解构时字段重命名

pub fn all_or_nothing_system(
    query: Query<(Entity, &AllOrNothing, &ScorerSpan)>,
    mut scores: Query<&mut Score>,
) {
    for (
        aon_ent,
        AllOrNothing {
            threshold,
            scorers: children, // 这里解构时为字段进行了重命名.
        },
        _span,
    ) in query.iter()
      {
        let mut sum = 0.0;
        for Scorer(child) in children.iter() {
            let score = scores.get_mut(*child).expect("where is it?");
            if score.0 < *threshold {
                sum = 0.0;
                break;
            } else {
                sum += score.0;
            }
        }
        let mut score = scores.get_mut(aon_ent).expect("where did it go?");
        score.set(crate::evaluators::clamp(sum, 0.0, 1.0));
        #[cfg(feature = "trace")]
        {
            let _guard = _span.span().enter();
            trace!("AllOrNothing score: {}", score.get());
        }
    }
}

struct Point {
    x: i32,
    y: i32,
}

fn main() {
    let p = Point { x: 10, y: 20 };
    let Point { x: horizontal, y: vertical } = p;
    println!("Horizontal: {}, Vertical: {}", horizontal, vertical);
}