Is there another option to share an Arc in multiple closures besides cloning it before each closure?

by

There is no way around it. You should clone the Arc before it is used in a closure. The common pattern is to re-bind the cloned Arc to the same name in a nested scope:

use std::sync::Arc;

fn main() {    
    let arc = Arc::new(42);
    {
        let arc = arc.clone();
        move || { /* do something with arc */ };
    }
    {
        let arc = arc.clone();
        move || { /* do something else with arc */ };
    }
}

This is usually done together with thread::spawn():

use std::sync::{Arc, Mutex};
use std::thread;

const NUM_THREADS: usize = 4;

fn main() {
    let arc = Arc::new(Mutex::new(42));
    for _ in 0..NUM_THREADS {
        let arc = arc.clone();
        thread::spawn(move || {
            let mut shared_data = arc.lock().unwrap();
            *shared_data += 1;
        });
    }
}

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