Simplify trait bounds

Author: watsaig

src/stacking.rs

@@ -33,10 +33,10 @@ use crate::imp_prelude::*;
 ///                  [3., 3.]]))
 /// );
 /// ```
-pub fn concatenate<S, D, A>(axis: Axis, arrays: &[ArrayBase<S, D, A>]) -> Result<Array<A, D>, ShapeError>
+pub fn concatenate<S, D>(axis: Axis, arrays: &[ArrayBase<S, D>]) -> Result<Array<S::Elem, D>, ShapeError>
 where
-    S: Data<Elem = A>,
-    A: Clone,
+    S: Data,
+    S::Elem: Clone,
     D: RemoveAxis,
 {
     if arrays.is_empty() {
@@ -97,12 +97,11 @@ where
 /// );
 /// # }
 /// ```
-pub fn stack<S, D, A>(axis: Axis, arrays: &[ArrayBase<S, D, A>]) -> Result<Array<A, D::Larger>, ShapeError>
+pub fn stack<S, D>(axis: Axis, arrays: &[ArrayBase<S, D>]) -> Result<Array<S::Elem, D::Larger>, ShapeError>
 where
-    S: Data<Elem = A>,
-    A: Clone,
+    S: Data,
+    S::Elem: Clone,
     D: Dimension,
-    D::Larger: RemoveAxis,
 {
     if arrays.is_empty() {
         return Err(from_kind(ErrorKind::Unsupported));

tests/stacking.rs

@@ -1,24 +1,19 @@
 use ndarray::{arr2, arr3, aview1, aview2, concatenate, stack, Array2, Axis, ErrorKind, Ix1, ViewRepr};
 
 #[test]
-fn concatenating()
-{
+fn concatenating() {
     let a = arr2(&[[2., 2.], [3., 3.]]);
     let b = ndarray::concatenate(Axis(0), &[a.view(), a.view()]).unwrap();
     assert_eq!(b, arr2(&[[2., 2.], [3., 3.], [2., 2.], [3., 3.]]));
 
     let c = concatenate![Axis(0), a, b];
-    assert_eq!(
-        c,
-        arr2(&[[2., 2.], [3., 3.], [2., 2.], [3., 3.], [2., 2.], [3., 3.]])
-    );
+    assert_eq!(c, arr2(&[[2., 2.], [3., 3.], [2., 2.], [3., 3.], [2., 2.], [3., 3.]]));
 
     let d = concatenate![Axis(0), a.row(0), &[9., 9.]];
     assert_eq!(d, aview1(&[2., 2., 9., 9.]));
 
     let d = concatenate![Axis(1), a.row(0).insert_axis(Axis(1)), aview1(&[9., 9.]).insert_axis(Axis(1))];
-    assert_eq!(d, aview2(&[[2., 9.],
-                           [2., 9.]]));
+    assert_eq!(d, aview2(&[[2., 9.], [2., 9.]]));
 
     let d = concatenate![Axis(0), a.row(0).insert_axis(Axis(1)), aview1(&[9., 9.]).insert_axis(Axis(1))];
     assert_eq!(d, aview2(&[[2.], [2.], [9.], [9.]]));
@@ -29,13 +24,12 @@ fn concatenating()
     let res = ndarray::concatenate(Axis(2), &[a.view(), c.view()]);
     assert_eq!(res.unwrap_err().kind(), ErrorKind::OutOfBounds);
 
-    let res: Result<Array2<f64>, _> = ndarray::concatenate::<ViewRepr<&f64>, _, _>(Axis(0), &[]);
+    let res: Result<Array2<f64>, _> = ndarray::concatenate::<ViewRepr<&f64>, _>(Axis(0), &[]);
     assert_eq!(res.unwrap_err().kind(), ErrorKind::Unsupported);
 }
 
 #[test]
-fn stacking()
-{
+fn stacking() {
     let a = arr2(&[[2., 2.], [3., 3.]]);
     let b = ndarray::stack(Axis(0), &[a.view(), a.view()]).unwrap();
     assert_eq!(b, arr3(&[[[2., 2.], [3., 3.]], [[2., 2.], [3., 3.]]]));
@@ -50,6 +44,6 @@ fn stacking()
     let res = ndarray::stack(Axis(3), &[a.view(), a.view()]);
     assert_eq!(res.unwrap_err().kind(), ErrorKind::OutOfBounds);
 
-    let res: Result<Array2<f64>, _> = ndarray::stack::<ViewRepr<&f64>, Ix1, _>(Axis(0), &[]);
+    let res: Result<Array2<f64>, _> = ndarray::stack::<ViewRepr<&f64>, Ix1>(Axis(0), &[]);
     assert_eq!(res.unwrap_err().kind(), ErrorKind::Unsupported);
 }