simpleなrustのサンプル

main.rs

trait Task {
    fn update(&mut self);
    fn is_died(&self)->bool;
    fn spawn(&self)->Box<dyn Task>;
}

struct UnitA {
    name : String,
    life : i32,
}
struct UnitB {
    name : String,
    revival : i32,
}

impl Task for UnitA{
    fn update(&mut self){
        self.life -= 1;
        println!("{}'s life remain {}", self.name, self.life);
    }
    fn is_died(&self)->bool {
        self.life <= 0
    }
    fn spawn(&self)->Box<dyn Task>{
        println!("UnitA spawn UnitB");
        Box::new(UnitB::new())
    }
}
impl Task for UnitB{
    fn update(& mut self){
        self.revival -= 1;
        println!("{}'s will revive {}", self.name, self.revival);
    }
    fn is_died(&self)->bool {
        self.revival <= 0
    }
    fn spawn(&self)->Box<dyn Task>{
        println!("UnitB spawn UnitA");
        Box::new(UnitA::new())
    }
}

impl UnitA{
    fn new()->Self{
        UnitA{name: "human".to_string(), life: 50}
    }
}
impl UnitB{
    fn new()->Self{
        UnitB{name: "zombie".to_string(), revival: 40}
    }
}


fn main() {
    let mut units: Vec<Box<dyn Task>> = vec![
        Box::new(UnitA::new()),
        Box::new(UnitB::new())
        ];
    // ゲームループ想定で処理を回します
    loop{
        let mut i = 0;
        while i < units.len(){
            let unit = units[i].as_mut();
            unit.update();
            if unit.is_died(){
                println!("unit is died remove");
                let new_unit = unit.spawn();
                units.push(new_unit);
                units.remove(i);
            }
            else{
                i += 1;
            }
        }
    }
}