1 files changed, 25 insertions, 0 deletions

diff --git a/tests/ui/issues/issue-22036.rs b/tests/ui/issues/issue-22036.rs
new file mode 100644
index 00000000000..30da2130a31
--- /dev/null
+++ b/tests/ui/issues/issue-22036.rs
@@ -0,0 +1,25 @@
+// run-pass
+
+trait DigitCollection: Sized {
+    type Iter: Iterator<Item = u8>;
+    fn digit_iter(self) -> Self::Iter;
+
+    fn digit_sum(self) -> u32 {
+        self.digit_iter()
+            .map(|digit: u8| digit as u32)
+            .fold(0, |sum, digit| sum + digit)
+    }
+}
+
+impl<I> DigitCollection for I where I: Iterator<Item=u8> {
+    type Iter = I;
+
+    fn digit_iter(self) -> I {
+        self
+    }
+}
+
+fn main() {
+    let xs = vec![1, 2, 3, 4, 5];
+    assert_eq!(xs.into_iter().digit_sum(), 15);
+}