如何插入 LinkedList 的 HashMap 解引用迭代器？

Question

How to fix issue on a screenshot? I already tried to make it mutable, but that is not the point. What can it be, how to get rid of it? I will be thankful for the changes in the code.

screenshot:
_{(source: i.ibb.co )}

let mut buf = vec![0 as u8; 4096];
for stream in listener.incoming() {
    match stream {
        Ok(mut stream) => {
            match stream.read(&mut buf) {
                Ok(size) => {
                    //Get List of names
                    let names: LinkedList<String> = serde_json::from_slice(&buf[..size])?;
                    for name in names.iter() {
                        if (*data).available.contains_key(&*name) {
                            //If file already exist just update Vec of IP
                            (*data)
                                .available
                                .get_mut(&*name)
                                .unwrap()
                                .push(stream.peer_addr().unwrap());
                        } else {
                            //In another case - adding file with first IP that share it
                            let mut v: Vec<SocketAddr> = Vec::new();
                            v.push(stream.peer_addr().unwrap());
                            (*data).available.insert(*name, v);
                        }
                    }
                }
                Err(_) => {
                    println!("An error occurred, {}", stream.peer_addr().unwrap());
                }
            }
        }
        Err(e) => {
            println!("Error: {}", e);
        }
    }
}

Answer 1

Are you sure you want a LinkedList and not a Vec as output from your JSON parser? From the LinkedList docs:

It is almost always better to use Vec or VecDeque because array-based containers are generally faster, more memory efficient, and make better use of CPU cache.

To solve your problem, you should loop over names instead of names.iter() . This will make the list unusable after the for loop. You will then have to remove the dereferences in your code, ie write &name instead of " &*name " and name instead of *name . However, you shouldn't have written &*name at all because the & and * in &*name are cancelling each other out.