Release 0.9.6

Untagged and internally tagged enums

.travis.yml

@@ -1,27 +1,17 @@
 sudo: false
 language: rust
+cache: cargo
+
+# run builds for all the trains (and more)
 rust:
-- 1.12.0
+  - 1.13.0
-- 1.13.0
+  - stable
-- stable
+  - beta
-- beta
+  - nightly
-- nightly
+
-before_script:
+matrix:
-- pip install 'travis-cargo<0.2' --user
+  include:
-- export PATH=$HOME/.local/bin:$PATH
+    - rust: nightly
-script:
+      env: CLIPPY=true
-- (cd serde && travis-cargo build)
+
-- (cd serde && travis-cargo --skip nightly test)
+script: ./travis.sh
-- (cd serde && travis-cargo --only nightly test -- --features unstable-testing)
-- (cd serde && travis-cargo build -- --no-default-features)
-- (cd serde && travis-cargo --only nightly build -- --no-default-features --features alloc)
-- (cd serde && travis-cargo --only nightly build -- --no-default-features --features collections)
-- (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 && travis-cargo --only stable doc)
-env:
-  global:
-  - TRAVIS_CARGO_NIGHTLY_FEATURE=""

Cargo.toml

@@ -0,0 +1,9 @@
+[workspace]
+members = [
+    "serde",
+    "serde_codegen_internals",
+    "serde_derive",
+    "serde_test",
+    "test_suite",
+    "test_suite/no_std",
+]

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.
-

examples/serde-syntex-example/.gitignore

@@ -1,2 +0,0 @@
-target
-Cargo.lock

examples/serde-syntex-example/Cargo.toml

@@ -1,18 +0,0 @@
-[package]
-name = "serde-syntex-example"
-version = "0.1.0"
-authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
-build = "build.rs"
-publish = false
-
-[features]
-default = ["serde_codegen"]
-unstable = ["serde_derive"]
-
-[build-dependencies]
-serde_codegen = { version = "^0.8", optional = true, path = "../../serde_codegen" }
-
-[dependencies]
-serde = "^0.8"
-serde_derive = { version = "^0.8", optional = true, path = "../../serde_derive" }
-serde_json = "^0.8"

examples/serde-syntex-example/README.md

@@ -1,20 +0,0 @@
-This example demonstrates how to use Serde with Syntex. On stable or nightly
-with Syntex, it can be built with:
-
-```
-% rustup run stable cargo run
-     Running `target/debug/serde-syntex-example`
-{"x":1,"y":2}
-Point { x: 1, y: 2 }
-
-% rustup run nightly cargo run
-     Running `target/debug/serde-syntex-example`
-{"x":1,"y":2}
-Point { x: 1, y: 2 }
-```
-
-On nightly, it can use a plugin with:
-
-```
-% rustup run nightly cargo run --features unstable --no-default-features
-```

examples/serde-syntex-example/build.rs

@@ -1,25 +0,0 @@
-#[cfg(not(feature = "serde_derive"))]
-mod inner {
-    extern crate serde_codegen;
-
-    use std::env;
-    use std::path::Path;
-
-    pub fn main() {
-        let out_dir = env::var_os("OUT_DIR").unwrap();
-
-        let src = Path::new("src/main.rs.in");
-        let dst = Path::new(&out_dir).join("main.rs");
-
-        serde_codegen::expand(&src, &dst).unwrap();
-    }
-}
-
-#[cfg(feature = "serde_derive")]
-mod inner {
-    pub fn main() {}
-}
-
-fn main() {
-    inner::main();
-}

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

@@ -1,12 +0,0 @@
-#[cfg(feature = "serde_derive")]
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
-extern crate serde_json;
-
-#[cfg(feature = "serde_derive")]
-include!("main.rs.in");
-
-#[cfg(not(feature = "serde_derive"))]
-include!(concat!(env!("OUT_DIR"), "/main.rs"));

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

@@ -1,16 +0,0 @@
-#[derive(Serialize, Deserialize, Debug)]
-struct Point {
-    x: i32,
-    y: i32,
-}
-
-fn main() {
-    let point = Point { x: 1, y: 2 };
-    let serialized = serde_json::to_string(&point).unwrap();
-
-    println!("{}", serialized);
-
-    let deserialized: Point = serde_json::from_str(&serialized).unwrap();
-
-    println!("{:?}", deserialized);
-}

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "0.9.0-rc1"
+version = "0.9.6"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"
@@ -9,8 +9,12 @@ 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"]
 
+[badges]
+travis-ci = { repository = "serde-rs/serde" }
+
 [features]
 default = ["std"]
 
@@ -18,7 +22,7 @@ std = []
 unstable = []
 alloc = ["unstable"]
 collections = ["alloc"]
-unstable-testing = ["clippy", "unstable", "std"]
+unstable-testing = ["unstable", "std"]
 
-[dependencies]
+[dev-dependencies]
-clippy = { version = "^0.*", optional = true }
+serde_derive = "0.9"

serde/src/bytes.rs

@@ -1,4 +1,20 @@
-//! Helper module to enable serializing bytes more efficiently
+//! Wrapper types to enable optimized handling of `&[u8]` and `Vec<u8>`.
+//!
+//! Without specialization, Rust forces us to treat `&[u8]` just like any other
+//! slice and `Vec<u8>` just like any other vector. In reality this particular
+//! slice and vector can often be serialized and deserialized in a more
+//! efficient, compact representation in many formats.
+//!
+//! When working with such a format, you can opt into specialized handling of
+//! `&[u8]` by wrapping it in `bytes::Bytes` and `Vec<u8>` by wrapping it in
+//! `bytes::ByteBuf`.
+//!
+//! Rust support for specialization is being tracked in
+//! [rust-lang/rust#31844][specialization]. Once it lands in the stable compiler
+//! we will be deprecating these wrapper types in favor of optimizing `&[u8]`
+//! and `Vec<u8>` out of the box.
+//!
+//! [specialization]: https://github.com/rust-lang/rust/issues/31844
 
 use core::{ops, fmt, char, iter, slice};
 use core::fmt::Write;
@@ -6,14 +22,36 @@ use core::fmt::Write;
 use ser;
 
 #[cfg(any(feature = "std", feature = "collections"))]
-pub use self::bytebuf::{ByteBuf, ByteBufVisitor};
+pub use self::bytebuf::ByteBuf;
+
+#[cfg(any(feature = "std", feature = "collections"))]
+#[doc(hidden)] // does anybody need this?
+pub use self::bytebuf::ByteBufVisitor;
 
 #[cfg(feature = "collections")]
 use collections::Vec;
 
 ///////////////////////////////////////////////////////////////////////////////
 
-/// `Bytes` wraps a `&[u8]` in order to serialize into a byte array.
+/// Wraps a `&[u8]` in order to serialize in an efficient way. Does not support
+/// deserialization.
+///
+/// ```rust
+/// # #[macro_use] extern crate serde_derive;
+/// # extern crate serde;
+/// # use std::net::IpAddr;
+/// #
+/// use serde::bytes::Bytes;
+///
+/// # #[allow(dead_code)]
+/// #[derive(Serialize)]
+/// struct Packet<'a> {
+///     destination: IpAddr,
+///     payload: Bytes<'a>,
+/// }
+/// #
+/// # fn main() {}
+/// ```
 #[derive(Clone, Copy, Eq, Hash, PartialEq, PartialOrd, Ord)]
 pub struct Bytes<'a> {
     bytes: &'a [u8],
@@ -86,7 +124,25 @@ mod bytebuf {
     #[cfg(feature = "collections")]
     use collections::{String, Vec};
 
-    /// `ByteBuf` wraps a `Vec<u8>` and serializes as a byte array.
+    /// Wraps a `Vec<u8>` in order to serialize and deserialize in an efficient
+    /// way.
+    ///
+    /// ```rust
+    /// # #[macro_use] extern crate serde_derive;
+    /// # extern crate serde;
+    /// # use std::net::IpAddr;
+    /// #
+    /// use serde::bytes::ByteBuf;
+    ///
+    /// # #[allow(dead_code)]
+    /// #[derive(Serialize, Deserialize)]
+    /// struct Packet {
+    ///     destination: IpAddr,
+    ///     payload: ByteBuf,
+    /// }
+    /// #
+    /// # fn main() {}
+    /// ```
     #[derive(Clone, Default, Eq, Hash, PartialEq, PartialOrd, Ord)]
     pub struct ByteBuf {
         bytes: Vec<u8>,
@@ -181,6 +237,10 @@ 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>(self) -> Result<ByteBuf, E>
             where E: de::Error,
@@ -234,7 +294,7 @@ mod bytebuf {
         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/content.rs

