Add DimAdd bounds to Dimension trait

This reduces how often an explicit `DimAdd` bound is necessary.

Author: jturner314

src/dimension/dimension_trait.rs

@@ -13,6 +13,7 @@ use alloc::vec::Vec;
 
 use super::axes_of;
 use super::conversion::Convert;
+use super::ops::DimAdd;
 use super::{stride_offset, stride_offset_checked};
 use crate::itertools::{enumerate, zip};
 use crate::{Axis, DimMax};
@@ -51,6 +52,12 @@ pub trait Dimension:
     + DimMax<IxDyn, Output=IxDyn>
     + DimMax<<Self as Dimension>::Smaller, Output=Self>
     + DimMax<<Self as Dimension>::Larger, Output=<Self as Dimension>::Larger>
+    + DimAdd<Self>
+    + DimAdd<<Self as Dimension>::Smaller>
+    + DimAdd<<Self as Dimension>::Larger>
+    + DimAdd<Ix0, Out = Self>
+    + DimAdd<Ix1, Out = <Self as Dimension>::Larger>
+    + DimAdd<IxDyn, Out = IxDyn>
 {
     /// For fixed-size dimension representations (e.g. `Ix2`), this should be
     /// `Some(ndim)`, and for variable-size dimension representations (e.g.

src/dimension/ops.rs

@@ -1,7 +1,7 @@
 use crate::imp_prelude::*;
 
 /// Adds the two dimensions at compile time.
-pub trait DimAdd<D: Dimension>: Dimension {
+pub trait DimAdd<D: Dimension> {
     /// The sum of the two dimensions.
     type Out: Dimension;
 }

src/slice.rs

@@ -661,14 +661,14 @@ pub trait SliceArg {
     /// Number of dimensions that this slicing argument produces in the output array.
     type OutDim: Dimension;
 
-    fn next_in_dim<D>(&self, _: PhantomData<D>) -> PhantomData<D::Out>
+    fn next_in_dim<D>(&self, _: PhantomData<D>) -> PhantomData<<D as DimAdd<Self::InDim>>::Out>
     where
         D: Dimension + DimAdd<Self::InDim>,
     {
         PhantomData
     }
 
-    fn next_out_dim<D>(&self, _: PhantomData<D>) -> PhantomData<D::Out>
+    fn next_out_dim<D>(&self, _: PhantomData<D>) -> PhantomData<<D as DimAdd<Self::OutDim>>::Out>
     where
         D: Dimension + DimAdd<Self::OutDim>,
     {