Release 0.9.0-rc3

Support serde_derive on no_std

.travis.yml

@@ -1,8 +1,7 @@
 sudo: false
 language: rust
 rust:
-- 1.11.0
-- 1.12.0
+- 1.13.0
 - stable
 - beta
 - nightly
@@ -19,8 +18,9 @@ script:
 - (cd testing && travis-cargo --skip nightly test)
 - (cd testing && travis-cargo --only nightly test -- --features unstable-testing)
 - (cd serde_derive && travis-cargo --only nightly test)
-- (cd examples/serde-syntex-example && travis-cargo --skip nightly run)
-- (cd examples/serde-syntex-example && travis-cargo --only nightly run -- --no-default-features --features unstable)
+- (cd serde_derive/no-std-tests && travis-cargo --only nightly build)
+#- (cd examples/serde-syntex-example && travis-cargo --skip nightly run)
+#- (cd examples/serde-syntex-example && travis-cargo --only nightly run -- --no-default-features --features unstable)
 - (cd serde && travis-cargo --only stable doc)
 env:
   global:

LICENSE

@@ -1,33 +0,0 @@
-See LICENSE-APACHE and LICENSE-MIT.
-
-----
-
-bench_log is derived from https://github.com/cloudflare/goser, which has the
-following license:
-
-Copyright (c) 2013, CloudFlare, Inc.
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-
-* Redistributions of source code must retain the above copyright
-  notice, this list of conditions and the following disclaimer.
-* Redistributions in binary form must reproduce the above copyright
-  notice, this list of conditions and the following disclaimer in the
-  documentation and/or other materials provided with the distribution.
-* Neither the name of the author nor the
-  names of its contributors may be used to endorse or promote products
-  derived from this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
-DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-

README.md

@@ -11,12 +11,11 @@ You may be looking for:
 - [Setting up `#[derive(Serialize, Deserialize)]`](https://serde.rs/codegen.html)
 - [Examples](https://serde.rs/examples.html)
 - [API documentation](https://docs.serde.rs/serde/)
+- [Release notes](https://github.com/serde-rs/serde/releases)
 
 ## Serde in action
 
 ```rust
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 
@@ -50,8 +49,9 @@ fn main() {
 Serde developers live in the #serde channel on
 [`irc.mozilla.org`](https://wiki.mozilla.org/IRC). The #rust channel is also a
 good resource with generally faster response time but less specific knowledge
-about Serde. If IRC is not your thing, we are happy to respond to [GitHub
-issues](https://github.com/serde-rs/serde/issues/new) as well.
+about Serde. If IRC is not your thing or you don't get a good response, we are
+happy to respond to [GitHub issues](https://github.com/serde-rs/serde/issues/new)
+as well.
 
 ## License
 

examples/serde-syntex-example/Cargo.toml

@@ -3,6 +3,7 @@ name = "serde-syntex-example"
 version = "0.1.0"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 build = "build.rs"
+publish = false
 
 [features]
 default = ["serde_codegen"]

examples/serde-syntex-example/src/main.rs

@@ -1,5 +1,3 @@
-#![cfg_attr(feature = "serde_derive", feature(proc_macro))]
-
 #[cfg(feature = "serde_derive")]
 #[macro_use]
 extern crate serde_derive;

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "0.8.20"
+version = "0.9.0-rc3"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"
@@ -9,6 +9,7 @@ repository = "https://github.com/serde-rs/serde"
 documentation = "https://docs.serde.rs/serde/"
 readme = "../README.md"
 keywords = ["serde", "serialization"]
+categories = ["encoding"]
 include = ["Cargo.toml", "src/**/*.rs"]
 
 [features]

serde/src/bytes.rs

@@ -65,7 +65,7 @@ impl<'a> ops::Deref for Bytes<'a> {
 
 impl<'a> ser::Serialize for Bytes<'a> {
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: ser::Serializer
     {
         serializer.serialize_bytes(self.bytes)
@@ -84,7 +84,7 @@ mod bytebuf {
     use de;
 
     #[cfg(feature = "collections")]
-    use collections::Vec;
+    use collections::{String, Vec};
 
     /// `ByteBuf` wraps a `Vec<u8>` and serializes as a byte array.
     #[derive(Clone, Default, Eq, Hash, PartialEq, PartialOrd, Ord)]
@@ -168,7 +168,7 @@ mod bytebuf {
     }
 
     impl ser::Serialize for ByteBuf {
-        fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
             where S: ser::Serializer
         {
             serializer.serialize_bytes(self)
@@ -181,15 +181,19 @@ mod bytebuf {
     impl de::Visitor for ByteBufVisitor {
         type Value = ByteBuf;
 
+        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            formatter.write_str("byte array")
+        }
+
         #[inline]
-        fn visit_unit<E>(&mut self) -> Result<ByteBuf, E>
+        fn visit_unit<E>(self) -> Result<ByteBuf, E>
             where E: de::Error,
         {
             Ok(ByteBuf::new())
         }
 
         #[inline]
-        fn visit_seq<V>(&mut self, mut visitor: V) -> Result<ByteBuf, V::Error>
+        fn visit_seq<V>(self, mut visitor: V) -> Result<ByteBuf, V::Error>
             where V: de::SeqVisitor,
         {
             let (len, _) = visitor.size_hint();
@@ -199,20 +203,30 @@ mod bytebuf {
                 values.push(value);
             }
 
-            try!(visitor.end());
-
             Ok(ByteBuf::from(values))
         }
 
         #[inline]
-        fn visit_bytes<E>(&mut self, v: &[u8]) -> Result<ByteBuf, E>
+        fn visit_bytes<E>(self, v: &[u8]) -> Result<ByteBuf, E>
             where E: de::Error,
         {
-            self.visit_byte_buf(v.to_vec())
+            Ok(ByteBuf::from(v))
         }
 
         #[inline]
-        fn visit_byte_buf<E>(&mut self, v: Vec<u8>) -> Result<ByteBuf, E>
+        fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<ByteBuf, E>
+            where E: de::Error,
+        {
+            Ok(ByteBuf::from(v))
+        }
+
+        fn visit_str<E>(self, v: &str) -> Result<ByteBuf, E>
+            where E: de::Error,
+        {
+            Ok(ByteBuf::from(v))
+        }
+
+        fn visit_string<E>(self, v: String) -> Result<ByteBuf, E>
             where E: de::Error,
         {
             Ok(ByteBuf::from(v))
@@ -221,10 +235,10 @@ mod bytebuf {
 
     impl de::Deserialize for ByteBuf {
         #[inline]
-        fn deserialize<D>(deserializer: &mut D) -> Result<ByteBuf, D::Error>
+        fn deserialize<D>(deserializer: D) -> Result<ByteBuf, D::Error>
             where D: de::Deserializer
         {
-            deserializer.deserialize_bytes(ByteBufVisitor)
+            deserializer.deserialize_byte_buf(ByteBufVisitor)
         }
     }
 }

serde/src/de/private.rs

@@ -0,0 +1,40 @@
+use core::marker::PhantomData;
+
+use de::{Deserialize, Deserializer, Error, Visitor};
+
+/// If the missing field is of type `Option<T>` then treat is as `None`,
+/// otherwise it is an error.
+pub fn missing_field<V, E>(field: &'static str) -> Result<V, E>
+    where V: Deserialize,
+          E: Error
+{
+    struct MissingFieldDeserializer<E>(&'static str, PhantomData<E>);
+
+    impl<E> Deserializer for MissingFieldDeserializer<E>
+        where E: Error
+    {
+        type Error = E;
+
+        fn deserialize<V>(self, _visitor: V) -> Result<V::Value, E>
+            where V: Visitor
+        {
+            Err(Error::missing_field(self.0))
+        }
+
+        fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, E>
+            where V: Visitor
+        {
+            visitor.visit_none()
+        }
+
+        forward_to_deserialize! {
+            bool usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 char str
+            string unit seq seq_fixed_size bytes byte_buf map unit_struct
+            newtype_struct tuple_struct struct struct_field tuple enum
+            ignored_any
+        }
+    }
+
+    let deserializer = MissingFieldDeserializer(field, PhantomData);
+    Deserialize::deserialize(deserializer)
+}

serde/src/error.rs

@@ -1,30 +1,7 @@
 //! A stand-in for `std::error`
-use core::any::TypeId;
 use core::fmt::{Debug, Display};
 
-
 /// A stand-in for `std::error::Error`, which requires no allocation.
-#[cfg(feature = "unstable")]
-pub trait Error: Debug + Display + ::core::marker::Reflect {
-    /// A short description of the error.
-    ///
-    /// The description should not contain newlines or sentence-ending
-    /// punctuation, to facilitate embedding in larger user-facing
-    /// strings.
-    fn description(&self) -> &str;
-
-    /// The lower-level cause of this error, if any.
-    fn cause(&self) -> Option<&Error> { None }
-
-    /// Get the `TypeId` of `self`
-    #[doc(hidden)]
-    fn type_id(&self) -> TypeId where Self: 'static {
-        TypeId::of::<Self>()
-    }
-}
-
-/// A stand-in for `std::error::Error`, which requires no allocation.
-#[cfg(not(feature = "unstable"))]
 pub trait Error: Debug + Display {
     /// A short description of the error.
     ///
@@ -35,10 +12,4 @@ pub trait Error: Debug + Display {
 
     /// The lower-level cause of this error, if any.
     fn cause(&self) -> Option<&Error> { None }
-
-    /// Stubbed! Returns type_id of `()`
-    #[doc(hidden)]
-    fn type_id(&self) -> TypeId where Self: 'static {
-        TypeId::of::<()>()
-    }
 }

serde/src/export.rs

@@ -0,0 +1,33 @@
+#[cfg(all(feature = "collections", not(feature = "std")))]
+use collections::String;
+
+#[cfg(feature = "std")]
+use std::borrow::Cow;
+#[cfg(all(feature = "collections", not(feature = "std")))]
+use collections::borrow::Cow;
+
+pub use core::default::Default;
+pub use core::fmt;
+pub use core::marker::PhantomData;
+pub use core::result::Result;
+
+#[cfg(any(feature = "collections", feature = "std"))]
+pub fn from_utf8_lossy(bytes: &[u8]) -> Cow<str> {
+    String::from_utf8_lossy(bytes)
+}
+
+// The generated code calls this like:
+//
+//     let value = &_serde::export::from_utf8_lossy(bytes);
+//     Err(_serde::de::Error::unknown_variant(value, VARIANTS))
+//
+// so it is okay for the return type to be different from the std case as long
+// as the above works.
+#[cfg(not(any(feature = "collections", feature = "std")))]
+pub fn from_utf8_lossy(bytes: &[u8]) -> &str {
+    use core::str;
+    // Three unicode replacement characters if it fails. They look like a
+    // white-on-black question mark. The user will recognize it as invalid
+    // UTF-8.
+    str::from_utf8(bytes).unwrap_or("\u{fffd}\u{fffd}\u{fffd}")
+}

serde/src/lib.rs

@@ -11,39 +11,33 @@
 
 #![doc(html_root_url="https://docs.serde.rs")]
 #![cfg_attr(not(feature = "std"), no_std)]
-#![cfg_attr(feature = "unstable", feature(reflect_marker, unicode, nonzero, plugin, step_trait, zero_one))]
+#![cfg_attr(feature = "unstable", feature(nonzero, inclusive_range, zero_one))]
 #![cfg_attr(feature = "alloc", feature(alloc))]
 #![cfg_attr(feature = "collections", feature(collections, enumset))]
+#![cfg_attr(feature = "clippy", feature(plugin))]
 #![cfg_attr(feature = "clippy", plugin(clippy))]
-#![cfg_attr(feature = "clippy", allow(linkedlist))]
-
-#![cfg_attr(any(not(feature = "std"), feature = "unstable"), allow(unused_variables, unused_imports, unused_features, dead_code))]
-
+#![cfg_attr(feature = "clippy", allow(linkedlist, type_complexity))]
 #![deny(missing_docs)]
 
-#[cfg(all(feature = "unstable", feature = "collections"))]
+#[cfg(feature = "collections")]
 extern crate collections;
 
-#[cfg(all(feature = "unstable", feature = "alloc"))]
+#[cfg(feature = "alloc")]
 extern crate alloc;
 
+#[cfg(feature = "unstable")]
+extern crate core as actual_core;
+
 #[cfg(feature = "std")]
 mod core {
     pub use std::{ops, hash, fmt, cmp, marker, mem, i8, i16, i32, i64, u8, u16, u32, u64, isize,
-            usize, f32, f64, char, str, num, slice, iter};
+            usize, f32, f64, char, str, num, slice, iter, cell, default, result};
     #[cfg(feature = "unstable")]
-    extern crate core;
-    #[cfg(feature = "unstable")]
-    pub use self::core::nonzero;
+    pub use actual_core::nonzero;
 }
 
 pub use ser::{Serialize, Serializer};
-pub use de::{Deserialize, Deserializer, Error};
-
-#[cfg(not(feature = "std"))]
-macro_rules! format {
-    ($s:expr, $($rest:tt)*) => ($s)
-}
+pub use de::{Deserialize, Deserializer};
 
 #[macro_use]
 mod macros;
@@ -53,6 +47,10 @@ pub mod de;
 #[cfg(feature = "std")]
 pub mod iter;
 pub mod ser;
-#[cfg(not(feature = "std"))]
+#[cfg_attr(feature = "std", doc(hidden))]
 pub mod error;
 mod utils;
+
+// Generated code uses these to support no_std. Not public API.
+#[doc(hidden)]
+pub mod export;

serde/src/macros.rs

@@ -4,7 +4,7 @@
 macro_rules! forward_to_deserialize_method {
     ($func:ident($($arg:ty),*)) => {
         #[inline]
-        fn $func<__V>(&mut self, $(_: $arg,)* visitor: __V) -> ::std::result::Result<__V::Value, Self::Error>
+        fn $func<__V>(self, $(_: $arg,)* visitor: __V) -> ::std::result::Result<__V::Value, Self::Error>
             where __V: $crate::de::Visitor
         {
             self.deserialize(visitor)
@@ -18,7 +18,7 @@ macro_rules! forward_to_deserialize_method {
 macro_rules! forward_to_deserialize_method {
     ($func:ident($($arg:ty),*)) => {
         #[inline]
-        fn $func<__V>(&mut self, $(_: $arg,)* visitor: __V) -> ::core::result::Result<__V::Value, Self::Error>
+        fn $func<__V>(self, $(_: $arg,)* visitor: __V) -> ::core::result::Result<__V::Value, Self::Error>
             where __V: $crate::de::Visitor
         {
             self.deserialize(visitor)
@@ -26,34 +26,6 @@ macro_rules! forward_to_deserialize_method {
     };
 }
 
-#[cfg(feature = "std")]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! forward_to_deserialize_enum {
-    () => {
-        #[inline]
-        fn deserialize_enum<__V>(&mut self, _: &str, _: &[&str], _: __V) -> ::std::result::Result<__V::Value, Self::Error>
-            where __V: $crate::de::EnumVisitor
-        {
-            Err($crate::de::Error::invalid_type($crate::de::Type::Enum))
-        }
-    };
-}
-
-#[cfg(not(feature = "std"))]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! forward_to_deserialize_enum {
-    () => {
-        #[inline]
-        fn deserialize_enum<__V>(&mut self, _: &str, _: &[&str], _: __V) -> ::core::result::Result<__V::Value, Self::Error>
-            where __V: $crate::de::EnumVisitor
-        {
-            Err($crate::de::Error::invalid_type($crate::de::Type::Enum))
-        }
-    };
-}
-
 #[doc(hidden)]
 #[macro_export]
 macro_rules! forward_to_deserialize_helper {
@@ -120,6 +92,9 @@ macro_rules! forward_to_deserialize_helper {
     (bytes) => {
         forward_to_deserialize_method!{deserialize_bytes()}
     };
+    (byte_buf) => {
+        forward_to_deserialize_method!{deserialize_byte_buf()}
+    };
     (map) => {
         forward_to_deserialize_method!{deserialize_map()}
     };
@@ -141,12 +116,12 @@ macro_rules! forward_to_deserialize_helper {
     (tuple) => {
         forward_to_deserialize_method!{deserialize_tuple(usize)}
     };
+    (enum) => {
+        forward_to_deserialize_method!{deserialize_enum(&'static str, &'static [&'static str])}
+    };
     (ignored_any) => {
         forward_to_deserialize_method!{deserialize_ignored_any()}
     };
-    (enum) => {
-        forward_to_deserialize_enum!();
-    };
 }
 
 /// Helper to forward `Deserializer` methods to `Deserializer::deserialize`.
@@ -156,7 +131,7 @@ macro_rules! forward_to_deserialize_helper {
 ///
 /// ```rust,ignore
 /// impl Deserializer for MyDeserializer {
-///     fn deserialize<V>(&mut self, visitor: V) -> Result<V::Value, Self::Error>
+///     fn deserialize<V>(self, visitor: V) -> Result<V::Value, Self::Error>
 ///         where V: Visitor
 ///     {
 ///         /* ... */

serde/src/ser/impls.rs

@@ -30,19 +30,18 @@ use collections::{
     Vec,
 };
 
-#[cfg(all(feature = "unstable", feature = "collections"))]
+#[cfg(feature = "collections")]
 use collections::enum_set::{CLike, EnumSet};
-#[cfg(all(feature = "unstable", feature = "collections"))]
+#[cfg(feature = "collections")]
 use collections::borrow::ToOwned;
 
+#[cfg(feature = "std")]
 use core::hash::{Hash, BuildHasher};
 #[cfg(feature = "unstable")]
 use core::iter;
 #[cfg(feature = "std")]
 use std::net;
 #[cfg(feature = "unstable")]
-use core::num;
-#[cfg(feature = "unstable")]
 use core::ops;
 #[cfg(feature = "std")]
 use std::path;
@@ -67,10 +66,16 @@ use core::marker::PhantomData;
 use core::nonzero::{NonZero, Zeroable};
 
 use super::{
-    Error,
     Serialize,
+    SerializeSeq,
+    SerializeTuple,
     Serializer,
 };
+#[cfg(any(feature = "std", feature = "unstable"))]
+use super::Error;
+
+#[cfg(feature = "unstable")]
+use super::Iterator;
 
 ///////////////////////////////////////////////////////////////////////////////
 
@@ -78,7 +83,7 @@ macro_rules! impl_visit {
     ($ty:ty, $method:ident) => {
         impl Serialize for $ty {
             #[inline]
-            fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                 where S: Serializer,
             {
                 serializer.$method(*self)
@@ -106,7 +111,7 @@ impl_visit!(char, serialize_char);
 
 impl Serialize for str {
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         serializer.serialize_str(self)
@@ -116,7 +121,7 @@ impl Serialize for str {
 #[cfg(any(feature = "std", feature = "collections"))]
 impl Serialize for String {
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         (&self[..]).serialize(serializer)
@@ -125,9 +130,11 @@ impl Serialize for String {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-impl<T> Serialize for Option<T> where T: Serialize {
+impl<T> Serialize for Option<T>
+    where T: Serialize
+{
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         match *self {
@@ -141,7 +148,7 @@ impl<T> Serialize for Option<T> where T: Serialize {
 
 impl<T> Serialize for PhantomData<T> {
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         serializer.serialize_unit_struct("PhantomData")
@@ -155,14 +162,14 @@ impl<T> Serialize for [T]
     where T: Serialize,
 {
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
-        let mut state = try!(serializer.serialize_seq(Some(self.len())));
+        let mut seq = try!(serializer.serialize_seq(Some(self.len())));
         for e in self {
-            try!(serializer.serialize_seq_elt(&mut state, e));
+            try!(seq.serialize_element(e));
         }
-        serializer.serialize_seq_end(state)
+        seq.end()
     }
 }
 
@@ -172,14 +179,14 @@ macro_rules! array_impls {
     ($len:expr) => {
         impl<T> Serialize for [T; $len] where T: Serialize {
             #[inline]
-            fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                 where S: Serializer,
             {
-                let mut state = try!(serializer.serialize_seq_fixed_size($len));
+                let mut seq = try!(serializer.serialize_seq_fixed_size($len));
                 for e in self {
-                    try!(serializer.serialize_seq_elt(&mut state, e));
+                    try!(seq.serialize_element(e));
                 }
-                serializer.serialize_seq_end(state)
+                seq.end()
             }
         }
     }
@@ -221,17 +228,44 @@ array_impls!(32);
 
 ///////////////////////////////////////////////////////////////////////////////
 
+#[cfg(feature = "unstable")]
+impl<'a, I> Serialize for Iterator<I>
+    where I: IntoIterator, <I as IntoIterator>::Item: Serialize
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where S: Serializer,
+    {
+        // FIXME: use specialization to prevent invalidating the object in case of clonable iterators?