@@ -0,0 +1,743 @@
+// This module is doc(hidden) and nothing here should be used outside of
+// generated code.
+//
+// We will iterate on the implementation for a few releases and only have to
+// worry about backward compatibility for the `untagged` and `tag` attributes
+// rather than for this entire mechanism.
+//
+// This issue is tracking making some of this stuff public:
+// https://github.com/serde-rs/serde/issues/741
+
+#![doc(hidden)]
+
+use core::fmt;
+use core::marker::PhantomData;
+
+#[cfg(all(not(feature = "std"), feature = "collections"))]
+use collections::{String, Vec};
+
+#[cfg(all(feature = "alloc", not(feature = "std")))]
+use alloc::boxed::Box;
+
+use de::{
+    self,
+    Deserialize,
+    DeserializeSeed,
+    Deserializer,
+    Visitor,
+    SeqVisitor,
+    MapVisitor,
+    EnumVisitor,
+};
+
+/// Used from generated code to buffer the contents of the Deserializer when
+/// deserializing untagged enums and internally tagged enums.
+///
+/// Not public API. Use serde-value instead.
+#[derive(Debug)]
+pub enum Content<E> {
+    // Don't mind the PhantomData, just need to use E somewhere.
+    Bool(bool, PhantomData<E>),
+
+    U8(u8),
+    U16(u16),
+    U32(u32),
+    U64(u64),
+
+    I8(i8),
+    I16(i16),
+    I32(i32),
+    I64(i64),
+
+    F32(f32),
+    F64(f64),
+
+    Char(char),
+    String(String),
+    Bytes(Vec<u8>),
+
+    None,
+    Some(Box<Content<E>>),
+
+    Unit,
+    Newtype(Box<Content<E>>),
+    Seq(Vec<Content<E>>),
+    Map(Vec<(Content<E>, Content<E>)>),
+}
+
+impl<E> Deserialize for Content<E> {
+    fn deserialize<D: Deserializer>(deserializer: D) -> Result<Self, D::Error> {
+        // Untagged and internally tagged enums are only supported in
+        // self-describing formats.
+        deserializer.deserialize(ContentVisitor::new())
+    }
+}
+
+struct ContentVisitor<E> {
+    err: PhantomData<E>,
+}
+
+impl<E> ContentVisitor<E> {
+    fn new() -> Self {
+        ContentVisitor {
+            err: PhantomData,
+        }
+    }
+}
+
+impl<E> Visitor for ContentVisitor<E> {
+    type Value = Content<E>;
+
+    fn expecting(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.write_str("any value")
+    }
+
+    fn visit_bool<F>(self, value: bool) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::Bool(value, PhantomData))
+    }
+
+    fn visit_i8<F>(self, value: i8) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::I8(value))
+    }
+
+    fn visit_i16<F>(self, value: i16) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::I16(value))
+    }
+
+    fn visit_i32<F>(self, value: i32) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::I32(value))
+    }
+
+    fn visit_i64<F>(self, value: i64) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::I64(value))
+    }
+
+    fn visit_u8<F>(self, value: u8) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::U8(value))
+    }
+
+    fn visit_u16<F>(self, value: u16) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::U16(value))
+    }
+
+    fn visit_u32<F>(self, value: u32) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::U32(value))
+    }
+
+    fn visit_u64<F>(self, value: u64) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::U64(value))
+    }
+
+    fn visit_f32<F>(self, value: f32) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::F32(value))
+    }
+
+    fn visit_f64<F>(self, value: f64) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::F64(value))
+    }
+
+    fn visit_char<F>(self, value: char) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::Char(value))
+    }
+
+    fn visit_str<F>(self, value: &str) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::String(value.into()))
+    }
+
+    fn visit_string<F>(self, value: String) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::String(value))
+    }
+
+    fn visit_bytes<F>(self, value: &[u8]) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::Bytes(value.into()))
+    }
+
+    fn visit_byte_buf<F>(self, value: Vec<u8>) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::Bytes(value))
+    }
+
+    fn visit_unit<F>(self) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::Unit)
+    }
+
+    fn visit_none<F>(self) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        Ok(Content::None)
+    }
+
+    fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+        where D: Deserializer
+    {
+        Deserialize::deserialize(deserializer).map(|v| Content::Some(Box::new(v)))
+    }
+
+    fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+        where D: Deserializer
+    {
+        Deserialize::deserialize(deserializer).map(|v| Content::Newtype(Box::new(v)))
+    }
+
+    fn visit_seq<V>(self, mut visitor: V) -> Result<Self::Value, V::Error>
+        where V: SeqVisitor
+    {
+        let mut vec = Vec::with_capacity(visitor.size_hint().0);
+        while let Some(e) = try!(visitor.visit()) {
+            vec.push(e);
+        }
+        Ok(Content::Seq(vec))
+    }
+
+    fn visit_map<V>(self, mut visitor: V) -> Result<Self::Value, V::Error>
+        where V: MapVisitor
+    {
+        let mut vec = Vec::with_capacity(visitor.size_hint().0);
+        while let Some(kv) = try!(visitor.visit()) {
+            vec.push(kv);
+        }
+        Ok(Content::Map(vec))
+    }
+
+    fn visit_enum<V>(self, _visitor: V) -> Result<Self::Value, V::Error>
+        where V: EnumVisitor
+    {
+        Err(de::Error::custom("untagged and internally tagged enums do not support enum input"))
+    }
+}
+
+/// This is the type of the map keys in an internally tagged enum.
+///
+/// Not public API.
+pub enum TagOrContent<E> {
+    Tag,
+    Content(Content<E>),
+}
+
+struct TagOrContentVisitor<E> {
+    name: &'static str,
+    err: PhantomData<E>,
+}
+
+impl<E> TagOrContentVisitor<E> {
+    fn new(name: &'static str) -> Self {
+        TagOrContentVisitor {
+            name: name,
+            err: PhantomData,
+        }
+    }
+}
+
+impl<E> DeserializeSeed for TagOrContentVisitor<E> {
+    type Value = TagOrContent<E>;
+
+    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+        where D: Deserializer
+    {
+        // Internally tagged enums are only supported in self-describing
+        // formats.
+        deserializer.deserialize(self)
+    }
+}
+
+impl<E> Visitor for TagOrContentVisitor<E> {
+    type Value = TagOrContent<E>;
+
+    fn expecting(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "a type tag `{}` or any other value", self.name)
+    }
+
+    fn visit_bool<F>(self, value: bool) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_bool(value).map(TagOrContent::Content)
+    }
+
+    fn visit_i8<F>(self, value: i8) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_i8(value).map(TagOrContent::Content)
+    }
+
+    fn visit_i16<F>(self, value: i16) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_i16(value).map(TagOrContent::Content)
+    }
+
+    fn visit_i32<F>(self, value: i32) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_i32(value).map(TagOrContent::Content)
+    }
+
+    fn visit_i64<F>(self, value: i64) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_i64(value).map(TagOrContent::Content)
+    }
+
+    fn visit_u8<F>(self, value: u8) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_u8(value).map(TagOrContent::Content)
+    }
+
+    fn visit_u16<F>(self, value: u16) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_u16(value).map(TagOrContent::Content)
+    }
+
+    fn visit_u32<F>(self, value: u32) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_u32(value).map(TagOrContent::Content)
+    }
+
+    fn visit_u64<F>(self, value: u64) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_u64(value).map(TagOrContent::Content)
+    }
+
+    fn visit_f32<F>(self, value: f32) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_f32(value).map(TagOrContent::Content)
+    }
+
+    fn visit_f64<F>(self, value: f64) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_f64(value).map(TagOrContent::Content)
+    }
+
+    fn visit_char<F>(self, value: char) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_char(value).map(TagOrContent::Content)
+    }
+
+    fn visit_str<F>(self, value: &str) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        if value == self.name {
+            Ok(TagOrContent::Tag)
+        } else {
+            ContentVisitor::new().visit_str(value).map(TagOrContent::Content)
+        }
+    }
+
+    fn visit_string<F>(self, value: String) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        if value == self.name {
+            Ok(TagOrContent::Tag)
+        } else {
+            ContentVisitor::new().visit_string(value).map(TagOrContent::Content)
+        }
+    }
+
+    fn visit_bytes<F>(self, value: &[u8]) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        if value == self.name.as_bytes() {
+            Ok(TagOrContent::Tag)
+        } else {
+            ContentVisitor::new().visit_bytes(value).map(TagOrContent::Content)
+        }
+    }
+
+    fn visit_byte_buf<F>(self, value: Vec<u8>) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        if value == self.name.as_bytes() {
+            Ok(TagOrContent::Tag)
+        } else {
+            ContentVisitor::new().visit_byte_buf(value).map(TagOrContent::Content)
+        }
+    }
+
+    fn visit_unit<F>(self) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_unit().map(TagOrContent::Content)
+    }
+
+    fn visit_none<F>(self) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor::new().visit_none().map(TagOrContent::Content)
+    }
+
+    fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+        where D: Deserializer
+    {
+        ContentVisitor::new().visit_some(deserializer).map(TagOrContent::Content)
+    }
+
+    fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+        where D: Deserializer
+    {
+        ContentVisitor::new().visit_newtype_struct(deserializer).map(TagOrContent::Content)
+    }
+
+    fn visit_seq<V>(self, visitor: V) -> Result<Self::Value, V::Error>
+        where V: SeqVisitor
+    {
+        ContentVisitor::new().visit_seq(visitor).map(TagOrContent::Content)
+    }
+
+    fn visit_map<V>(self, visitor: V) -> Result<Self::Value, V::Error>
+        where V: MapVisitor
+    {
+        ContentVisitor::new().visit_map(visitor).map(TagOrContent::Content)
+    }
+
+    fn visit_enum<V>(self, visitor: V) -> Result<Self::Value, V::Error>
+        where V: EnumVisitor
+    {
+        ContentVisitor::new().visit_enum(visitor).map(TagOrContent::Content)
+    }
+}
+
+/// Used by generated code to deserialize an internally tagged enum.
+///
+/// Not public API.
+pub struct TaggedContent<T, E> {
+    pub tag: T,
+    pub content: Content<E>,
+}
+
+/// Not public API.
+pub struct TaggedContentVisitor<T, E> {
+    tag_name: &'static str,
+    tag: PhantomData<T>,
+    err: PhantomData<E>,
+}
+
+impl<T, E> TaggedContentVisitor<T, E> {
+    /// Visitor for the content of an internally tagged enum with the given tag
+    /// name.
+    pub fn new(name: &'static str) -> Self {
+        TaggedContentVisitor {
+            tag_name: name,
+            tag: PhantomData,
+            err: PhantomData,
+        }
+    }
+}
+
+impl<T, E> DeserializeSeed for TaggedContentVisitor<T, E>
+    where T: Deserialize
+{
+    type Value = TaggedContent<T, E>;
+
+    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+        where D: Deserializer
+    {
+        // Internally tagged enums are only supported in self-describing
+        // formats.
+        deserializer.deserialize(self)
+    }
+}
+
+impl<T, E> Visitor for TaggedContentVisitor<T, E>
+    where T: Deserialize
+{
+    type Value = TaggedContent<T, E>;
+
+    fn expecting(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.write_str("any value")
+    }
+
+    fn visit_map<V>(self, mut visitor: V) -> Result<Self::Value, V::Error>
+        where V: MapVisitor
+    {
+        let mut tag = None;
+        let mut vec = Vec::with_capacity(visitor.size_hint().0);
+        while let Some(k) = try!(visitor.visit_key_seed(TagOrContentVisitor::new(self.tag_name))) {
+            match k {
+                TagOrContent::Tag => {
+                    if tag.is_some() {
+                        return Err(de::Error::duplicate_field(self.tag_name));
+                    }
+                    tag = Some(try!(visitor.visit_value()));
+                }
+                TagOrContent::Content(k) => {
+                    let v = try!(visitor.visit_value());
+                    vec.push((k, v));
+                }
+            }
+        }
+        match tag {
+            None => {
+                Err(de::Error::missing_field(self.tag_name))
+            }
+            Some(tag) => {
+                Ok(TaggedContent {
+                    tag: tag,
+                    content: Content::Map(vec),
+                })
+            }
+        }
+    }
+}
+
+/// Used when deserializing an internally tagged enum because the content will
+/// be used exactly once.
+impl<E> Deserializer for Content<E>
+    where E: de::Error
+{
+    type Error = E;
+
+    fn deserialize<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor
+    {
+        match self {
+            Content::Bool(v, _) => visitor.visit_bool(v),
+            Content::U8(v) => visitor.visit_u8(v),
+            Content::U16(v) => visitor.visit_u16(v),
+            Content::U32(v) => visitor.visit_u32(v),
+            Content::U64(v) => visitor.visit_u64(v),
+            Content::I8(v) => visitor.visit_i8(v),
+            Content::I16(v) => visitor.visit_i16(v),
+            Content::I32(v) => visitor.visit_i32(v),
+            Content::I64(v) => visitor.visit_i64(v),
+            Content::F32(v) => visitor.visit_f32(v),
+            Content::F64(v) => visitor.visit_f64(v),
+            Content::Char(v) => visitor.visit_char(v),
+            Content::String(v) => visitor.visit_string(v),
+            Content::Unit => visitor.visit_unit(),
+            Content::None => visitor.visit_none(),
+            Content::Some(v) => visitor.visit_some(*v),
+            Content::Newtype(v) => visitor.visit_newtype_struct(*v),
+            Content::Seq(v) => {
+                let seq = v.into_iter();
+                let mut seq_visitor = de::value::SeqDeserializer::new(seq);
+                let value = try!(visitor.visit_seq(&mut seq_visitor));
+                try!(seq_visitor.end());
+                Ok(value)
+            },
+            Content::Map(v) => {
+                let map = v.into_iter();
+                let mut map_visitor = de::value::MapDeserializer::new(map);
+                let value = try!(visitor.visit_map(&mut map_visitor));
+                try!(map_visitor.end());
+                Ok(value)
+            },
+            Content::Bytes(v) => visitor.visit_byte_buf(v),
+        }
+    }
+
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor
+    {
+        match self {
+            Content::None => visitor.visit_none(),
+            Content::Some(v) => visitor.visit_some(*v),
+            Content::Unit => visitor.visit_unit(),
+            _ => visitor.visit_some(self)
+        }
+    }
+
+    fn deserialize_newtype_struct<V>(self, _name: &str, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor
+    {
+        visitor.visit_newtype_struct(self)
+    }
+
+    forward_to_deserialize! {
+        bool u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string unit seq
+        seq_fixed_size bytes byte_buf map unit_struct tuple_struct struct
+        struct_field tuple enum ignored_any
+    }
+}
+
+impl<E> de::value::ValueDeserializer<E> for Content<E>
+    where E: de::Error
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
+/// Used when deserializing an untagged enum because the content may need to be
+/// used more than once.
+impl<'a, E> Deserializer for &'a Content<E>
+    where E: de::Error
+{
+    type Error = E;
+
+    fn deserialize<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor
+    {
+        match *self {
+            Content::Bool(v, _) => visitor.visit_bool(v),
+            Content::U8(v) => visitor.visit_u8(v),
+            Content::U16(v) => visitor.visit_u16(v),
+            Content::U32(v) => visitor.visit_u32(v),
+            Content::U64(v) => visitor.visit_u64(v),
+            Content::I8(v) => visitor.visit_i8(v),
+            Content::I16(v) => visitor.visit_i16(v),
+            Content::I32(v) => visitor.visit_i32(v),
+            Content::I64(v) => visitor.visit_i64(v),
+            Content::F32(v) => visitor.visit_f32(v),
+            Content::F64(v) => visitor.visit_f64(v),
+            Content::Char(v) => visitor.visit_char(v),
+            Content::String(ref v) => visitor.visit_str(v),
+            Content::Unit => visitor.visit_unit(),
+            Content::None => visitor.visit_none(),
+            Content::Some(ref v) => visitor.visit_some(&**v),
+            Content::Newtype(ref v) => visitor.visit_newtype_struct(&**v),
+            Content::Seq(ref v) => {
+                let seq = v.into_iter();
+                let mut seq_visitor = de::value::SeqDeserializer::new(seq);
+                let value = try!(visitor.visit_seq(&mut seq_visitor));
+                try!(seq_visitor.end());
+                Ok(value)
+            },
+            Content::Map(ref v) => {
+                let map = v.into_iter().map(|&(ref k, ref v)| (k, v));
+                let mut map_visitor = de::value::MapDeserializer::new(map);
+                let value = try!(visitor.visit_map(&mut map_visitor));
+                try!(map_visitor.end());
+                Ok(value)
+            },
+            Content::Bytes(ref v) => visitor.visit_bytes(v),
+        }
+    }
+
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor
+    {
+        match *self {
+            Content::None => visitor.visit_none(),
+            Content::Some(ref v) => visitor.visit_some(&**v),
+            Content::Unit => visitor.visit_unit(),
+            _ => visitor.visit_some(self)
+        }
+    }
+
+    fn deserialize_newtype_struct<V>(self, _name: &str, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor
+    {
+        visitor.visit_newtype_struct(self)
+    }
+
+    forward_to_deserialize! {
+        bool u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string unit seq
+        seq_fixed_size bytes byte_buf map unit_struct tuple_struct struct
+        struct_field tuple enum ignored_any
+    }
+}
+
+impl<'a, E> de::value::ValueDeserializer<E> for &'a Content<E>
+    where E: de::Error
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
+/// Visitor for deserializing an internally tagged unit variant.
+///
+/// Not public API.
+pub struct InternallyTaggedUnitVisitor<'a> {
+    type_name: &'a str,
+    variant_name: &'a str,
+}
+
+impl<'a> InternallyTaggedUnitVisitor<'a> {
+    /// Not public API.
+    pub fn new(type_name: &'a str, variant_name: &'a str) -> Self {
+        InternallyTaggedUnitVisitor {
+            type_name: type_name,
+            variant_name: variant_name,
+        }
+    }
+}
+
+impl<'a> Visitor for InternallyTaggedUnitVisitor<'a> {
+    type Value = ();
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "unit variant {}::{}", self.type_name, self.variant_name)
+    }
+
+    fn visit_map<V>(self, _: V) -> Result<(), V::Error>
+        where V: MapVisitor
+    {
+        Ok(())
+    }
+}
+
+/// Visitor for deserializing an untagged unit variant.
+///
+/// Not public API.
+pub struct UntaggedUnitVisitor<'a> {
+    type_name: &'a str,
+    variant_name: &'a str,
+}
+
+impl<'a> UntaggedUnitVisitor<'a> {
+    /// Not public API.
+    pub fn new(type_name: &'a str, variant_name: &'a str) -> Self {
+        UntaggedUnitVisitor {
+            type_name: type_name,
+            variant_name: variant_name,
+        }
+    }
+}
+
+impl<'a> Visitor for UntaggedUnitVisitor<'a> {
+    type Value = ();
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "unit variant {}::{}", self.type_name, self.variant_name)
+    }
+
+    fn visit_unit<E>(self) -> Result<(), E>
+        where E: de::Error
+    {
+        Ok(())
+    }
+}

