make body return borrowed decoder

examples/async.rs

@@ -1,17 +1,40 @@
-#![deny(warnings)]
+#![allow(warnings)] // remove when error_chain is fixed
+
 extern crate futures;
 extern crate reqwest;
 extern crate tokio_core;
+#[macro_use]
+extern crate error_chain;
 
-use futures::Future;
+use std::mem;
+use std::io::{self, Cursor};
+use futures::{Future, Stream};
+use reqwest::unstable::async::{Client, Decoder};
+
+error_chain! {
+    foreign_links {
+        ReqError(reqwest::Error);
+        IoError(io::Error);
+    }
+}
 
 fn main() {
     let mut core = tokio_core::reactor::Core::new().unwrap();
-    let client = reqwest::unstable::async::Client::new(&core.handle()).unwrap();
+    let client = Client::new(&core.handle()).unwrap();
 
-    let work = client.get("https://hyper.rs").unwrap().send().map(|res| {
-        println!("{}", res.status());
-    });
+    let work = client.get("https://hyper.rs").unwrap()
+        .send()
+        .map_err(|e| Error::from(e))
+        .and_then(|mut res| {
+            println!("{}", res.status());
+
+            let body = mem::replace(res.body_mut(), Decoder::empty());
+            body.concat2().map_err(Into::into)
+        })
+        .and_then(|body| {
+            let mut body = Cursor::new(body);
+            io::copy(&mut body, &mut io::stdout()).map_err(Into::into)
+        });
 
     core.run(work).unwrap();
 }