+        let iter = match self.0.borrow_mut().take() {
+            Some(iter) => iter.into_iter(),
+            None => return Err(Error::custom("Iterator used twice")),
+        };
+        let size = match iter.size_hint() {
+            (lo, Some(hi)) if lo == hi => Some(lo),
+            _ => None,
+        };
+        let mut seq = try!(serializer.serialize_seq(size));
+        for e in iter {
+            try!(seq.serialize_element(&e));
+        }
+        seq.end()
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
 macro_rules! serialize_seq {
     () => {
         #[inline]
-        fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
             where S: Serializer,
         {
-            let mut state = try!(serializer.serialize_seq(Some(self.len())));
+            let mut seq = try!(serializer.serialize_seq(Some(self.len())));
             for e in self {
-                try!(serializer.serialize_seq_elt(&mut state, e));
+                try!(seq.serialize_element(&e));
             }
-            serializer.serialize_seq_end(state)
+            seq.end()
         }
     }
 }
@@ -250,7 +284,7 @@ impl<T> Serialize for BTreeSet<T>
     serialize_seq!();
 }
 
-#[cfg(all(feature = "unstable", feature = "collections"))]
+#[cfg(feature = "collections")]
 impl<T> Serialize for EnumSet<T>
     where T: Serialize + CLike
 {
@@ -273,30 +307,50 @@ impl<T> Serialize for LinkedList<T>
 }
 
 #[cfg(any(feature = "std", feature = "collections"))]
-impl<T> Serialize for Vec<T> where T: Serialize {
+impl<T> Serialize for Vec<T>
+    where T: Serialize
+{
     serialize_seq!();
 }
 
 #[cfg(any(feature = "std", feature = "collections"))]
-impl<T> Serialize for VecDeque<T> where T: Serialize {
+impl<T> Serialize for VecDeque<T>
+    where T: Serialize
+{
     serialize_seq!();
 }
 
 #[cfg(feature = "unstable")]
 impl<A> Serialize for ops::Range<A>
-    where A: Serialize + Clone + iter::Step + num::One,
-          for<'a> &'a A: ops::Add<&'a A, Output = A>,
+    where ops::Range<A>: ExactSizeIterator + iter::Iterator<Item = A> + Clone,
+          A: Serialize,
 {
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
-        let len = iter::Step::steps_between(&self.start, &self.end, &A::one());
-        let mut state = try!(serializer.serialize_seq(len));
+        let mut seq = try!(serializer.serialize_seq(Some(self.len())));
         for e in self.clone() {
-            try!(serializer.serialize_seq_elt(&mut state, e));
+            try!(seq.serialize_element(&e));
         }
-        serializer.serialize_seq_end(state)
+        seq.end()
+    }
+}
+
+#[cfg(feature = "unstable")]
+impl<A> Serialize for ops::RangeInclusive<A>
+    where ops::RangeInclusive<A>: ExactSizeIterator + iter::Iterator<Item = A> + Clone,
+          A: Serialize,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where S: Serializer,
+    {
+        let mut seq = try!(serializer.serialize_seq(Some(self.len())));
+        for e in self.clone() {
+            try!(seq.serialize_element(&e));
+        }
+        seq.end()
     }
 }
 
@@ -304,7 +358,7 @@ impl<A> Serialize for ops::Range<A>
 
 impl Serialize for () {
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         serializer.serialize_unit()
@@ -324,14 +378,14 @@ macro_rules! tuple_impls {
                 where $($T: Serialize),+
             {
                 #[inline]
-                fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+                fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                     where S: Serializer,
                 {
-                    let mut state = try!(serializer.serialize_tuple($len));
+                    let mut tuple = try!(serializer.serialize_tuple($len));
                     $(
-                        try!(serializer.serialize_tuple_elt(&mut state, &self.$idx));
+                        try!(tuple.serialize_element(&self.$idx));
                     )+
-                    serializer.serialize_tuple_end(state)
+                    tuple.end()
                 }
             }
         )+
@@ -514,15 +568,16 @@ tuple_impls! {
 macro_rules! serialize_map {
     () => {
         #[inline]
-        fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
             where S: Serializer,
         {
-            let mut state = try!(serializer.serialize_map(Some(self.len())));
+            use super::SerializeMap;
+            let mut map = try!(serializer.serialize_map(Some(self.len())));
             for (k, v) in self {
-                try!(serializer.serialize_map_key(&mut state, k));
-                try!(serializer.serialize_map_value(&mut state, v));
+                try!(map.serialize_key(k));
+                try!(map.serialize_value(v));
             }
-            serializer.serialize_map_end(state)
+            map.end()
         }
     }
 }
@@ -548,7 +603,7 @@ impl<K, V, H> Serialize for HashMap<K, V, H>
 
 impl<'a, T: ?Sized> Serialize for &'a T where T: Serialize {
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         (**self).serialize(serializer)
@@ -557,7 +612,7 @@ impl<'a, T: ?Sized> Serialize for &'a T where T: Serialize {
 
 impl<'a, T: ?Sized> Serialize for &'a mut T where T: Serialize {
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         (**self).serialize(serializer)
@@ -565,9 +620,11 @@ impl<'a, T: ?Sized> Serialize for &'a mut T where T: Serialize {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-impl<T: ?Sized> Serialize for Box<T> where T: Serialize {
+impl<T: ?Sized> Serialize for Box<T>
+    where T: Serialize
+{
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         (**self).serialize(serializer)
@@ -575,9 +632,11 @@ impl<T: ?Sized> Serialize for Box<T> where T: Serialize {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-impl<T> Serialize for Rc<T> where T: Serialize, {
+impl<T> Serialize for Rc<T>
+    where T: Serialize
+{
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         (**self).serialize(serializer)
@@ -585,9 +644,11 @@ impl<T> Serialize for Rc<T> where T: Serialize, {
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-impl<T> Serialize for Arc<T> where T: Serialize, {
+impl<T> Serialize for Arc<T>
+    where T: Serialize
+{
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         (**self).serialize(serializer)
@@ -595,9 +656,11 @@ impl<T> Serialize for Arc<T> where T: Serialize, {
 }
 
 #[cfg(any(feature = "std", feature = "collections"))]
-impl<'a, T: ?Sized> Serialize for Cow<'a, T> where T: Serialize + ToOwned, {
+impl<'a, T: ?Sized> Serialize for Cow<'a, T>
+    where T: Serialize + ToOwned
+{
     #[inline]
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         (**self).serialize(serializer)
@@ -606,8 +669,13 @@ impl<'a, T: ?Sized> Serialize for Cow<'a, T> where T: Serialize + ToOwned, {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-impl<T, E> Serialize for Result<T, E> where T: Serialize, E: Serialize {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: Serializer {
+impl<T, E> Serialize for Result<T, E>
+    where T: Serialize,
+          E: Serialize
+{
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where S: Serializer
+    {
         match *self {
             Result::Ok(ref value) => {
                 serializer.serialize_newtype_variant("Result", 0, "Ok", value)
@@ -623,13 +691,14 @@ impl<T, E> Serialize for Result<T, E> where T: Serialize, E: Serialize {
 
 #[cfg(feature = "std")]
 impl Serialize for Duration {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
+        use super::SerializeStruct;
         let mut state = try!(serializer.serialize_struct("Duration", 2));
-        try!(serializer.serialize_struct_elt(&mut state, "secs", self.as_secs()));
-        try!(serializer.serialize_struct_elt(&mut state, "nanos", self.subsec_nanos()));
-        serializer.serialize_struct_end(state)
+        try!(state.serialize_field("secs", &self.as_secs()));
+        try!(state.serialize_field("nanos", &self.subsec_nanos()));
+        state.end()
     }
 }
 
@@ -637,7 +706,7 @@ impl Serialize for Duration {
 
 #[cfg(feature = "std")]
 impl Serialize for net::IpAddr {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         self.to_string().serialize(serializer)
@@ -646,7 +715,7 @@ impl Serialize for net::IpAddr {
 
 #[cfg(feature = "std")]
 impl Serialize for net::Ipv4Addr {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         self.to_string().serialize(serializer)
@@ -655,7 +724,7 @@ impl Serialize for net::Ipv4Addr {
 
 #[cfg(feature = "std")]
 impl Serialize for net::Ipv6Addr {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         self.to_string().serialize(serializer)
@@ -666,7 +735,7 @@ impl Serialize for net::Ipv6Addr {
 
 #[cfg(feature = "std")]
 impl Serialize for net::SocketAddr {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         match *self {
@@ -678,7 +747,7 @@ impl Serialize for net::SocketAddr {
 
 #[cfg(feature = "std")]
 impl Serialize for net::SocketAddrV4 {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         self.to_string().serialize(serializer)
@@ -687,7 +756,7 @@ impl Serialize for net::SocketAddrV4 {
 
 #[cfg(feature = "std")]
 impl Serialize for net::SocketAddrV6 {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         self.to_string().serialize(serializer)
@@ -698,19 +767,19 @@ impl Serialize for net::SocketAddrV6 {
 
 #[cfg(feature = "std")]
 impl Serialize for path::Path {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         match self.to_str() {
             Some(s) => s.serialize(serializer),
-            None => Err(Error::invalid_value("Path contains invalid UTF-8 characters")),
+            None => Err(Error::custom("Path contains invalid UTF-8 characters")),
         }
     }
 }
 
 #[cfg(feature = "std")]
 impl Serialize for path::PathBuf {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer,
     {
         self.as_path().serialize(serializer)
@@ -718,8 +787,12 @@ impl Serialize for path::PathBuf {
 }
 
 #[cfg(feature = "unstable")]
-impl<T> Serialize for NonZero<T> where T: Serialize + Zeroable {
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: Serializer {
+impl<T> Serialize for NonZero<T>
+    where T: Serialize + Zeroable
+{
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where S: Serializer
+    {
         (**self).serialize(serializer)
     }
 }

serde/src/ser/mod.rs

@@ -15,8 +15,10 @@ use std::error;
 #[cfg(not(feature = "std"))]
 use error;
 
-#[cfg(all(feature = "collections", not(feature = "std")))]
-use collections::String;
+#[cfg(feature = "unstable")]
+use core::cell::RefCell;
+
+use core::fmt::Display;
 
 pub mod impls;
 
@@ -26,17 +28,7 @@ pub mod impls;
 /// `Serializer` error.
 pub trait Error: Sized + error::Error {
     /// Raised when there is a general error when serializing a type.
-    #[cfg(any(feature = "std", feature = "collections"))]
-    fn custom<T: Into<String>>(msg: T) -> Self;
-
-    /// Raised when there is a general error when serializing a type.
-    #[cfg(all(not(feature = "std"), not(feature = "collections")))]
-    fn custom<T: Into<&'static str>>(msg: T) -> Self;
-
-    /// Raised when a `Serialize` was passed an incorrect value.
-    fn invalid_value(msg: &str) -> Self {
-        Error::custom(format!("invalid value: {}", msg))
-    }
+    fn custom<T: Display>(msg: T) -> Self;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -44,7 +36,7 @@ pub trait Error: Sized + error::Error {
 /// A trait that describes a type that can be serialized by a `Serializer`.
 pub trait Serialize {
     /// Serializes this value into this serializer.
-    fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error>
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer;
 }
 
@@ -53,7 +45,7 @@ pub trait Serialize {
 /// A trait that describes a type that can serialize a stream of values into the underlying format.
 ///
 /// # For `Serialize` Developers
-/// Non-aggrergate types like integers and strings can be serialized directly by calling the
+/// Non-aggregate types like integers and strings can be serialized directly by calling the
 /// appropriate function. For Aggregate types there's an initial `serialize_T` method that yields
 /// a State object that you should not interact with. For each part of the aggregate there's a
 /// `serialize_T_elt` method that allows you to pass values or key/value pairs. The types of the
@@ -72,341 +64,372 @@ pub trait Serialize {
 /// state object, as it is expected that the user will not modify it. Due to the generic nature
 /// of the `Serialize` impls, modifying the object is impossible on stable Rust.
 pub trait Serializer {
-    /// The error type that can be returned if some error occurs during serialization.
+    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// `Serializer` should set `Ok = ()`.
+    type Ok;
+
+    /// The error type when some error occurs during serialization.
     type Error: Error;
 
-    /// A state object that is initialized by `serialize_seq`, passed to
-    /// `serialize_seq_elt`, and consumed by `serialize_seq_end`. Use `()` if no
-    /// state is required.
-    type SeqState;
-    /// A state object that is initialized by `serialize_tuple`, passed to
-    /// `serialize_tuple_elt`, and consumed by `serialize_tuple_end`. Use `()`
-    /// if no state is required.
-    type TupleState;
-    /// A state object that is initialized by `serialize_tuple_struct`, passed
-    /// to `serialize_tuple_struct_elt`, and consumed by
-    /// `serialize_tuple_struct_end`. Use `()` if no state is required.
-    type TupleStructState;
-    /// A state object that is initialized by `serialize_tuple_variant`, passed
-    /// to `serialize_tuple_variant_elt`, and consumed by
-    /// `serialize_tuple_variant_end`. Use `()` if no state is required.
-    type TupleVariantState;
-    /// A state object that is initialized by `serialize_map`, passed to
-    /// `serialize_map_elt`, and consumed by `serialize_map_end`. Use `()` if no
-    /// state is required.
-    type MapState;
-    /// A state object that is initialized by `serialize_struct`, passed to
-    /// `serialize_struct_elt`, and consumed by `serialize_struct_end`. Use `()`
-    /// if no state is required.
-    type StructState;
-    /// A state object that is initialized by `serialize_struct_variant`, passed
-    /// to `serialize_struct_variant_elt`, and consumed by
-    /// `serialize_struct_variant_end`. Use `()` if no state is required.
-    type StructVariantState;
+    /// Type returned from `serialize_seq` and `serialize_seq_fixed_size` for
+    /// serializing the content of the sequence.
+    type SerializeSeq: SerializeSeq<Ok=Self::Ok, Error=Self::Error>;
+
+    /// Type returned from `serialize_tuple` for serializing the content of the
+    /// tuple.
+    type SerializeTuple: SerializeTuple<Ok=Self::Ok, Error=Self::Error>;
+
+    /// Type returned from `serialize_tuple_struct` for serializing the content
+    /// of the tuple struct.
+    type SerializeTupleStruct: SerializeTupleStruct<Ok=Self::Ok, Error=Self::Error>;
+
+    /// Type returned from `serialize_tuple_variant` for serializing the content
+    /// of the tuple variant.
+    type SerializeTupleVariant: SerializeTupleVariant<Ok=Self::Ok, Error=Self::Error>;
+
+    /// Type returned from `serialize_map` for serializing the content of the
+    /// map.
+    type SerializeMap: SerializeMap<Ok=Self::Ok, Error=Self::Error>;
+
+    /// Type returned from `serialize_struct` for serializing the content of the
+    /// struct.
+    type SerializeStruct: SerializeStruct<Ok=Self::Ok, Error=Self::Error>;
+
+    /// Type returned from `serialize_struct_variant` for serializing the
+    /// content of the struct variant.
+    type SerializeStructVariant: SerializeStructVariant<Ok=Self::Ok, Error=Self::Error>;
 
     /// Serializes a `bool` value.
-    fn serialize_bool(&mut self, v: bool) -> Result<(), Self::Error>;
+    fn serialize_bool(self, v: bool) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes an `isize` value. If the format does not differentiate
     /// between `isize` and `i64`, a reasonable implementation would be to cast
     /// the value to `i64` and forward to `serialize_i64`.
-    fn serialize_isize(&mut self, v: isize) -> Result<(), Self::Error>;
+    fn serialize_isize(self, v: isize) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes an `i8` value. If the format does not differentiate between
     /// `i8` and `i64`, a reasonable implementation would be to cast the value
     /// to `i64` and forward to `serialize_i64`.
-    fn serialize_i8(&mut self, v: i8) -> Result<(), Self::Error>;
+    fn serialize_i8(self, v: i8) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes an `i16` value. If the format does not differentiate between
     /// `i16` and `i64`, a reasonable implementation would be to cast the value
     /// to `i64` and forward to `serialize_i64`.
-    fn serialize_i16(&mut self, v: i16) -> Result<(), Self::Error>;
+    fn serialize_i16(self, v: i16) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes an `i32` value. If the format does not differentiate between
     /// `i32` and `i64`, a reasonable implementation would be to cast the value
     /// to `i64` and forward to `serialize_i64`.
-    fn serialize_i32(&mut self, v: i32) -> Result<(), Self::Error>;
+    fn serialize_i32(self, v: i32) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes an `i64` value.
-    fn serialize_i64(&mut self, v: i64) -> Result<(), Self::Error>;
+    fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a `usize` value. If the format does not differentiate between
     /// `usize` and `u64`, a reasonable implementation would be to cast the
     /// value to `u64` and forward to `serialize_u64`.
-    fn serialize_usize(&mut self, v: usize) -> Result<(), Self::Error>;
+    fn serialize_usize(self, v: usize) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a `u8` value. If the format does not differentiate between
     /// `u8` and `u64`, a reasonable implementation would be to cast the value
     /// to `u64` and forward to `serialize_u64`.
-    fn serialize_u8(&mut self, v: u8) -> Result<(), Self::Error>;
+    fn serialize_u8(self, v: u8) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a `u16` value. If the format does not differentiate between
     /// `u16` and `u64`, a reasonable implementation would be to cast the value
     /// to `u64` and forward to `serialize_u64`.
-    fn serialize_u16(&mut self, v: u16) -> Result<(), Self::Error>;
+    fn serialize_u16(self, v: u16) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a `u32` value. If the format does not differentiate between
     /// `u32` and `u64`, a reasonable implementation would be to cast the value
     /// to `u64` and forward to `serialize_u64`.
-    fn serialize_u32(&mut self, v: u32) -> Result<(), Self::Error>;
+    fn serialize_u32(self, v: u32) -> Result<Self::Ok, Self::Error>;
 
     /// `Serializes a `u64` value.
-    fn serialize_u64(&mut self, v: u64) -> Result<(), Self::Error>;
+    fn serialize_u64(self, v: u64) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes an `f32` value. If the format does not differentiate between
     /// `f32` and `f64`, a reasonable implementation would be to cast the value
     /// to `f64` and forward to `serialize_f64`.
-    fn serialize_f32(&mut self, v: f32) -> Result<(), Self::Error>;
+    fn serialize_f32(self, v: f32) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes an `f64` value.
-    fn serialize_f64(&mut self, v: f64) -> Result<(), Self::Error>;
+    fn serialize_f64(self, v: f64) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a character. If the format does not support characters,
     /// it is reasonable to serialize it as a single element `str` or a `u32`.
-    fn serialize_char(&mut self, v: char) -> Result<(), Self::Error>;
+    fn serialize_char(self, v: char) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a `&str`.
-    fn serialize_str(&mut self, value: &str) -> Result<(), Self::Error>;
+    fn serialize_str(self, value: &str) -> Result<Self::Ok, Self::Error>;
 
     /// Enables serializers to serialize byte slices more compactly or more
     /// efficiently than other types of slices. If no efficient implementation
     /// is available, a reasonable implementation would be to forward to
     /// `serialize_seq`. If forwarded, the implementation looks usually just like this:
     /// ```rust
-    /// let mut state = try!(self.serialize_seq(value));
+    /// let mut seq = self.serialize_seq(Some(value.len()))?;
     /// for b in value {
-    ///     try!(self.serialize_seq_elt(&mut state, b));
+    ///     seq.serialize_element(b)?;
     /// }
-    /// self.serialize_seq_end(state)
+    /// seq.end()
     /// ```
-    fn serialize_bytes(&mut self, value: &[u8]) -> Result<(), Self::Error>;
+    fn serialize_bytes(self, value: &[u8]) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a `()` value. It's reasonable to just not serialize anything.
-    fn serialize_unit(&mut self) -> Result<(), Self::Error>;
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a unit struct value. A reasonable implementation would be to
     /// forward to `serialize_unit`.
     fn serialize_unit_struct(
-        &mut self,
+        self,
         name: &'static str,
-    ) -> Result<(), Self::Error>;
+    ) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a unit variant, otherwise known as a variant with no
     /// arguments. A reasonable implementation would be to forward to
     /// `serialize_unit`.
     fn serialize_unit_variant(
-        &mut self,
+        self,
         name: &'static str,
         variant_index: usize,
         variant: &'static str,
-    ) -> Result<(), Self::Error>;
+    ) -> Result<Self::Ok, Self::Error>;
 
     /// Allows a tuple struct with a single element, also known as a newtype
     /// struct, to be more efficiently serialized than a tuple struct with
     /// multiple items. A reasonable implementation would be to forward to
     /// `serialize_tuple_struct` or to just serialize the inner value without wrapping.
-    fn serialize_newtype_struct<T: Serialize>(
-        &mut self,
+    fn serialize_newtype_struct<T: ?Sized + Serialize>(
+        self,
         name: &'static str,
-        value: T,
-    ) -> Result<(), Self::Error>;
+        value: &T,
+    ) -> Result<Self::Ok, Self::Error>;
 
     /// Allows a variant with a single item to be more efficiently serialized
     /// than a variant with multiple items. A reasonable implementation would be
     /// to forward to `serialize_tuple_variant`.
-    fn serialize_newtype_variant<T: Serialize>(
-        &mut self,
+    fn serialize_newtype_variant<T: ?Sized + Serialize>(
+        self,
         name: &'static str,
         variant_index: usize,
         variant: &'static str,
-        value: T,
-    ) -> Result<(), Self::Error>;
+        value: &T,
+    ) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a `None` value.
-    fn serialize_none(&mut self) -> Result<(), Self::Error>;
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error>;
 
     /// Serializes a `Some(...)` value.
-    fn serialize_some<T: Serialize>(
-        &mut self,
-        value: T,
-    ) -> Result<(), Self::Error>;
+    fn serialize_some<T: ?Sized + Serialize>(
+        self,
+        value: &T,
+    ) -> Result<Self::Ok, Self::Error>;
 
     /// Begins to serialize a sequence. This call must be followed by zero or
     /// more calls to `serialize_seq_elt`, then a call to `serialize_seq_end`.
     fn serialize_seq(
-        &mut self,
+        self,
         len: Option<usize>,
-    ) -> Result<Self::SeqState, Self::Error>;
-
-    /// Serializes a sequence element. Must have previously called
-    /// `serialize_seq`.
-    fn serialize_seq_elt<T: Serialize>(
-        &mut self,
-        state: &mut Self::SeqState,
-        value: T,
-    ) -> Result<(), Self::Error>;
-
-    /// Finishes serializing a sequence.
-    fn serialize_seq_end(
-        &mut self,
-        state: Self::SeqState,
-    ) -> Result<(), Self::Error>;
+    ) -> Result<Self::SerializeSeq, Self::Error>;
 
     /// Begins to serialize a sequence whose length will be known at
     /// deserialization time. This call must be followed by zero or more calls
     /// to `serialize_seq_elt`, then a call to `serialize_seq_end`. A reasonable
     /// implementation would be to forward to `serialize_seq`.
     fn serialize_seq_fixed_size(
-        &mut self,
+        self,
         size: usize,
-    ) -> Result<Self::SeqState, Self::Error>;
+    ) -> Result<Self::SerializeSeq, Self::Error>;
 
     /// Begins to serialize a tuple. This call must be followed by zero or more
     /// calls to `serialize_tuple_elt`, then a call to `serialize_tuple_end`. A
     /// reasonable implementation would be to forward to `serialize_seq`.
     fn serialize_tuple(
-        &mut self,
+        self,
         len: usize,
-    ) -> Result<Self::TupleState, Self::Error>;
-
-    /// Serializes a tuple element. Must have previously called
-    /// `serialize_tuple`.
