shared.rs

shared.rs

use std::sync::{Arc, RwLock};

struct Foo {
    f: Arc<RwLock<i32>>
}

trait Formattable {
    fn own_format(&mut self);
}

impl Formattable for Foo {
    fn own_format(&mut self) {
        let value = *self.f.read().unwrap();
        self.f = Arc::new(RwLock::new(value));
    }
}

fn main() {
    let mut foo = Foo { f: Arc::new(RwLock::new(21)) };
    let mut bar = Foo { f: foo.f.clone() };

    {
        let mut x = foo.f.write().unwrap();
        *x = 22;
    }

    {
        let y = bar.f.read().unwrap();
        println!("{}", *y);
    }

    bar.own_format();

    {
        let mut x = bar.f.write().unwrap();
        *x = 122;
    }
    
    {
        let y = bar.f.read().unwrap();
        println!("{}", *y);
    }
    {
        let y = foo.f.read().unwrap();
        println!("{}", *y);
    }

}