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35 lines
1.2 KiB
Markdown
35 lines
1.2 KiB
Markdown
[](https://crates.io/crates/generic-array)
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[](https://travis-ci.org/fizyk20/generic-array)
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# generic-array
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This crate implements generic array types for Rust.
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[Documentation](http://fizyk20.github.io/generic-array/generic_array/)
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## Usage
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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:
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```rust
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struct Foo<N> {
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data: [i32; N]
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}
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```
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**generic-array** defines a new trait `ArrayLength<T>` and a struct `GenericArray<T, N: ArrayLength<T>>`, which let the above be implemented as:
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```rust
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struct Foo<N: ArrayLength<i32>> {
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data: GenericArray<i32, N>
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}
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```
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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]` :)
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In version 0.1.1 an `arr!` macro was introduced, allowing for creation of arrays as shown below:
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```rust
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let array = arr![u32; 1, 2, 3];
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assert_eq!(array[2], 3);
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```
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