1 files changed, 33 insertions, 0 deletions
diff --git a/tests/ui/span/issue-23729.rs b/tests/ui/span/issue-23729.rs
new file mode 100644
index 00000000000..ca33f9c7730
--- /dev/null
+++ b/tests/ui/span/issue-23729.rs
@@ -0,0 +1,33 @@
+// Regression test for #23729
+
+fn main() {
+    let fib = {
+        struct Recurrence {
+            mem: [u64; 2],
+            pos: usize,
+        }
+
+        impl Iterator for Recurrence {
+            //~^ ERROR E0046
+            #[inline]
+            fn next(&mut self) -> Option<u64> {
+                if self.pos < 2 {
+                    let next_val = self.mem[self.pos];
+                    self.pos += 1;
+                    Some(next_val)
+                } else {
+                    let next_val = self.mem[0] + self.mem[1];
+                    self.mem[0] = self.mem[1];
+                    self.mem[1] = next_val;
+                    Some(next_val)
+                }
+            }
+        }
+
+        Recurrence { mem: [0, 1], pos: 0 }
+    };
+
+    for e in fib.take(10) {
+        println!("{}", e)
+    }
+}