serde/src/de/impls.rs

@@ -2,7 +2,7 @@
 
 #[cfg(feature = "std")]
 use std::borrow::Cow;
-#[cfg(all(feature = "unstable", feature = "collections", not(feature = "std")))]
+#[cfg(all(feature = "collections", not(feature = "std")))]
 use collections::borrow::Cow;
 
 #[cfg(all(feature = "collections", not(feature = "std")))]
@@ -27,11 +27,11 @@ use std::collections::{
     VecDeque,
 };
 
-#[cfg(all(feature = "unstable", feature = "collections"))]
+#[cfg(feature = "collections")]
-use collections::enum_set::{CLike, EnumSet};
-#[cfg(all(feature = "unstable", feature = "collections"))]
 use collections::borrow::ToOwned;
 
+use core::fmt;
+#[cfg(feature = "std")]
 use core::hash::{Hash, BuildHasher};
 use core::marker::PhantomData;
 #[cfg(feature = "std")]
@@ -42,15 +42,15 @@ use core::str;
 
 #[cfg(feature = "std")]
 use std::rc::Rc;
-#[cfg(all(feature = "unstable", feature = "alloc", not(feature = "std")))]
+#[cfg(all(feature = "alloc", not(feature = "std")))]
 use alloc::rc::Rc;
 
 #[cfg(feature = "std")]
 use std::sync::Arc;
-#[cfg(all(feature = "unstable", feature = "alloc", not(feature = "std")))]
+#[cfg(all(feature = "alloc", not(feature = "std")))]
 use alloc::arc::Arc;
 
-#[cfg(all(feature = "unstable", feature = "alloc", not(feature = "std")))]
+#[cfg(all(feature = "alloc", not(feature = "std")))]
 use alloc::boxed::Box;
 
 #[cfg(feature = "std")]
@@ -60,6 +60,7 @@ use std::time::Duration;
 use core::nonzero::{NonZero, Zeroable};
 
 #[cfg(feature = "unstable")]
+#[allow(deprecated)] // required for impl Deserialize for NonZero<T>
 use core::num::Zero;
 
 use de::{
@@ -69,7 +70,7 @@ use de::{
     Error,
     MapVisitor,
     SeqVisitor,
-    Type,
+    Unexpected,
     VariantVisitor,
     Visitor,
 };
@@ -83,6 +84,10 @@ pub struct UnitVisitor;
 impl Visitor for UnitVisitor {
     type Value = ();
 
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("unit")
+    }
+
     fn visit_unit<E>(self) -> Result<(), E>
         where E: Error,
     {
@@ -112,6 +117,10 @@ pub struct BoolVisitor;
 impl Visitor for BoolVisitor {
     type Value = bool;
 
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("a boolean")
+    }
+
     fn visit_bool<E>(self, v: bool) -> Result<bool, E>
         where E: Error,
     {
@@ -124,7 +133,7 @@ impl Visitor for BoolVisitor {
         match s.trim_matches(::utils::Pattern_White_Space) {
             "true" => Ok(true),
             "false" => Ok(false),
-            _ => Err(Error::invalid_type(Type::Bool)),
+            _ => Err(Error::invalid_type(Unexpected::Str(s), &self)),
         }
     }
 }
@@ -140,81 +149,68 @@ impl Deserialize for bool {
 ///////////////////////////////////////////////////////////////////////////////
 
 macro_rules! impl_deserialize_num_method {
-    ($src_ty:ty, $method:ident, $from_method:ident, $ty:expr) => {
+    ($ty:ident, $src_ty:ident, $method:ident, $from_method:ident, $group:ident, $group_ty:ident) => {
         #[inline]
-        fn $method<E>(self, v: $src_ty) -> Result<T, E>
+        fn $method<E>(self, v: $src_ty) -> Result<$ty, E>
             where E: Error,
         {
             match FromPrimitive::$from_method(v) {
                 Some(v) => Ok(v),
-                None => Err(Error::invalid_type($ty)),
+                None => Err(Error::invalid_value(Unexpected::$group(v as $group_ty), &self)),
             }
         }
     }
 }
 
