我对以下行为感到困惑：有人可以解释发生了什么吗？
考虑代码：
struct Point {
cx : u32,
}
fn main() {
let mut p1 = Point { cx: 100 };
let p2 = p1;
p1.cx = 5000;
// println!("p1.x = {}", p1.cx); // disallowed as p1.cx is "moved" ... ok
println!("p2.x = {}", p2.cx); // ==> prints 100 (!)
}
具体来说，我很困惑：
p1.cxp2.x实际上不是更新后的 5000，而是旧的100.我期待新值，因为没有复制特征（因此移动），所以期待只有一个单元格的更新值（5000）应该被打印。
但是，我一定错过了什么。有小费吗？提前致谢！
现在这是被禁止的。
以前是允许的。然而，这是旧借用检查器中的一个错误，并且在引入新的借用检查器 (NLL) 时已发出警告，然后出现错误。
例如，对于rustc 1.39.02015 版，您会收到以下警告：
warning[E0382]: assign to part of moved value: `p1`
--> a.rs:8:5
|
6 | let mut p1 = Point { cx: 100 };
| ------ move occurs because `p1` has type `Point`, which does not implement the `Copy` trait
7 | let p2 = p1;
| -- value moved here
8 | p1.cx = 5000;
| ^^^^^^^^^^^^ value partially assigned here after move
|
= warning: this error has been downgraded to a warning for backwards compatibility with previous releases
= warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
= note: for more information, try `rustc --explain E0729`
rustc 1.40.0把它变成了一个错误：
error[E0382]: assign to part of moved value: `p1`
--> src/main.rs:7:5
|
5 | let mut p1 = Point { cx: 100 };
| ------ move occurs because `p1` has type `Point`, which does not implement the `Copy` trait
6 | let p2 = p1;
| -- value moved here
7 | p1.cx = 5000;
| ^^^^^^^^^^^^ value partially assigned here after move
error: aborting due to previous error
另请注意，这是 2018 版较长时间的错误（可能自该版本创建以来）。
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