1 files changed, 22 insertions, 0 deletions
diff --git a/tests/ui/span/mut-arg-hint.rs b/tests/ui/span/mut-arg-hint.rs
new file mode 100644
index 000000000..d7ff1f0de
--- /dev/null
+++ b/tests/ui/span/mut-arg-hint.rs
@@ -0,0 +1,22 @@
+trait B {
+    fn foo(mut a: &String) {
+        a.push_str("bar"); //~ ERROR cannot borrow `*a` as mutable, as it is behind a `&` reference
+    }
+}
+
+pub fn foo<'a>(mut a: &'a String) {
+    a.push_str("foo"); //~ ERROR cannot borrow `*a` as mutable, as it is behind a `&` reference
+}
+
+struct A {}
+
+impl A {
+    pub fn foo(mut a: &String) {
+        a.push_str("foo"); //~ ERROR cannot borrow `*a` as mutable, as it is behind a `&` reference
+    }
+}
+
+fn main() {
+    foo(&"a".to_string());
+    A::foo(&"a".to_string());
+}