-/// A visitor that produces a primitive type.
-struct PrimitiveVisitor<T> {
-    marker: PhantomData<T>,
-}
-
-impl<T> PrimitiveVisitor<T> {
-    /// Construct a new `PrimitiveVisitor`.
-    #[inline]
-    fn new() -> Self {
-        PrimitiveVisitor {
-            marker: PhantomData,
-        }
-    }
-}
-
-impl<T> Visitor for PrimitiveVisitor<T>
-    where T: Deserialize + FromPrimitive + str::FromStr
-{
-    type Value = T;
-
-    impl_deserialize_num_method!(isize, visit_isize, from_isize, Type::Isize);
-    impl_deserialize_num_method!(i8, visit_i8, from_i8, Type::I8);
-    impl_deserialize_num_method!(i16, visit_i16, from_i16, Type::I16);
-    impl_deserialize_num_method!(i32, visit_i32, from_i32, Type::I32);
-    impl_deserialize_num_method!(i64, visit_i64, from_i64, Type::I64);
-    impl_deserialize_num_method!(usize, visit_usize, from_usize, Type::Usize);
-    impl_deserialize_num_method!(u8, visit_u8, from_u8, Type::U8);
-    impl_deserialize_num_method!(u16, visit_u16, from_u16, Type::U16);
-    impl_deserialize_num_method!(u32, visit_u32, from_u32, Type::U32);
-    impl_deserialize_num_method!(u64, visit_u64, from_u64, Type::U64);
-    impl_deserialize_num_method!(f32, visit_f32, from_f32, Type::F32);
-    impl_deserialize_num_method!(f64, visit_f64, from_f64, Type::F64);
-
-    #[inline]
-    fn visit_str<E>(self, s: &str) -> Result<T, E>
-        where E: Error,
-    {
-        str::FromStr::from_str(s.trim_matches(::utils::Pattern_White_Space)).or_else(|_| {
-            Err(Error::invalid_type(Type::Str))
-        })
-    }
-}
-
 macro_rules! impl_deserialize_num {
-    ($ty:ty, $method:ident) => {
+    ($ty:ident, $method:ident) => {
         impl Deserialize for $ty {
             #[inline]
             fn deserialize<D>(deserializer: D) -> Result<$ty, D::Error>
                 where D: Deserializer,
             {
-                deserializer.$method(PrimitiveVisitor::new())
+                struct PrimitiveVisitor;
+
+                impl Visitor for PrimitiveVisitor {
+                    type Value = $ty;
+
+                    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                        formatter.write_str(stringify!($ty))
+                    }
+
+                    impl_deserialize_num_method!($ty, i8, visit_i8, from_i8, Signed, i64);
+                    impl_deserialize_num_method!($ty, i16, visit_i16, from_i16, Signed, i64);
+                    impl_deserialize_num_method!($ty, i32, visit_i32, from_i32, Signed, i64);
+                    impl_deserialize_num_method!($ty, i64, visit_i64, from_i64, Signed, i64);
+                    impl_deserialize_num_method!($ty, u8, visit_u8, from_u8, Unsigned, u64);
+                    impl_deserialize_num_method!($ty, u16, visit_u16, from_u16, Unsigned, u64);
+                    impl_deserialize_num_method!($ty, u32, visit_u32, from_u32, Unsigned, u64);
+                    impl_deserialize_num_method!($ty, u64, visit_u64, from_u64, Unsigned, u64);
+                    impl_deserialize_num_method!($ty, f32, visit_f32, from_f32, Float, f64);
+                    impl_deserialize_num_method!($ty, f64, visit_f64, from_f64, Float, f64);
+
+                    #[inline]
+                    fn visit_str<E>(self, s: &str) -> Result<$ty, E>
+                        where E: Error,
+                    {
+                        str::FromStr::from_str(s.trim_matches(::utils::Pattern_White_Space)).or_else(|_| {
+                            Err(Error::invalid_type(Unexpected::Str(s), &self))
+                        })
+                    }
+                }
+
+                deserializer.$method(PrimitiveVisitor)
             }
         }
     }
 }
 
-impl_deserialize_num!(isize, deserialize_isize);
+impl_deserialize_num!(isize, deserialize_i64);
 impl_deserialize_num!(i8, deserialize_i8);
 impl_deserialize_num!(i16, deserialize_i16);
 impl_deserialize_num!(i32, deserialize_i32);
 impl_deserialize_num!(i64, deserialize_i64);
-impl_deserialize_num!(usize, deserialize_usize);
+impl_deserialize_num!(usize, deserialize_u64);
 impl_deserialize_num!(u8, deserialize_u8);
 impl_deserialize_num!(u16, deserialize_u16);
 impl_deserialize_num!(u32, deserialize_u32);
@@ -229,6 +225,10 @@ struct CharVisitor;
 impl Visitor for CharVisitor {
     type Value = char;
 
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("a character")
+    }
+
     #[inline]
     fn visit_char<E>(self, v: char) -> Result<char, E>
         where E: Error,
@@ -241,14 +241,9 @@ impl Visitor for CharVisitor {
         where E: Error,
     {
         let mut iter = v.chars();
-        if let Some(v) = iter.next() {
+        match (iter.next(), iter.next()) {
-            if iter.next().is_some() {
+            (Some(c), None) => Ok(c),
-                Err(Error::invalid_type(Type::Char))
+            _ => Err(Error::invalid_value(Unexpected::Str(v), &self)),
-            } else {
-                Ok(v)
-            }
-        } else {
-            Err(Error::end_of_stream())
         }
     }
 }
@@ -271,6 +266,10 @@ struct StringVisitor;
 impl Visitor for StringVisitor {
     type Value = String;
 
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("a string")
+    }
+
     fn visit_str<E>(self, v: &str) -> Result<String, E>
         where E: Error,
     {
@@ -294,7 +293,7 @@ impl Visitor for StringVisitor {
     {
         match str::from_utf8(v) {
             Ok(s) => Ok(s.to_owned()),
-            Err(_) => Err(Error::invalid_type(Type::String)),
+            Err(_) => Err(Error::invalid_value(Unexpected::Bytes(v), &self)),
         }
     }
 
@@ -303,7 +302,7 @@ impl Visitor for StringVisitor {
     {
         match String::from_utf8(v) {
             Ok(s) => Ok(s),
-            Err(_) => Err(Error::invalid_type(Type::String)),
+            Err(e) => Err(Error::invalid_value(Unexpected::Bytes(&e.into_bytes()), &self)),
         }
     }
 }
@@ -328,6 +327,10 @@ impl<
 > Visitor for OptionVisitor<T> {
     type Value = Option<T>;
 
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("option")
+    }
+
     #[inline]
     fn visit_unit<E>(self) -> Result<Option<T>, E>
         where E: Error,
@@ -368,6 +371,10 @@ pub struct PhantomDataVisitor<T> {
 impl<T> Visitor for PhantomDataVisitor<T> {
     type Value = PhantomData<T>;
 
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("unit")
+    }
+
     #[inline]
     fn visit_unit<E>(self) -> Result<PhantomData<T>, E>
         where E: Error,
@@ -417,6 +424,10 @@ macro_rules! seq_impl {
         {
             type Value = $ty;
 
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter.write_str("a sequence")
+            }
+
             #[inline]
             fn visit_unit<E>(self) -> Result<$ty, E>
                 where E: Error,
@@ -468,15 +479,6 @@ seq_impl!(
     BTreeSet::new(),
     BTreeSet::insert);
 
-#[cfg(all(feature = "unstable", feature = "collections"))]
-seq_impl!(
-    EnumSet<T>,
-    EnumSetVisitor<T: Deserialize + CLike>,
-    visitor,
-    EnumSet::new(),
-    EnumSet::new(),
-    EnumSet::insert);
-
 #[cfg(any(feature = "std", feature = "collections"))]
 seq_impl!(
     LinkedList<T>,
@@ -531,6 +533,10 @@ impl<A> ArrayVisitor<A> {
 impl<T> Visitor for ArrayVisitor<[T; 0]> where T: Deserialize {
     type Value = [T; 0];
 
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("an empty array")
+    }
+
     #[inline]
     fn visit_unit<E>(self) -> Result<[T; 0], E>
         where E: Error,
@@ -557,11 +563,15 @@ impl<T> Deserialize for [T; 0]
 }
 
 macro_rules! array_impls {
-    ($($len:expr => ($($name:ident)+))+) => {
+    ($($len:expr => ($($n:tt $name:ident)+))+) => {
         $(
             impl<T> Visitor for ArrayVisitor<[T; $len]> where T: Deserialize {
                 type Value = [T; $len];
 
+                fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str(concat!("an array of length ", $len))
+                }
+
                 #[inline]
                 fn visit_seq<V>(self, mut visitor: V) -> Result<[T; $len], V::Error>
                     where V: SeqVisitor,
@@ -569,7 +579,7 @@ macro_rules! array_impls {
                     $(
                         let $name = match try!(visitor.visit()) {
                             Some(val) => val,
-                            None => return Err(Error::end_of_stream()),
+                            None => return Err(Error::invalid_length($n, &self)),
                         };
                     )+
 
@@ -591,44 +601,44 @@ macro_rules! array_impls {
 }
 
 array_impls! {
-    1 => (a)
+    1 => (0 a)
-    2 => (a b)
+    2 => (0 a 1 b)
-    3 => (a b c)
+    3 => (0 a 1 b 2 c)
-    4 => (a b c d)
+    4 => (0 a 1 b 2 c 3 d)
-    5 => (a b c d e)
+    5 => (0 a 1 b 2 c 3 d 4 e)
-    6 => (a b c d e f)
+    6 => (0 a 1 b 2 c 3 d 4 e 5 f)
-    7 => (a b c d e f g)
+    7 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g)
-    8 => (a b c d e f g h)
+    8 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h)
-    9 => (a b c d e f g h i)
+    9 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i)
-    10 => (a b c d e f g h i j)
+    10 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j)
-    11 => (a b c d e f g h i j k)
+    11 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k)
-    12 => (a b c d e f g h i j k l)
+    12 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l)
-    13 => (a b c d e f g h i j k l m)
+    13 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m)
-    14 => (a b c d e f g h i j k l m n)
+    14 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n)
-    15 => (a b c d e f g h i j k l m n o)
+    15 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o)
-    16 => (a b c d e f g h i j k l m n o p)
+    16 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p)
-    17 => (a b c d e f g h i j k l m n o p q)
+    17 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q)
-    18 => (a b c d e f g h i j k l m n o p q r)
+    18 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r)
-    19 => (a b c d e f g h i j k l m n o p q r s)
+    19 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s)
-    20 => (a b c d e f g h i j k l m n o p q r s t)
+    20 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t)
-    21 => (a b c d e f g h i j k l m n o p q r s t u)
+    21 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u)
-    22 => (a b c d e f g h i j k l m n o p q r s t u v)
+    22 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v)
-    23 => (a b c d e f g h i j k l m n o p q r s t u v w)
+    23 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w)
-    24 => (a b c d e f g h i j k l m n o p q r s t u v w x)
+    24 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x)
-    25 => (a b c d e f g h i j k l m n o p q r s t u v w x y)
+    25 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y)
-    26 => (a b c d e f g h i j k l m n o p q r s t u v w x y z)
+    26 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z)
-    27 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa)
+    27 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa)
-    28 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab)
+    28 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab)
-    29 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac)
+    29 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac)
-    30 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad)
+    30 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac 29 ad)
-    31 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae)
+    31 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac 29 ad 30 ae)
-    32 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af)
+    32 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac 29 ad 30 ae 31 af)
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 macro_rules! tuple_impls {
-    ($($len:expr => $visitor:ident => ($($name:ident)+))+) => {
+    ($($len:expr => $visitor:ident => ($($n:tt $name:ident)+))+) => {
         $(
             /// Construct a tuple visitor.
             pub struct $visitor<$($name,)+> {
@@ -645,6 +655,10 @@ macro_rules! tuple_impls {
             impl<$($name: Deserialize),+> Visitor for $visitor<$($name,)+> {
                 type Value = ($($name,)+);
 
+                fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str(concat!("a tuple of size ", $len))
+                }
+
                 #[inline]
                 #[allow(non_snake_case)]
                 fn visit_seq<V>(self, mut visitor: V) -> Result<($($name,)+), V::Error>
@@ -653,7 +667,7 @@ macro_rules! tuple_impls {
                     $(
                         let $name = match try!(visitor.visit()) {
                             Some(value) => value,
-                            None => return Err(Error::end_of_stream()),
+                            None => return Err(Error::invalid_length($n, &self)),
                         };
                     )+
 
