What is the difference between HttpServer::listen() and HttpServer::bind() in actix-web?

Question

I'm currently working on an actix-web application but I have some difficulty in understanding how HttpServer.listen() and HttpServer.bind() are different and what do these functions do.

Answer 1

HttpServer::bind takes a (bunch of) socket address(es), resolves them, opens the corresponding connections, then listens.

HttpServer::listen just listens.

rustdoc has a source link next to most functions, so you can actually browse the code to bind and it's pretty straightforward:

    pub fn bind<A: net::ToSocketAddrs>(mut self, addrs: A) -> io::Result<Self> {
        let sockets = self.bind2(addrs)?;

        for lst in sockets {
            self = self.listen(lst)?;
        }

        Ok(self)
    }