I'm trying to init the listener with the following options (from arguments)

let session = librqbit::Session::new_with_opts(
    match preload {
        Some(ref p) => p.path(),
        None => PathBuf::new(),
    },
    SessionOptions {
        listen: Some(match config.listen {
            Some(l) => ListenerOptions {
                listen_addr: std::net::SocketAddr::from_str(&l)?,
                enable_upnp_port_forwarding: config.listen_upnp,
                ..ListenerOptions::default()
            },
            None => ListenerOptions {
                enable_upnp_port_forwarding: config.listen_upnp,
                ..ListenerOptions::default()
            },
        }),
...

In this case, when the listen_addr is not provided (None) I have following error:

Error: error starting listeners

Caused by:
    you must set the listen port explicitly

The ..ListenerOptions::default() should autocomplete default values, or that's not yet implemented and autoinit works only when the entire listen member is None?

I would like to return None but on example above I have enable_upnp_port_forwarding handler, so can't simply return the None for entire struct. As the solution, I think we can make listen_addr accepting None values, or maybe make it as optional array, for multi-binding ability.

• also, thoughts about the None value for the first librqbit::Session::new_with_opts argument (PathBuf) - I provide empty path there, but it could be None instead.