@@ -674,22 +688,22 @@ macro_rules! tuple_impls {
 }
 
 tuple_impls! {
-    1 => TupleVisitor1 => (T0)
+    1 => TupleVisitor1 => (0 T0)
-    2 => TupleVisitor2 => (T0 T1)
+    2 => TupleVisitor2 => (0 T0 1 T1)
-    3 => TupleVisitor3 => (T0 T1 T2)
+    3 => TupleVisitor3 => (0 T0 1 T1 2 T2)
-    4 => TupleVisitor4 => (T0 T1 T2 T3)
+    4 => TupleVisitor4 => (0 T0 1 T1 2 T2 3 T3)
-    5 => TupleVisitor5 => (T0 T1 T2 T3 T4)
+    5 => TupleVisitor5 => (0 T0 1 T1 2 T2 3 T3 4 T4)
-    6 => TupleVisitor6 => (T0 T1 T2 T3 T4 T5)
+    6 => TupleVisitor6 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5)
-    7 => TupleVisitor7 => (T0 T1 T2 T3 T4 T5 T6)
+    7 => TupleVisitor7 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6)
-    8 => TupleVisitor8 => (T0 T1 T2 T3 T4 T5 T6 T7)
+    8 => TupleVisitor8 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7)
-    9 => TupleVisitor9 => (T0 T1 T2 T3 T4 T5 T6 T7 T8)
+    9 => TupleVisitor9 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8)
-    10 => TupleVisitor10 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9)
+    10 => TupleVisitor10 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9)
-    11 => TupleVisitor11 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10)
+    11 => TupleVisitor11 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10)
-    12 => TupleVisitor12 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11)
+    12 => TupleVisitor12 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11)
-    13 => TupleVisitor13 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12)
+    13 => TupleVisitor13 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12)
-    14 => TupleVisitor14 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13)
+    14 => TupleVisitor14 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13)
-    15 => TupleVisitor15 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14)
+    15 => TupleVisitor15 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13 14 T14)
-    16 => TupleVisitor16 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15)
+    16 => TupleVisitor16 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13 14 T14 15 T15)
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -723,6 +737,10 @@ macro_rules! map_impl {
         {
             type Value = $ty;
 
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter.write_str("a map")
+            }
+
             #[inline]
             fn visit_unit<E>(self) -> Result<$ty, E>
                 where E: Error,
@@ -785,7 +803,7 @@ impl Deserialize for net::IpAddr {
         let s = try!(String::deserialize(deserializer));
         match s.parse() {
             Ok(s) => Ok(s),
-            Err(err) => Err(D::Error::invalid_value(&err.to_string())),
+            Err(err) => Err(D::Error::custom(err)),
         }
     }
 }
@@ -798,7 +816,7 @@ impl Deserialize for net::Ipv4Addr {
         let s = try!(String::deserialize(deserializer));
         match s.parse() {
             Ok(s) => Ok(s),
-            Err(err) => Err(D::Error::invalid_value(&err.to_string())),
+            Err(err) => Err(D::Error::custom(err)),
         }
     }
 }
@@ -811,7 +829,7 @@ impl Deserialize for net::Ipv6Addr {
         let s = try!(String::deserialize(deserializer));
         match s.parse() {
             Ok(s) => Ok(s),
-            Err(err) => Err(D::Error::invalid_value(&err.to_string())),
+            Err(err) => Err(D::Error::custom(err)),
         }
     }
 }
@@ -826,7 +844,7 @@ impl Deserialize for net::SocketAddr {
         let s = try!(String::deserialize(deserializer));
         match s.parse() {
             Ok(s) => Ok(s),
-            Err(err) => Err(D::Error::invalid_value(&err.to_string())),
+            Err(err) => Err(D::Error::custom(err)),
         }
     }
 }
@@ -839,7 +857,7 @@ impl Deserialize for net::SocketAddrV4 {
         let s = try!(String::deserialize(deserializer));
         match s.parse() {
             Ok(s) => Ok(s),
-            Err(err) => Err(D::Error::invalid_value(&err.to_string())),
+            Err(err) => Err(D::Error::custom(err)),
         }
     }
 }
@@ -852,7 +870,7 @@ impl Deserialize for net::SocketAddrV6 {
         let s = try!(String::deserialize(deserializer));
         match s.parse() {
             Ok(s) => Ok(s),
-            Err(err) => Err(D::Error::invalid_value(&err.to_string())),
+            Err(err) => Err(D::Error::custom(err)),
         }
     }
 }
@@ -866,6 +884,10 @@ struct PathBufVisitor;
 impl Visitor for PathBufVisitor {
     type Value = path::PathBuf;
 
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("path string")
+    }
+
     fn visit_str<E>(self, v: &str) -> Result<path::PathBuf, E>
         where E: Error,
     {
@@ -875,7 +897,7 @@ impl Visitor for PathBufVisitor {
     fn visit_string<E>(self, v: String) -> Result<path::PathBuf, E>
         where E: Error,
     {
-        self.visit_str(&v)
+        Ok(From::from(v))
     }
 }
 
@@ -977,14 +999,8 @@ impl Deserialize for Duration {
                 impl Visitor for FieldVisitor {
                     type Value = Field;
 
-                    fn visit_usize<E>(self, value: usize) -> Result<Field, E>
+                    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                        where E: Error,
+                        formatter.write_str("`secs` or `nanos`")
-                    {
-                        match value {
-                            0usize => Ok(Field::Secs),
-                            1usize => Ok(Field::Nanos),
-                            _ => Err(Error::invalid_value("expected a field")),
-                        }
                     }
 
                     fn visit_str<E>(self, value: &str) -> Result<Field, E>
@@ -993,7 +1009,7 @@ impl Deserialize for Duration {
                         match value {
                             "secs" => Ok(Field::Secs),
                             "nanos" => Ok(Field::Nanos),
-                            _ => Err(Error::unknown_field(value)),
+                            _ => Err(Error::unknown_field(value, FIELDS)),
                         }
                     }
 
@@ -1005,7 +1021,7 @@ impl Deserialize for Duration {
                             b"nanos" => Ok(Field::Nanos),
                             _ => {
                                 let value = String::from_utf8_lossy(value);
-                                Err(Error::unknown_field(&value))
+                                Err(Error::unknown_field(&value, FIELDS))
                             }
                         }
                     }
@@ -1020,19 +1036,23 @@ impl Deserialize for Duration {
         impl Visitor for DurationVisitor {
             type Value = Duration;
 
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter.write_str("struct Duration")
+            }
+
             fn visit_seq<V>(self, mut visitor: V) -> Result<Duration, V::Error>
                 where V: SeqVisitor,
             {
                 let secs: u64 = match try!(visitor.visit()) {
                     Some(value) => value,
                     None => {
-                        return Err(Error::invalid_length(0));
+                        return Err(Error::invalid_length(0, &self));
                     }
                 };
                 let nanos: u32 = match try!(visitor.visit()) {
                     Some(value) => value,
                     None => {
-                        return Err(Error::invalid_length(1));
+                        return Err(Error::invalid_length(1, &self));
                     }
                 };
                 Ok(Duration::new(secs, nanos))
@@ -1061,11 +1081,11 @@ impl Deserialize for Duration {
                 }
                 let secs = match secs {
                     Some(secs) => secs,
-                    None => try!(visitor.missing_field("secs")),
+                    None => return Err(<V::Error as Error>::missing_field("secs")),
                 };
                 let nanos = match nanos {
                     Some(nanos) => nanos,
-                    None => try!(visitor.missing_field("nanos")),
+                    None => return Err(<V::Error as Error>::missing_field("nanos")),
                 };
                 Ok(Duration::new(secs, nanos))
             }
@@ -1079,11 +1099,12 @@ impl Deserialize for Duration {
 ///////////////////////////////////////////////////////////////////////////////
 
 #[cfg(feature = "unstable")]
+#[allow(deprecated)] // num::Zero is deprecated but there is no replacement
 impl<T> Deserialize for NonZero<T> where T: Deserialize + PartialEq + Zeroable + Zero {
     fn deserialize<D>(deserializer: D) -> Result<NonZero<T>, D::Error> where D: Deserializer {
         let value = try!(Deserialize::deserialize(deserializer));
         if value == Zero::zero() {
-            return Err(Error::invalid_value("expected a non-zero value"))
+            return Err(Error::custom("expected a non-zero value"))
         }
         unsafe {
             Ok(NonZero::new(value))
@@ -1112,23 +1133,15 @@ impl<T, E> Deserialize for Result<T, E> where T: Deserialize, E: Deserialize {
                 impl Visitor for FieldVisitor {
                     type Value = Field;
 
-                    #[cfg(any(feature = "std", feature = "collections"))]
+                    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                    fn visit_usize<E>(self, value: usize) -> Result<Field, E> where E: Error {
+                        formatter.write_str("`Ok` or `Err`")
-                        #[cfg(feature = "collections")]
-                        use collections::string::ToString;
-                        match value {
-                            0 => Ok(Field::Ok),
-                            1 => Ok(Field::Err),
-                            _ => Err(Error::unknown_field(&value.to_string())),
-                        }
                     }
 
-                    #[cfg(all(not(feature = "std"), not(feature = "collections")))]
+                    fn visit_u32<E>(self, value: u32) -> Result<Field, E> where E: Error {
-                    fn visit_usize<E>(self, value: usize) -> Result<Field, E> where E: Error {
                         match value {
                             0 => Ok(Field::Ok),
                             1 => Ok(Field::Err),
-                            _ => Err(Error::unknown_field("some number")),
+                            _ => Err(Error::invalid_value(Unexpected::Unsigned(value as u64), &self)),
                         }
                     }
 
@@ -1136,7 +1149,7 @@ impl<T, E> Deserialize for Result<T, E> where T: Deserialize, E: Deserialize {
                         match value {
                             "Ok" => Ok(Field::Ok),
                             "Err" => Ok(Field::Err),
-                            _ => Err(Error::unknown_field(value)),
+                            _ => Err(Error::unknown_variant(value, VARIANTS)),
                         }
                     }
 
@@ -1146,8 +1159,8 @@ impl<T, E> Deserialize for Result<T, E> where T: Deserialize, E: Deserialize {
                             b"Err" => Ok(Field::Err),
                             _ => {
                                 match str::from_utf8(value) {
-                                    Ok(value) => Err(Error::unknown_field(value)),
+                                    Ok(value) => Err(Error::unknown_variant(value, VARIANTS)),
-                                    Err(_) => Err(Error::invalid_type(Type::String)),
+                                    Err(_) => Err(Error::invalid_value(Unexpected::Bytes(value), &self)),
                                 }
                             }
                         }
@@ -1166,6 +1179,10 @@ impl<T, E> Deserialize for Result<T, E> where T: Deserialize, E: Deserialize {
         {
             type Value = Result<T, E>;
 
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter.write_str("enum Result")
+            }
+
             fn visit_enum<V>(self, visitor: V) -> Result<Result<T, E>, V::Error>
                 where V: EnumVisitor
             {
@@ -1198,6 +1215,10 @@ impl Deserialize for IgnoredAny {
         impl Visitor for IgnoredAnyVisitor {
             type Value = IgnoredAny;
 
+            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter.write_str("anything at all")
+            }
+
             #[inline]
             fn visit_bool<E>(self, _: bool) -> Result<IgnoredAny, E> {
                 Ok(IgnoredAny)

serde/src/de/private.rs

@@ -0,0 +1,47 @@
+use core::marker::PhantomData;
+
+use de::{Deserialize, Deserializer, Error, Visitor};
+
+#[cfg(any(feature = "std", feature = "collections"))]
+pub use de::content::{
+    Content,
+    TaggedContentVisitor,
+    InternallyTaggedUnitVisitor,
+    UntaggedUnitVisitor,
+};
+
+/// 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 u8 u16 u32 u64 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 +1,34 @@
+#[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::option::Option::{self, None, Some};
+pub use core::result::Result::{self, Ok, Err};
+
+#[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

