add test 12969 and 9841

Author: tesuji

tests/ui/explicit_auto_deref.fixed

@@ -345,3 +345,35 @@ fn main() {
         let _ = &mut ({ *x.u }).x;
     }
 }
+
+mod issue_12969 {
+    use std::ops::Deref;
+
+    struct Wrapper<T>(T);
+
+    impl<T> Deref for Wrapper<T> {
+        type Target = T;
+
+        fn deref(&self) -> &T {
+            &self.0
+        }
+    }
+
+    fn foo(_bar: &str) {}
+
+    fn bar() {
+        let wrapped_bar = Wrapper("");
+
+        foo(wrapped_bar);
+    }
+}
+
+mod issue_9841 {
+    fn takes_array_ref<T, const N: usize>(array: &&[T; N]) {
+        takes_slice(array)
+    }
+
+    fn takes_slice<T>(slice: &[T]) {
+        todo!()
+    }
+}

tests/ui/explicit_auto_deref.rs

@@ -345,3 +345,35 @@ fn main() {
         let _ = &mut ({ *x.u }).x;
     }
 }
+
+mod issue_12969 {
+    use std::ops::Deref;
+
+    struct Wrapper<T>(T);
+
+    impl<T> Deref for Wrapper<T> {
+        type Target = T;
+
+        fn deref(&self) -> &T {
+            &self.0
+        }
+    }
+
+    fn foo(_bar: &str) {}
+
+    fn bar() {
+        let wrapped_bar = Wrapper("");
+
+        foo(&*wrapped_bar);
+    }
+}
+
+mod issue_9841 {
+    fn takes_array_ref<T, const N: usize>(array: &&[T; N]) {
+        takes_slice(*array)
+    }
+
+    fn takes_slice<T>(slice: &[T]) {
+        todo!()
+    }
+}

tests/ui/explicit_auto_deref.stderr

@@ -271,5 +271,17 @@ error: deref which would be done by auto-deref
 LL |         let _ = &mut (*{ x.u }).x;
    |                      ^^^^^^^^^^ help: try: `{ x.u }`
 
-error: aborting due to 45 previous errors
+error: deref which would be done by auto-deref
+  --> tests/ui/explicit_auto_deref.rs:367:13
+   |
+LL |         foo(&*wrapped_bar);
+   |             ^^^^^^^^^^^^^ help: try: `wrapped_bar`
+
+error: deref which would be done by auto-deref
+  --> tests/ui/explicit_auto_deref.rs:373:21
+   |
+LL |         takes_slice(*array)
+   |                     ^^^^^^ help: try: `array`
+
+error: aborting due to 47 previous errors