Macro components_arena::Component

macro_rules! Component {
    (($(class = $class : ident) ?) $vis : vis enum $name : ident $($body : tt) *) => { ... };
    (($(class = $class : ident) ?) $vis : vis struct $name : ident $($body : tt)
 *) => { ... };
}

Macro attribute for deriving Component trait.

Examples

Non-generic component

macro_attr! {
    #[derive(Component!)]
    struct Item { /* ... */ }
}

// ...

let mut arena = Arena::new();
let id = arena.insert(|id| (Item { /* ... */ }, id));

Generic component

macro_attr! {
    #[derive(Component!(class=ItemComponent))]
    struct Item<T> {
        context: T
    }
}

// ...

let mut arena_u8 = Arena::new();
let _ = arena_u8.insert(|id| (Item { context: 7u8 }, id));

let mut arena_u32 = Arena::new();
let _ = arena_u32.insert(|id| (Item { context: 7u32 }, id));