@@ -1,58 +1,107 @@
-//! Serde Serialization Framework
+//! # Serde
 //!
-//! Serde is a powerful framework that enables serialization libraries to generically serialize
+//! Serde is a framework for ***ser***ializing and ***de***serializing Rust data
-//! Rust data structures without the overhead of runtime type information. In many situations, the
+//! structures efficiently and generically.
-//! handshake protocol between serializers and serializees can be completely optimized away,
-//! leaving serde to perform roughly the same speed as a hand written serializer for a specific
-//! type.
 //!
-//! For a detailed tutorial on the different ways to use serde please check out the
+//! The Serde ecosystem consists of data structures that know how to serialize
-//! [github repository](https://github.com/serde-rs/serde)
+//! and deserialize themselves along with data formats that know how to
+//! serialize and deserialize other things. Serde provides the layer by which
+//! these two groups interact with each other, allowing any supported data
+//! structure to be serialized and deserialized using any supported data format.
+//!
+//! See the Serde website https://serde.rs/ for additional documentation and
+//! usage examples.
+//!
+//! ### Design
+//!
+//! Where many other languages rely on runtime reflection for serializing data,
+//! Serde is instead built on Rust's powerful trait system. A data structure
+//! that knows how to serialize and deserialize itself is one that implements
+//! Serde's `Serialize` and `Deserialize` traits (or uses Serde's code
+//! generation to automatically derive implementations at compile time). This
+//! avoids any overhead of reflection or runtime type information. In fact in
+//! many situations the interaction between data structure and data format can
+//! be completely optimized away by the Rust compiler, leaving Serde
+//! serialization to perform roughly the same speed as a handwritten serializer
+//! for the specific selection of data structure and data format.
+//!
+//! ### Data formats
+//!
+//! The following is a partial list of data formats that have been implemented
+//! for Serde by the community.
+//!
+//! - [JSON](https://github.com/serde-rs/json), the ubiquitous JavaScript Object
+//!   Notation used by many HTTP APIs.
+//! - [Bincode](https://github.com/TyOverby/bincode), a compact binary format
+//!   used for IPC within the Servo rendering engine.
+//! - [CBOR](https://github.com/pyfisch/cbor), a Concise Binary Object
+//!   Representation designed for small message size without the need for
+//!   version negotiation.
+//! - [YAML](https://github.com/dtolnay/serde-yaml), a popular human-friendly
+//!   configuration language that ain't markup language.
+//! - [MessagePack](https://github.com/3Hren/msgpack-rust), an efficient binary
+//!   format that resembles a compact JSON.
+//! - [TOML](https://github.com/alexcrichton/toml-rs), a minimal configuration
+//!   format used by [Cargo](http://doc.crates.io/manifest.html).
+//! - [Pickle](https://github.com/birkenfeld/serde-pickle), a format common in
+//!   the Python world.
+//! - [Hjson](https://github.com/laktak/hjson-rust), a variant of JSON designed
+//!   to be readable and writable by humans.
+//! - [BSON](https://github.com/zonyitoo/bson-rs), the data storage and network
+//!   transfer format used by MongoDB.
+//! - [URL](https://github.com/nox/serde_urlencoded), the x-www-form-urlencoded
+//!   format.
+//! - [XML](https://github.com/serde-rs/xml), the flexible machine-friendly W3C
+//!   standard. *(deserialization only)*
+//! - [Envy](https://github.com/softprops/envy), a way to deserialize
+//!   environment variables into Rust structs. *(deserialization only)*
+//! - [Redis](https://github.com/OneSignal/serde-redis), deserialize values from
+//!   Redis when using [redis-rs](https://crates.io/crates/redis).
+//!   *(deserialization only)*
 
 #![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 = "collections", feature(collections))]
-#![cfg_attr(feature = "clippy", plugin(clippy))]
+#![cfg_attr(feature = "cargo-clippy", allow(linkedlist, type_complexity, doc_markdown))]
-#![cfg_attr(feature = "clippy", allow(linkedlist))]
-
-#![cfg_attr(any(not(feature = "std"), feature = "unstable"), allow(unused_variables, unused_imports, unused_features, dead_code))]
-
 #![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, cell};
+            usize, f32, f64, char, str, num, slice, iter, cell, default, result, option};
     #[cfg(feature = "unstable")]
-    extern crate core;
+    pub use actual_core::nonzero;
-    #[cfg(feature = "unstable")]
-    pub use self::core::nonzero;
 }
 
+#[doc(inline)]
 pub use ser::{Serialize, Serializer};
+#[doc(inline)]
 pub use de::{Deserialize, Deserializer};
 
-#[cfg(not(feature = "std"))]
-macro_rules! format {
-    ($s:expr, $($rest:tt)*) => ($s)
-}
-
 #[macro_use]
 mod macros;
 
 pub mod bytes;
 pub mod de;
 #[cfg(feature = "std")]
+#[doc(hidden)]
 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

@@ -32,9 +32,6 @@ macro_rules! forward_to_deserialize_helper {
     (bool) => {
         forward_to_deserialize_method!{deserialize_bool()}
     };
-    (usize) => {
-        forward_to_deserialize_method!{deserialize_usize()}
-    };
     (u8) => {
         forward_to_deserialize_method!{deserialize_u8()}
     };
@@ -47,9 +44,6 @@ macro_rules! forward_to_deserialize_helper {
     (u64) => {
         forward_to_deserialize_method!{deserialize_u64()}
     };
-    (isize) => {
-        forward_to_deserialize_method!{deserialize_isize()}
-    };
     (i8) => {
         forward_to_deserialize_method!{deserialize_i8()}
     };
@@ -92,6 +86,9 @@ 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()}
     };
@@ -121,28 +118,70 @@ macro_rules! forward_to_deserialize_helper {
     };
 }
 
-/// Helper to forward `Deserializer` methods to `Deserializer::deserialize`.
+// Super explicit first paragraph because this shows up at the top level and
-/// Every given method ignores all arguments and forwards to `deserialize`.
+// trips up people who are just looking for basic Serialize / Deserialize
-/// Note that `deserialize_enum` simply returns an `Error::invalid_type`; a
+// documentation.
-/// better approach is tracked in [serde-rs/serde#521][1].
+//
+/// Helper macro when implementing the `Deserializer` part of a new data format
+/// for Serde.
 ///
-/// ```rust,ignore
+/// Some `Deserializer` implementations for self-describing formats do not care
+/// what hint the `Visitor` gives them, they just want to blindly call the
+/// `Visitor` method corresponding to the data they can tell is in the input.
+/// This requires repetitive implementations of all the `Deserializer` trait
+/// methods.
+///
+/// ```rust
+/// # #[macro_use] extern crate serde;
+/// # use serde::de::{value, Deserializer, Visitor};
+/// # pub struct MyDeserializer;
+/// # impl Deserializer for MyDeserializer {
+/// #     type Error = value::Error;
+/// #     fn deserialize<V>(self, _: V) -> Result<V::Value, Self::Error>
+/// #         where V: Visitor
+/// #     { unimplemented!() }
+/// #
+/// #[inline]
+/// fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+///     where V: Visitor
+/// {
+///     self.deserialize(visitor)
+/// }
+/// #     forward_to_deserialize! {
+/// #         u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string unit option
+/// #         seq seq_fixed_size bytes byte_buf map unit_struct newtype_struct
+/// #         tuple_struct struct struct_field tuple enum ignored_any
+/// #     }
+/// # }
+/// # fn main() {}
+/// ```
+///
+/// The `forward_to_deserialize!` macro implements these simple forwarding
+/// methods so that they forward directly to `Deserializer::deserialize`. You
+/// can choose which methods to forward.
+///
+/// ```rust
+/// # #[macro_use] extern crate serde;
+/// # use serde::de::{value, Deserializer, Visitor};
+/// # pub struct MyDeserializer;
 /// impl Deserializer for MyDeserializer {
+/// #   type Error = value::Error;
 ///     fn deserialize<V>(self, visitor: V) -> Result<V::Value, Self::Error>
 ///         where V: Visitor
 ///     {
 ///         /* ... */
+/// #       let _ = visitor;
+/// #       unimplemented!()
 ///     }
 ///
 ///     forward_to_deserialize! {
-///         bool usize u8 u16 u32 u64 isize i8 i16 i32 i64 f32 f64 char str string
+///         bool u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string unit option
-///         unit option seq seq_fixed_size bytes map unit_struct newtype_struct
+///         seq seq_fixed_size bytes byte_buf map unit_struct newtype_struct
 ///         tuple_struct struct struct_field tuple enum ignored_any
 ///     }
 /// }
+/// # fn main() {}
 /// ```
-///
-/// [1]: https://github.com/serde-rs/serde/issues/521
 #[macro_export]
 macro_rules! forward_to_deserialize {
     ($($func:ident)*) => {

serde/src/ser/impls.rs

@@ -1,9 +1,3 @@
-//! Implementations for all of Rust's builtin types. Tuples implement the `Serialize` trait if they
-//! have at most 16 fields. Arrays implement the `Serialize` trait if their length is 32 or less.
-//! You can always forward array serialization to slice serialization, which works for any length.
-//! Long tuples are best replaced by tuple structs, for which you can use `derive(Serialize)`. In
-//! that case the number of fields is irrelevant.
-
 #[cfg(feature = "std")]
 use std::borrow::Cow;
 #[cfg(all(feature = "collections", not(feature = "std")))]
@@ -30,19 +24,16 @@ use collections::{
     Vec,
 };
 
-#[cfg(all(feature = "unstable", feature = "collections"))]
+#[cfg(feature = "collections")]
-use collections::enum_set::{CLike, EnumSet};
-#[cfg(all(feature = "unstable", 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;
@@ -67,14 +58,13 @@ use core::marker::PhantomData;
 use core::nonzero::{NonZero, Zeroable};
 
 use super::{
-    Error,
     Serialize,
-    SerializeMap,
     SerializeSeq,
-    SerializeStruct,
     SerializeTuple,
     Serializer,
 };
+#[cfg(any(feature = "std", feature = "unstable"))]
+use super::Error;
 
