rust - 当分配了移动值的成员时，为什么编译不会失败？

我正在通过Rust by Example中的示例进行工作。

#[derive(Debug)]
struct Point {
    x: f64,
    y: f64,
}

#[derive(Debug)]
struct Rectangle {
    p1: Point,
    p2: Point,
}

fn main() {
    let mut point: Point = Point { x: 0.3, y: 0.4 };
    println!("point coordinates: ({}, {})", point.x, point.y);

    let rectangle = Rectangle {
        p1: Point { x: 1.0, y: 1.0 },
        p2: point,
    };

    point.x = 0.5; // Why does the compiler not break here,
    println!(" x is {}", point.x); // but it breaks here?

    println!("rectangle is {:?} ", rectangle);
}

我收到此错误(Rust 1.25.0):

error[E0382]: use of moved value: `point.x`
  --> src/main.rs:23:26
   |
19 |         p2: point,
   |             ----- value moved here
...
23 |     println!(" x is {}", point.x);
   |                          ^^^^^^^ value used here after move
   |
   = note: move occurs because `point` has type `Point`, which does not implement the `Copy` trait

我知道我已将point赋予Rectangle对象，这就是为什么我无法再访问它，但是为什么编译在println!上失败，而不是在前一行上的赋值失败？

最佳答案

到底发生了什么

fn main() {
    let mut point: Point = Point { x: 0.3, y: 0.4 };
    println!("point coordinates: ({}, {})", point.x, point.y);

    drop(point);

    {
        let mut point: Point;
        point.x = 0.5;
    }

    println!(" x is {}", point.x);
}

事实证明，它已经被称为issue #21232。

关于rust - 当分配了移动值的成员时，为什么编译不会失败？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/42566669/