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

Question

I'm new in Rust and in low level programming in general. I try to understand ownership and how the memory work with Rust.

But I don't understand how I can call multiple setters in a principle method of my object.

#[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);
    }

I understand that I can't moved twice variables, but how in the context we can move just one time if we wan't to set props not in one time..

Thank's all.

Answer 1

You are moving your object, you probably just want to use references to it, either inmutable &self or mutable &mut self ones:

    // 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);
    }