 #[cfg(feature = "unstable")]
 use super::Iterator;
@@ -82,25 +72,25 @@ use super::Iterator;
 ///////////////////////////////////////////////////////////////////////////////
 
 macro_rules! impl_visit {
-    ($ty:ty, $method:ident) => {
+    ($ty:ty, $method:ident $($cast:tt)*) => {
         impl Serialize for $ty {
             #[inline]
             fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                 where S: Serializer,
             {
-                serializer.$method(*self)
+                serializer.$method(*self $($cast)*)
             }
         }
     }
 }
 
 impl_visit!(bool, serialize_bool);
-impl_visit!(isize, serialize_isize);
+impl_visit!(isize, serialize_i64 as i64);
 impl_visit!(i8, serialize_i8);
 impl_visit!(i16, serialize_i16);
 impl_visit!(i32, serialize_i32);
 impl_visit!(i64, serialize_i64);
-impl_visit!(usize, serialize_usize);
+impl_visit!(usize, serialize_u64 as u64);
 impl_visit!(u8, serialize_u8);
 impl_visit!(u16, serialize_u16);
 impl_visit!(u32, serialize_u32);
@@ -239,9 +229,9 @@ impl<'a, I> Serialize for Iterator<I>
         where S: Serializer,
     {
         // FIXME: use specialization to prevent invalidating the object in case of clonable iterators?
-        let iter = match self.0.borrow_mut().take() {
+        let iter = match self.data.borrow_mut().take() {
             Some(iter) => iter.into_iter(),
-            None => return Err(S::Error::custom("Iterator used twice")),
+            None => return Err(Error::custom("Iterator used twice")),
         };
         let size = match iter.size_hint() {
             (lo, Some(hi)) if lo == hi => Some(lo),
@@ -249,7 +239,7 @@ impl<'a, I> Serialize for Iterator<I>
         };
         let mut seq = try!(serializer.serialize_seq(size));
         for e in iter {
-            try!(seq.serialize_element(e));
+            try!(seq.serialize_element(&e));
         }
         seq.end()
     }
@@ -265,7 +255,7 @@ macro_rules! serialize_seq {
         {
             let mut seq = try!(serializer.serialize_seq(Some(self.len())));
             for e in self {
-                try!(seq.serialize_element(e));
+                try!(seq.serialize_element(&e));
             }
             seq.end()
         }
@@ -286,13 +276,6 @@ impl<T> Serialize for BTreeSet<T>
     serialize_seq!();
 }
 
-#[cfg(all(feature = "unstable", feature = "collections"))]
-impl<T> Serialize for EnumSet<T>
-    where T: Serialize + CLike
-{
-    serialize_seq!();
-}
-
 #[cfg(feature = "std")]
 impl<T, H> Serialize for HashSet<T, H>
     where T: Serialize + Eq + Hash,
@@ -324,17 +307,33 @@ impl<T> Serialize for VecDeque<T>
 
 #[cfg(feature = "unstable")]
 impl<A> Serialize for ops::Range<A>
-    where A: Serialize + Clone + iter::Step + num::One,
+    where ops::Range<A>: ExactSizeIterator + iter::Iterator<Item = A> + Clone,
-          for<'a> &'a A: ops::Add<&'a A, Output = A>,
+          A: Serialize,
 {
     #[inline]
     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 seq = try!(serializer.serialize_seq(Some(self.len())));
-        let mut seq = try!(serializer.serialize_seq(len));
         for e in self.clone() {
-            try!(seq.serialize_element(e));
+            try!(seq.serialize_element(&e));
+        }
+        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()
     }
@@ -557,10 +556,10 @@ macro_rules! serialize_map {
         fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
             where S: Serializer,
         {
+            use super::SerializeMap;
             let mut map = try!(serializer.serialize_map(Some(self.len())));
             for (k, v) in self {
-                try!(map.serialize_key(k));
+                try!(map.serialize_entry(k, v));
-                try!(map.serialize_value(v));
             }
             map.end()
         }
@@ -679,9 +678,10 @@ impl Serialize for Duration {
     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!(state.serialize_field("secs", self.as_secs()));
+        try!(state.serialize_field("secs", &self.as_secs()));
-        try!(state.serialize_field("nanos", self.subsec_nanos()));
+        try!(state.serialize_field("nanos", &self.subsec_nanos()));
         state.end()
     }
 }
@@ -756,7 +756,7 @@ impl Serialize for path::Path {
     {
         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")),
         }
     }
 }

serde/src/ser/impossible.rs

@@ -0,0 +1,177 @@
+//! This module contains `Impossible` serializer and its implementations.
+
+use core::marker::PhantomData;
+
+use ser::{
+    self,
+    Serialize,
+    SerializeSeq,
+    SerializeTuple,
+    SerializeTupleStruct,
+    SerializeTupleVariant,
+    SerializeMap,
+    SerializeStruct,
+    SerializeStructVariant,
+};
+
+/// Helper type for implementing a `Serializer` that does not support
+/// serializing one of the compound types.
+///
+/// This type cannot be instantiated, but implements every one of the traits
+/// corresponding to the `Serializer` compound types: `SerializeSeq`,
+/// `SerializeTuple`, `SerializeTupleStruct`, `SerializeTupleVariant`,
+/// `SerializeMap`, `SerializeStruct`, and `SerializeStructVariant`.
+///
+/// ```rust,ignore
+/// impl Serializer for MySerializer {
+///     type Ok = ();
+///     type Error = Error;
+///
+///     type SerializeSeq = Impossible<(), Error>;
+///     /* other associated types */
+///
+///     /// This data format does not support serializing sequences.
+///     fn serialize_seq(self,
+///                      len: Option<usize>)
+///                      -> Result<Self::SerializeSeq, Error> {
+///         // Given Impossible cannot be instantiated, the only
+///         // thing we can do here is to return an error.
+///         Err(...)
+///     }
+///
+///     /* other Serializer methods */
+/// }
+/// ```
+pub struct Impossible<Ok, E> {
+    void: Void,
+    _marker: PhantomData<(Ok, E)>,
+}
+
+enum Void {}
+
+impl<Ok, E> SerializeSeq for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_element<T: ?Sized + Serialize>(&mut self,
+                                                _value: &T)
+                                                -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeTuple for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_element<T: ?Sized + Serialize>(&mut self,
+                                                _value: &T)
+                                                -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeTupleStruct for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_field<T: ?Sized + Serialize>(&mut self,
+                                              _value: &T)
+                                              -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeTupleVariant for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_field<T: ?Sized + Serialize>(&mut self,
+                                              _value: &T)
+                                              -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeMap for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_key<T: ?Sized + Serialize>(&mut self,
+                                                 _key: &T)
+                                            -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn serialize_value<T: ?Sized + Serialize>(&mut self,
+                                              _value: &T)
+                                              -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeStruct for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_field<T: ?Sized + Serialize>(&mut self,
+                                                   _key: &'static str,
+                                              _value: &T)
+                                              -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeStructVariant for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_field<T: ?Sized + Serialize>(&mut self,
+                                                   _key: &'static str,
+                                              _value: &T)
+                                              -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}

serde/src/ser/mod.rs

@@ -1,84 +1,254 @@
-//! Generic serialization framework.
+//! Generic data structure serialization framework.
-//! # For Developers who want to serialize objects
-//! Implement the `Serialize` trait for the type of objects you want to serialize. Call methods of
-//! the `serializer` object. For which methods to call and how to do so, look at the documentation
-//! of the `Serializer` trait.
 //!
-//! # For Serialization Format Developers
+//! The two most important traits in this module are `Serialize` and
-//! Implement the `Serializer` trait for a structure that contains fields that enable it to write
+//! `Serializer`.
-//! the serialization result to your target. When a method's argument is an object of type
+//!
-//! `Serialize`, you can either forward the serializer object (`self`) or create a new one,
+//!  - **A type that implements `Serialize` is a data structure** that can be
-//! depending on the quirks of your format.
+//!    serialized to any data format supported by Serde, and conversely
+//!  - **A type that implements `Serializer` is a data format** that can
+//!    serialize any data structure supported by Serde.
+//!
+//! # The Serialize trait
+//!
+//! Serde provides `Serialize` implementations for many Rust primitive and
+//! standard library types. The complete list is below. All of these can be
+//! serialized using Serde out of the box.
+//!
+//! Additionally, Serde provides a procedural macro called `serde_derive` to
+//! automatically generate `Serialize` implementations for structs and enums in
+//! your program. See the [codegen section of the manual][codegen] for how to
+//! use this.
+//!
+//! In rare cases it may be necessary to implement `Serialize` manually for some
+//! type in your program. See the [Implementing `Serialize`][impl-serialize]
+//! section of the manual for more about this.
+//!
+//! Third-party crates may provide `Serialize` implementations for types that
+//! they expose. For example the `linked-hash-map` crate provides a
+//! `LinkedHashMap<K, V>` type that is serializable by Serde because the crate
+//! provides an implementation of `Serialize` for it.
+//!
+//! # The Serializer trait
+//!
+//! `Serializer` implementations are provided by third-party crates, for example
+//! [`serde_json`][serde_json], [`serde_yaml`][serde_yaml] and
+//! [`bincode`][bincode].
+//!
+//! A partial list of well-maintained formats is given on the [Serde
+//! website][data-formats].
+//!
+//! # Implementations of Serialize provided by Serde
+//!
+//!  - **Primitive types**:
+//!    - bool
+//!    - isize, i8, i16, i32, i64
+//!    - usize, u8, u16, u32, u64
+//!    - f32, f64
+//!    - char
+//!    - str
+//!    - &T and &mut T
+//!  - **Compound types**:
+//!    - [T]
+//!    - [T; 0] through [T; 32]
+//!    - tuples up to size 16
+//!  - **Common standard library types**:
+//!    - String
+//!    - Option\<T\>
+//!    - Result\<T, E\>
+//!    - PhantomData\<T\>
+//!  - **Wrapper types**:
+//!    - Box\<T\>
+//!    - Rc\<T\>
+//!    - Arc\<T\>
+//!    - Cow\<'a, T\>
+//!  - **Collection types**:
+//!    - BTreeMap\<K, V\>
+//!    - BTreeSet\<T\>
+//!    - BinaryHeap\<T\>
+//!    - HashMap\<K, V, H\>
+//!    - HashSet\<T, H\>
+//!    - LinkedList\<T\>
+//!    - VecDeque\<T\>
+//!    - Vec\<T\>
+//!    - EnumSet\<T\> (unstable)
+//!    - Range\<T\> (unstable)
+//!    - RangeInclusive\<T\> (unstable)
+//!  - **Miscellaneous standard library types**:
+//!    - Duration
+//!    - Path
+//!    - PathBuf
+//!    - NonZero\<T\> (unstable)
+//!  - **Net types**:
+//!    - IpAddr
+//!    - Ipv4Addr
+//!    - Ipv6Addr
+//!    - SocketAddr
+//!    - SocketAddrV4
+//!    - SocketAddrV6
+//!
+//! [codegen]: https://serde.rs/codegen.html
+//! [impl-serialize]: https://serde.rs/impl-serialize.html
+//! [serde_json]: https://github.com/serde-rs/json
+//! [serde_yaml]: https://github.com/dtolnay/serde-yaml
+//! [bincode]: https://github.com/TyOverby/bincode
+//! [data-formats]: https://serde.rs/#data-formats
 
 #[cfg(feature = "std")]
 use std::error;
 #[cfg(not(feature = "std"))]
 use error;
 
-#[cfg(all(feature = "collections", not(feature = "std")))]
-use collections::String;
-
-#[cfg(feature = "unstable")]
-use core::marker::PhantomData;
 #[cfg(feature = "unstable")]
 use core::cell::RefCell;
 
-pub mod impls;
+use core::fmt::Display;
+
+mod impls;
+mod impossible;
+
+// Helpers used by generated code. Not public API.
+#[doc(hidden)]
+pub mod private;
+
+pub use self::impossible::Impossible;
 
