From 294df80e2cdfbd16b9e5531b0581f8710b7b8862 Mon Sep 17 00:00:00 2001
From: y21 <30553356+y21@users.noreply.github.com>
Date: Fri, 3 Nov 2023 21:04:14 +0100
Subject: [PATCH] [`unused_enumerate_index`]: don't ICE on empty tuples

---
 clippy_lints/src/loops/unused_enumerate_index.rs | 6 +++---
 tests/ui/crashes/ice-11755.rs                    | 5 +++++
 2 files changed, 8 insertions(+), 3 deletions(-)
 create mode 100644 tests/ui/crashes/ice-11755.rs

diff --git a/clippy_lints/src/loops/unused_enumerate_index.rs b/clippy_lints/src/loops/unused_enumerate_index.rs
index 62a2ab1ccb4..dd7fae79d9b 100644
--- a/clippy_lints/src/loops/unused_enumerate_index.rs
+++ b/clippy_lints/src/loops/unused_enumerate_index.rs
@@ -9,7 +9,7 @@
 
 /// Checks for the `UNUSED_ENUMERATE_INDEX` lint.
 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, arg: &'tcx Expr<'_>, body: &'tcx Expr<'_>) {
-    let PatKind::Tuple(tuple, _) = pat.kind else {
+    let PatKind::Tuple([index, elem], _) = pat.kind else {
         return;
     };
 
@@ -19,7 +19,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, arg: &'tcx
 
     let ty = cx.typeck_results().expr_ty(arg);
 
-    if !pat_is_wild(cx, &tuple[0].kind, body) {
+    if !pat_is_wild(cx, &index.kind, body) {
         return;
     }
 
@@ -53,7 +53,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, arg: &'tcx
                 diag,
                 "remove the `.enumerate()` call",
                 vec![
-                    (pat.span, snippet(cx, tuple[1].span, "..").into_owned()),
+                    (pat.span, snippet(cx, elem.span, "..").into_owned()),
                     (arg.span, base_iter.to_string()),
                 ],
             );
diff --git a/tests/ui/crashes/ice-11755.rs b/tests/ui/crashes/ice-11755.rs
new file mode 100644
index 00000000000..367cb699857
--- /dev/null
+++ b/tests/ui/crashes/ice-11755.rs
@@ -0,0 +1,5 @@
+#![warn(clippy::unused_enumerate_index)]
+
+fn main() {
+    for () in [()].iter() {}
+}