Struct MultiArrayList

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pub struct MultiArrayList<T>where
    T: 'static,
    [(); { _ }]:,
{ /* private fields */ }

Expand description

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) function.

Implementations§

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impl<T> MultiArrayList<T>
where T: 'static, [(); { _ }]:,

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pub fn new() -> MultiArrayList<T>

Constructs a new, empty MultiArrayList<T>.

§Examples

#![allow(incomplete_features)]
#![feature(generic_const_exprs)]
struct Point {
    x: i32,
    y: i32
}
let mut list: MultiArrayList<Point> = MultiArrayList::new();

§Type can’t be not a struct

#![allow(incomplete_features)]
#![feature(generic_const_exprs)]
use multi_array_list::MultiArrayList;
#[repr(u8)]
enum Random {
    Four,
}
let m = MultiArrayList::<Random>::new();

§Type can’t be empty

#![allow(incomplete_features)]
#![feature(generic_const_exprs)]
use multi_array_list::MultiArrayList;
let m = MultiArrayList::<()>::new();

Source

pub fn with_capacity(capacity: usize) -> MultiArrayList<T>

Constructs a new, empty MultiArrayList<T> with at least the specified capacity.

§Examples

#![allow(incomplete_features)]
#![feature(generic_const_exprs)]
struct Point {
    x: i32,
    y: i32
}
let mut list: MultiArrayList<Point> = MultiArrayList::with_capacity(10);

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pub fn capacity(&self) -> usize

Returns the total number of elements the vector can hold without reallocating.

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pub fn len(&self) -> usize

Returns the number of elements in the MultiArrayList, also referred to as its ‘length’.

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pub fn push(&mut self, value: T)

Appends an element to the back of a collection.

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pub fn pop(&mut self) -> Option<Box<T>>

Removes the last element from the MultiArrayList and returns it, or None if it is empty.

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pub fn iter<'a>(&'a self) -> Iter<'a, T> ⓘ

Returns an iterator over the MultiArrayList.

The iterator yields all items from start to end.

#![allow(incomplete_features)]
#![feature(generic_const_exprs)]
use multi_array_list::MultiArrayList;

struct Point {
    x: i32,
    y: i32,
}

let mut points = MultiArrayList::<Point>::new();
points.push(Point { x: 1, y: 0 });
for point in points.iter() {
    assert_eq!(1, *point.get::<"x", _>());
    assert_eq!(0, *point.get::<"y", _>());
}

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pub fn items<'a, const NAME: &'static str, V: 'static>(&'a self) -> Slice<'a, V> ⓘ

Get an iterator of values for a specified field.

§Compile errors

Fails to compile if the requested field does not exist.
Fails to compile if the requested type does not match the found field (by size).

#![allow(incomplete_features)]
#![feature(generic_const_exprs)]
use multi_array_list::MultiArrayList;
struct HereBeDragons {
    x: u32,
    y: (u8, u16),
}
let mut list = MultiArrayList::<HereBeDragons>::new();
_ = list.items::<"y", (u16, u8)>(); // will not compile

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