-    fn serialize_tuple_elt<T: Serialize>(
-        &mut self,
-        state: &mut Self::TupleState,
-        value: T,
-    ) -> Result<(), Self::Error>;
-
-    /// Finishes serializing a tuple.
-    fn serialize_tuple_end(
-        &mut self,
-        state: Self::TupleState,
-    ) -> Result<(), Self::Error>;
+    ) -> Result<Self::SerializeTuple, Self::Error>;
 
     /// Begins to serialize a tuple struct. This call must be followed by zero
     /// or more calls to `serialize_tuple_struct_elt`, then a call to
     /// `serialize_tuple_struct_end`. A reasonable implementation would be to
     /// forward to `serialize_tuple`.
     fn serialize_tuple_struct(
-        &mut self,
+        self,
         name: &'static str,
         len: usize,
-    ) -> Result<Self::TupleStructState, Self::Error>;
-
-    /// Serializes a tuple struct element. Must have previously called
-    /// `serialize_tuple_struct`.
-    fn serialize_tuple_struct_elt<T: Serialize>(
-        &mut self,
-        state: &mut Self::TupleStructState,
-        value: T,
-    ) -> Result<(), Self::Error>;
-
-    /// Finishes serializing a tuple struct.
-    fn serialize_tuple_struct_end(
-        &mut self,
-        state: Self::TupleStructState,
-    ) -> Result<(), Self::Error>;
+    ) -> Result<Self::SerializeTupleStruct, Self::Error>;
 
     /// Begins to serialize a tuple variant. This call must be followed by zero
     /// or more calls to `serialize_tuple_variant_elt`, then a call to
     /// `serialize_tuple_variant_end`. A reasonable implementation would be to
     /// forward to `serialize_tuple_struct`.
     fn serialize_tuple_variant(
-        &mut self,
+        self,
         name: &'static str,
         variant_index: usize,
         variant: &'static str,
         len: usize,
-    ) -> Result<Self::TupleVariantState, Self::Error>;
-
-    /// Serializes a tuple variant element. Must have previously called
-    /// `serialize_tuple_variant`.
-    fn serialize_tuple_variant_elt<T: Serialize>(
-        &mut self,
-        state: &mut Self::TupleVariantState,
-        value: T,
-    ) -> Result<(), Self::Error>;
-
-    /// Finishes serializing a tuple variant.
-    fn serialize_tuple_variant_end(
-        &mut self,
-        state: Self::TupleVariantState,
-    ) -> Result<(), Self::Error>;
+    ) -> Result<Self::SerializeTupleVariant, Self::Error>;
 
     /// Begins to serialize a map. This call must be followed by zero or more
     /// calls to `serialize_map_key` and `serialize_map_value`, then a call to
     /// `serialize_map_end`.
     fn serialize_map(
-        &mut self,
+        self,
         len: Option<usize>,
-    ) -> Result<Self::MapState, Self::Error>;
-
-    /// Serialize a map key. Must have previously called `serialize_map`.
-    fn serialize_map_key<T: Serialize>(
-        &mut self,
-        state: &mut Self::MapState,
-        key: T
-    ) -> Result<(), Self::Error>;
-
-    /// Serialize a map value. Must have previously called `serialize_map`.
-    fn serialize_map_value<T: Serialize>(
-        &mut self,
-        state: &mut Self::MapState,
-        value: T
-    ) -> Result<(), Self::Error>;
-
-    /// Finishes serializing a map.
-    fn serialize_map_end(
-        &mut self,
-        state: Self::MapState,
-    ) -> Result<(), Self::Error>;
+    ) -> Result<Self::SerializeMap, Self::Error>;
 
     /// Begins to serialize a struct. This call must be followed by zero or more
     /// calls to `serialize_struct_elt`, then a call to `serialize_struct_end`.
     fn serialize_struct(
-        &mut self,
+        self,
         name: &'static str,
         len: usize,
-    ) -> Result<Self::StructState, Self::Error>;
-
-    /// Serializes a struct field. Must have previously called
-    /// `serialize_struct`.
-    fn serialize_struct_elt<V: Serialize>(
-        &mut self,
-        state: &mut Self::StructState,
-        key: &'static str,
-        value: V,
-    ) -> Result<(), Self::Error>;
-
-    /// Finishes serializing a struct.
-    fn serialize_struct_end(
-        &mut self,
-        state: Self::StructState,
-    ) -> Result<(), Self::Error>;
+    ) -> Result<Self::SerializeStruct, Self::Error>;
 
     /// Begins to serialize a struct variant. This call must be followed by zero
     /// or more calls to `serialize_struct_variant_elt`, then a call to
     /// `serialize_struct_variant_end`.
     fn serialize_struct_variant(
-        &mut self,
+        self,
         name: &'static str,
         variant_index: usize,
         variant: &'static str,
         len: usize,
-    ) -> Result<Self::StructVariantState, Self::Error>;
+    ) -> Result<Self::SerializeStructVariant, Self::Error>;
+}
 
-    /// Serialize a struct variant element. Must have previously called
-    /// `serialize_struct_variant`.
-    fn serialize_struct_variant_elt<V: Serialize>(
-        &mut self,
-        state: &mut Self::StructVariantState,
-        key: &'static str,
-        value: V,
-    ) -> Result<(), Self::Error>;
+/// Returned from `Serializer::serialize_seq` and
+/// `Serializer::serialize_seq_fixed_size`.
+pub trait SerializeSeq {
+    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// `SerializeSeq` should set `Ok = ()`.
+    type Ok;
+
+    /// The error type when some error occurs during serialization.
+    type Error: Error;
+
+    /// Serializes a sequence element.
+    fn serialize_element<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error>;
+
+    /// Finishes serializing a sequence.
+    fn end(self) -> Result<Self::Ok, Self::Error>;
+}
+
+/// Returned from `Serializer::serialize_tuple`.
+pub trait SerializeTuple {
+    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// `SerializeTuple` should set `Ok = ()`.
+    type Ok;
+
+    /// The error type when some error occurs during serialization.
+    type Error: Error;
+
+    /// Serializes a tuple element.
+    fn serialize_element<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error>;
+
+    /// Finishes serializing a tuple.
+    fn end(self) -> Result<Self::Ok, Self::Error>;
+}
+
+/// Returned from `Serializer::serialize_tuple_struct`.
+pub trait SerializeTupleStruct {
+    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// `SerializeTupleStruct` should set `Ok = ()`.
+    type Ok;
+
+    /// The error type when some error occurs during serialization.
+    type Error: Error;
+
+    /// Serializes a tuple struct element.
+    fn serialize_field<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error>;
+
+    /// Finishes serializing a tuple struct.
+    fn end(self) -> Result<Self::Ok, Self::Error>;
+}
+
+/// Returned from `Serializer::serialize_tuple_variant`.
+pub trait SerializeTupleVariant {
+    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// `SerializeTupleVariant` should set `Ok = ()`.
+    type Ok;
+
+    /// The error type when some error occurs during serialization.
+    type Error: Error;
+
+    /// Serializes a tuple variant element.
+    fn serialize_field<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error>;
+
+    /// Finishes serializing a tuple variant.
+    fn end(self) -> Result<Self::Ok, Self::Error>;
+}
+
+/// Returned from `Serializer::serialize_map`.
+pub trait SerializeMap {
+    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// `SerializeMap` should set `Ok = ()`.
+    type Ok;
+
+    /// The error type when some error occurs during serialization.
+    type Error: Error;
+
+    /// Serialize a map key.
+    fn serialize_key<T: ?Sized + Serialize>(&mut self, key: &T) -> Result<(), Self::Error>;
+
+    /// Serialize a map value.
+    fn serialize_value<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error>;
+
+    /// Finishes serializing a map.
+    fn end(self) -> Result<Self::Ok, Self::Error>;
+}
+
+/// Returned from `Serializer::serialize_struct`.
+pub trait SerializeStruct {
+    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// `SerializeStruct` should set `Ok = ()`.
+    type Ok;
+
+    /// The error type when some error occurs during serialization.
+    type Error: Error;
+
+    /// Serializes a struct field.
+    fn serialize_field<T: ?Sized + Serialize>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>;
+
+    /// Finishes serializing a struct.
+    fn end(self) -> Result<Self::Ok, Self::Error>;
+}
+
+/// Returned from `Serializer::serialize_struct_variant`.
+pub trait SerializeStructVariant {
+    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// `SerializeStructVariant` should set `Ok = ()`.
+    type Ok;
+
+    /// The error type when some error occurs during serialization.
+    type Error: Error;
+
+    /// Serialize a struct variant element.
+    fn serialize_field<T: ?Sized + Serialize>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>;
 
     /// Finishes serializing a struct variant.
-    fn serialize_struct_variant_end(
-        &mut self,
-        state: Self::StructVariantState,
-    ) -> Result<(), Self::Error>;
+    fn end(self) -> Result<Self::Ok, Self::Error>;
+}
+
+/// A wrapper type for iterators that implements `Serialize` for iterators whose items implement
+/// `Serialize`. Don't use multiple times. Create new versions of this with the `iterator` function
+/// every time you want to serialize an iterator.
+#[cfg(feature = "unstable")]
+pub struct Iterator<I>(RefCell<Option<I>>)
+    where <I as IntoIterator>::Item: Serialize,
+          I: IntoIterator;
+
+/// Creates a temporary type that can be passed to any function expecting a `Serialize` and will
+/// serialize the given iterator as a sequence
+#[cfg(feature = "unstable")]
+pub fn iterator<I>(iter: I) -> Iterator<I>
+    where <I as IntoIterator>::Item: Serialize,
+          I: IntoIterator
+{
+    Iterator(RefCell::new(Some(iter)))
 }

serde_codegen/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_codegen"
-version = "0.8.20"
+version = "0.9.0-rc3"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Macros to auto-generate implementations for the serde framework"
@@ -23,7 +23,7 @@ with-syn = []
 [dependencies]
 clippy = { version = "^0.*", optional = true }
 quote = "0.3.8"
-serde_codegen_internals = { version = "=0.11.2", default-features = false, path = "../serde_codegen_internals" }
+serde_codegen_internals = { version = "=0.11.3", default-features = false, path = "../serde_codegen_internals" }
 syn = { version = "0.10", features = ["aster", "visit"] }
-syntex = { version = "^0.50.0", optional = true }
-syntex_syntax = { version = "^0.50.0", optional = true }
+syntex = { version = "^0.54.0", optional = true }
+syntex_syntax = { version = "^0.54.0", optional = true }

serde_codegen/src/de.rs

@@ -1,4 +1,4 @@
-use syn::{self, aster};
+use syn::{self, aster, Ident};
 use quote::{self, Tokens};
 
 use bound;
@@ -28,16 +28,16 @@ pub fn expand_derive_deserialize(item: &syn::MacroInput) -> Result<Tokens, Strin
 
     let where_clause = &impl_generics.where_clause;
 
-    let dummy_const = aster::id(format!("_IMPL_DESERIALIZE_FOR_{}", item.ident));
+    let dummy_const = Ident::new(format!("_IMPL_DESERIALIZE_FOR_{}", item.ident));
 
     Ok(quote! {
         #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
         const #dummy_const: () = {
             extern crate serde as _serde;
             #[automatically_derived]
-            impl #impl_generics _serde::de::Deserialize for #ty #where_clause {
-                fn deserialize<__D>(deserializer: &mut __D) -> ::std::result::Result<#ty, __D::Error>
-                    where __D: _serde::de::Deserializer
+            impl #impl_generics _serde::Deserialize for #ty #where_clause {
+                fn deserialize<__D>(deserializer: __D) -> _serde::export::Result<#ty, __D::Error>
+                    where __D: _serde::Deserializer
                 #body
             }
         };
@@ -61,7 +61,7 @@ fn build_impl_generics(item: &Item) -> syn::Generics {
         None => {
             let generics = bound::with_bound(item, &generics,
                 needs_deserialize_bound,
-                &aster::path().ids(&["_serde", "de", "Deserialize"]).build());
+                &aster::path().ids(&["_serde", "Deserialize"]).build());
             bound::with_bound(item, &generics,
                 requires_default,
                 &aster::path().global().ids(&["std", "default", "Default"]).build())
@@ -158,11 +158,11 @@ fn deserialize_visitor(generics: &syn::Generics) -> (Tokens, Tokens, Tokens) {
         let phantom_types = generics.lifetimes.iter()
             .map(|lifetime_def| {
                 let lifetime = &lifetime_def.lifetime;
-                quote!(::std::marker::PhantomData<& #lifetime ()>)
+                quote!(_serde::export::PhantomData<& #lifetime ()>)
             }).chain(generics.ty_params.iter()
                 .map(|ty_param| {
                     let ident = &ty_param.ident;
-                    quote!(::std::marker::PhantomData<#ident>)
+                    quote!(_serde::export::PhantomData<#ident>)
                 }));
 
         let all_params = generics.lifetimes.iter()
@@ -175,20 +175,14 @@ fn deserialize_visitor(generics: &syn::Generics) -> (Tokens, Tokens, Tokens) {
                     quote!(#ident)
                 }));
 
-        let ty_param_idents: Vec<_> = generics.ty_params.iter()
-            .map(|t| {
-                let ident = &t.ident;
-                quote!(#ident)
-            })
-            .collect();
-
-        let ty_param_idents = if ty_param_idents.is_empty() {
+        let ty_param_idents = if generics.ty_params.is_empty() {
             None
         } else {
+            let ty_param_idents = generics.ty_params.iter().map(|t| &t.ident);
             Some(quote!(::<#(#ty_param_idents),*>))
         };
 
-        let phantom_exprs = iter::repeat(quote!(::std::marker::PhantomData)).take(num_phantoms);
+        let phantom_exprs = iter::repeat(quote!(_serde::export::PhantomData)).take(num_phantoms);
 
         (
             quote! {
@@ -206,25 +200,30 @@ fn deserialize_unit_struct(
 ) -> Tokens {
     let type_name = item_attrs.name().deserialize_name();
 
+    let expecting = format!("unit struct {}", type_ident);
+
     quote!({
         struct __Visitor;
 
         impl _serde::de::Visitor for __Visitor {
             type Value = #type_ident;
 
+            fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
+                formatter.write_str(#expecting)
+            }
+
             #[inline]
-            fn visit_unit<__E>(&mut self) -> ::std::result::Result<#type_ident, __E>
+            fn visit_unit<__E>(self) -> _serde::export::Result<#type_ident, __E>
                 where __E: _serde::de::Error,
             {
                 Ok(#type_ident)
             }
 
             #[inline]
-            fn visit_seq<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<#type_ident, __V::Error>
+            fn visit_seq<__V>(self, _: __V) -> _serde::export::Result<#type_ident, __V::Error>
                 where __V: _serde::de::SeqVisitor,
             {
-                try!(visitor.end());
-                self.visit_unit()
+                Ok(#type_ident)
             }
         }
 
@@ -249,6 +248,10 @@ fn deserialize_tuple(
         Some(variant_ident) => quote!(#type_ident::#variant_ident),
         None => quote!(#type_ident),
     };
+    let expecting = match variant_ident {
+        Some(variant_ident) => format!("tuple variant {}::{}", type_ident, variant_ident),
+        None => format!("tuple struct {}", type_ident),
+    };
 
     let nfields = fields.len();
 
@@ -272,7 +275,7 @@ fn deserialize_tuple(
     );
 
     let dispatch = if is_enum {
-        quote!(visitor.visit_tuple(#nfields, #visitor_expr))
+        quote!(_serde::de::VariantVisitor::visit_tuple(visitor, #nfields, #visitor_expr))
     } else if nfields == 1 {
         let type_name = item_attrs.name().deserialize_name();
         quote!(deserializer.deserialize_newtype_struct(#type_name, #visitor_expr))
@@ -281,16 +284,27 @@ fn deserialize_tuple(
         quote!(deserializer.deserialize_tuple_struct(#type_name, #nfields, #visitor_expr))
     };
 
+    let all_skipped = fields.iter().all(|field| field.attrs.skip_deserializing());
+    let visitor_var = if all_skipped {
+        quote!(_)
+    } else {
+        quote!(mut visitor)
+    };
+
     quote!({
         #visitor_item
 
         impl #impl_generics _serde::de::Visitor for #visitor_ty #where_clause {
             type Value = #ty;
 
+            fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
+                formatter.write_str(#expecting)
+            }
+
             #visit_newtype_struct
 
             #[inline]
-            fn visit_seq<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<#ty, __V::Error>
+            fn visit_seq<__V>(self, #visitor_var: __V) -> _serde::export::Result<#ty, __V::Error>
                 where __V: _serde::de::SeqVisitor
             {
                 #visit_seq
@@ -308,15 +322,20 @@ fn deserialize_seq(
     fields: &[Field],
     is_struct: bool,
 ) -> Tokens {
+    let vars = (0..fields.len()).map(field_i as fn(_) -> _);
+
+    let deserialized_count = fields.iter()
+        .filter(|field| !field.attrs.skip_deserializing())
+        .count();
+    let expecting = format!("tuple of {} elements", deserialized_count);
+
     let mut index_in_seq = 0usize;
-    let let_values: Vec<_> = fields.iter()
-        .enumerate()
-        .map(|(i, field)| {
-            let name = aster::id(format!("__field{}", i));
+    let let_values = vars.clone().zip(fields)
+        .map(|(var, field)| {
             if field.attrs.skip_deserializing() {
                 let default = expr_is_missing(&field.attrs);
                 quote! {
-                    let #name = #default;
+                    let #var = #default;
                 }
             } else {
                 let visit = match field.attrs.deserialize_with() {
@@ -335,43 +354,31 @@ fn deserialize_seq(
                     }
                 };
                 let assign = quote! {
-                    let #name = match #visit {
+                    let #var = match #visit {
                         Some(value) => { value },
                         None => {
-                            try!(visitor.end());
-                            return Err(_serde::de::Error::invalid_length(#index_in_seq));
+                            return Err(_serde::de::Error::invalid_length(#index_in_seq, &#expecting));
                         }
                     };
                 };
                 index_in_seq += 1;
                 assign
             }
-        })
-        .collect();
+        });
 
     let result = if is_struct {
-        let args = fields.iter()
-            .enumerate()
-            .map(|(i, field)| {
-                let ident = field.ident.clone().expect("struct contains unnamed fields");
-                let value = aster::id(format!("__field{}", i));
-                quote!(#ident: #value)
-            });
+        let names = fields.iter().map(|f| &f.ident);
         quote! {
-            #type_path { #(#args),* }
+            #type_path { #( #names: #vars ),* }
         }
     } else {
-        let args = (0..fields.len()).map(|i| aster::id(format!("__field{}", i)));
         quote! {
-            #type_path ( #(#args),* )
+            #type_path ( #(#vars),* )
         }
     };
 
     quote! {
         #(#let_values)*
-
-        try!(visitor.end());
-
         Ok(#result)
     }
 }
@@ -401,8 +408,8 @@ fn deserialize_newtype_struct(
     };
     quote! {
         #[inline]
-        fn visit_newtype_struct<__E>(&mut self, __e: &mut __E) -> ::std::result::Result<Self::Value, __E::Error>
-            where __E: _serde::de::Deserializer,
+        fn visit_newtype_struct<__E>(self, __e: __E) -> _serde::export::Result<Self::Value, __E::Error>
+            where __E: _serde::Deserializer,
         {
             Ok(#type_path(#value))
         }
@@ -425,6 +432,10 @@ fn deserialize_struct(
         Some(variant_ident) => quote!(#type_ident::#variant_ident),
         None => quote!(#type_ident),
     };
+    let expecting = match variant_ident {
+        Some(variant_ident) => format!("struct variant {}::{}", type_ident, variant_ident),
+        None => format!("struct {}", type_ident),
+    };
 
     let visit_seq = deserialize_seq(
         type_ident,
@@ -445,7 +456,7 @@ fn deserialize_struct(
     let is_enum = variant_ident.is_some();
     let dispatch = if is_enum {
         quote! {
-            visitor.visit_struct(FIELDS, #visitor_expr)
+            _serde::de::VariantVisitor::visit_struct(visitor, FIELDS, #visitor_expr)
         }
     } else {
         let type_name = item_attrs.name().deserialize_name();
@@ -454,6 +465,13 @@ fn deserialize_struct(
         }
     };
 
+    let all_skipped = fields.iter().all(|field| field.attrs.skip_deserializing());
+    let visitor_var = if all_skipped {
+        quote!(_)
+    } else {
+        quote!(mut visitor)
+    };
+
     quote!({
         #field_visitor
 
@@ -462,15 +480,19 @@ fn deserialize_struct(
         impl #impl_generics _serde::de::Visitor for #visitor_ty #where_clause {
             type Value = #ty;
 
+            fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
+                formatter.write_str(#expecting)
+            }
+
             #[inline]
-            fn visit_seq<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<#ty, __V::Error>
+            fn visit_seq<__V>(self, #visitor_var: __V) -> _serde::export::Result<#ty, __V::Error>
                 where __V: _serde::de::SeqVisitor
             {
                 #visit_seq
             }
 
             #[inline]
-            fn visit_map<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<#ty, __V::Error>
+            fn visit_map<__V>(self, mut visitor: __V) -> _serde::export::Result<#ty, __V::Error>
                 where __V: _serde::de::MapVisitor
             {
                 #visit_map
@@ -494,49 +516,64 @@ fn deserialize_item_enum(
 
     let type_name = item_attrs.name().deserialize_name();
 
+    let expecting = format!("enum {}", type_ident);
+
+    let variant_names_idents: Vec<_> = variants.iter()
+        .enumerate()
+        .filter(|&(_, variant)| !variant.attrs.skip_deserializing())
+        .map(|(i, variant)| (variant.attrs.name().deserialize_name(), field_i(i)))
+        .collect();
+
+    let variants_stmt = {
+        let variant_names = variant_names_idents.iter().map(|&(ref name, _)| name);
+        quote! {
+            const VARIANTS: &'static [&'static str] = &[ #(#variant_names),* ];
+        }
+    };
+
     let variant_visitor = deserialize_field_visitor(
-        variants.iter()
-            .filter(|variant| !variant.attrs.skip_deserializing())
-            .map(|variant| variant.attrs.name().deserialize_name())
-            .collect(),
+        variant_names_idents,
         item_attrs,
         true,
     );
 
-    let variant_names = variants.iter().map(|variant| variant.ident.to_string());
-
-    let variants_stmt = quote! {
-        const VARIANTS: &'static [&'static str] = &[ #(#variant_names),* ];
-    };
-
-    let ignored_arm = if item_attrs.deny_unknown_fields() {
-        None
-    } else {
-        Some(quote! {
-            __Field::__ignore => { Err(_serde::de::Error::end_of_stream()) }
-        })
-    };
-
     // Match arms to extract a variant from a string
-    let mut variant_arms = vec![];
-    for (i, variant) in variants.iter().filter(|variant| !variant.attrs.skip_deserializing()).enumerate() {
-        let variant_name = aster::id(format!("__field{}", i));
-        let variant_name = quote!(__Field::#variant_name);
+    let variant_arms = variants.iter()
+        .enumerate()
+        .filter(|&(_, variant)| !variant.attrs.skip_deserializing())
+        .map(|(i, variant)| {
+            let variant_name = field_i(i);
 
-        let block = deserialize_variant(
-            type_ident,
-            impl_generics,
-            ty.clone(),
-            variant,
-            item_attrs,
-        );
+            let block = deserialize_variant(
+                type_ident,
+                impl_generics,
+                ty.clone(),
+                variant,
+                item_attrs,
+            );
 
-        let arm = quote! {
-            #variant_name => #block
-        };
-        variant_arms.push(arm);
-    }
-    variant_arms.extend(ignored_arm.into_iter());
+            quote! {
+                (__Field::#variant_name, visitor) => #block
+            }
+        });
+
+    let all_skipped = variants.iter().all(|variant| variant.attrs.skip_deserializing());
+    let match_variant = if all_skipped {
+        // This is an empty enum like `enum Impossible {}` or an enum in which
+        // all variants have `#[serde(skip_deserializing)]`.
