Scoped threads in Rust

thread::scope lets threads borrow local data, because they cannot outlive the scope.

use std::thread;

fn main() {
    let scores = vec![91, 104, 87, 96];

    thread::scope(|s| {
        s.spawn(|| {
            let total: i32 = scores.iter().sum();
            println!("sum {total}");
        });
        s.spawn(|| {
            println!("max {:?}", scores.iter().max());
        });
    });

    println!("still ours: {:?}", scores);
}

How it works

1. Scoped threads may hold references to the stack.
2. The scope joins every thread before it returns.
3. No Arc is needed for read-only sharing.

Keywords and builtins used here

• fn
• i32
• let
• main
• use

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Type this snippet

Step 3 of 3 in Threads, step 3 of 15 in Concurrency & async.

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