add an enumerated method to DimensionedSlice

crates/cross/src/dim.rs

@@ -1,3 +1,4 @@
+use core::iter::Zip;
 use core::ops::{Index, IndexMut};
 
 use crate::vec::Vec3u;
@@ -18,6 +19,12 @@ impl<T> DimensionedSlice<T> {
     }
 }
 
+impl<T: IntoIterator> DimensionedSlice<T> {
+    pub fn enumerated(self) -> Zip<Vec3uIter, T::IntoIter> {
+        self.indices().zip(self.into_iter())
+    }
+}
+
 fn index(loc: Vec3u, dim: Vec3u) -> usize {
     ((loc.z()*dim.y() + loc.y())*dim.x() + loc.x()) as usize
 }
@@ -242,5 +249,49 @@ mod test {
         assert!(s.indices().next() == None);
         assert!(s.indices().next() == None);
     }
+
+    #[test]
+    fn dimensioned_slice_enumerated() {
+        let data = [
+            10, 11,
+            20, 21,
+            30, 31,
+        ];
+        let s = DimensionedSlice::new(Vec3u::new(1, 2, 3), &data);
+        let mut i = s.enumerated();
+        assert!(i.next().unwrap() == (Vec3u::new(0, 0, 0), &10));
+        assert!(i.next().unwrap() == (Vec3u::new(0, 1, 0), &11));
+        assert!(i.next().unwrap() == (Vec3u::new(0, 0, 1), &20));
+        assert!(i.next().unwrap() == (Vec3u::new(0, 1, 1), &21));
+        assert!(i.next().unwrap() == (Vec3u::new(0, 0, 2), &30));
+        assert!(i.next().unwrap() == (Vec3u::new(0, 1, 2), &31));
+        assert!(i.next() == None);
+    }
+
+    #[test]
+    fn dimensioned_slice_enumerated_mut() {
+        let mut data = [
+            10, 11,
+            20, 21,
+            30, 31,
+        ];
+        let s = DimensionedSlice::new(Vec3u::new(2, 1, 3), &mut data);
+        let mut i = s.enumerated();
+
+        let (idx, v) = i.next().unwrap();
+        assert!(idx == Vec3u::new(0, 0, 0));
+        *v = 100;
+
+        let (idx, v) = i.next().unwrap();
+        assert!(idx == Vec3u::new(1, 0, 0));
+        *v = 110;
+        i.next().unwrap();
+
+        let (idx, v) = i.next().unwrap();
+        assert!(idx == Vec3u::new(1, 0, 1));
+        *v = 210;
+
+        assert_eq!(data, [100, 110, 20, 210, 30, 31]);
+    }
 }