+        quote! {
+            // FIXME: Once we drop support for Rust 1.15:
+            // let Err(err) = visitor.visit_variant::<__Field>();
+            // Err(err)
+            visitor.visit_variant::<__Field>().map(|(impossible, _)| match impossible {})
+        }
+    } else {
+        quote! {
+            match try!(visitor.visit_variant()) {
+                #(#variant_arms)*
+            }
+        }
+    };
 
     let (visitor_item, visitor_ty, visitor_expr) = deserialize_visitor(impl_generics);
 
@@ -545,15 +582,17 @@ fn deserialize_item_enum(
 
         #visitor_item
 
-        impl #impl_generics _serde::de::EnumVisitor for #visitor_ty #where_clause {
+        impl #impl_generics _serde::de::Visitor for #visitor_ty #where_clause {
             type Value = #ty;
 
-            fn visit<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<#ty, __V::Error>
-                where __V: _serde::de::VariantVisitor,
+            fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
+                formatter.write_str(#expecting)
+            }
+
+            fn visit_enum<__V>(self, visitor: __V) -> _serde::export::Result<#ty, __V::Error>
+                where __V: _serde::de::EnumVisitor,
             {
-                match try!(visitor.visit_variant()) {
-                    #(#variant_arms)*
-                }
+                #match_variant
             }
         }
 
@@ -575,7 +614,7 @@ fn deserialize_variant(
     match variant.style {
         Style::Unit => {
             quote!({
-                try!(visitor.visit_unit());
+                try!(_serde::de::VariantVisitor::visit_unit(visitor));
                 Ok(#type_ident::#variant_ident)
             })
         }
@@ -619,7 +658,9 @@ fn deserialize_newtype_variant(
     let visit = match field.attrs.deserialize_with() {
         None => {
             let field_ty = &field.ty;
-            quote!(try!(visitor.visit_newtype::<#field_ty>()))
+            quote! {
+                try!(_serde::de::VariantVisitor::visit_newtype::<#field_ty>(visitor))
+            }
         }
         Some(path) => {
             let (wrapper, wrapper_impl, wrapper_ty) = wrap_deserialize_with(
@@ -627,7 +668,7 @@ fn deserialize_newtype_variant(
             quote!({
                 #wrapper
                 #wrapper_impl
-                try!(visitor.visit_newtype::<#wrapper_ty>()).value
+                try!(_serde::de::VariantVisitor::visit_newtype::<#wrapper_ty>(visitor)).value
             })
         }
     };
@@ -637,105 +678,63 @@ fn deserialize_newtype_variant(
 }
 
 fn deserialize_field_visitor(
-    field_names: Vec<String>,
+    fields: Vec<(String, Ident)>,
     item_attrs: &attr::Item,
     is_variant: bool,
 ) -> Tokens {
-    // Create the field names for the fields.
-    let field_idents: Vec<_> = (0 .. field_names.len())
-        .map(|i| aster::id(format!("__field{}", i)))
-        .collect();
+    let field_strs = fields.iter().map(|&(ref name, _)| name);
+    let field_bytes = fields.iter().map(|&(ref name, _)| quote::ByteStr(name));
+    let field_idents: &Vec<_> = &fields.iter().map(|&(_, ref ident)| ident).collect();
 
-    let ignore_variant = if item_attrs.deny_unknown_fields() {
+    let ignore_variant = if is_variant || item_attrs.deny_unknown_fields() {
         None
     } else {
         Some(quote!(__ignore,))
     };
 
-    let index_field_arms: Vec<_> = field_idents.iter()
-        .enumerate()
-        .map(|(field_index, field_ident)| {
-            quote! {
-                #field_index => { Ok(__Field::#field_ident) }
+    let visit_usize = if is_variant {
+        let variant_indices = 0usize..;
+        let fallthrough_msg = format!("variant index 0 <= i < {}", fields.len());
+        Some(quote! {
+            fn visit_usize<__E>(self, value: usize) -> _serde::export::Result<__Field, __E>
+                where __E: _serde::de::Error
+            {
+                match value {
+                    #(
+                        #variant_indices => Ok(__Field::#field_idents),
+                    )*
+                    _ => Err(_serde::de::Error::invalid_value(
+                                _serde::de::Unexpected::Unsigned(value as u64),
+                                &#fallthrough_msg))
+                }
             }
         })
-        .collect();
-
-    let (index_error_msg, unknown_ident) = if is_variant {
-        ("expected a variant", aster::id("unknown_variant"))
     } else {
-        ("expected a field", aster::id("unknown_field"))
+        None
     };
 
-    let fallthrough_index_arm_expr = if !is_variant && !item_attrs.deny_unknown_fields() {
+    let fallthrough_arm = if is_variant {
+        quote! {
+            Err(_serde::de::Error::unknown_variant(value, VARIANTS))
+        }
+    } else if item_attrs.deny_unknown_fields() {
+        quote! {
+            Err(_serde::de::Error::unknown_field(value, FIELDS))
+        }
+    } else {
         quote! {
             Ok(__Field::__ignore)
         }
-    } else {
-        quote! {
-            Err(_serde::de::Error::invalid_value(#index_error_msg))
-        }
     };
 
-    let index_body = quote! {
-        match value {
-            #(#index_field_arms)*
-            _ => #fallthrough_index_arm_expr
-        }
-    };
-
-    // Match arms to extract a field from a string
-    let str_field_arms: Vec<_> = field_idents.iter().zip(field_names.iter())
-        .map(|(field_ident, field_name)| {
-            quote! {
-                #field_name => { Ok(__Field::#field_ident) }
-            }
+    let bytes_to_str = if is_variant || item_attrs.deny_unknown_fields() {
+        Some(quote! {
+            // TODO https://github.com/serde-rs/serde/issues/666
+            // update this to use str::from_utf8(value).unwrap_or("���") on no_std
+            let value = &_serde::export::from_utf8_lossy(value);
         })
-        .collect();
-
-    let fallthrough_str_arm_expr = if !is_variant && !item_attrs.deny_unknown_fields() {
-        quote! {
-            Ok(__Field::__ignore)
-        }
     } else {
-        quote! {
-            Err(_serde::de::Error::#unknown_ident(value))
-        }
-    };
-
-    let str_body = quote! {
-        match value {
-            #(#str_field_arms)*
-            _ => #fallthrough_str_arm_expr
-        }
-    };
-
-    // Match arms to extract a field from a string
-    let bytes_field_arms: Vec<_> = field_idents.iter().zip(field_names.iter())
-        .map(|(field_ident, field_name)| {
-            let bytes_field_name = quote::ByteStr(field_name);
-            quote! {
-                #bytes_field_name => { Ok(__Field::#field_ident) }
-            }
-        })
-        .collect();
-
-    let fallthrough_bytes_arm_expr = if !is_variant && !item_attrs.deny_unknown_fields() {
-        quote! {
-            Ok(__Field::__ignore)
-        }
-    } else {
-        quote!({
-            let value = ::std::string::String::from_utf8_lossy(value);
-            Err(_serde::de::Error::#unknown_ident(&value))
-        })
-    };
-
-    let bytes_body = quote! {
-        match value {
-            #(#bytes_field_arms)*
-            _ => #fallthrough_bytes_arm_expr
-        }
+        None
     };
 
     quote! {
@@ -745,32 +744,45 @@ fn deserialize_field_visitor(
             #ignore_variant
         }
 
-        impl _serde::de::Deserialize for __Field {
+        impl _serde::Deserialize for __Field {
             #[inline]
-            fn deserialize<__D>(deserializer: &mut __D) -> ::std::result::Result<__Field, __D::Error>
-                where __D: _serde::de::Deserializer,
+            fn deserialize<__D>(deserializer: __D) -> _serde::export::Result<__Field, __D::Error>
+                where __D: _serde::Deserializer,
             {
                 struct __FieldVisitor;
 
                 impl _serde::de::Visitor for __FieldVisitor {
                     type Value = __Field;
 
-                    fn visit_usize<__E>(&mut self, value: usize) -> ::std::result::Result<__Field, __E>
-                        where __E: _serde::de::Error
-                    {
-                        #index_body
+                    fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
+                        formatter.write_str("field name")
                     }
 
-                    fn visit_str<__E>(&mut self, value: &str) -> ::std::result::Result<__Field, __E>
+                    #visit_usize
+
+                    fn visit_str<__E>(self, value: &str) -> _serde::export::Result<__Field, __E>
                         where __E: _serde::de::Error
                     {
-                        #str_body
+                        match value {
+                            #(
+                                #field_strs => Ok(__Field::#field_idents),
+                            )*
+                            _ => #fallthrough_arm
+                        }
                     }
 
-                    fn visit_bytes<__E>(&mut self, value: &[u8]) -> ::std::result::Result<__Field, __E>
+                    fn visit_bytes<__E>(self, value: &[u8]) -> _serde::export::Result<__Field, __E>
                         where __E: _serde::de::Error
                     {
-                        #bytes_body
+                        match value {
+                            #(
+                                #field_bytes => Ok(__Field::#field_idents),
+                            )*
+                            _ => {
+                                #bytes_to_str
+                                #fallthrough_arm
+                            }
+                        }
                     }
                 }
 
@@ -787,12 +799,21 @@ fn deserialize_struct_visitor(
     fields: &[Field],
     item_attrs: &attr::Item,
 ) -> (Tokens, Tokens, Tokens) {
-    let field_exprs = fields.iter()
-        .map(|field| field.attrs.name().deserialize_name())
+    let field_names_idents: Vec<_> = fields.iter()
+        .enumerate()
+        .filter(|&(_, field)| !field.attrs.skip_deserializing())
+        .map(|(i, field)| (field.attrs.name().deserialize_name(), field_i(i)))
         .collect();
 
+    let fields_stmt = {
+        let field_names = field_names_idents.iter().map(|&(ref name, _)| name);
+        quote! {
+            const FIELDS: &'static [&'static str] = &[ #(#field_names),* ];
+        }
+    };
+
     let field_visitor = deserialize_field_visitor(
-        field_exprs,
+        field_names_idents,
         item_attrs,
         false,
     );
@@ -805,14 +826,6 @@ fn deserialize_struct_visitor(
         item_attrs,
     );
 
-    let field_names = fields.iter().map(|field| {
-        field.ident.clone().expect("struct contains unnamed field").to_string()
-    });
-
-    let fields_stmt = quote! {
-        const FIELDS: &'static [&'static str] = &[ #(#field_names),* ];
-    };
-
     (field_visitor, fields_stmt, visit_map)
 }
 
@@ -824,22 +837,20 @@ fn deserialize_map(
     item_attrs: &attr::Item,
 ) -> Tokens {
     // Create the field names for the fields.
-    let fields_names = fields.iter()
+    let fields_names: Vec<_> = fields.iter()
         .enumerate()
-        .map(|(i, field)|
-             (field, aster::id(format!("__field{}", i))))
-        .collect::<Vec<_>>();
+        .map(|(i, field)| (field, field_i(i)))
+        .collect();
 
     // Declare each field that will be deserialized.
-    let let_values: Vec<_> = fields_names.iter()
+    let let_values = fields_names.iter()
         .filter(|&&(field, _)| !field.attrs.skip_deserializing())
         .map(|&(field, ref name)| {
             let field_ty = &field.ty;
             quote! {
                 let mut #name: Option<#field_ty> = None;
             }
-        })
-        .collect();
+        });
 
     // Match arms to extract a value for a field.
     let value_arms = fields_names.iter()
@@ -872,21 +883,7 @@ fn deserialize_map(
                     #name = Some(#visit);
                 }
             }
-        })
-        .collect::<Vec<_>>();
-
-    // Match arms to ignore value for fields that have `skip_deserializing`.
-    // Ignored even if `deny_unknown_fields` is set.
-    let skipped_arms = fields_names.iter()
-        .filter(|&&(field, _)| field.attrs.skip_deserializing())
-        .map(|&(_, ref name)| {
-            quote! {
-                __Field::#name => {
-                    let _ = try!(visitor.visit_value::<_serde::de::impls::IgnoredAny>());
-                }
-            }
-        })
-        .collect::<Vec<_>>();
+        });
 
     // Visit ignored values to consume them
     let ignored_arm = if item_attrs.deny_unknown_fields() {
@@ -897,6 +894,24 @@ fn deserialize_map(
         })
     };
 
+    let all_skipped = fields.iter().all(|field| field.attrs.skip_deserializing());
+    let match_keys = if item_attrs.deny_unknown_fields() && all_skipped {
+        quote! {
+            // FIXME: Once we drop support for Rust 1.15:
+            // let None::<__Field> = try!(visitor.visit_key());
+            try!(visitor.visit_key::<__Field>()).map(|impossible| match impossible {});
+        }
+    } else {
+        quote! {
+            while let Some(key) = try!(visitor.visit_key::<__Field>()) {
+                match key {
+                    #(#value_arms)*
+                    #ignored_arm
+                }
+            }
+        }
+    };
+
     let extract_values = fields_names.iter()
         .filter(|&&(field, _)| !field.attrs.skip_deserializing())
         .map(|&(field, ref name)| {
@@ -908,8 +923,7 @@ fn deserialize_map(
                     None => #missing_expr
                 };
             }
-        })
-        .collect::<Vec<_>>();
+        });
 
     let result = fields_names.iter()
         .map(|&(field, ref name)| {
@@ -925,15 +939,7 @@ fn deserialize_map(
     quote! {
         #(#let_values)*
 
-        while let Some(key) = try!(visitor.visit_key::<__Field>()) {
-            match key {
-                #(#value_arms)*
-                #(#skipped_arms)*
-                #ignored_arm
-            }
-        }
-
-        try!(visitor.end());
+        #match_keys
 
         #(#extract_values)*
 
@@ -941,6 +947,10 @@ fn deserialize_map(
     }
 }
 
+fn field_i(i: usize) -> Ident {
+    Ident::new(format!("__field{}", i))
+}
+
 /// This function wraps the expression in `#[serde(deserialize_with="...")]` in
 /// a trait to prevent it from accessing the internal `Deserialize` state.
