| [](https://crates.io/crates/generic-array) |
| [](https://travis-ci.org/fizyk20/generic-array) |
| # generic-array |
| |
| This crate implements generic array types for Rust. |
| |
| [Documentation](http://fizyk20.github.io/generic-array/generic_array/) |
| |
| ## Usage |
| |
| The Rust arrays `[T; N]` are problematic in that they can't be used generically with respect to `N`, so for example this won't work: |
| |
| ```rust |
| struct Foo<N> { |
| data: [i32; N] |
| } |
| ``` |
| |
| **generic-array** defines a new trait `ArrayLength<T>` and a struct `GenericArray<T, N: ArrayLength<T>>`, which let the above be implemented as: |
| |
| ```rust |
| struct Foo<N: ArrayLength<i32>> { |
| data: GenericArray<i32, N> |
| } |
| ``` |
| |
| To actually define a type implementing `ArrayLength`, you can use unsigned integer types defined in [typenum](https://github.com/paholg/typenum) crate - for example, `GenericArray<T, U5>` would work almost like `[T; 5]` :) |
| |
| In version 0.1.1 an `arr!` macro was introduced, allowing for creation of arrays as shown below: |
| |
| ```rust |
| let array = arr![u32; 1, 2, 3]; |
| assert_eq!(array[2], 3); |
| ``` |
