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# array_trait
A trait for any array, with item as an associated type, and length as an assiciated constant.
This crate is a subset of the crate [`array_ops`](https://crates.io/crates/array_ops).
## Examples
```rust
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());
```
```rust
#![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
```rust
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](https://www.crates.io/crates/array__ops).