我想在一个结构体中可变地覆盖两个元素，但我得到了一个错误。下面是简化的代码：

use std::collections::HashMap;

struct Attr {
    value1: usize,
    value2: Vec<usize>
}

impl Default for Attr {
    fn default() -> Self {
        Self { 
            value1: 100,
            value2: vec![1;1000],
        }
    }
}

struct Data {
    inner: Vec<usize>, //A complex structure in real code
    attrs: HashMap<usize, Attr>,
}

fn iter_data(d: &mut Data) -> impl Iterator<Item = (usize, &mut Attr)> {
    d.inner.iter().map(|x| (*x, d.attrs.get_mut(x).unwrap()))
}

fn main() {
    let mut data = Data {
        inner: Vec::new(),
        attrs: HashMap::new()
    };
    
    for i in 1..100 { 
        data.inner.push(i);
        data.attrs.insert(i, Default::default());
    }

   for (k, v) in iter_data(&mut data){ // mutably iterate data
  
   }
}

字符串
这是一个错误：

error: captured variable cannot escape `FnMut` closure body
  --> src/main.rs:25:28
   |
24 | fn iter_data(d: &mut Data) -> impl Iterator<Item = (usize, &mut Attr)> {
   |              - variable defined here
25 |     d.inner.iter().map(|x| (*x, d.attrs.get_mut(x).unwrap()))
   |                          - ^^^^^-^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |                          | |    |
   |                          | |    variable captured here
   |                          | returns a reference to a captured variable which escapes the closure body
   |                          inferred to be a `FnMut` closure
   |
   = note: `FnMut` closures only have access to their captured variables while they are executing...
   = note: ...therefore, they cannot allow references to captured variables to escape

型
我想知道如何避免这个错误？我只是想将Data中的每个元素都重新编译，并修改每个元素的attrs。我知道我可以直接用(key, value)重新编译attrs，但在真实的代码中存在一些问题。