Use question_mark feature in libserialize.

Author: ahmedcharles

src/libserialize/json.rs

@@ -475,15 +475,14 @@ impl<'a> Encoder<'a> {
 }
 
 macro_rules! emit_enquoted_if_mapkey {
-    ($enc:ident,$e:expr) => {
+    ($enc:ident,$e:expr) => ({
         if $enc.is_emitting_map_key {
-            try!(write!($enc.writer, "\"{}\"", $e));
-            Ok(())
+            write!($enc.writer, "\"{}\"", $e)?;
         } else {
-            try!(write!($enc.writer, "{}", $e));
-            Ok(())
+            write!($enc.writer, "{}", $e)?;
         }
-    }
+        Ok(())
+    })
 }
 
 impl<'a> ::Encoder for Encoder<'a> {

src/libserialize/serialize.rs

@@ -511,10 +511,10 @@ macro_rules! tuple {
                 let len: usize = count_idents!($($name,)*);
                 d.read_tuple(len, |d| {
                     let mut i = 0;
-                    let ret = ($(try!(d.read_tuple_arg({ i+=1; i-1 },
-                                                       |d| -> Result<$name,D::Error> {
+                    let ret = ($(d.read_tuple_arg({ i+=1; i-1 },
+                                                  |d| -> Result<$name,D::Error> {
                         Decodable::decode(d)
-                    })),)*);
+                    })?,)*);
                     Ok(ret)
                 })
             }
@@ -527,7 +527,7 @@ macro_rules! tuple {
                 $(let $name = $name; n += 1;)*
                 s.emit_tuple(n, |s| {
                     let mut i = 0;
-                    $(try!(s.emit_tuple_arg({ i+=1; i-1 }, |s| $name.encode(s)));)*
+                    $(s.emit_tuple_arg({ i+=1; i-1 }, |s| $name.encode(s))?;)*
                     Ok(())
                 })
             }