struct Test {
a: i32,
b: i32,
}
fn other(x: &mut i32, _refs: &Vec<&i32>) {
*x += 1;
}
fn main() {
let mut xes: Vec<Test> = vec![Test { a: 3, b: 5 }];
let mut refs: Vec<&i32> = Vec::new();
for y in &xes {
refs.push(&y.a);
}
xes.iter_mut().for_each(|val| other(&mut val.b, &refs));
}
尽管refs
仅包含对xes
中元素的a
成员的引用,而函数other
使用了b
成员,但Rust会产生以下错误:
error[E0502]: cannot borrow `xes` as mutable because it is also borrowed as immutable
--> /src/main.rs:16:5
|
13 | for y in &xes {
| ---- immutable borrow occurs here
...
16 | xes.iter_mut().for_each(|val| other(&mut val.b, &refs));
| ^^^ mutable borrow occurs here ---- immutable borrow later captured here by closure
闭包有问题吗?通常情况下分裂借用应该是允许的,我错过了什么吗?