1 files changed, 20 insertions, 7 deletions
diff --git a/tests/ui/lint/suspicious-double-ref-op.rs b/tests/ui/lint/suspicious-double-ref-op.rs
index b9bcd31c2..bc8c23c7b 100644
--- a/tests/ui/lint/suspicious-double-ref-op.rs
+++ b/tests/ui/lint/suspicious-double-ref-op.rs
@@ -1,6 +1,14 @@
 #![feature(lazy_cell)]
 #![deny(suspicious_double_ref_op, noop_method_call)]
 
+use std::borrow::Borrow;
+use std::ops::Deref;
+
+struct PlainType<T>(T);
+
+#[derive(Clone)]
+struct CloneType<T>(T);
+
 pub fn clone_on_double_ref() {
     let x = vec![1];
     let y = &&x;
@@ -20,11 +28,16 @@ fn rust_clippy_issue_9272() {
     println!("{str}")
 }
 
-fn check(mut encoded: &[u8]) {
-    let _ = &mut encoded.clone();
-    //~^ ERROR call to `.clone()` on a reference in this situation does nothing
-    let _ = &encoded.clone();
-    //~^ ERROR call to `.clone()` on a reference in this situation does nothing
-}
+fn main() {
+    let clone_type_ref = &&CloneType(1u32);
+    let clone_type_ref_clone: &CloneType<u32> = clone_type_ref.clone();
+    //~^ ERROR using `.clone()` on a double reference, which returns `&CloneType<u32>`
+
+    let non_deref_type = &&PlainType(1u32);
+    let non_deref_type_deref: &PlainType<u32> = non_deref_type.deref();
+    //~^ ERROR using `.deref()` on a double reference, which returns `&PlainType<u32>`
 
-fn main() {}
+    let xs = ["a", "b", "c"];
+    let _v: Vec<&str> = xs.iter().map(|x| x.clone()).collect(); // could use `*x` instead
+    //~^ ERROR using `.clone()` on a double reference, which returns `&str`
+}