MultiArrayList

Experimental: Only a small subset of a the array list API is implemented.

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A MultiArrayList stores a list of a struct.

Instead of storing a single list of items, MultiArrayList stores separate lists for each field of the struct. This allows for memory savings if the struct has padding, and also improves cache usage if only some fields are needed for a computation.

The primary API for accessing fields is the [items(name)][MultiArrayList::items()] function.

---

inspired by Zig's MultiArrayList.

Example

use multi_array_list::MultiArrayList;
use facet::Facet;

#[derive(Facet, Clone)]
struct Pizza {
    radius: u32,
    toppings: Vec<Topping>,
}

#[derive(Facet, Clone, Copy)]
#[repr(u8)]
enum Topping {
    Tomato,
    Mozzarella,
    Anchovies,
}

let mut order = MultiArrayList::<Pizza>::new();

let margherita = Pizza {
    radius: 12,
    toppings: vec![Topping::Tomato],
};
order.push(margherita);

let napoli = Pizza {
    radius: 12,
    toppings: vec![Topping::Tomato, Topping::Anchovies],
};
order.push(napoli);

for topping in order.items_mut::<Vec<Topping>>("toppings") {
    topping.push(Topping::Mozzarella);
}

License

MIT. See LICENSE.