Basic traits restrictions for Dimension::Pattern

[termoshtt]

The Pattern associated type of Dimension is used in several top level API e.g. ArrayBase::dim, but its definition lacks restrictions Eq, Debug, and others. Here is my code:

fn assert_equal_size<A, S1, S2, D>(test: &ArrayBase<S1, D>, truth: &ArrayBase<S2, D>)
where
    A: LinalgScalar,
    S1: Data<Elem = A>,
    S2: Data<Elem = A>,
    D: Dimension,
    D::Pattern: PartialEq + Debug,   // I'd like to remove this line !!
{
    assert_eq!(test.dim(), truth.dim());
}

Summary

• Add Clone, Debug, PartialEq, Eq, and Default restrictions to Dimension::Pattern
• Copy is not added because IxDyn is not Copy

[jturner314]

This looks good to me and AFAIK is not a breaking change (since no external crates can implement Dimension.)

[LukeMathWalker]

If you run cargo fmt we should be able to merge it without conflicts @termoshtt 🚀