array_trait

A trait for any array, with item as an associated type, and length as an assiciated constant.

Examples

use array_trait::*;

type Arr3 = [i8; 3];

const A: Arr3 = [1, 2, 3];

// The assiciated constant `LENGTH` equals the length of the array
assert_eq!(Arr3::LENGTH, 3);
assert_eq!(Arr3::LENGTH, A.len());

#![feature(const_trait_impl)]
#![feature(generic_const_exprs)]

use array_trait::*;

type Arr3 = [i8; 3];

const A: Arr3 = [1, 2, 3];

/// The trait can be used in a function like this:
const fn first<'a, T: ~const Array>(array: &'a T) -> Option<&'a T::Item>
where
    [(); T::LENGTH]: // This is required for now.
{
    array.as_array().first()
}
assert_eq!(first(&A), Some(&1));

N-dimensional arrays

There is also a trait for N-dimensional arrays, which contain information on its inner structure, and supports a depth up to 64 dimensions.

The associated constants DIMENSIONS and FLAT_LENGTH vary depending on the chosen depth.

The assiciated type ItemNd represents the innermost type given a chosen depth.

Examples

use array_trait::*;

type Mat2x3 = [[i8; 3]; 2];

/// The number of dimensions
const DEPTH: usize = 2;

// `FLAT_LENGTH` is the combined length if the N-dimensional array was flattened,
// i.e. the product of the lengths of each dimension.
assert_eq!(<Mat2x3 as ArrayNd<DEPTH>>::FLAT_LENGTH, 6);

// `DIMENSIONS` contains the lengths of each dimension ordered outermost to innermost.
assert_eq!(<Mat2x3 as ArrayNd<DEPTH>>::DIMENSIONS, [2, 3]);

More operations

For more operations with arrays, using this as a basis, check out the crate array__ops.