cross: OffsetDimSlice: implement enumeration

crates/cross/src/dim/dim_slice.rs

@@ -17,6 +17,9 @@ impl<T> DimSlice<T> {
     pub fn indices(&self) -> DimIter {
         DimIter::new(self.dim)
     }
+    pub fn dim(&self) -> Vec3u {
+        self.dim
+    }
 }
 
 #[cfg(feature = "iter")]

crates/cross/src/dim/offset_dim_slice.rs

@@ -1,3 +1,4 @@
+use core::iter::Zip;
 use core::ops::{Index, IndexMut};
 
 use crate::dim::{DimIter, DimSlice};
@@ -18,6 +19,13 @@ impl<T> OffsetDimSlice<T> {
     }
 }
 
+#[cfg(feature = "iter")]
+impl<T: IntoIterator> OffsetDimSlice<T> {
+    pub fn enumerated(self) -> Zip<OffsetDimIter, T::IntoIter> {
+        self.indices().zip(self.into_iter())
+    }
+}
+
 impl<T> Index<Vec3u> for OffsetDimSlice<T>
 where
     DimSlice<T>: Index<Vec3u>
@@ -144,6 +152,46 @@ mod test {
         assert_eq!(i.next().unwrap(), Vec3u::new(10, 20, 31));
         assert_eq!(i.next().unwrap(), Vec3u::new(11, 20, 31));
         assert_eq!(i.next(), None);
+    }
+
+    #[test]
+    fn offset_dim_slice_enumerated() {
+        let data = [
+            10, 11,
+            20, 21,
+            30, 31,
+        ];
+        let s = OffsetDimSlice::new(Vec3u::new(10, 20, 30), Vec3u::new(1, 2, 2), &data);
+        let mut i = s.enumerated();
+        assert_eq!(i.next().unwrap(), (Vec3u::new(10, 20, 30), &10));
+        assert_eq!(i.next().unwrap(), (Vec3u::new(10, 21, 30), &11));
+        assert_eq!(i.next().unwrap(), (Vec3u::new(10, 20, 31), &20));
+        assert_eq!(i.next().unwrap(), (Vec3u::new(10, 21, 31), &21));
         assert_eq!(i.next(), None);
     }
+
+    #[test]
+    fn offset_dim_slice_enumerated_mut() {
+        let mut data = [
+            10, 11,
+            20, 21,
+        ];
+        let s = OffsetDimSlice::new(Vec3u::new(10, 20, 30), Vec3u::new(2, 1, 2), &mut data);
+        let mut i = s.enumerated();
+
+        let (idx, v) = i.next().unwrap();
+        assert_eq!(idx, Vec3u::new(10, 20, 30));
+        *v = 100;
+
+        i.next().unwrap();
+        i.next().unwrap();
+
+        let (idx, v) = i.next().unwrap();
+        assert_eq!(idx, Vec3u::new(11, 20, 31));
+        *v = 210;
+
+        assert_eq!(i.next(), None);
+
+        assert_eq!(data, [100, 11, 20, 210]);
+    }
 }