Crate array_map[−][src]

Expand description

no_std compatible Map and Set backed by arrays. This crate will evolve as more const-generic features become available.

Features:

derive: Includes the Indexable derive macro
serde: Includes serde impls for ArrayMap and ArraySet
std: Includes From implementations between ArrayMap<K, AtomicBool, M> and ArraySet<K, S>

This is especially useful if you have a bare enum where you want to treat each key as a field. This also has the benefit that adding a new enum variant forces you to update your code.

use array_map::*;
#[repr(u8)]
#[derive(Indexable)]
enum DetectionType {
  Person,
  Vehicle,
  Bicycle,
}

let thresholds = ArrayMap::<DetectionType, f32, {DetectionType::count()}>::from_closure(|dt| match dt {
    DetectionType::Person => 0.8,
    DetectionType::Vehicle => 0.9,
    DetectionType::Bicycle => 0.7,
  });

let person_threshold = thresholds[DetectionType::Person];

This can also be used to memoize some common computations (this is 2x as fast as doing the computation on aarch64)

use array_map::*;
let u8_to_f32_cache = ArrayMap::<u8, f32, {u8::SIZE}>::from_closure(|u|f32::from(*u) / 255.0);
// take some bytes and convert them to f32
let floats = bytes.iter().copied().map(|b|u8_to_f32_cache[b]).collect::<Vec<_>>();