--- a/rust/land2d/src/lib.rs	Thu Nov 08 00:00:58 2018 +0100
+++ b/rust/land2d/src/lib.rs	Thu Nov 08 07:15:22 2018 +0300
@@ -84,7 +84,7 @@
     }
 
     #[inline]
-    pub fn rows(&self) -> impl Iterator<Item = &[T]> {
+    pub fn rows(&self) -> impl DoubleEndedIterator<Item = &[T]> {
         self.pixels.rows()
     }