 fn wrap_deserialize_with(
@@ -971,18 +981,18 @@ fn wrap_deserialize_with(
         quote! {
             struct __SerdeDeserializeWithStruct #impl_generics #where_clause {
                 value: #field_ty,
-                phantom: ::std::marker::PhantomData<#phantom_ty>,
+                phantom: _serde::export::PhantomData<#phantom_ty>,
             }
         },
         quote! {
-            impl #impl_generics _serde::de::Deserialize for #wrapper_ty #where_clause {
-                fn deserialize<__D>(__d: &mut __D) -> ::std::result::Result<Self, __D::Error>
-                    where __D: _serde::de::Deserializer
+            impl #impl_generics _serde::Deserialize for #wrapper_ty #where_clause {
+                fn deserialize<__D>(__d: __D) -> _serde::export::Result<Self, __D::Error>
+                    where __D: _serde::Deserializer
                 {
                     let value = try!(#deserialize_with(__d));
                     Ok(__SerdeDeserializeWithStruct {
                         value: value,
-                        phantom: ::std::marker::PhantomData,
+                        phantom: _serde::export::PhantomData,
                     })
                 }
             }
@@ -994,7 +1004,7 @@ fn wrap_deserialize_with(
 fn expr_is_missing(attrs: &attr::Field) -> Tokens {
     match *attrs.default() {
         attr::FieldDefault::Default => {
-            return quote!(::std::default::Default::default());
+            return quote!(_serde::export::Default::default());
         }
         attr::FieldDefault::Path(ref path) => {
             return quote!(#path());
@@ -1006,7 +1016,7 @@ fn expr_is_missing(attrs: &attr::Field) -> Tokens {
     match attrs.deserialize_with() {
         None => {
             quote! {
-                try!(visitor.missing_field(#name))
+                try!(_serde::de::private::missing_field(#name))
             }
         }
         Some(_) => {

serde_codegen/src/lib.rs

@@ -38,11 +38,11 @@ fn syntex_registry() -> syntex::Registry {
 
         impl fold::Folder for StripAttributeFolder {
             fn fold_attribute(&mut self, attr: ast::Attribute) -> Option<ast::Attribute> {
-                match attr.node.value.node {
-                    ast::MetaItemKind::List(ref n, _) if n == &"serde" => { return None; }
-                    _ => {}
+                if attr.value.name == "serde" {
+                    if let ast::MetaItemKind::List(..) = attr.value.node {
+                        return None;
+                    }
                 }
-
                 Some(attr)
             }
 
@@ -116,13 +116,12 @@ macro_rules! shim {
 
             use syntax::{attr, ast, visit};
             struct MarkSerdeAttributesUsed;
-            impl visit::Visitor for MarkSerdeAttributesUsed {
+            impl<'a> visit::Visitor<'a> for MarkSerdeAttributesUsed {
                 fn visit_attribute(&mut self, attr: &ast::Attribute) {
-                    match attr.node.value.node {
-                        ast::MetaItemKind::List(ref name, _) if name == "serde" => {
+                    if attr.value.name == "serde" {
+                        if let ast::MetaItemKind::List(..) = attr.value.node {
                             attr::mark_used(attr);
                         }
-                        _ => {}
                     }
                 }
             }

serde_codegen/src/ser.rs

@@ -1,4 +1,4 @@
-use syn::{self, aster};
+use syn::{self, aster, Ident};
 use quote::Tokens;
 
 use bound;
@@ -22,16 +22,16 @@ pub fn expand_derive_serialize(item: &syn::MacroInput) -> Result<Tokens, String>
 
     let where_clause = &impl_generics.where_clause;
 
-    let dummy_const = aster::id(format!("_IMPL_SERIALIZE_FOR_{}", item.ident));
+    let dummy_const = Ident::new(format!("_IMPL_SERIALIZE_FOR_{}", item.ident));
 
     Ok(quote! {
         #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
         const #dummy_const: () = {
             extern crate serde as _serde;
             #[automatically_derived]
-            impl #impl_generics _serde::ser::Serialize for #ty #where_clause {
-                fn serialize<__S>(&self, _serializer: &mut __S) -> ::std::result::Result<(), __S::Error>
-                    where __S: _serde::ser::Serializer
+            impl #impl_generics _serde::Serialize for #ty #where_clause {
+                fn serialize<__S>(&self, _serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+                    where __S: _serde::Serializer
                 {
                     #body
                 }
@@ -56,7 +56,7 @@ fn build_impl_generics(item: &Item) -> syn::Generics {
         None => {
             bound::with_bound(item, &generics,
                 needs_serialize_bound,
-                &aster::path().ids(&["_serde", "ser", "Serialize"]).build())
+                &aster::path().ids(&["_serde", "Serialize"]).build())
         }
     }
 }
@@ -159,7 +159,7 @@ fn serialize_tuple_struct(
         fields,
         impl_generics,
         false,
-        aster::id("serialize_tuple_struct_elt"),
+        quote!(_serde::ser::SerializeTupleStruct::serialize_field),
     );
 
     let type_name = item_attrs.name().serialize_name();
@@ -169,7 +169,7 @@ fn serialize_tuple_struct(
     quote! {
         let #let_mut __serde_state = try!(_serializer.serialize_tuple_struct(#type_name, #len));
         #(#serialize_stmts)*
-        _serializer.serialize_tuple_struct_end(__serde_state)
+        _serde::ser::SerializeTupleStruct::end(__serde_state)
     }
 }
 
@@ -184,7 +184,7 @@ fn serialize_struct(
         fields,
         impl_generics,
         false,
-        aster::id("serialize_struct_elt"),
+        quote!(_serde::ser::SerializeStruct::serialize_field),
     );
 
     let type_name = item_attrs.name().serialize_name();
@@ -210,7 +210,7 @@ fn serialize_struct(
     quote! {
         let #let_mut __serde_state = try!(_serializer.serialize_struct(#type_name, #len));
         #(#serialize_fields)*
-        _serializer.serialize_struct_end(__serde_state)
+        _serde::ser::SerializeStruct::end(__serde_state)
     }
 }
 
@@ -256,76 +256,80 @@ fn serialize_variant(
     let variant_ident = variant.ident.clone();
     let variant_name = variant.attrs.name().serialize_name();
 
-    match variant.style {
-        Style::Unit => {
-            quote! {
-                #type_ident::#variant_ident =>
-                    _serde::ser::Serializer::serialize_unit_variant(
-                        _serializer,
-                        #type_name,
-                        #variant_index,
-                        #variant_name,
-                    ),
-            }
-        },
-        Style::Newtype => {
-            let block = serialize_newtype_variant(
-                type_name,
-                variant_index,
-                variant_name,
-                ty,
-                generics,
-                &variant.fields[0],
-            );
-
-            quote! {
-                #type_ident::#variant_ident(ref __simple_value) => #block,
-            }
-        },
-        Style::Tuple => {
-            let field_names: Vec<Tokens> = (0 .. variant.fields.len())
-                .map(|i| {
-                    let id = aster::id(format!("__field{}", i));
-                    quote!(ref #id)
-                })
-                .collect();
-
-            let pat = quote!(#type_ident::#variant_ident(#(#field_names),*));
-
-            let block = serialize_tuple_variant(
-                type_name,
-                variant_index,
-                variant_name,
-                generics,
-                ty,
-                &variant.fields,
-            );
-
-            quote! {
-                #pat => { #block }
-            }
+    if variant.attrs.skip_serializing() {
+        let skipped_msg = format!("the enum variant {}::{} cannot be serialized",
+                                type_ident, variant_ident);
+        let skipped_err = quote! {
+            Err(_serde::ser::Error::custom(#skipped_msg))
+        };
+        let fields_pat = match variant.style {
+            Style::Unit => quote!(),
+            Style::Newtype | Style::Tuple => quote!( (..) ),
+            Style::Struct => quote!( {..} ),
+        };
+        quote! {
+            #type_ident::#variant_ident #fields_pat => #skipped_err,
         }
-        Style::Struct => {
-            let fields = variant.fields.iter().map(|field| {
-                let id = match field.ident {
-                    Some(ref name) => name.clone(),
-                    None => panic!("struct variant has unnamed fields"),
-                };
-                quote!(ref #id)
-            });
-            let pat = quote!(#type_ident::#variant_ident { #(#fields),* });
+    } else { // variant wasn't skipped
+        match variant.style {
+            Style::Unit => {
+                quote! {
+                    #type_ident::#variant_ident =>
+                        _serde::Serializer::serialize_unit_variant(
+                            _serializer,
+                            #type_name,
+                            #variant_index,
+                            #variant_name,
+                        ),
+                }
+            },
+            Style::Newtype => {
+                let block = serialize_newtype_variant(
+                    type_name,
+                    variant_index,
+                    variant_name,
+                    ty,
+                    generics,
+                    &variant.fields[0],
+                );
 
-            let block = serialize_struct_variant(
-                variant_index,
-                variant_name,
-                generics,
-                ty,
-                &variant.fields,
-                item_attrs,
-            );
+                quote! {
+                    #type_ident::#variant_ident(ref __simple_value) => #block,
+                }
+            },
+            Style::Tuple => {
+                let field_names = (0 .. variant.fields.len())
+                    .map(|i| Ident::new(format!("__field{}", i)));
 
-            quote! {
-                #pat => { #block }
+                let block = serialize_tuple_variant(
+                    type_name,
+                    variant_index,
+                    variant_name,
+                    generics,
+                    ty,
+                    &variant.fields,
+                );
+
+                quote! {
+                    #type_ident::#variant_ident(#(ref #field_names),*) => { #block }
+                }
+            }
+            Style::Struct => {
+                let fields = variant.fields.iter()
+                    .map(|f| f.ident.clone().expect("struct variant has unnamed fields"));
+
+                let block = serialize_struct_variant(
+                    variant_index,
+                    variant_name,
+                    generics,
+                    ty,
+                    &variant.fields,
+                    item_attrs,
+                );
+
+                quote! {
+                    #type_ident::#variant_ident { #(ref #fields),* } => { #block }
+                }
             }
         }
     }
@@ -346,7 +350,7 @@ fn serialize_newtype_variant(
     }
 
     quote! {
-        _serde::ser::Serializer::serialize_newtype_variant(
+        _serde::Serializer::serialize_newtype_variant(
             _serializer,
             #type_name,
             #variant_index,
@@ -369,7 +373,7 @@ fn serialize_tuple_variant(
         fields,
         generics,
         true,
-        aster::id("serialize_tuple_variant_elt"),
+        quote!(_serde::ser::SerializeTupleVariant::serialize_field),
     );
 
     let len = serialize_stmts.len();
@@ -382,7 +386,7 @@ fn serialize_tuple_variant(
             #variant_name,
             #len));
         #(#serialize_stmts)*
-        _serializer.serialize_tuple_variant_end(__serde_state)
+        _serde::ser::SerializeTupleVariant::end(__serde_state)
     }
 }
 
@@ -399,7 +403,7 @@ fn serialize_struct_variant(
         fields,
         generics,
         true,
-        aster::id("serialize_struct_variant_elt"),
+        quote!(_serde::ser::SerializeStructVariant::serialize_field),
     );
 
     let item_name = item_attrs.name().serialize_name();
@@ -429,7 +433,7 @@ fn serialize_struct_variant(
             #len,
         ));
         #(#serialize_fields)*
-        _serializer.serialize_struct_variant_end(__serde_state)
+        _serde::ser::SerializeStructVariant::end(__serde_state)
     }
 }
 
@@ -438,16 +442,16 @@ fn serialize_tuple_struct_visitor(
     fields: &[Field],
     generics: &syn::Generics,
     is_enum: bool,
-    func: syn::Ident,
+    func: Tokens,
 ) -> Vec<Tokens> {
     fields.iter()
         .enumerate()
         .map(|(i, field)| {
             let mut field_expr = if is_enum {
-                let id = aster::id(format!("__field{}", i));
+                let id = Ident::new(format!("__field{}", i));
                 quote!(#id)
             } else {
-                let i = aster::id(i);
+                let i = Ident::new(i);
                 quote!(&self.#i)
             };
 
@@ -460,7 +464,7 @@ fn serialize_tuple_struct_visitor(
             }
 
             let ser = quote! {
-                try!(_serializer.#func(&mut __serde_state, #field_expr));
+                try!(#func(&mut __serde_state, #field_expr));
             };
 
             match skip {
@@ -476,7 +480,7 @@ fn serialize_struct_visitor(
     fields: &[Field],
     generics: &syn::Generics,
     is_enum: bool,
-    func: syn::Ident,
+    func: Tokens,
 ) -> Vec<Tokens> {
     fields.iter()
         .filter(|&field| !field.attrs.skip_serializing())
@@ -499,7 +503,7 @@ fn serialize_struct_visitor(
             }
 
             let ser = quote! {
-                try!(_serializer.#func(&mut __serde_state, #key_expr, #field_expr));
+                try!(#func(&mut __serde_state, #key_expr, #field_expr));
             };
 
             match skip {
@@ -536,15 +540,15 @@ fn wrap_serialize_with(
             phantom: ::std::marker::PhantomData<#item_ty>,
         }
 
-        impl #wrapper_generics _serde::ser::Serialize for #wrapper_ty #where_clause {
-            fn serialize<__S>(&self, __s: &mut __S) -> ::std::result::Result<(), __S::Error>
-                where __S: _serde::ser::Serializer
+        impl #wrapper_generics _serde::Serialize for #wrapper_ty #where_clause {
+            fn serialize<__S>(&self, __s: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+                where __S: _serde::Serializer
             {
                 #path(self.value, __s)
             }
         }
 
-        __SerializeWith {
+        &__SerializeWith {
             value: #value,
             phantom: ::std::marker::PhantomData::<#item_ty>,
         }
@@ -554,7 +558,7 @@ fn wrap_serialize_with(
 // Serialization of an empty struct results in code like:
 //
 //     let mut __serde_state = try!(serializer.serialize_struct("S", 0));
-//     serializer.serialize_struct_end(__serde_state)
+//     _serde::ser::SerializeStruct::end(__serde_state)
 //
 // where we want to omit the `mut` to avoid a warning.
 fn mut_if(is_mut: bool) -> Option<Tokens> {

serde_codegen_internals/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_codegen_internals"
-version = "0.11.2"
+version = "0.11.3"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "AST representation used by Serde codegen. Unstable."

serde_codegen_internals/src/attr.rs

@@ -188,6 +188,7 @@ impl Item {
 pub struct Variant {
     name: Name,
     skip_deserializing: bool,
+    skip_serializing: bool,
 }
 
 impl Variant {
@@ -195,6 +196,7 @@ impl Variant {
         let mut ser_name = Attr::none(cx, "rename");
         let mut de_name = Attr::none(cx, "rename");
         let mut skip_deserializing = BoolAttr::none(cx, "skip_deserializing");
+        let mut skip_serializing = BoolAttr::none(cx, "skip_serializing");
 
         for meta_items in variant.attrs.iter().filter_map(get_serde_meta_items) {
             for meta_item in meta_items {
@@ -218,6 +220,10 @@ impl Variant {
                     MetaItem(Word(ref name)) if name == "skip_deserializing" => {
                         skip_deserializing.set_true();
                     }
+                    // Parse `#[serde(skip_serializing)]`
+                    MetaItem(Word(ref name)) if name == "skip_serializing" => {
+                        skip_serializing.set_true();
+                    }
 
                     MetaItem(ref meta_item) => {
                         cx.error(format!("unknown serde variant attribute `{}`",
@@ -237,6 +243,7 @@ impl Variant {
                 deserialize: de_name.get().unwrap_or_else(|| variant.ident.to_string()),
             },
             skip_deserializing: skip_deserializing.get(),
+            skip_serializing: skip_serializing.get(),
         }
     }
 
@@ -247,6 +254,10 @@ impl Variant {
     pub fn skip_deserializing(&self) -> bool {
         self.skip_deserializing
     }
+
+    pub fn skip_serializing(&self) -> bool {
+        self.skip_serializing
+    }
 }
 
 /// Represents field attribute information

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "0.8.20"
+version = "0.9.0-rc3"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"
@@ -15,7 +15,7 @@ name = "serde_derive"
 proc-macro = true
 
 [dependencies.serde_codegen]
-version = "=0.8.20"
+version = "=0.9.0-rc3"
 path = "../serde_codegen"
 default-features = false
 features = ["with-syn"]
@@ -23,5 +23,5 @@ features = ["with-syn"]
 [dev-dependencies]
 compiletest_rs = "^0.2.0"
 fnv = "1.0"
-serde = { version = "0.8.20", path = "../serde" }
-serde_test = { version = "0.8.20", path = "../serde_test" }
+serde = { version = "0.9.0-rc3", path = "../serde" }
+serde_test = { version = "0.9.0-rc3", path = "../serde_test" }

serde_derive/no-std-tests/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "serde_derive_tests_no_std"
+version = "0.9.0-rc3"
+publish = false
+
+[dependencies]
+serde = { path = "../../serde", default-features = false }
+serde_derive = { path = ".." }

serde_derive/no-std-tests/src/main.rs

@@ -0,0 +1,50 @@
+#![feature(lang_items, start, libc)]
+#![no_std]
+
+extern crate libc;
+
+#[start]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+    0
+}
+
+#[lang = "eh_personality"]
+#[no_mangle]
+pub extern fn rust_eh_personality() {}
+
+#[lang = "eh_unwind_resume"]
+#[no_mangle]
+pub extern fn rust_eh_unwind_resume() {}
+
+#[lang = "panic_fmt"]
+#[no_mangle]
+pub extern fn rust_begin_panic(_msg: core::fmt::Arguments,
+                               _file: &'static str,
+                               _line: u32) -> ! {
+    loop {}
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[macro_use]
+extern crate serde_derive;
+
+#[derive(Serialize, Deserialize)]
+struct Unit;
+
+#[derive(Serialize, Deserialize)]
+struct Newtype(u8);
+
+#[derive(Serialize, Deserialize)]
+struct Tuple(u8, u8);
+
+#[derive(Serialize, Deserialize)]
+struct Struct { f: u8 }
+
+#[derive(Serialize, Deserialize)]
+enum Enum {
+    Unit,
+    Newtype(u8),
+    Tuple(u8, u8),
+    Struct { f: u8 },
+}

serde_derive/src/lib.rs

@@ -1,6 +1,3 @@
-#![feature(proc_macro, proc_macro_lib)]
-#![cfg(not(test))]
-
 extern crate proc_macro;
 extern crate serde_codegen;
 

serde_derive/tests/compile-fail/duplicate-attribute/rename-and-ser.rs

@@ -1,5 +1,3 @@
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 

serde_derive/tests/compile-fail/duplicate-attribute/rename-rename-de.rs

@@ -1,5 +1,3 @@
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 

serde_derive/tests/compile-fail/duplicate-attribute/rename-ser-rename-ser.rs

@@ -1,5 +1,3 @@
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 

serde_derive/tests/compile-fail/duplicate-attribute/rename-ser-rename.rs

@@ -1,5 +1,3 @@
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 

serde_derive/tests/compile-fail/duplicate-attribute/rename-ser-ser.rs

@@ -1,5 +1,3 @@
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 

serde_derive/tests/compile-fail/duplicate-attribute/two-rename-ser.rs

@@ -1,5 +1,3 @@
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 

serde_derive/tests/compile-fail/str_ref_deser.rs

@@ -1,5 +1,3 @@
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 

serde_derive/tests/compile-fail/unknown-attribute/container.rs

@@ -1,5 +1,3 @@
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 

serde_derive/tests/compile-fail/unknown-attribute/field.rs

@@ -1,5 +1,3 @@
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 

serde_derive/tests/compile-fail/unknown-attribute/variant.rs

@@ -1,5 +1,3 @@
-#![feature(proc_macro)]
-
 #[macro_use]
 extern crate serde_derive;
 

serde_derive/tests/run-pass/identity-op.rs

@@ -1,4 +1,3 @@
-#![feature(proc_macro)]
 #![deny(identity_op)]
 
 #[macro_use]

serde_derive/tests/test.rs

@@ -1,4 +1,4 @@
-#![feature(test, proc_macro)]
+#![feature(test)]
 
 #[macro_use]
 extern crate serde_derive;

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "0.8.20"
+version = "0.9.0-rc3"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Token De/Serializer for testing De/Serialize implementations"
@@ -12,4 +12,4 @@ keywords = ["serde", "serialization"]
 include = ["Cargo.toml", "src/**/*.rs"]
 
 [dependencies]
-serde = { version = "0.8.20", path = "../serde" }
+serde = { version = "0.9.0-rc3", path = "../serde" }

serde_test/src/de.rs

@@ -3,12 +3,14 @@ use std::iter;
 use serde::de::{
     self,
     Deserialize,
+    DeserializeSeed,
     EnumVisitor,
     MapVisitor,
     SeqVisitor,
     VariantVisitor,
     Visitor,
 };
+use serde::de::value::ValueDeserializer;
 
 use error::Error;
 use token::Token;
@@ -32,174 +34,207 @@ impl<I> Deserializer<I>
         self.tokens.next()
     }
 
-    fn visit_seq<V>(&mut self, len: Option<usize>, mut visitor: V) -> Result<V::Value, Error>
-        where V: Visitor,
-    {
-        visitor.visit_seq(DeserializerSeqVisitor {
-            de: self,
-            len: len,
-        })
+    pub fn expect_token(&mut self, expected: Token) -> Result<(), Error> {
+        match self.tokens.next() {
+            Some(token) => {
+                if expected == token {
+                    Ok(())
+                } else {
+                    Err(Error::UnexpectedToken(token))
+                }
+            }
+            None => Err(Error::EndOfTokens),
+        }
     }
 
-    fn visit_array<V>(&mut self, len: usize, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_seq<V>(&mut self, len: Option<usize>, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
-        visitor.visit_seq(DeserializerArrayVisitor {
+        let value = try!(visitor.visit_seq(DeserializerSeqVisitor {
             de: self,
             len: len,
-        })
+        }));
+        try!(self.expect_token(Token::SeqEnd));
+        Ok(value)
     }
 
-    fn visit_tuple<V>(&mut self, len: usize, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_array<V>(&mut self, len: usize, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
-        visitor.visit_seq(DeserializerTupleVisitor {
+        let value = try!(visitor.visit_seq(DeserializerArrayVisitor {
             de: self,
             len: len,
-        })
+        }));
+        try!(self.expect_token(Token::SeqEnd));
+        Ok(value)
     }
 
-    fn visit_tuple_struct<V>(&mut self, len: usize, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_tuple<V>(&mut self, len: usize, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
-        visitor.visit_seq(DeserializerTupleStructVisitor {
+        let value = try!(visitor.visit_seq(DeserializerTupleVisitor {
             de: self,
             len: len,
-        })
+        }));
+        try!(self.expect_token(Token::TupleEnd));
+        Ok(value)
     }
 
-    fn visit_variant_seq<V>(&mut self, len: Option<usize>, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_tuple_struct<V>(&mut self, len: usize, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
-        visitor.visit_seq(DeserializerVariantSeqVisitor {
+        let value = try!(visitor.visit_seq(DeserializerTupleStructVisitor {
             de: self,
             len: len,
-        })
+        }));
+        try!(self.expect_token(Token::TupleStructEnd));
+        Ok(value)
     }
 
-    fn visit_map<V>(&mut self, len: Option<usize>, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_variant_seq<V>(&mut self, len: Option<usize>, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
-        visitor.visit_map(DeserializerMapVisitor {
+        let value = try!(visitor.visit_seq(DeserializerVariantSeqVisitor {
             de: self,
             len: len,
-        })
+        }));
+        try!(self.expect_token(Token::EnumSeqEnd));
+        Ok(value)
     }
 
-    fn visit_struct<V>(&mut self, len: Option<usize>, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_map<V>(&mut self, len: Option<usize>, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
-        visitor.visit_map(DeserializerStructVisitor {
+        let value = try!(visitor.visit_map(DeserializerMapVisitor {
             de: self,
             len: len,
-        })
+        }));
+        try!(self.expect_token(Token::MapEnd));
+        Ok(value)
     }
 
-    fn visit_variant_map<V>(&mut self, len: Option<usize>, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_struct<V>(&mut self, fields: &'static [&'static str], visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
-        visitor.visit_map(DeserializerVariantMapVisitor {
+        let value = try!(visitor.visit_map(DeserializerStructVisitor {
+            de: self,
+            len: fields.len(),
+        }));
+        try!(self.expect_token(Token::StructEnd));
+        Ok(value)
+    }
+
+    fn visit_variant_map<V>(&mut self, len: Option<usize>, visitor: V) -> Result<V::Value, Error>
+        where V: Visitor,
+    {
+        let value = try!(visitor.visit_map(DeserializerVariantMapVisitor {
             de: self,
             len: len,
-        })
+        }));
+        try!(self.expect_token(Token::EnumMapEnd));
+        Ok(value)
     }
 }
 
-impl<I> de::Deserializer for Deserializer<I>
+impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
     where I: Iterator<Item=Token<'static>>,
 {
     type Error = Error;
 
-    fn deserialize_seq<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_seq<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_struct_field<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_struct_field<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_map<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_map<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_unit<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_unit<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_bytes<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_bytes<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_ignored_any<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_byte_buf<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_string<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_ignored_any<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_str<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_string<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_char<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_str<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_i64<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_char<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_i32<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_i64<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_i16<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_i32<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_i8<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_i16<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_u64<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_i8<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_u32<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_u64<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_u16<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_u32<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_u8<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_u16<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_f32<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_u8<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_f64<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_f32<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_bool<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_f64<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_usize<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_bool<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
-    fn deserialize_isize<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
+    fn deserialize_usize<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
+        where __V: de::Visitor {
+        self.deserialize(visitor)
+    }
+    fn deserialize_isize<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
         where __V: de::Visitor {
         self.deserialize(visitor)
     }
 
-    fn deserialize<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+    fn deserialize<V>(self, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
         match self.tokens.next() {
@@ -220,10 +255,11 @@ impl<I> de::Deserializer for Deserializer<I>
             Some(Token::Str(v)) => visitor.visit_str(v),
             Some(Token::String(v)) => visitor.visit_string(v),
             Some(Token::Bytes(v)) => visitor.visit_bytes(v),
+            Some(Token::ByteBuf(v)) => visitor.visit_byte_buf(v),
             Some(Token::Option(false)) => visitor.visit_none(),
             Some(Token::Option(true)) => visitor.visit_some(self),
             Some(Token::Unit) => visitor.visit_unit(),
-            Some(Token::UnitStruct(name)) => visitor.visit_unit_struct(name),
+            Some(Token::UnitStruct(_name)) => visitor.visit_unit(),
             Some(Token::SeqStart(len)) => {
                 self.visit_seq(len, visitor)
             }
@@ -237,13 +273,13 @@ impl<I> de::Deserializer for Deserializer<I>
                 self.visit_map(Some(len), visitor)
             }
             Some(token) => Err(Error::UnexpectedToken(token)),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
     /// Hook into `Option` deserializing so we can treat `Unit` as a
     /// `None`, or a regular value as `Some(value)`.
