early drop.rs

// error[E0597]: `arc` does not live long enough

use std::cmp::min;
use std::io::{self, Write};
use std::sync::Arc;
use tokio::sync::Mutex;
use tokio_executor::blocking;

fn send<T: Write + 'static + Send + Sync>(
    dest: &Arc<Mutex<T>>,
    mut buf: Vec<u8>,
) -> impl Future<Output = Result<Vec<u8>, io::Error>> {
    let arc = dest.clone();
    async move {
        let mut lock = arc.lock();
                    // ^^^-------
                    // |
                    // borrowed value does not live long enough
                    // argument requires that `arc` is borrowed for `'static`
        let mut dest = lock.await;
        let result = blocking::run(move || {
            let len = dest.write(&buf[..])?;
            let remainder = buf.len() - len;
            if buf.len() - len > 0 {
                buf.copy_within(len.., 0);
                buf.truncate(len);
            } else {
                buf.clear();
            }
            Ok(buf)
        })
        .await;
        result
    }
    // - `arc` dropped here while still borrowed
}