Touch up the byteorder example

src/basics.md

@@ -51,45 +51,37 @@ fn main() { run().unwrap() }
 ```rust
 extern crate byteorder;
 
-use std::io::Cursor;
+use std::io;
+
 use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 
-#[derive(Default, Eq, PartialEq, Debug)]
+#[derive(Default, PartialEq, Debug)]
 struct Payload {
-  kind: u8,
-  value: u16,
+    kind: u8,
+    value: u16,
 }
 
-fn run() -> Result<()> {
-   let original_payload = Payload::default();
-   let encoded_buf = encode(&original_payload)?;
-   let decoded_payload = decode(&encoded_buf)?;
-   assert_eq!(original_payload, decoded_payload);
-   Ok(())
+fn run() -> io::Result<()> {
+    let original_payload = Payload::default();
+    let encoded_bytes = encode(&original_payload)?;
+    let decoded_payload = decode(&encoded_bytes)?;
+    assert_eq!(original_payload, decoded_payload);
+    Ok(())
 }
 
-fn encode(payload: &Payload) -> Result<Vec<u8>> {
-   let mut wtr = vec![];
-   wtr.write_u8(payload.kind)?;
-   wtr.write_u16::<LittleEndian>(payload.value)?;
-   Ok(wtr)
+fn encode(payload: &Payload) -> io::Result<Vec<u8>> {
+    let mut bytes = vec![];
+    bytes.write_u8(payload.kind)?;
+    bytes.write_u16::<LittleEndian>(payload.value)?;
+    Ok(bytes)
 }
 
-fn decode(buf: &[u8]) -> Result<Payload> {
-    let mut rdr = Cursor::new(buf);
-    Ok(Payload {
-        kind: rdr.read_u8()?,
-        value: rdr.read_u16::<LittleEndian>()?,
-    })
-}
-
-#[macro_use]
-extern crate error_chain;
-
-error_chain! {
-    foreign_links {
-        Io(::std::io::Error);
-    }
+fn decode(mut bytes: &[u8]) -> io::Result<Payload> {
+    let payload = Payload {
+        kind: bytes.read_u8()?,
+        value: bytes.read_u16::<LittleEndian>()?,
+    };
+    Ok(payload)
 }
 
 fn main() { run().unwrap() }