Function scope 

pub async fn scope<'scope, F, O>(f: F) -> Vec<Result<O, JoinError>>
where
    for<'spawner> F: FnOnce(Token<'scope, 'spawner, O>),
    O: Send + 'static,

Async scope helper

This function helps you write unsafe asynchronous structured concurrent code more easily. but it is still unsafe, so need to be careful when using it.

To use it safely, the user needs to ensure that the task is done within used reference lifetime. Due to std::mem::forget, the Rust currently cannot guarantee it.

From a practical point of view, the following points need to be note

• .await as early as possible
• Don’t put task into container unless you know what you are doing
• Don’t call std::mem::forget

Example

let list: Vec<u32> = vec![1, 2, 3, 4];

rspack_parallel::scope(|token| {
  for i in 0..list.len() {
    let s = unsafe { token.used(&list) };

    s.spawn(move |list| async move {
      &list[i];
    });
  }
})
.await;

This doesn’t compile

rspack_parallel::scope(|token| {
  let list: Vec<u32> = vec![1, 2, 3, 4];

  for i in 0..list.len() {
    let s = unsafe { token.used(&list) };

    s.spawn(move |list| async move {
      &list[i];
    });
  }
})
.await;