NdIndex<IxDyn>: tidy for Vec<Ix> and impl for &T

Author: bderrett

Diff for: src/dimension/ndindex.rs

@@ -219,15 +219,6 @@ impl<'a> IntoDimension for &'a [Ix] {
     }
 }
 
-unsafe impl<'a> NdIndex<IxDyn> for &'a IxDyn {
-    fn index_checked(&self, dim: &IxDyn, strides: &IxDyn) -> Option<isize> {
-        (**self).index_checked(dim, strides)
-    }
-    fn index_unchecked(&self, strides: &IxDyn) -> isize {
-        (**self).index_unchecked(strides)
-    }
-}
-
 unsafe impl<'a> NdIndex<IxDyn> for &'a [Ix] {
     fn index_checked(&self, dim: &IxDyn, strides: &IxDyn) -> Option<isize> {
         stride_offset_checked(dim.ix(), strides.ix(), *self)
@@ -239,24 +230,23 @@ unsafe impl<'a> NdIndex<IxDyn> for &'a [Ix] {
     }
 }
 
-unsafe impl<'a> NdIndex<IxDyn> for &'a Vec<Ix> {
+unsafe impl<'a, T> NdIndex<IxDyn> for &T
+where
+    T: NdIndex<IxDyn>,
+{
     fn index_checked(&self, dim: &IxDyn, strides: &IxDyn) -> Option<isize> {
-        stride_offset_checked(dim.ix(), strides.ix(), *self)
+        (*self).index_checked(dim, strides)
     }
     fn index_unchecked(&self, strides: &IxDyn) -> isize {
-        zip(strides.ix(), *self)
-            .map(|(&s, &i)| stride_offset(i, s))
-            .sum()
+        (*self).index_unchecked(strides)
     }
 }
 
 unsafe impl<'a> NdIndex<IxDyn> for Vec<Ix> {
     fn index_checked(&self, dim: &IxDyn, strides: &IxDyn) -> Option<isize> {
-        stride_offset_checked(dim.ix(), strides.ix(), self)
+        (&**self).index_checked(dim, strides)
     }
     fn index_unchecked(&self, strides: &IxDyn) -> isize {
-        zip(strides.ix(), self)
-            .map(|(&s, i)| stride_offset(*i, s))
-            .sum()
+        (&**self).index_unchecked(strides)
     }
 }