-    fn deserialize_option<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
         match self.tokens.peek() {
@@ -260,21 +296,21 @@ impl<I> de::Deserializer for Deserializer<I>
                 visitor.visit_none()
             }
             Some(_) => visitor.visit_some(self),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn deserialize_enum<V>(&mut self,
+    fn deserialize_enum<V>(self,
                      name: &str,
                      _variants: &'static [&'static str],
-                     mut visitor: V) -> Result<V::Value, Error>
-        where V: EnumVisitor,
+                     visitor: V) -> Result<V::Value, Error>
+        where V: Visitor,
     {
         match self.tokens.peek() {
             Some(&Token::EnumStart(n)) if name == n => {
                 self.tokens.next();
 
-                visitor.visit(DeserializerVariantVisitor {
+                visitor.visit_enum(DeserializerEnumVisitor {
                     de: self,
                 })
             }
@@ -282,7 +318,7 @@ impl<I> de::Deserializer for Deserializer<I>
             | Some(&Token::EnumNewType(n, _))
             | Some(&Token::EnumSeqStart(n, _, _))
             | Some(&Token::EnumMapStart(n, _, _)) if name == n => {
-                visitor.visit(DeserializerVariantVisitor {
+                visitor.visit_enum(DeserializerEnumVisitor {
                     de: self,
                 })
             }
@@ -290,11 +326,11 @@ impl<I> de::Deserializer for Deserializer<I>
                 let token = self.tokens.next().unwrap();
                 Err(Error::UnexpectedToken(token))
             }
-            None => { return Err(Error::EndOfStream); }
+            None => { return Err(Error::EndOfTokens); }
         }
     }
 
-    fn deserialize_unit_struct<V>(&mut self, name: &str, mut visitor: V) -> Result<V::Value, Error>
+    fn deserialize_unit_struct<V>(self, name: &str, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
         match self.tokens.peek() {
@@ -307,13 +343,13 @@ impl<I> de::Deserializer for Deserializer<I>
                 }
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn deserialize_newtype_struct<V>(&mut self,
+    fn deserialize_newtype_struct<V>(self,
                                      name: &str,
-                                     mut visitor: V) -> Result<V::Value, Error>
+                                     visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
         match self.tokens.peek() {
@@ -326,11 +362,11 @@ impl<I> de::Deserializer for Deserializer<I>
                 }
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn deserialize_seq_fixed_size<V>(&mut self,
+    fn deserialize_seq_fixed_size<V>(self,
                                        len: usize,
                                        visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
@@ -341,13 +377,13 @@ impl<I> de::Deserializer for Deserializer<I>
                 self.visit_array(len, visitor)
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn deserialize_tuple<V>(&mut self,
+    fn deserialize_tuple<V>(self,
                             len: usize,
-                            mut visitor: V) -> Result<V::Value, Error>
+                            visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
         match self.tokens.peek() {
@@ -376,14 +412,14 @@ impl<I> de::Deserializer for Deserializer<I>
                 self.visit_tuple_struct(len, visitor)
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn deserialize_tuple_struct<V>(&mut self,
+    fn deserialize_tuple_struct<V>(self,
                                    name: &str,
                                    len: usize,
-                                   mut visitor: V) -> Result<V::Value, Error>
+                                   visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
         match self.tokens.peek() {
@@ -420,11 +456,11 @@ impl<I> de::Deserializer for Deserializer<I>
                 }
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn deserialize_struct<V>(&mut self,
+    fn deserialize_struct<V>(self,
                              name: &str,
                              fields: &'static [&'static str],
                              visitor: V) -> Result<V::Value, Error>
@@ -434,7 +470,7 @@ impl<I> de::Deserializer for Deserializer<I>
             Some(&Token::StructStart(n, _)) => {
                 self.tokens.next();
                 if name == n {
-                    self.visit_struct(Some(fields.len()), visitor)
+                    self.visit_struct(fields, visitor)
                 } else {
                     Err(Error::InvalidName(n))
                 }
@@ -444,7 +480,7 @@ impl<I> de::Deserializer for Deserializer<I>
                 self.visit_map(Some(fields.len()), visitor)
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 }
@@ -461,30 +497,21 @@ impl<'a, I> SeqVisitor for DeserializerSeqVisitor<'a, I>
 {
     type Error = Error;
 
-    fn visit<T>(&mut self) -> Result<Option<T>, Error>
-        where T: Deserialize,
+    fn visit_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
+        where T: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::SeqSep) => {
                 self.de.tokens.next();
                 self.len = self.len.map(|len| len - 1);
-                Ok(Some(try!(Deserialize::deserialize(self.de))))
+                seed.deserialize(&mut *self.de).map(Some)
             }
             Some(&Token::SeqEnd) => Ok(None),
             Some(_) => {
                 let token = self.de.tokens.next().unwrap();
                 Err(Error::UnexpectedToken(token))
             }
-            None => Err(Error::EndOfStream),
-        }
-    }
-
-    fn end(&mut self) -> Result<(), Error> {
-        //assert_eq!(self.len.unwrap_or(0), 0);
-        match self.de.tokens.next() {
-            Some(Token::SeqEnd) => Ok(()),
-            Some(token) => Err(Error::UnexpectedToken(token)),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -506,30 +533,21 @@ impl<'a, I> SeqVisitor for DeserializerArrayVisitor<'a, I>
 {
     type Error = Error;
 
-    fn visit<T>(&mut self) -> Result<Option<T>, Error>
-        where T: Deserialize,
+    fn visit_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
+        where T: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::SeqSep) => {
                 self.de.tokens.next();
                 self.len -= 1;
-                Ok(Some(try!(Deserialize::deserialize(self.de))))
+                seed.deserialize(&mut *self.de).map(Some)
             }
             Some(&Token::SeqEnd) => Ok(None),
             Some(_) => {
                 let token = self.de.tokens.next().unwrap();
                 Err(Error::UnexpectedToken(token))
             }
-            None => Err(Error::EndOfStream),
-        }
-    }
-
-    fn end(&mut self) -> Result<(), Error> {
-        assert_eq!(self.len, 0);
-        match self.de.tokens.next() {
-            Some(Token::SeqEnd) => Ok(()),
-            Some(token) => Err(Error::UnexpectedToken(token)),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -550,30 +568,21 @@ impl<'a, I> SeqVisitor for DeserializerTupleVisitor<'a, I>
 {
     type Error = Error;
 
-    fn visit<T>(&mut self) -> Result<Option<T>, Error>
-        where T: Deserialize,
+    fn visit_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
+        where T: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::TupleSep) => {
                 self.de.tokens.next();
                 self.len -= 1;
-                Ok(Some(try!(Deserialize::deserialize(self.de))))
+                seed.deserialize(&mut *self.de).map(Some)
             }
             Some(&Token::TupleEnd) => Ok(None),
             Some(_) => {
                 let token = self.de.tokens.next().unwrap();
                 Err(Error::UnexpectedToken(token))
             }
-            None => Err(Error::EndOfStream),
-        }
-    }
-
-    fn end(&mut self) -> Result<(), Error> {
-        assert_eq!(self.len, 0);
-        match self.de.tokens.next() {
-            Some(Token::TupleEnd) => Ok(()),
-            Some(token) => Err(Error::UnexpectedToken(token)),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -594,30 +603,21 @@ impl<'a, I> SeqVisitor for DeserializerTupleStructVisitor<'a, I>
 {
     type Error = Error;
 
-    fn visit<T>(&mut self) -> Result<Option<T>, Error>
-        where T: Deserialize,
+    fn visit_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
+        where T: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::TupleStructSep) => {
                 self.de.tokens.next();
                 self.len -= 1;
-                Ok(Some(try!(Deserialize::deserialize(self.de))))
+                seed.deserialize(&mut *self.de).map(Some)
             }
             Some(&Token::TupleStructEnd) => Ok(None),
             Some(_) => {
                 let token = self.de.tokens.next().unwrap();
                 Err(Error::UnexpectedToken(token))
             }
-            None => Err(Error::EndOfStream),
-        }
-    }
-
-    fn end(&mut self) -> Result<(), Error> {
-        assert_eq!(self.len, 0);
-        match self.de.tokens.next() {
-            Some(Token::TupleStructEnd) => Ok(()),
-            Some(token) => Err(Error::UnexpectedToken(token)),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -638,30 +638,21 @@ impl<'a, I> SeqVisitor for DeserializerVariantSeqVisitor<'a, I>
 {
     type Error = Error;
 
-    fn visit<T>(&mut self) -> Result<Option<T>, Error>
-        where T: Deserialize,
+    fn visit_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
+        where T: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::EnumSeqSep) => {
                 self.de.tokens.next();
                 self.len = self.len.map(|len| len - 1);
-                Ok(Some(try!(Deserialize::deserialize(self.de))))
+                seed.deserialize(&mut *self.de).map(Some)
             }
             Some(&Token::EnumSeqEnd) => Ok(None),
             Some(_) => {
                 let token = self.de.tokens.next().unwrap();
                 Err(Error::UnexpectedToken(token))
             }
-            None => Err(Error::EndOfStream),
-        }
-    }
-
-    fn end(&mut self) -> Result<(), Error> {
-        //assert_eq!(self.len.unwrap_or(0), 0);
-        match self.de.tokens.next() {
-            Some(Token::EnumSeqEnd) => Ok(()),
-            Some(token) => Err(Error::UnexpectedToken(token)),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -683,37 +674,28 @@ impl<'a, I> MapVisitor for DeserializerMapVisitor<'a, I>
 {
     type Error = Error;
 
-    fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
-        where K: Deserialize,
+    fn visit_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
+        where K: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::MapSep) => {
                 self.de.tokens.next();
                 self.len = self.len.map(|len| if len > 0 { len - 1} else { 0 });
-                Ok(Some(try!(Deserialize::deserialize(self.de))))
+                seed.deserialize(&mut *self.de).map(Some)
             }
             Some(&Token::MapEnd) => Ok(None),
             Some(_) => {
                 let token = self.de.tokens.next().unwrap();
                 Err(Error::UnexpectedToken(token))
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn visit_value<V>(&mut self) -> Result<V, Error>
-        where V: Deserialize,
+    fn visit_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
+        where V: DeserializeSeed,
     {
-        Ok(try!(Deserialize::deserialize(self.de)))
-    }
-
-    fn end(&mut self) -> Result<(), Error> {
-        //assert_eq!(self.len.unwrap_or(0), 0);
-        match self.de.tokens.next() {
-            Some(Token::MapEnd) => Ok(()),
-            Some(token) => Err(Error::UnexpectedToken(token)),
-            None => Err(Error::EndOfStream),
-        }
+        seed.deserialize(&mut *self.de)
     }
 
     fn size_hint(&self) -> (usize, Option<usize>) {
@@ -726,7 +708,7 @@ impl<'a, I> MapVisitor for DeserializerMapVisitor<'a, I>
 
 struct DeserializerStructVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
     de: &'a mut Deserializer<I>,
-    len: Option<usize>,
+    len: usize,
 }
 
 impl<'a, I> MapVisitor for DeserializerStructVisitor<'a, I>
@@ -734,76 +716,74 @@ impl<'a, I> MapVisitor for DeserializerStructVisitor<'a, I>
 {
     type Error = Error;
 
-    fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
-        where K: Deserialize,
+    fn visit_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
+        where K: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::StructSep) => {
                 self.de.tokens.next();
-                self.len = self.len.map(|len| if len > 0 { len - 1} else { 0 });
-                Ok(Some(try!(Deserialize::deserialize(self.de))))
+                self.len = self.len.saturating_sub(1);
+                seed.deserialize(&mut *self.de).map(Some)
             }
             Some(&Token::StructEnd) => Ok(None),
             Some(_) => {
                 let token = self.de.tokens.next().unwrap();
                 Err(Error::UnexpectedToken(token))
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn visit_value<V>(&mut self) -> Result<V, Error>
-        where V: Deserialize,
+    fn visit_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
+        where V: DeserializeSeed,
     {
-        Ok(try!(Deserialize::deserialize(self.de)))
-    }
-
-    fn end(&mut self) -> Result<(), Error> {
-        //assert_eq!(self.len.unwrap_or(0), 0);
-        match self.de.tokens.next() {
-            Some(Token::StructEnd) => Ok(()),
-            Some(token) => Err(Error::UnexpectedToken(token)),
-            None => Err(Error::EndOfStream),
-        }
+        seed.deserialize(&mut *self.de)
     }
 
     fn size_hint(&self) -> (usize, Option<usize>) {
-        let len = self.len.unwrap_or(0);
-        (len, self.len)
+        (self.len, Some(self.len))
     }
 }
 
 //////////////////////////////////////////////////////////////////////////
 
-struct DeserializerVariantVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
+struct DeserializerEnumVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
     de: &'a mut Deserializer<I>,
 }
 
-impl<'a, I> VariantVisitor for DeserializerVariantVisitor<'a, I>
+impl<'a, I> EnumVisitor for DeserializerEnumVisitor<'a, I>
     where I: Iterator<Item=Token<'static>>,
 {
     type Error = Error;
+    type Variant = Self;
 
-    fn visit_variant<V>(&mut self) -> Result<V, Error>
-        where V: Deserialize,
+    fn visit_variant_seed<V>(self, seed: V) -> Result<(V::Value, Self), Error>
+        where V: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::EnumUnit(_, v))
             | Some(&Token::EnumNewType(_, v))
             | Some(&Token::EnumSeqStart(_, v, _))
             | Some(&Token::EnumMapStart(_, v, _)) => {
-                let mut de = de::value::ValueDeserializer::<Error>::into_deserializer(v);
-                let value = try!(Deserialize::deserialize(&mut de));
-                Ok(value)
+                let de = v.into_deserializer();
+                let value = try!(seed.deserialize(de));
+                Ok((value, self))
             }
             Some(_) => {
-                Deserialize::deserialize(self.de)
+                let value = try!(seed.deserialize(&mut *self.de));
+                Ok((value, self))
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
+}
 
-    fn visit_unit(&mut self) -> Result<(), Error> {
+impl<'a, I> VariantVisitor for DeserializerEnumVisitor<'a, I>
+    where I: Iterator<Item=Token<'static>>
+{
+    type Error = Error;
+
+    fn visit_unit(self) -> Result<(), Error> {
         match self.de.tokens.peek() {
             Some(&Token::EnumUnit(_, _)) => {
                 self.de.tokens.next();
@@ -812,26 +792,26 @@ impl<'a, I> VariantVisitor for DeserializerVariantVisitor<'a, I>
             Some(_) => {
                 Deserialize::deserialize(self.de)
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn visit_newtype<T>(&mut self) -> Result<T, Self::Error>
-        where T: Deserialize,
+    fn visit_newtype_seed<T>(self, seed: T) -> Result<T::Value, Self::Error>
+        where T: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::EnumNewType(_, _)) => {
                 self.de.tokens.next();
-                Deserialize::deserialize(self.de)
+                seed.deserialize(self.de)
             }
             Some(_) => {
-                Deserialize::deserialize(self.de)
+                seed.deserialize(self.de)
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn visit_tuple<V>(&mut self,
+    fn visit_tuple<V>(self,
                       len: usize,
                       visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
@@ -856,13 +836,13 @@ impl<'a, I> VariantVisitor for DeserializerVariantVisitor<'a, I>
                 }
             }
             Some(_) => {
-                Deserialize::deserialize(self.de)
+                de::Deserializer::deserialize(self.de, visitor)
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn visit_struct<V>(&mut self,
+    fn visit_struct<V>(self,
                        fields: &'static [&'static str],
                        visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
@@ -887,9 +867,9 @@ impl<'a, I> VariantVisitor for DeserializerVariantVisitor<'a, I>
                 }
             }
             Some(_) => {
-                Deserialize::deserialize(self.de)
+                de::Deserializer::deserialize(self.de, visitor)
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 }
@@ -906,37 +886,28 @@ impl<'a, I> MapVisitor for DeserializerVariantMapVisitor<'a, I>
 {
     type Error = Error;
 
-    fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
-        where K: Deserialize,
+    fn visit_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
+        where K: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::EnumMapSep) => {
                 self.de.tokens.next();
                 self.len = self.len.map(|len| if len > 0 { len - 1} else { 0 });
-                Ok(Some(try!(Deserialize::deserialize(self.de))))
+                seed.deserialize(&mut *self.de).map(Some)
             }
             Some(&Token::EnumMapEnd) => Ok(None),
             Some(_) => {
                 let token = self.de.tokens.next().unwrap();
                 Err(Error::UnexpectedToken(token))
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn visit_value<V>(&mut self) -> Result<V, Error>
-        where V: Deserialize,
+    fn visit_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
+        where V: DeserializeSeed,
     {
-        Ok(try!(Deserialize::deserialize(self.de)))
-    }
-
-    fn end(&mut self) -> Result<(), Error> {
-        //assert_eq!(self.len.unwrap_or(0), 0);
-        match self.de.tokens.next() {
-            Some(Token::EnumMapEnd) => Ok(()),
-            Some(token) => Err(Error::UnexpectedToken(token)),
-            None => Err(Error::EndOfStream),
-        }
+        seed.deserialize(&mut *self.de)
     }
 
     fn size_hint(&self) -> (usize, Option<usize>) {

serde_test/src/error.rs

@@ -1,4 +1,5 @@
-use std::{error, fmt};
+use std::error;
+use std::fmt::{self, Display};
 
 use serde::{ser, de};
 
@@ -6,82 +7,42 @@ use token::Token;
 
 #[derive(Clone, PartialEq, Debug)]
 pub enum Error {
-    // Shared
-    Custom(String),
-    InvalidValue(String),
-
-    // De
-    EndOfStream,
-    InvalidType(de::Type),
-    InvalidLength(usize),
-    UnknownVariant(String),
-    UnknownField(String),
-    MissingField(&'static str),
-    DuplicateField(&'static str),
+    Message(String),
     InvalidName(&'static str),
     UnexpectedToken(Token<'static>),
+    EndOfTokens,
 }
 
 impl ser::Error for Error {
-    fn custom<T: Into<String>>(msg: T) -> Error {
-        Error::Custom(msg.into())
-    }
-
-    fn invalid_value(msg: &str) -> Error {
-        Error::InvalidValue(msg.to_owned())
+    fn custom<T: Display>(msg: T) -> Error {
+        Error::Message(msg.to_string())
     }
 }
 
 impl de::Error for Error {
-    fn custom<T: Into<String>>(msg: T) -> Error {
-        Error::Custom(msg.into())
-    }
-
-    fn end_of_stream() -> Error {
-        Error::EndOfStream
-    }
-
-    fn invalid_type(ty: de::Type) -> Error {
-        Error::InvalidType(ty)
-    }
-
-    fn invalid_value(msg: &str) -> Error {
-        Error::InvalidValue(msg.to_owned())
-    }
-
-    fn invalid_length(len: usize) -> Error {
-        Error::InvalidLength(len)
-    }
-
-    fn unknown_variant(variant: &str) -> Error {
-        Error::UnknownVariant(variant.to_owned())
-    }
-
-    fn unknown_field(field: &str) -> Error {
-        Error::UnknownField(field.to_owned())
-    }
-
-    fn missing_field(field: &'static str) -> Error {
-        Error::MissingField(field)
-    }
-
-    fn duplicate_field(field: &'static str) -> Error {
-        Error::DuplicateField(field)
+    fn custom<T: Display>(msg: T) -> Error {
+        Error::Message(msg.to_string())
     }
 }
 
 impl fmt::Display for Error {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-        formatter.write_str(format!("{:?}", self).as_ref())
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Error::Message(ref msg) => formatter.write_str(msg),
+            Error::InvalidName(name) => write!(formatter, "invalid name `{}`", name),
+            Error::UnexpectedToken(_) => formatter.write_str("unexpected token"),
+            Error::EndOfTokens => formatter.write_str("end of tokens"),
+        }
     }
 }
 
 impl error::Error for Error {
     fn description(&self) -> &str {
-        "Serde Error"
-    }
-
-    fn cause(&self) -> Option<&error::Error> {
-        None
+        match *self {
+            Error::Message(ref msg) => msg,
+            Error::InvalidName(_) => "invalid name",
+            Error::UnexpectedToken(_) => "unexpected token",
+            Error::EndOfTokens => "end of tokens",
+        }
     }
 }

serde_test/src/ser.rs

@@ -1,9 +1,6 @@
 use std::marker::PhantomData;
 
-use serde::ser::{
-    self,
-    Serialize,
-};
+use serde::{ser, Serialize};
 
 use error::Error;
 use token::Token;
@@ -30,294 +27,330 @@ impl<'a, I> Serializer<'a, I>
     }
 }
 
-impl<'a, I> ser::Serializer for Serializer<'a, I>
+impl<'s, 'a, I> ser::Serializer for &'s mut Serializer<'a, I>
     where I: Iterator<Item=&'a Token<'a>>,
 {
+    type Ok = ();
     type Error = Error;
