无法调用我的对象的两个方法，因为我 "use of moved value: `self`"

Question

我是 Rust 和一般低级编程的新手。我试图了解所有权以及内存如何与 Rust 一起工作。

但我不明白如何在我的对象的主要方法中调用多个 setter。

#[derive(Default, Clone)]
pub struct Metric {
    loads: (f32, f32, f32),
    memory: (String, String),
}

    // Main method
    pub fn get_metrics(self) {
        let sys = System::new();
        match sys.load_average() {
            Ok(loadavg) => self.set_loads(loadavg.one, loadavg.five, loadavg.fifteen),
            Err(x) => println!("\nLoad average: error: {}", x),
        }

        match sys.memory() {
            Ok(mem) => self.set_memory(
                saturating_sub_bytes(mem.total, mem.free).to_string(),
                mem.total.to_string(),
            ),
            Err(x) => println!("\nMemory: error: {}", x),
        }
    }

    // Setters
    fn set_loads(mut self, one: f32, five: f32, fifteen: f32) {
        self.loads = (one, five, fifteen);
        println!(
            "\nLoad average {} {} {}",
            self.loads.0, self.loads.1, self.loads.2
        );
        self;
    }
    fn set_memory(mut self, used: String, total: String) {
        self.memory = (used, total);
        println!("\nLoad average {} {}", self.memory.0, self.memory.1);
    }

我知道我不能移动两次变量，但是如果我们不想一次性设置道具，在上下文中我们如何才能移动一次..

谢谢大家。

Answer 1

您正在移动您的对象，您可能只想对它使用引用，不可变的&self或可变的&mut self 个：

    // Getters
    pub fn get_metrics(&mut self) {
        let sys = System::new();
        match sys.load_average() {
            Ok(loadavg) => self.set_loads(loadavg.one, loadavg.five, loadavg.fifteen),
            Err(x) => println!("\nLoad average: error: {}", x),
        }

        match sys.memory() {
            Ok(mem) => self.set_memory(
                saturating_sub_bytes(mem.total, mem.free).to_string(),
                mem.total.to_string(),
            ),
            Err(x) => println!("\nMemory: error: {}", x),
        }
    }

    // Setters
    fn set_loads(&mut self, one: f32, five: f32, fifteen: f32) {
        self.loads = (one, five, fifteen);
        println!(
            "\nLoad average {} {} {}",
            self.loads.0, self.loads.1, self.loads.2
        );
    }

    fn set_memory(&mut self, used: String, total: String) {
        self.memory = (used, total);
        println!("\nLoad average {} {}", self.memory.0, self.memory.1);
    }

无法调用我的对象的两个方法，因为我 "use of moved value: `self`"

Can't call to two methods of my object because I "use of moved value: `self`"

struct

rust

ownership