Compilation error with Hyper - rust

Question

I'm running into a compilation error I don't quite understand with a slight modification of the examples from the master branch of Hyper. Given the following code:
extern crate futures;
extern crate hyper;
use futures::future::FutureResult;
use hyper::header::{ContentLength, ContentType};
use hyper::server::{Http, Service, Request, Response, Server, NewService};
use hyper::Body;
use std::fmt::Display;
use std::result;
static PHRASE: &'static [u8] = b"Hello World!";
#[derive(Clone, Copy)]
pub struct MyService {}
impl Service for MyService {
type Request = Request;
type Response = Response;
type Error = hyper::Error;
type Future = FutureResult<Response, hyper::Error>;
fn call(&self, _req: Request) -> Self::Future {
return futures::future::ok(Response::new()
.with_header(ContentLength(PHRASE.len() as u64))
.with_header(ContentType::plaintext())
.with_body(PHRASE));
}
}
#[derive(Clone)]
pub struct MyServer {}
#[derive(Debug)]
pub struct MyServeError(String);
impl<T: Display> From<T> for MyServeError {
fn from(e: T) -> MyServeError {
return MyServeError(format!("{}", e));
}
}
type Result<T> = result::Result<T, MyServeError>;
impl MyServer {
pub fn new() -> MyServer {
return MyServer {};
}
fn get_server(&self) -> Result<Server<&MyServer, Body>> {
let addr = format!("127.0.0.1:8080").parse()?;
return Ok(Http::new().bind(&addr, self)?);
}
}
impl NewService for MyServer {
type Request = Request;
type Response = Response;
type Instance = MyService;
type Error = hyper::Error;
fn new_service(&self) -> std::io::Result<Self::Instance> {
let service = MyService {};
Ok(service)
}
}
I get this compilation error:
Compiling hyper-problem-demo v0.1.0 (file:///.../hyper-problem-demo)
error[E0277]: the trait bound `MyServer: std::ops::Fn<()>` is not satisfied
--> src/lib.rs:50:31
|
50 | return Ok(Http::new().bind(&addr, self)?);
| ^^^^ the trait `std::ops::Fn<()>` is not implemented for `MyServer`
|
= note: required because of the requirements on the impl of `std::ops::FnOnce<()>` for `&MyServer`
= note: required because of the requirements on the impl of `hyper::server::NewService` for `&MyServer`
error[E0277]: the trait bound `MyServer: std::ops::FnOnce<()>` is not satisfied
--> src/lib.rs:50:31
|
50 | return Ok(Http::new().bind(&addr, self)?);
| ^^^^ the trait `std::ops::FnOnce<()>` is not implemented for `MyServer`
|
= note: required because of the requirements on the impl of `hyper::server::NewService` for `&MyServer`
Which I don't really understand. My intention was just to use the MyServer object to create new instances of MyService for hyper so it seems to make sense to implement NewService, but I don't understand why that would require an implementation of Fn(). NewService is actually implemented for Fn() -> io::Result<Service so maybe that's clashing somehow?
There's a full sample project here.

Answer 1

You have implemented NewService for MyServer however you are providing bind a &MyServer which it cannot find an implementation of NewService for.
The solution you go for will depend largely upon why you want to do this, but you could implement NewService for &MyServer:
impl<'a> NewService for &'a MyServer {
...
}