-    type MapState = ();
-    type SeqState = ();
-    type TupleState = ();
-    type TupleStructState = ();
-    type TupleVariantState = ();
-    type StructState = ();
-    type StructVariantState = ();
 
-    fn serialize_unit(&mut self) -> Result<(), Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::Unit));
-        Ok(())
-    }
+    type SerializeSeq = Self;
+    type SerializeTuple = Self;
+    type SerializeTupleStruct = Self;
+    type SerializeTupleVariant = Self;
+    type SerializeMap = Self;
+    type SerializeStruct = Self;
+    type SerializeStructVariant = Self;
 
-    fn serialize_newtype_variant<T>(&mut self,
-                                name: &str,
-                                _variant_index: usize,
-                                variant: &str,
-                                value: T) -> Result<(), Error>
-        where T: Serialize,
-    {
-        assert_eq!(self.tokens.next(), Some(&Token::EnumNewType(name, variant)));
-        value.serialize(self)
-    }
-
-    fn serialize_unit_struct(&mut self, name: &str) -> Result<(), Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::UnitStruct(name)));
-        Ok(())
-    }
-
-    fn serialize_unit_variant(&mut self,
-                          name: &str,
-                          _variant_index: usize,
-                          variant: &str) -> Result<(), Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::EnumUnit(name, variant)));
-
-        Ok(())
-    }
-
-    fn serialize_bool(&mut self, v: bool) -> Result<(), Error> {
+    fn serialize_bool(self, v: bool) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::Bool(v)));
         Ok(())
     }
 
-    fn serialize_isize(&mut self, v: isize) -> Result<(), Error> {
+    fn serialize_isize(self, v: isize) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::Isize(v)));
         Ok(())
     }
 
-    fn serialize_i8(&mut self, v: i8) -> Result<(), Error> {
+    fn serialize_i8(self, v: i8) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::I8(v)));
         Ok(())
     }
 
-    fn serialize_i16(&mut self, v: i16) -> Result<(), Error> {
+    fn serialize_i16(self, v: i16) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::I16(v)));
         Ok(())
     }
 
-    fn serialize_i32(&mut self, v: i32) -> Result<(), Error> {
+    fn serialize_i32(self, v: i32) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::I32(v)));
         Ok(())
     }
 
-    fn serialize_i64(&mut self, v: i64) -> Result<(), Error> {
+    fn serialize_i64(self, v: i64) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::I64(v)));
         Ok(())
     }
 
-    fn serialize_usize(&mut self, v: usize) -> Result<(), Error> {
+    fn serialize_usize(self, v: usize) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::Usize(v)));
         Ok(())
     }
 
-    fn serialize_u8(&mut self, v: u8) -> Result<(), Error> {
+    fn serialize_u8(self, v: u8) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::U8(v)));
         Ok(())
     }
 
-    fn serialize_u16(&mut self, v: u16) -> Result<(), Error> {
+    fn serialize_u16(self, v: u16) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::U16(v)));
         Ok(())
     }
 
-    fn serialize_u32(&mut self, v: u32) -> Result<(), Error> {
+    fn serialize_u32(self, v: u32) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::U32(v)));
         Ok(())
     }
 
-    fn serialize_u64(&mut self, v: u64) -> Result<(), Error> {
+    fn serialize_u64(self, v: u64) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::U64(v)));
         Ok(())
     }
 
-    fn serialize_f32(&mut self, v: f32) -> Result<(), Error> {
+    fn serialize_f32(self, v: f32) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::F32(v)));
         Ok(())
     }
 
-    fn serialize_f64(&mut self, v: f64) -> Result<(), Error> {
+    fn serialize_f64(self, v: f64) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::F64(v)));
         Ok(())
     }
 
-    fn serialize_char(&mut self, v: char) -> Result<(), Error> {
+    fn serialize_char(self, v: char) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::Char(v)));
         Ok(())
     }
 
-    fn serialize_str(&mut self, v: &str) -> Result<(), Error> {
+    fn serialize_str(self, v: &str) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::Str(v)));
         Ok(())
     }
 
-    fn serialize_none(&mut self) -> Result<(), Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::Option(false)));
+    fn serialize_bytes(self, value: &[u8]) -> Result<(), Self::Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::Bytes(value)));
         Ok(())
     }
 
-    fn serialize_some<V>(&mut self, value: V) -> Result<(), Error>
-        where V: Serialize,
-    {
-        assert_eq!(self.tokens.next(), Some(&Token::Option(true)));
-        value.serialize(self)
-    }
-
-    fn serialize_seq<'b>(&'b mut self, len: Option<usize>) -> Result<(), Error>
-    {
-        assert_eq!(self.tokens.next(), Some(&Token::SeqStart(len)));
+    fn serialize_unit(self) -> Result<(), Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::Unit));
         Ok(())
     }
 
-    fn serialize_seq_elt<T>(&mut self, _: &mut (), value: T) -> Result<(), Error>
-        where T: Serialize
-    {
-        assert_eq!(self.tokens.next(), Some(&Token::SeqSep));
-        value.serialize(self)
-    }
-
-    fn serialize_seq_end(&mut self, _: ()) -> Result<(), Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::SeqEnd));
+    fn serialize_unit_struct(self, name: &str) -> Result<(), Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::UnitStruct(name)));
         Ok(())
     }
 
-    fn serialize_seq_fixed_size(&mut self, len: usize) -> Result<(), Error>
-    {
-        assert_eq!(self.tokens.next(), Some(&Token::SeqArrayStart(len)));
+    fn serialize_unit_variant(self,
+                              name: &str,
+                              _variant_index: usize,
+                              variant: &str) -> Result<(), Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::EnumUnit(name, variant)));
         Ok(())
     }
 
-    fn serialize_tuple(&mut self, len: usize) -> Result<(), Error>
-    {
-        assert_eq!(self.tokens.next(), Some(&Token::TupleStart(len)));
-        Ok(())
-    }
-
-    fn serialize_tuple_elt<T>(&mut self, _: &mut (), value: T) -> Result<(), Error>
-        where T: Serialize
-    {
-        assert_eq!(self.tokens.next(), Some(&Token::TupleSep));
-        value.serialize(self)
-    }
-
-    fn serialize_tuple_end(&mut self, _: ()) -> Result<(), Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::TupleEnd));
-        Ok(())
-    }
-
-    fn serialize_newtype_struct<T>(&mut self,
-                                   name: &'static str,
-                                   value: T) -> Result<(), Error>
+    fn serialize_newtype_struct<T: ?Sized>(self,
+                                           name: &'static str,
+                                           value: &T) -> Result<(), Error>
         where T: Serialize,
     {
         assert_eq!(self.tokens.next(), Some(&Token::StructNewType(name)));
         value.serialize(self)
     }
 
-    fn serialize_tuple_struct(&mut self, name: &'static str, len: usize) -> Result<(), Error>
+    fn serialize_newtype_variant<T: ?Sized>(self,
+                                            name: &str,
+                                            _variant_index: usize,
+                                            variant: &str,
+                                            value: &T) -> Result<(), Error>
+        where T: Serialize,
     {
-        assert_eq!(self.tokens.next(), Some(&Token::TupleStructStart(name, len)));
-
-        Ok(())
-    }
-
-    fn serialize_tuple_struct_elt<T>(&mut self, _: &mut (), value: T) -> Result<(), Error>
-        where T: Serialize
-    {
-        assert_eq!(self.tokens.next(), Some(&Token::TupleStructSep));
+        assert_eq!(self.tokens.next(), Some(&Token::EnumNewType(name, variant)));
         value.serialize(self)
     }
 
-    fn serialize_tuple_struct_end(&mut self, _: ()) -> Result<(), Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::TupleStructEnd));
+    fn serialize_none(self) -> Result<(), Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::Option(false)));
         Ok(())
     }
 
-    fn serialize_tuple_variant(&mut self,
+    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<(), Error>
+        where T: Serialize,
+    {
+        assert_eq!(self.tokens.next(), Some(&Token::Option(true)));
+        value.serialize(self)
+    }
+
+    fn serialize_seq(self, len: Option<usize>) -> Result<Self, Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::SeqStart(len)));
+        Ok(self)
+    }
+
+    fn serialize_seq_fixed_size(self, len: usize) -> Result<Self, Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::SeqArrayStart(len)));
+        Ok(self)
+    }
+
+    fn serialize_tuple(self, len: usize) -> Result<Self, Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::TupleStart(len)));
+        Ok(self)
+    }
+
+    fn serialize_tuple_struct(self, name: &'static str, len: usize) -> Result<Self, Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::TupleStructStart(name, len)));
+        Ok(self)
+    }
+
+    fn serialize_tuple_variant(self,
                                name: &str,
                                _variant_index: usize,
                                variant: &str,
-                               len: usize) -> Result<(), Error>
+                               len: usize) -> Result<Self, Error>
     {
         assert_eq!(self.tokens.next(), Some(&Token::EnumSeqStart(name, variant, len)));
-
-        Ok(())
+        Ok(self)
     }
 
-    fn serialize_tuple_variant_elt<T>(&mut self, _: &mut (), value: T) -> Result<(), Error>
-        where T: Serialize
-    {
-        assert_eq!(self.tokens.next(), Some(&Token::EnumSeqSep));
-        value.serialize(self)
-    }
-
-    fn serialize_tuple_variant_end(&mut self, _: ()) -> Result<(), Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::EnumSeqEnd));
-        Ok(())
-    }
-
-    fn serialize_map(&mut self, len: Option<usize>) -> Result<(), Error>
-    {
+    fn serialize_map(self, len: Option<usize>) -> Result<Self, Error> {
         assert_eq!(self.tokens.next(), Some(&Token::MapStart(len)));
-
-        Ok(())
+        Ok(self)
     }
 
-    fn serialize_map_key<T>(&mut self, _: &mut (), key: T) -> Result<(), Self::Error> where T: Serialize {
-        assert_eq!(self.tokens.next(), Some(&Token::MapSep));
-        key.serialize(self)
-    }
-
-    fn serialize_map_value<T>(&mut self, _: &mut (), value: T) -> Result<(), Self::Error> where T: Serialize {
-        value.serialize(self)
-    }
-
-    fn serialize_map_end(&mut self, _: ()) -> Result<(), Self::Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::MapEnd));
-        Ok(())
-    }
-
-    fn serialize_struct(&mut self, name: &str, len: usize) -> Result<(), Error>
-    {
+    fn serialize_struct(self, name: &str, len: usize) -> Result<Self, Error> {
         assert_eq!(self.tokens.next(), Some(&Token::StructStart(name, len)));
-
-        Ok(())
+        Ok(self)
     }
 
-    fn serialize_struct_elt<V>(&mut self, _: &mut (), key: &'static str, value: V) -> Result<(), Self::Error> where V: Serialize {
-        assert_eq!(self.tokens.next(), Some(&Token::StructSep));
-        try!(key.serialize(self));
-        value.serialize(self)
-    }
-
-    fn serialize_struct_end(&mut self, _: ()) -> Result<(), Self::Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::StructEnd));
-        Ok(())
-    }
-
-    fn serialize_struct_variant(&mut self,
+    fn serialize_struct_variant(self,
                                 name: &str,
                                 _variant_index: usize,
                                 variant: &str,
-                                len: usize) -> Result<(), Error>
+                                len: usize) -> Result<Self, Error>
     {
         assert_eq!(self.tokens.next(), Some(&Token::EnumMapStart(name, variant, len)));
+        Ok(self)
+    }
+}
 
+impl<'s, 'a, I> ser::SerializeSeq for &'s mut Serializer<'a, I>
+    where I: Iterator<Item=&'a Token<'a>>,
+{
+    type Ok = ();
+    type Error = Error;
+
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+        where T: Serialize
+    {
+        assert_eq!(self.tokens.next(), Some(&Token::SeqSep));
+        value.serialize(&mut **self)
+    }
+
+    fn end(self) -> Result<(), Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::SeqEnd));
         Ok(())
     }
+}
 
-    fn serialize_struct_variant_elt<V>(&mut self, _: &mut (), key: &'static str, value: V) -> Result<(), Self::Error> where V: Serialize {
-        assert_eq!(self.tokens.next(), Some(&Token::EnumMapSep));
-        try!(key.serialize(self));
-        value.serialize(self)
+impl<'s, 'a, I> ser::SerializeTuple for &'s mut Serializer<'a, I>
+    where I: Iterator<Item=&'a Token<'a>>,
+{
+    type Ok = ();
+    type Error = Error;
+
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+        where T: Serialize
+    {
+        assert_eq!(self.tokens.next(), Some(&Token::TupleSep));
+        value.serialize(&mut **self)
     }
 
-    fn serialize_struct_variant_end(&mut self, _: ()) -> Result<(), Self::Error> {
+    fn end(self) -> Result<(), Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::TupleEnd));
+        Ok(())
+    }
+}
+
+impl<'s, 'a, I> ser::SerializeTupleStruct for &'s mut Serializer<'a, I>
+    where I: Iterator<Item=&'a Token<'a>>,
+{
+    type Ok = ();
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+        where T: Serialize
+    {
+        assert_eq!(self.tokens.next(), Some(&Token::TupleStructSep));
+        value.serialize(&mut **self)
+    }
+
+    fn end(self) -> Result<(), Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::TupleStructEnd));
+        Ok(())
+    }
+}
+
+impl<'s, 'a, I> ser::SerializeTupleVariant for &'s mut Serializer<'a, I>
+    where I: Iterator<Item=&'a Token<'a>>,
+{
+    type Ok = ();
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
+        where T: Serialize
+    {
+        assert_eq!(self.tokens.next(), Some(&Token::EnumSeqSep));
+        value.serialize(&mut **self)
+    }
+
+    fn end(self) -> Result<(), Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::EnumSeqEnd));
+        Ok(())
+    }
+}
+
+impl<'s, 'a, I> ser::SerializeMap for &'s mut Serializer<'a, I>
+    where I: Iterator<Item=&'a Token<'a>>,
+{
+    type Ok = ();
+    type Error = Error;
+
+    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error> where T: Serialize {
+        assert_eq!(self.tokens.next(), Some(&Token::MapSep));
+        key.serialize(&mut **self)
+    }
+
+    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> where T: Serialize {
+        value.serialize(&mut **self)
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::MapEnd));
+        Ok(())
+    }
+}
+
+impl<'s, 'a, I> ser::SerializeStruct for &'s mut Serializer<'a, I>
+    where I: Iterator<Item=&'a Token<'a>>,
+{
+    type Ok = ();
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error> where T: Serialize {
+        assert_eq!(self.tokens.next(), Some(&Token::StructSep));
+        try!(key.serialize(&mut **self));
+        value.serialize(&mut **self)
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        assert_eq!(self.tokens.next(), Some(&Token::StructEnd));
+        Ok(())
+    }
+}
+
+impl<'s, 'a, I> ser::SerializeStructVariant for &'s mut Serializer<'a, I>
+    where I: Iterator<Item=&'a Token<'a>>,
+{
+    type Ok = ();
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error> where T: Serialize {
+        assert_eq!(self.tokens.next(), Some(&Token::EnumMapSep));
+        try!(key.serialize(&mut **self));
+        value.serialize(&mut **self)
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
         assert_eq!(self.tokens.next(), Some(&Token::EnumMapEnd));
         Ok(())
     }
-
-    fn serialize_bytes(&mut self, value: &[u8]) -> Result<(), Self::Error> {
-        let mut state = try!(self.serialize_seq(Some(value.len())));
-        for c in value {
-            try!(self.serialize_seq_elt(&mut state, c));
-        }
-        self.serialize_seq_end(state)
-    }
 }

serde_test/src/token.rs

@@ -17,6 +17,7 @@ pub enum Token<'a> {
     Str(&'a str),
     String(String),
     Bytes(&'a [u8]),
+    ByteBuf(Vec<u8>),
 
     Option(bool),
 

testing/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_testing"
-version = "0.8.20"
+version = "0.9.0-rc3"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"
@@ -10,6 +10,7 @@ documentation = "https://docs.serde.rs/serde/"
 readme = "README.md"
 keywords = ["serialization"]
 build = "build.rs"
+publish = false
 
 [features]
 unstable-testing = ["clippy", "serde/unstable-testing", "serde_codegen/unstable-testing"]

testing/tests/test.rs

@@ -1,4 +1,6 @@
 #![cfg_attr(feature = "clippy", feature(plugin))]
 #![cfg_attr(feature = "clippy", plugin(clippy))]
 
+#![cfg_attr(feature = "unstable-testing", feature(non_ascii_idents))]
+
 include!(concat!(env!("OUT_DIR"), "/test.rs"));

testing/tests/test.rs.in

@@ -1,4 +1,5 @@
 extern crate serde;
+extern crate serde_test;
 
 #[macro_use]
 mod macros;

testing/tests/test_annotations.rs

@@ -20,12 +20,12 @@ trait ShouldSkip: Sized {
 }
 
 trait SerializeWith: Sized {
-    fn serialize_with<S>(&self, ser: &mut S) -> Result<(), S::Error>
+    fn serialize_with<S>(&self, ser: S) -> Result<S::Ok, S::Error>
         where S: Serializer;
 }
 
 trait DeserializeWith: Sized {
-    fn deserialize_with<D>(de: &mut D) -> Result<Self, D::Error>
+    fn deserialize_with<D>(de: D) -> Result<Self, D::Error>
         where D: Deserializer;
 }
 
@@ -38,7 +38,7 @@ impl ShouldSkip for i32 {
 }
 
 impl SerializeWith for i32 {
-    fn serialize_with<S>(&self, ser: &mut S) -> Result<(), S::Error>
+    fn serialize_with<S>(&self, ser: S) -> Result<S::Ok, S::Error>
         where S: Serializer
     {
         if *self == 123 {
@@ -50,7 +50,7 @@ impl SerializeWith for i32 {
 }
 
 impl DeserializeWith for i32 {
-    fn deserialize_with<D>(de: &mut D) -> Result<Self, D::Error>
+    fn deserialize_with<D>(de: D) -> Result<Self, D::Error>
         where D: Deserializer
     {
         if try!(Deserialize::deserialize(de)) {
@@ -145,7 +145,7 @@ fn test_default_enum() {
     assert_de_tokens(
         &DefaultEnum::Struct { a1: 1, a2: 2, a3: 3, a4: 0, a5: 123 },
         &[
-            Token::EnumMapStart("DefaultEnum", "Struct", 5),
+            Token::EnumMapStart("DefaultEnum", "Struct", 3),
 
             Token::EnumMapSep,
             Token::Str("a1"),
@@ -174,7 +174,7 @@ fn test_default_enum() {
     assert_de_tokens(
         &DefaultEnum::Struct { a1: 1, a2: 0, a3: 123, a4: 0, a5: 123 },
         &[
-            Token::EnumMapStart("DefaultEnum", "Struct", 5),
+            Token::EnumMapStart("DefaultEnum", "Struct", 3),
 
             Token::EnumMapSep,
             Token::Str("a1"),
@@ -239,7 +239,7 @@ impl Default for NotDeserializeStruct {
 }
 
 impl DeserializeWith for NotDeserializeStruct {
-    fn deserialize_with<D>(_: &mut D) -> Result<Self, D::Error>
+    fn deserialize_with<D>(_: D) -> Result<Self, D::Error>
         where D: Deserializer
     {
         panic!()
@@ -343,7 +343,7 @@ fn test_ignore_unknown() {
             Token::StructSep,
             Token::Str("whoops"),
         ],
-        Error::UnknownField("whoops".to_owned())
+        Error::Message("unknown field `whoops`, expected `a1`".to_owned())
     );
 }
 
@@ -642,7 +642,7 @@ struct NotSerializeStruct(i8);
 enum NotSerializeEnum { Trouble }
 
 impl SerializeWith for NotSerializeEnum {
-    fn serialize_with<S>(&self, ser: &mut S) -> Result<(), S::Error>
+    fn serialize_with<S>(&self, ser: S) -> Result<S::Ok, S::Error>
         where S: Serializer
     {
         "trouble".serialize(ser)
@@ -905,7 +905,7 @@ fn test_missing_renamed_field_struct() {
 
             Token::StructEnd,
         ],
-        Error::MissingField("a3"),
+        Error::Message("missing field `a3`".to_owned()),
     );
 
     assert_de_tokens_error::<RenameStructSerializeDeserialize>(
@@ -918,7 +918,7 @@ fn test_missing_renamed_field_struct() {
 
             Token::StructEnd,
         ],
-        Error::MissingField("a5"),
+        Error::Message("missing field `a5`".to_owned()),
     );
 }
 
@@ -930,7 +930,7 @@ fn test_missing_renamed_field_enum() {
 
             Token::EnumMapEnd,
         ],
-        Error::MissingField("b"),
+        Error::Message("missing field `b`".to_owned()),
     );
 
     assert_de_tokens_error::<RenameEnumSerializeDeserialize<i8>>(
@@ -943,7 +943,7 @@ fn test_missing_renamed_field_enum() {
 
             Token::EnumMapEnd,
         ],
-        Error::MissingField("d"),
+        Error::Message("missing field `d`".to_owned()),
     );
 }
 
@@ -962,7 +962,7 @@ fn test_invalid_length_enum() {
                 Token::I32(1),
             Token::EnumSeqEnd,
         ],
-        Error::InvalidLength(1),
+        Error::Message("invalid length 1, expected tuple of 3 elements".to_owned()),
     );
     assert_de_tokens_error::<InvalidLengthEnum>(
         &[
@@ -971,6 +971,6 @@ fn test_invalid_length_enum() {
                 Token::I32(1),
             Token::EnumSeqEnd,
         ],
-        Error::InvalidLength(1),
+        Error::Message("invalid length 1, expected tuple of 2 elements".to_owned()),
     );
 }

testing/tests/test_bytes.rs

@@ -1,460 +1,55 @@
-use std::fmt;
-use std::error;
-
-use serde::{Serialize, Serializer, Deserialize, Deserializer};
 use serde::bytes::{ByteBuf, Bytes};
-use serde::ser;
-use serde::de;
-
-///////////////////////////////////////////////////////////////////////////////
-
-#[derive(Debug, PartialEq)]
-struct Error;
-
-impl ser::Error for Error {
-    fn custom<T: Into<String>>(_: T) -> Error { Error }
-}
-
-impl de::Error for Error {
-    fn custom<T: Into<String>>(_: T) -> Error { Error }
-
-    fn end_of_stream() -> Error { Error }
-}
-
-impl fmt::Display for Error {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-        formatter.write_str(format!("{:?}", self).as_ref())
-    }
-}
-
-impl error::Error for Error {
-    fn description(&self) -> &str {
-        "Serde Deserialization Error"
-    }
-
-    fn cause(&self) -> Option<&error::Error> {
-        None
-    }
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-struct BytesSerializer {
-    bytes: Vec<u8>,
-}
-
-impl BytesSerializer {
-    fn new(bytes: Vec<u8>) -> Self {
