Macro find_trait

macro_rules! find_trait {
    ($component:expr, $trait:ty) => { ... };
}

Returns an optional reference to a trait for an object within the component.

Examples

#![feature(lazy_cell)]
use gear_objects::*;
use paste::paste;

struct Apple {}
register_type!(Apple);

trait Fruit {
    fn eat(&self) -> String;
}
register_type!(Fruit);

impl Fruit for Apple {
    fn eat(&self) -> String {
        "yum!".to_owned()
    }
}

let apple = Apple {};
let mut component = Component::new("apple");
add_object!(component, Apple, apple, [Fruit]);

let fruit = find_trait!(component, Fruit);
assert_eq!(fruit.unwrap().eat(), "yum!");