2 files changed, 38 insertions, 0 deletions
diff --git a/tests/ui/typeck/bad-index-modulo-higher-ranked-regions.rs b/tests/ui/typeck/bad-index-modulo-higher-ranked-regions.rs
new file mode 100644
index 00000000000..c8f6db7aef3
--- /dev/null
+++ b/tests/ui/typeck/bad-index-modulo-higher-ranked-regions.rs
@@ -0,0 +1,29 @@
+// Test against ICE in #118111
+
+use std::ops::Index;
+
+struct Map<T, F> {
+    f: F,
+    inner: T,
+}
+
+impl<T, F, Idx> Index<Idx> for Map<T, F>
+where
+    T: Index<Idx>,
+    F: FnOnce(&T, Idx) -> Idx,
+{
+    type Output = T::Output;
+
+    fn index(&self, index: Idx) -> &Self::Output {
+        todo!()
+    }
+}
+
+fn main() {
+    Map { inner: [0_usize], f: |_, i: usize| 1_usize }[0];
+    //~^ ERROR cannot index into a value of type
+    // Problem here is that
+    //   `f: |_, i: usize| ...`
+    // should be
+    //   `f: |_: &_, i: usize| ...`
+}
diff --git a/tests/ui/typeck/bad-index-modulo-higher-ranked-regions.stderr b/tests/ui/typeck/bad-index-modulo-higher-ranked-regions.stderr
new file mode 100644
index 00000000000..7c978430839
--- /dev/null
+++ b/tests/ui/typeck/bad-index-modulo-higher-ranked-regions.stderr
@@ -0,0 +1,9 @@
+error[E0608]: cannot index into a value of type `Map<[usize; 1], {closure@$DIR/bad-index-modulo-higher-ranked-regions.rs:23:32: 23:45}>`
+  --> $DIR/bad-index-modulo-higher-ranked-regions.rs:23:55
+   |
+LL |     Map { inner: [0_usize], f: |_, i: usize| 1_usize }[0];
+   |                                                       ^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0608`.