1 files changed, 20 insertions, 0 deletions
diff --git a/library/core/tests/iter/adapters/scan.rs b/library/core/tests/iter/adapters/scan.rs
new file mode 100644
index 000000000..1d28ca6b7
--- /dev/null
+++ b/library/core/tests/iter/adapters/scan.rs
@@ -0,0 +1,20 @@
+use core::iter::*;
+
+#[test]
+fn test_iterator_scan() {
+    // test the type inference
+    fn add(old: &mut isize, new: &usize) -> Option<f64> {
+        *old += *new as isize;
+        Some(*old as f64)
+    }
+    let xs = [0, 1, 2, 3, 4];
+    let ys = [0f64, 1.0, 3.0, 6.0, 10.0];
+
+    let it = xs.iter().scan(0, add);
+    let mut i = 0;
+    for x in it {
+        assert_eq!(x, ys[i]);
+        i += 1;
+    }
+    assert_eq!(i, ys.len());
+}