Function divide_and_conquer

src/scope.rs:1281–1297

(
        scope: &'scope Scope<'scope, 'env>,
        counter: &'scope AtomicUsize,
        size: usize,
    )

    #[test]
    fn scope_sleeping_future() {
        static THREAD_POOL: ThreadPool = ThreadPool::new();
        THREAD_POOL.resize_to_available();

        let mut complete = false;
        THREAD_POOL.scope(|scope| {
            scope.spawn(async {
                // Spawn a count future onto the thread pool, then have this
                // future sleep until that future is done.
                THREAD_POOL.spawn(CountFuture::default()).await;
                complete = true;
            })
        });

        assert!(complete);

        THREAD_POOL.depopulate();
    }

    /// Tests that blocking functions like `join` can be nested within scopes.
    #[test]