borrowed-futs.rs

trait AsyncRead {
    async fn read(&self, buf: &mut [u8]) -> io::Result<usize>;
}

fn main () {
    let mut buf = vec![0; 1024];
    let bytes_read = read(&mut buf).await?;
    dbg!(buf);
}

////

trait AsyncRead {
    fn read(&self, buf: Vec<u8>) -> Future<Output = (io::Result<usize>>, Vec<u8>);
}

fn main () {
    let mut buf = vec![0; 1024];
    let (bytes_read, buf) = read(buf).await?;
    dbg!(buf);
}