Macro shipyard::system

macro_rules! system {
    ($function : expr) => { ... };
}

Reduce boilerplace to add a system to a workload and make it less error prone.

Example

use shipyard::{system, EntitiesViewMut, IntoIter, Shiperator, View, ViewMut, World};

fn add(mut usizes: ViewMut<usize>, u32s: View<u32>) {
    for (x, &y) in (&mut usizes, &u32s).iter() {
        *x += y as usize;
    }
}

fn check(usizes: View<usize>) {
    let mut iter = usizes.iter();
    assert_eq!(iter.next(), Some(&1));
    assert_eq!(iter.next(), Some(&5));
    assert_eq!(iter.next(), Some(&9));
}

let world = World::new();

world.run(
    |mut entities: EntitiesViewMut, mut usizes: ViewMut<usize>, mut u32s: ViewMut<u32>| {
        entities.add_entity((&mut usizes, &mut u32s), (0, 1));
        entities.add_entity((&mut usizes, &mut u32s), (2, 3));
        entities.add_entity((&mut usizes, &mut u32s), (4, 5));
    },
);

world
    .add_workload("Add & Check")
    .with_system(system!(add))
    .with_system(system!(check))
    .build();

world.run_default();