-        BytesSerializer {
-            bytes: bytes,
-        }
-    }
-}
-
-impl Serializer for BytesSerializer {
-    type Error = Error;
-    type SeqState = ();
-    type MapState = ();
-    type TupleState = ();
-    type TupleStructState = ();
-    type TupleVariantState = ();
-    type StructState = ();
-    type StructVariantState = ();
-
-    fn serialize_unit(&mut self) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_unit_struct(&mut self, _name: &'static str) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_unit_variant(&mut self, _: &'static str, _: usize, _: &'static str) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_bool(&mut self, _v: bool) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_isize(&mut self, _v: isize) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_usize(&mut self, _v: usize) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_i8(&mut self, _v: i8) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_u8(&mut self, _v: u8) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_i16(&mut self, _v: i16) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_u16(&mut self, _v: u16) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_i32(&mut self, _v: i32) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_u32(&mut self, _v: u32) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_i64(&mut self, _v: i64) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_u64(&mut self, _v: u64) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_f32(&mut self, _v: f32) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_f64(&mut self, _v: f64) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_char(&mut self, _v: char) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_str(&mut self, _v: &str) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_none(&mut self) -> Result<(), Error> {
-        Err(Error)
-    }
-
-    fn serialize_some<V>(&mut self, _value: V) -> Result<(), Error>
-        where V: Serialize,
-    {
-        Err(Error)
-    }
-
-    fn serialize_newtype_struct<V>(&mut self, _: &'static str, _value: V) -> Result<(), Error>
-        where V: Serialize,
-    {
-        Err(Error)
-    }
-
-    fn serialize_newtype_variant<V>(&mut self, _: &'static str, _: usize, _: &'static str, _value: V) -> Result<(), Error>
-        where V: Serialize,
-    {
-        Err(Error)
-    }
-
-    fn serialize_seq(&mut self, _len: Option<usize>) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_seq_fixed_size(&mut self, _len: usize) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_seq_elt<T>(&mut self, _: &mut (), _value: T) -> Result<(), Error>
-        where T: Serialize
-    {
-        Err(Error)
-    }
-
-    fn serialize_seq_end(&mut self, _: ()) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_tuple(&mut self, _len: usize) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_tuple_elt<T>(&mut self, _: &mut (), _value: T) -> Result<(), Error>
-        where T: Serialize
-    {
-        Err(Error)
-    }
-
-    fn serialize_tuple_end(&mut self, _: ()) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_tuple_struct(&mut self, _: &'static str, _len: usize) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_tuple_struct_elt<T>(&mut self, _: &mut (), _value: T) -> Result<(), Error>
-        where T: Serialize
-    {
-        Err(Error)
-    }
-
-    fn serialize_tuple_struct_end(&mut self, _: ()) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_tuple_variant(&mut self, _: &'static str, _: usize, _: &'static str, _len: usize) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_tuple_variant_elt<T>(&mut self, _: &mut (), _value: T) -> Result<(), Error>
-        where T: Serialize
-    {
-        Err(Error)
-    }
-
-    fn serialize_tuple_variant_end(&mut self, _: ()) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_map(&mut self, _: Option<usize>) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_map_key<T>(&mut self, _: &mut (), _key: T) -> Result<(), Error>
-        where T: Serialize
-    {
-        Err(Error)
-    }
-
-    fn serialize_map_value<T>(&mut self, _: &mut (), _value: T) -> Result<(), Error>
-        where T: Serialize
-    {
-        Err(Error)
-    }
-
-    fn serialize_map_end(&mut self, _: ()) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_struct(&mut self, _: &'static str, _: usize) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_struct_elt<V>(&mut self, _: &mut (), _key: &'static str, _value: V) -> Result<(), Error>
-        where V: Serialize,
-    {
-        Err(Error)
-    }
-
-    fn serialize_struct_end(&mut self, _: ()) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_struct_variant(&mut self, _: &'static str, _: usize, _: &'static str, _: usize) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_struct_variant_elt<V>(&mut self, _: &mut (), _key: &'static str, _value: V) -> Result<(), Error>
-        where V: Serialize,
-    {
-        Err(Error)
-    }
-
-    fn serialize_struct_variant_end(&mut self, _: ()) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
-    fn serialize_bytes(&mut self, bytes: &[u8]) -> Result<(), Error> {
-        assert_eq!(self.bytes, bytes);
-        Ok(())
-    }
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-struct BytesDeserializer {
-    bytes: Option<Vec<u8>>,
-}
-
-impl BytesDeserializer {
-    fn new(bytes: Vec<u8>) -> Self {
-        BytesDeserializer {
-            bytes: Some(bytes),
-        }
-    }
-}
-
-impl Deserializer for BytesDeserializer {
-    type Error = Error;
-
-    fn deserialize<V>(&mut self, _visitor: V) -> Result<V::Value, Error>
-        where V: de::Visitor,
-    {
-        Err(Error)
-    }
-
-    fn deserialize_bytes<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
-        where V: de::Visitor,
-    {
-        visitor.visit_byte_buf(self.bytes.take().unwrap())
-    }
-
-    fn deserialize_seq<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_struct_field<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_map<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_unit<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_ignored_any<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_string<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_str<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_char<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_i64<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_i32<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_i16<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_i8<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_u64<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_u32<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_u16<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_u8<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_f32<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_f64<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_bool<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_usize<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_isize<__V>(&mut self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_option<__V>(&mut self, visitor: __V)
-     -> Result<__V::Value, Self::Error> where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_seq_fixed_size<__V>(&mut self, _: usize, visitor: __V)
-     -> Result<__V::Value, Self::Error> where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_unit_struct<__V>(&mut self, _: &str, visitor: __V)
-     -> Result<__V::Value, Self::Error> where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_newtype_struct<__V>(&mut self, _: &str, visitor: __V)
-     -> Result<__V::Value, Self::Error> where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_tuple_struct<__V>(&mut self, _: &str, _: usize, visitor: __V)
-     -> Result<__V::Value, Self::Error> where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_struct<__V>(&mut self, _: &str, _: &[&str], visitor: __V)
-     -> Result<__V::Value, Self::Error> where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_tuple<__V>(&mut self, _: usize, visitor: __V)
-     -> Result<__V::Value, Self::Error> where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_enum<__V>(&mut self, _: &str, _: &[&str], _visitor: __V)
-     -> Result<__V::Value, Self::Error> where __V: de::EnumVisitor {
-        Err(Error)
-    }
-}
-
-///////////////////////////////////////////////////////////////////////////////
+use serde_test::{assert_tokens, assert_ser_tokens, assert_de_tokens, Token};
 
 #[test]
-fn test_bytes_ser_bytes() {
-    let buf = vec![];
-    let bytes = Bytes::from(&buf);
-    let mut ser = BytesSerializer::new(vec![]);
-    bytes.serialize(&mut ser).unwrap();
+fn test_bytes() {
+    let empty = Bytes::new(&[]);
+    assert_ser_tokens(&empty, &[Token::Bytes(b"")]);
 
-    let buf = vec![1, 2, 3];
-    let bytes = Bytes::from(&buf);
-    let mut ser = BytesSerializer::new(vec![1, 2, 3]);
-    bytes.serialize(&mut ser).unwrap();
+    let buf = vec![65, 66, 67];
+    let bytes = Bytes::new(&buf);
+    assert_ser_tokens(&bytes, &[Token::Bytes(b"ABC")]);
 }
 
-///////////////////////////////////////////////////////////////////////////////
-
 #[test]
-fn test_byte_buf_de_bytes() {
-    let mut de = BytesDeserializer::new(vec![]);
-    let bytes = Deserialize::deserialize(&mut de);
-    assert_eq!(bytes, Ok(ByteBuf::new()));
+fn test_byte_buf() {
+    let empty = ByteBuf::new();
+    assert_tokens(&empty, &[Token::Bytes(b"")]);
+    assert_de_tokens(&empty, &[Token::ByteBuf(Vec::new())]);
+    assert_de_tokens(&empty, &[Token::Str("")]);
+    assert_de_tokens(&empty, &[Token::String(String::new())]);
+    assert_de_tokens(&empty, &[
+        Token::SeqStart(None),
+        Token::SeqEnd,
+    ]);
+    assert_de_tokens(&empty, &[
+        Token::SeqStart(Some(0)),
+        Token::SeqEnd,
+    ]);
 
-    let mut de = BytesDeserializer::new(vec![1, 2, 3]);
-    let bytes = Deserialize::deserialize(&mut de);
-    assert_eq!(bytes, Ok(ByteBuf::from(vec![1, 2, 3])));
+    let buf = ByteBuf::from(vec![65, 66, 67]);
+    assert_tokens(&buf, &[Token::Bytes(b"ABC")]);
+    assert_de_tokens(&buf, &[Token::ByteBuf(vec![65, 66, 67])]);
+    assert_de_tokens(&buf, &[Token::Str("ABC")]);
+    assert_de_tokens(&buf, &[Token::String("ABC".to_owned())]);
+    assert_de_tokens(&buf, &[
+        Token::SeqStart(None),
+        Token::SeqSep,
+        Token::U8(65),
+        Token::SeqSep,
+        Token::U8(66),
+        Token::SeqSep,
+        Token::U8(67),
+        Token::SeqEnd,
+    ]);
+    assert_de_tokens(&buf, &[
+        Token::SeqStart(Some(3)),
+        Token::SeqSep,
+        Token::U8(65),
+        Token::SeqSep,
+        Token::U8(66),
+        Token::SeqSep,
+        Token::U8(67),
+        Token::SeqEnd,
+    ]);
 }

testing/tests/test_de.rs

@@ -32,12 +32,41 @@ struct Struct {
     c: i32,
 }
 
+#[derive(PartialEq, Debug, Deserialize)]
+#[serde(deny_unknown_fields)]
+struct StructDenyUnknown {
+    a: i32,
+    #[serde(skip_deserializing)]
+    b: i32,
+}
+
+#[derive(PartialEq, Debug, Deserialize)]
+struct StructSkipAll {
+    #[serde(skip_deserializing)]
+    a: i32,
+}
+
+#[derive(PartialEq, Debug, Deserialize)]
+#[serde(deny_unknown_fields)]
+struct StructSkipAllDenyUnknown {
+    #[serde(skip_deserializing)]
+    a: i32,
+}
+
 #[derive(PartialEq, Debug, Deserialize)]
 enum Enum {
+    #[allow(dead_code)]
+    #[serde(skip_deserializing)]
+    Skipped,
     Unit,
     Simple(i32),
     Seq(i32, i32, i32),
     Map { a: i32, b: i32, c: i32 },
+}
+
+#[derive(PartialEq, Debug, Deserialize)]
+enum EnumSkipAll {
+    #[allow(dead_code)]
     #[serde(skip_deserializing)]
     Skipped,
 }
@@ -680,6 +709,29 @@ declare_tests! {
             Token::StructEnd,
         ],
     }
+    test_struct_skip_all {
+        StructSkipAll { a: 0 } => &[
+            Token::StructStart("StructSkipAll", 0),
+            Token::StructEnd,
+        ],
+        StructSkipAll { a: 0 } => &[
+            Token::StructStart("StructSkipAll", 1),
+                Token::StructSep,
+                Token::Str("a"),
+                Token::I32(1),
+
+                Token::StructSep,
+                Token::Str("b"),
+                Token::I32(2),
+            Token::StructEnd,
+        ],
+    }
+    test_struct_skip_all_deny_unknown {
+        StructSkipAllDenyUnknown { a: 0 } => &[
+            Token::StructStart("StructSkipAllDenyUnknown", 0),
+            Token::StructEnd,
+        ],
+    }
     test_enum_unit {
         Enum::Unit => &[
             Token::EnumUnit("Enum", "Unit"),
@@ -801,17 +853,51 @@ fn test_net_ipaddr() {
 }
 
 declare_error_tests! {
+    test_unknown_field<StructDenyUnknown> {
+        &[
+            Token::StructStart("StructDenyUnknown", 2),
+                Token::StructSep,
+                Token::Str("a"),
+                Token::I32(0),
+
+                Token::StructSep,
+                Token::Str("d"),
+        ],
+        Error::Message("unknown field `d`, expected `a`".to_owned()),
+    }
+    test_skipped_field_is_unknown<StructDenyUnknown> {
+        &[
+            Token::StructStart("StructDenyUnknown", 2),
+                Token::StructSep,
+                Token::Str("b"),
+        ],
+        Error::Message("unknown field `b`, expected `a`".to_owned()),
+    }
+    test_skip_all_deny_unknown<StructSkipAllDenyUnknown> {
+        &[
+            Token::StructStart("StructSkipAllDenyUnknown", 1),
+                Token::StructSep,
+                Token::Str("a"),
+        ],
+        Error::Message("unknown field `a`, there are no fields".to_owned()),
+    }
     test_unknown_variant<Enum> {
         &[
             Token::EnumUnit("Enum", "Foo"),
         ],
-        Error::UnknownVariant("Foo".to_owned()),
+        Error::Message("unknown variant `Foo`, expected one of `Unit`, `Simple`, `Seq`, `Map`".to_owned()),
     }
     test_enum_skipped_variant<Enum> {
         &[
             Token::EnumUnit("Enum", "Skipped"),
         ],
-        Error::UnknownVariant("Skipped".to_owned()),
+        Error::Message("unknown variant `Skipped`, expected one of `Unit`, `Simple`, `Seq`, `Map`".to_owned()),
+    }
+    test_enum_skip_all<EnumSkipAll> {
+        &[
+            Token::EnumUnit("EnumSkipAll", "Skipped"),
+        ],
+        Error::Message("unknown variant `Skipped`, there are no variants".to_owned()),
     }
     test_struct_seq_too_long<Struct> {
         &[
@@ -832,7 +918,7 @@ declare_error_tests! {
                 Token::MapSep,
                 Token::Str("a"),
         ],
-        Error::DuplicateField("a"),
+        Error::Message("duplicate field `a`".to_owned()),
     }
     test_duplicate_field_enum<Enum> {
         &[
@@ -844,6 +930,14 @@ declare_error_tests! {
                 Token::EnumMapSep,
                 Token::Str("a"),
         ],
-        Error::DuplicateField("a"),
+        Error::Message("duplicate field `a`".to_owned()),
+    }
+    test_enum_out_of_range<Enum> {
+        &[
+            Token::EnumStart("Enum"),
+            Token::Usize(4),
+            Token::Unit,
+        ],
+        Error::Message("invalid value: integer `4`, expected variant index 0 <= i < 4".into()),
     }
 }

testing/tests/test_gen.rs

@@ -202,6 +202,91 @@ fn test_gen() {
         EmptyStruct {},
     }
     assert::<EmptyEnumVariant>();
+
+    #[cfg(feature = "unstable-testing")]
+    #[cfg_attr(feature = "unstable-testing", derive(Serialize, Deserialize))]
+    struct NonAsciiIdents {
+        σ: f64
+    }
+
+    #[derive(Serialize, Deserialize)]
+    struct EmptyBraced {}
+
+    #[derive(Serialize, Deserialize)]
+    #[serde(deny_unknown_fields)]
+    struct EmptyBracedDenyUnknown {}
+
+    #[derive(Serialize, Deserialize)]
+    struct BracedSkipAll {
+        #[serde(skip_deserializing)]
+        f: u8,
+    }
+
+    #[derive(Serialize, Deserialize)]
+    #[serde(deny_unknown_fields)]
+    struct BracedSkipAllDenyUnknown {
+        #[serde(skip_deserializing)]
+        f: u8,
+    }
+
+    #[cfg(feature = "unstable-testing")]
+    #[cfg_attr(feature = "unstable-testing", derive(Serialize, Deserialize))]
+    struct EmptyTuple();
+
+    #[cfg(feature = "unstable-testing")]
+    #[cfg_attr(feature = "unstable-testing", derive(Serialize, Deserialize))]
+    #[serde(deny_unknown_fields)]
+    struct EmptyTupleDenyUnknown();
+
+    #[derive(Serialize, Deserialize)]
+    struct TupleSkipAll(#[serde(skip_deserializing)] u8);
+
+    #[derive(Serialize, Deserialize)]
+    #[serde(deny_unknown_fields)]
+    struct TupleSkipAllDenyUnknown(#[serde(skip_deserializing)] u8);
+
+    #[derive(Serialize, Deserialize)]
+    enum EmptyEnum {}
+
+    #[derive(Serialize, Deserialize)]
+    #[serde(deny_unknown_fields)]
+    enum EmptyEnumDenyUnknown {}
+
+    #[derive(Serialize, Deserialize)]
+    enum EnumSkipAll {
+        #[serde(skip_deserializing)]
+        #[allow(dead_code)]
+        Variant,
+    }
+
+    #[cfg(feature = "unstable-testing")]
+    #[cfg_attr(feature = "unstable-testing", derive(Serialize, Deserialize))]
+    enum EmptyVariants {
+        Braced {},
+        Tuple(),
+        BracedSkip {
+            #[serde(skip_deserializing)]
+            f: u8,
+        },
+        TupleSkip(#[serde(skip_deserializing)] u8),
+    }
+
+    #[cfg(feature = "unstable-testing")]
+    #[cfg_attr(feature = "unstable-testing", derive(Serialize, Deserialize))]
+    #[serde(deny_unknown_fields)]
+    enum EmptyVariantsDenyUnknown {
+        Braced {},
+        Tuple(),
+        BracedSkip {
+            #[serde(skip_deserializing)]
+            f: u8,
+        },
+        TupleSkip(#[serde(skip_deserializing)] u8),
+    }
+
+    #[derive(Serialize, Deserialize)]
+    #[serde(deny_unknown_fields)]
+    struct UnitDenyUnknown;
 }
 
 //////////////////////////////////////////////////////////////////////////
@@ -210,32 +295,32 @@ fn assert<T: Serialize + Deserialize>() {}
 fn assert_ser<T: Serialize>() {}
 
 trait SerializeWith {
-    fn serialize_with<S: Serializer>(_: &Self, _: &mut S) -> StdResult<(), S::Error>;
+    fn serialize_with<S: Serializer>(_: &Self, _: S) -> StdResult<S::Ok, S::Error>;
 }
 
 trait DeserializeWith: Sized {
-    fn deserialize_with<D: Deserializer>(_: &mut D) -> StdResult<Self, D::Error>;
+    fn deserialize_with<D: Deserializer>(_: D) -> StdResult<Self, D::Error>;
 }
 
 // Implements neither Serialize nor Deserialize
 struct X;
 
-fn ser_x<S: Serializer>(_: &X, _: &mut S) -> StdResult<(), S::Error> {
+fn ser_x<S: Serializer>(_: &X, _: S) -> StdResult<S::Ok, S::Error> {
     unimplemented!()
 }
 
-fn de_x<D: Deserializer>(_: &mut D) -> StdResult<X, D::Error> {
+fn de_x<D: Deserializer>(_: D) -> StdResult<X, D::Error> {
     unimplemented!()
 }
 
 impl SerializeWith for X {
-    fn serialize_with<S: Serializer>(_: &Self, _: &mut S) -> StdResult<(), S::Error> {
+    fn serialize_with<S: Serializer>(_: &Self, _: S) -> StdResult<S::Ok, S::Error> {
         unimplemented!()
     }
 }
 
 impl DeserializeWith for X {
-    fn deserialize_with<D: Deserializer>(_: &mut D) -> StdResult<Self, D::Error> {
+    fn deserialize_with<D: Deserializer>(_: D) -> StdResult<Self, D::Error> {
         unimplemented!()
     }
 }

testing/tests/test_ser.rs

@@ -15,6 +15,9 @@ use self::serde_test::{
 extern crate fnv;
 use self::fnv::FnvHasher;
 
+#[cfg(feature = "unstable")]
+use serde::ser::iterator;
+
 //////////////////////////////////////////////////////////////////////////
 
 #[derive(Serialize)]
@@ -30,12 +33,20 @@ struct Struct {
     c: i32,
 }
 
-#[derive(Serialize)]
+#[derive(Serialize, PartialEq, Debug)]
 enum Enum {
     Unit,
     One(i32),
     Seq(i32, i32),
     Map { a: i32, b: i32 },
+    #[serde(skip_serializing)]
+    SkippedUnit,
+    #[serde(skip_serializing)]
+    SkippedOne(i32),
+    #[serde(skip_serializing)]
+    SkippedSeq(i32, i32),
+    #[serde(skip_serializing)]
+    SkippedMap { _a: i32, _b: i32 },
 }
 
 //////////////////////////////////////////////////////////////////////////
@@ -361,6 +372,49 @@ declare_ser_tests! {
     }
 }
 
+
+#[cfg(feature = "unstable")]
+#[test]
+fn test_iterator() {
+    assert_ser_tokens(iterator([0; 0].iter()), &[
+        Token::SeqStart(Some(0)),
+        Token::SeqEnd,
+    ]);
+    assert_ser_tokens(iterator([1, 2, 3].iter()), &[
+        Token::SeqStart(Some(3)),
+            Token::SeqSep,
+            Token::I32(1),
+
+            Token::SeqSep,
+            Token::I32(2),
+
+            Token::SeqSep,
+            Token::I32(3),
+        Token::SeqEnd,
+    ]);
+    assert_ser_tokens(iterator([1, 2, 3].iter().map(|x| x * 2)), &[
+        Token::SeqStart(Some(3)),
+            Token::SeqSep,
+            Token::I32(2),
+
+            Token::SeqSep,
+            Token::I32(4),
+
+            Token::SeqSep,
+            Token::I32(6),
+        Token::SeqEnd,
+    ]);
+    assert_ser_tokens(iterator([1, 2, 3].iter().filter(|&x| x % 2 != 0)), &[
+        Token::SeqStart(None),
+            Token::SeqSep,
+            Token::I32(1),
+
+            Token::SeqSep,
+            Token::I32(3),
+        Token::SeqEnd,
+    ]);
+}
+
 #[cfg(feature = "unstable")]
 #[test]
 fn test_net_ipaddr() {
@@ -378,7 +432,7 @@ fn test_cannot_serialize_paths() {
     assert_ser_tokens_error(
         &Path::new(path),
         &[],
-        Error::InvalidValue("Path contains invalid UTF-8 characters".to_owned()));
+        Error::Message("Path contains invalid UTF-8 characters".to_owned()));
 
     let mut path_buf = PathBuf::new();
     path_buf.push(path);
@@ -386,5 +440,25 @@ fn test_cannot_serialize_paths() {
     assert_ser_tokens_error(
         &path_buf,
         &[],
-        Error::InvalidValue("Path contains invalid UTF-8 characters".to_owned()));
+        Error::Message("Path contains invalid UTF-8 characters".to_owned()));
+}
+
+#[test]
+fn test_enum_skipped() {
+    assert_ser_tokens_error(
+        &Enum::SkippedUnit,
+        &[],
+        Error::Message("the enum variant Enum::SkippedUnit cannot be serialized".to_owned()));
+    assert_ser_tokens_error(
+        &Enum::SkippedOne(42),
+        &[],
+        Error::Message("the enum variant Enum::SkippedOne cannot be serialized".to_owned()));
+    assert_ser_tokens_error(
+        &Enum::SkippedSeq(1, 2),
+        &[],
+        Error::Message("the enum variant Enum::SkippedSeq cannot be serialized".to_owned()));
+    assert_ser_tokens_error(
+        &Enum::SkippedMap { _a: 1, _b: 2 },
+        &[],
+        Error::Message("the enum variant Enum::SkippedMap cannot be serialized".to_owned()));
 }