Threads com Escopo

Threads normais nĂŁo podem emprestar de seu ambiente:

use std::thread;

fn foo() {
    let s = String::from("OlĂĄ");
    thread::spawn(|| {
        println!("Length: {}", s.len());
    });
}

fn main() {
    foo();
}

No entanto, vocĂȘ pode usar uma thread com escopo para isso:

use std::thread;

fn main() {
    let s = String::from("OlĂĄ");

    thread::scope(|scope| {
        scope.spawn(|| {
            println!("Length: {}", s.len());
        });
    });
}
  • The reason for that is that when the thread::scope function completes, all the threads are guaranteed to be joined, so they can return borrowed data.
  • Normal Rust borrowing rules apply: you can either borrow mutably by one thread, or immutably by any number of threads.