将闭包添加为struct方法

Question

我正在尝试这样做:调用modify()将使用环境变量更新r。

我读过闭包，但不知道如何将闭包添加到结构中。

fn main() {
    let r = Rect::new();
    let width:u32 = 10;
    let height:u32 = 10;

    r.modify();
}


struct Rect{
    width:u32,
    height:u32
}
impl Rect{
    fn new()->Self{
        Self{
            width:0,
            height:0,
        }
    }

    fn modify(&mut self){
        self.width = ...;
        self.height = ...;
    }
}

Answer 1

你可以做你想做的事，试试！

fn main() {
    let mut r = Rect::new();
    let width: u32 = 10;
    let height: u32 = 11;
    let cls = || (width, height);

    r.modify(cls);
    dbg! {r};
}

#[derive(Debug)]
struct Rect {
    width: u32,
    height: u32,
}

impl Rect {
    fn new() -> Self {
        Self {
            width: 0,
            height: 0,
        }
    }

    fn modify<T>(&mut self, cls: T)
    where
        T: Fn() -> (u32, u32)
    {
        self.width = cls().0;
        self.height = cls().1;
    }
}