rust - 许多结构的一个特征的类似实现

Question

在下面的代码中，唯一不同的是 println! 的实现。

感觉应该有办法让我不必写出两个完全不同的实现，但是我没有找到办法。

pub trait ChangeDecision{
    fn change_decision(&mut self);
}

impl ChangeDecision for Hero{
    fn change_decision(&mut self){
        self.should_change_decision = false;
        let rand_num = rand::thread_rng().gen_range(1, 101) as f32 / 100.;
        let mut prob_counter = 0.0;
        for (action, prob) in &mut self.decisions.iter(){
            prob_counter += *prob;
            match prob_counter{
                p if rand_num > p => {},
                _ => {println!("{}: {:?}", self.name, action); self.current_decision = *action; break},
            }
        }
    }
}

impl ChangeDecision for Team{
    fn change_decision(&mut self){
        self.should_change_decision = false;
        let rand_num = rand::thread_rng().gen_range(1, 101) as f32 / 100.;
        let mut prob_counter = 0.0;
        for (action, prob) in &mut self.decisions.iter(){
            prob_counter += *prob;
            match prob_counter{
                p if rand_num > p => {},
                _ => {println!("{:?}: {:?}", self.side, action); self.current_decision = *action; break},
            }
        }
    }
}

当实现完全相同时，我可以使用宏来实现两者。即

macro_rules! impl_SimilarStuff {
    ($T:ident) => {
        impl SimilarStuff for $T{
            fn my_func(&mut self){
                true
            }
        }
     }
}

impl_SimilarStuff!(ThingOne);
impl_SimilarStuff!(ThingTwo);

但是我找不到任何“宏观条件”的例子

Answer 1

我处理这个问题的方法是使用另一个特征来处理不同的部分。像这样的东西:

trait PrintSomething {
    fn print_something(&self, action: Action);
}

impl PrintSomething for Hero {
    fn print_something(&self, action: Action) {
        println!("{}: {:?}", self.name, action);
    }
}

impl PrintSomething for Team {
    fn print_something(&self, action: Action) {
        println!("{}: {:?}", self.side, action);
    }
}

// Now the macro would expand to:
impl ChangeDecision for Hero {
    fn change_decision(&mut self){
        self.should_change_decision = false;
        let rand_num = rand::thread_rng().gen_range(1, 101) as f32 / 100.;
        let mut prob_counter = 0.0;
        for (action, prob) in &mut self.decisions.iter(){
            prob_counter += *prob;
            match prob_counter{
                p if rand_num > p => {},
                _ => {
                    self.print_something(action);
                    self.current_decision = *action;
                    break
                 },
            }
        }
    }
}