shared.rs

struct Shared<T>(mpsc::Sender<T>);

impl Clone for Shared<T> {
  fn clone(&self) -> Shared<T> {
    Shared(self.0.clone())
  }
}

impl<T> Shared<T> {
  pub fn new(tx: mpsc::Sender<T>) -> Shared<T> {
    // this guarantees the safety of the `Sync` imlementation for `Shared
    tx.clone();
    Shared(tx)
  }
}

// safe because mpsc::Sender.clone() upgrades it to an internally thread-safe type
unsafe impl<T> Sync for Shared<T> {}