Can I reshape a non-contiguous view in rust-ndarray?

Question

This program compiles, but panics at run time with the message below. (playground)

use ndarray::prelude::*;

fn main() {
    let a = Array2::<i32>::zeros([100, 10]);
    let b = a.slice(s![5..15, ..8]);
    let c = b.into_shape((10, 2, 4)).expect("should work");
    dbg!(c);
}

thread 'main' panicked at 'should work: ShapeError/IncompatibleLayout: incompatible memory layout', src/main.rs:6:38

Reshaping fails because the view b is not contiguous.

But this reshape is just splitting one axis in two, which can always be done safely. Analogous code works fine in NumPy:

a = np.arange(1000).reshape((100, 10))
b = a[5:15, :8]
c = b.reshape((10, 2, 4))

# array([[[ 50,  51,  52,  53],
#         [ 54,  55,  56,  57]],
#
#        [[ 60,  61,  62,  63],
#         [ 64,  65,  66,  67]], ...])

How can I do that in Rust?

Answer 1

You can make it as contiguous using the as_standard_layout function.