hash(&self, hasher: &mut impl Hasher) {}
+    //~^ Error method `hash` has incompatible signature for trait
+}
+
+fn main() {}