forked from mirrors/gecko-dev
e76a11f1cf
This also upgrades the headers crate to 0.3.7. Webdriver depends on warp 0.2, which depends on headers 0.3. But headers < 0.3.7 depends on sha-1 < 0.10. We need sha-1 and sha2 at the same minor version to avoid duplicate block-buffer, generic-array, and digest crates. Differential Revision: https://phabricator.services.mozilla.com/D146010
1.7 KiB
1.7 KiB
generic-array
This crate implements generic array types for Rust.
Requires minumum Rust version of 1.36.0, or 1.41.0 for From<[T; N]> implementations
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:
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:
struct Foo<N: ArrayLength<i32>> {
data: GenericArray<i32, N>
}
The ArrayLength<T> trait is implemented by default for unsigned integer types from typenum crate:
use generic_array::typenum::U5;
struct Foo<N: ArrayLength<i32>> {
data: GenericArray<i32, N>
}
fn main() {
let foo = Foo::<U5>{data: GenericArray::default()};
}
For example, GenericArray<T, U5> would work almost like [T; 5]:
use generic_array::typenum::U5;
struct Foo<T, N: ArrayLength<T>> {
data: GenericArray<T, N>
}
fn main() {
let foo = Foo::<i32, U5>{data: GenericArray::default()};
}
In version 0.1.1 an arr! macro was introduced, allowing for creation of arrays as shown below:
let array = arr![u32; 1, 2, 3];
assert_eq!(array[2], 3);