 ///////////////////////////////////////////////////////////////////////////////
 
-/// `Error` is a trait that allows a `Serialize` to generically create a
+/// Trait used by `Serialize` implementations to generically construct errors
-/// `Serializer` error.
+/// belonging to the `Serializer` against which they are currently running.
 pub trait Error: Sized + error::Error {
-    /// Raised when there is a general error when serializing a type.
+    /// Raised when a `Serialize` implementation encounters a general error
-    #[cfg(any(feature = "std", feature = "collections"))]
+    /// while serializing a type.
-    fn custom<T: Into<String>>(msg: T) -> Self;
+    ///
-
+    /// The message should not be capitalized and should not end with a period.
-    /// Raised when there is a general error when serializing a type.
+    ///
-    #[cfg(all(not(feature = "std"), not(feature = "collections")))]
+    /// For example, a filesystem `Path` may refuse to serialize itself if it
-    fn custom<T: Into<&'static str>>(msg: T) -> Self;
+    /// contains invalid UTF-8 data.
-
+    ///
-    /// Raised when a `Serialize` was passed an incorrect value.
+    /// ```rust
-    fn invalid_value(msg: &str) -> Self {
+    /// # use serde::ser::{Serialize, Serializer, Error};
-        Error::custom(format!("invalid value: {}", msg))
+    /// # struct Path;
-    }
+    /// # impl Path { fn to_str(&self) -> Option<&str> { unimplemented!() } }
+    /// impl Serialize for Path {
+    ///     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::custom("path contains invalid UTF-8 characters")),
+    ///         }
+    ///     }
+    /// }
+    /// ```
+    fn custom<T: Display>(msg: T) -> Self;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
-/// A trait that describes a type that can be serialized by a `Serializer`.
+/// A **data structure** that can be serialized into any data format supported
+/// by Serde.
+///
+/// Serde provides `Serialize` implementations for many Rust primitive and
+/// standard library types. The complete list is [here][ser]. All of these can
+/// be serialized using Serde out of the box.
+///
+/// Additionally, Serde provides a procedural macro called `serde_derive` to
+/// automatically generate `Serialize` implementations for structs and enums in
+/// your program. See the [codegen section of the manual][codegen] for how to
+/// use this.
+///
+/// In rare cases it may be necessary to implement `Serialize` manually for some
+/// type in your program. See the [Implementing `Serialize`][impl-serialize]
+/// section of the manual for more about this.
+///
+/// Third-party crates may provide `Serialize` implementations for types that
+/// they expose. For example the `linked-hash-map` crate provides a
+/// `LinkedHashMap<K, V>` type that is serializable by Serde because the crate
+/// provides an implementation of `Serialize` for it.
+///
+/// [ser]: https://docs.serde.rs/serde/ser/index.html
+/// [codegen]: https://serde.rs/codegen.html
+/// [impl-serialize]: https://serde.rs/impl-serialize.html
 pub trait Serialize {
-    /// Serializes this value into this serializer.
+    /// Serialize this value into the given Serde serializer.
+    ///
+    /// See the [Implementing `Serialize`][impl-serialize] section of the manual
+    /// for more information about how to implement this method.
+    ///
+    /// [impl-serialize]: https://serde.rs/impl-serialize.html
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
         where S: Serializer;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
-/// A trait that describes a type that can serialize a stream of values into the underlying format.
+/// A **data format** that can serialize any data structure supported by Serde.
 ///
-/// # For `Serialize` Developers
+/// The role of this trait is to define the serialization half of the Serde data
-/// Non-aggregate types like integers and strings can be serialized directly by calling the
+/// model, which is a way to categorize every Rust data structure into one of 28
-/// appropriate function. For Aggregate types there's an initial `serialize_T` method that yields
+/// possible types. Each method of the `Serializer` trait corresponds to one of
-/// a State object that you should not interact with. For each part of the aggregate there's a
+/// the types of the data model.
-/// `serialize_T_elt` method that allows you to pass values or key/value pairs. The types of the
-/// values or the keys may change between calls, but the serialization format may not necessarily
-/// accept it. The `serialize_T_elt` method also takes a mutable reference to the state object.
-/// Make sure that you always use the same state object and only the state object that was returned
-/// by the `serialize_T` method. Finally, when your object is done, call the `serialize_T_end`
-/// method and pass the state object by value
 ///
-/// # For Serialization Format Developers
+/// Implementations of `Serialize` map themselves into this data model by
-/// If your format has different situations where it accepts different types, create a
+/// invoking exactly one of the `Serializer` methods.
-/// `Serializer` for each situation. You can create the sub-`Serializer` in one of the aggregate
+///
-/// `serialize_T` methods and return it as a state object. Remember to also set the corresponding
+/// The types that make up the Serde data model are:
-/// associated type `TState`. In the `serialize_T_elt` methods you will be given a mutable
+///
-/// reference to that state. You do not need to do any additional checks for the correctness of the
+///  - 12 primitive types:
-/// state object, as it is expected that the user will not modify it. Due to the generic nature
+///    - bool
-/// of the `Serialize` impls, modifying the object is impossible on stable Rust.
+///    - i8, i16, i32, i64
+///    - u8, u16, u32, u64
+///    - f32, f64
+///    - char
+///  - string
+///  - byte array - [u8]
+///  - option
+///    - either none or some value
+///  - unit
+///    - unit is the type of () in Rust
+///  - unit_struct
+///    - for example `struct Unit` or `PhantomData<T>`
+///  - unit_variant
+///    - the `E::A` and `E::B` in `enum E { A, B }`
+///  - newtype_struct
+///    - for example `struct Millimeters(u8)`
+///  - newtype_variant
+///    - the `E::N` in `enum E { N(u8) }`
+///  - seq
+///    - a dynamically sized sequence of values, for example `Vec<T>` or
+///      `HashSet<T>`
+///  - seq_fixed_size
+///    - a statically sized sequence of values for which the size will be known
+///      at deserialization time without looking at the serialized data, for
+///      example `[u64; 10]`
+///  - tuple
+///    - for example `(u8,)` or `(String, u64, Vec<T>)`
+///  - tuple_struct
+///    - for example `struct Rgb(u8, u8, u8)`
+///  - tuple_variant
+///    - the `E::T` in `enum E { T(u8, u8) }`
+///  - map
+///    - for example `BTreeMap<K, V>`
+///  - struct
+///    - a key-value pairing in which the keys will be known at deserialization
+///      time without looking at the serialized data, for example `struct S { r:
+///      u8, g: u8, b: u8 }`
+///  - struct_variant
+///    - the `E::S` in `enum E { S { r: u8, g: u8, b: u8 } }`
+///
+/// Many Serde serializers produce text or binary data as output, for example
+/// JSON or Bincode. This is not a requirement of the `Serializer` trait, and
+/// there are serializers that do not produce text or binary output. One example
+/// is the `serde_json::value::Serializer` (distinct from the main `serde_json`
+/// serializer) that produces a `serde_json::Value` data structure in memory as
+/// output.
 pub trait Serializer {
-    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// The output type produced by this `Serializer` during successful
-    /// `Serializer` should set `Ok = ()`.
+    /// serialization. Most serializers that produce text or binary output
+    /// should set `Ok = ()` and serialize into an `io::Write` or buffer
+    /// contained within the `Serializer` instance. Serializers that build
+    /// in-memory data structures may be simplified by using `Ok` to propagate
+    /// the data structure around.
     type Ok;
 
     /// The error type when some error occurs during serialization.
@@ -112,75 +282,85 @@ pub trait Serializer {
     /// content of the struct variant.
     type SerializeStructVariant: SerializeStructVariant<Ok=Self::Ok, Error=Self::Error>;
 
-    /// Serializes a `bool` value.
+    /// Serialize a `bool` value.
     fn serialize_bool(self, v: bool) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes an `isize` value. If the format does not differentiate
+    /// Serialize an `i8` value.
-    /// between `isize` and `i64`, a reasonable implementation would be to cast
+    ///
-    /// the value to `i64` and forward to `serialize_i64`.
+    /// If the format does not differentiate between `i8` and `i64`, a
-    fn serialize_isize(self, v: isize) -> Result<Self::Ok, Self::Error>;
+    /// reasonable implementation would be to cast the value to `i64` and
-
+    /// forward to `serialize_i64`.
-    /// 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(self, v: i8) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes an `i16` value. If the format does not differentiate between
+    /// Serialize an `i16` value.
-    /// `i16` and `i64`, a reasonable implementation would be to cast the value
+    ///
-    /// to `i64` and forward to `serialize_i64`.
+    /// 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(self, v: i16) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes an `i32` value. If the format does not differentiate between
+    /// Serialize an `i32` value.
-    /// `i32` and `i64`, a reasonable implementation would be to cast the value
+    ///
-    /// to `i64` and forward to `serialize_i64`.
+    /// 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(self, v: i32) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes an `i64` value.
+    /// Serialize an `i64` value.
     fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes a `usize` value. If the format does not differentiate between
+    /// Serialize a `u8` value.
-    /// `usize` and `u64`, a reasonable implementation would be to cast the
+    ///
-    /// value to `u64` and forward to `serialize_u64`.
+    /// If the format does not differentiate between `u8` and `u64`, a
-    fn serialize_usize(self, v: usize) -> Result<Self::Ok, Self::Error>;
+    /// reasonable implementation would be to cast the value to `u64` and
-
+    /// forward to `serialize_u64`.
-    /// 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(self, v: u8) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes a `u16` value. If the format does not differentiate between
+    /// Serialize a `u16` value.
-    /// `u16` and `u64`, a reasonable implementation would be to cast the value
+    ///
-    /// to `u64` and forward to `serialize_u64`.
+    /// 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(self, v: u16) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes a `u32` value. If the format does not differentiate between
+    /// Serialize a `u32` value.
-    /// `u32` and `u64`, a reasonable implementation would be to cast the value
+    ///
-    /// to `u64` and forward to `serialize_u64`.
+    /// 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(self, v: u32) -> Result<Self::Ok, Self::Error>;
 
-    /// `Serializes a `u64` value.
+    /// Serialize a `u64` value.
     fn serialize_u64(self, v: u64) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes an `f32` value. If the format does not differentiate between
+    /// Serialize an `f32` value.
-    /// `f32` and `f64`, a reasonable implementation would be to cast the value
+    ///
-    /// to `f64` and forward to `serialize_f64`.
+    /// 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(self, v: f32) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes an `f64` value.
+    /// Serialize an `f64` value.
     fn serialize_f64(self, v: f64) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes a character. If the format does not support characters,
+    /// Serialize a character.
-    /// it is reasonable to serialize it as a single element `str` or a `u32`.
+    ///
+    /// If the format does not support characters, it is reasonable to serialize
+    /// it as a single element `str` or a `u32`.
     fn serialize_char(self, v: char) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes a `&str`.
+    /// Serialize a `&str`.
     fn serialize_str(self, value: &str) -> Result<Self::Ok, Self::Error>;
 
+    /// Serialize a chunk of raw byte data.
+    ///
     /// 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:
+    /// `serialize_seq`. If forwarded, the implementation looks usually just
-    /// ```rust
+    /// like this:
+    ///
+    /// ```rust,ignore
     /// let mut seq = self.serialize_seq(Some(value.len()))?;
     /// for b in value {
     ///     seq.serialize_element(b)?;
@@ -189,19 +369,40 @@ pub trait Serializer {
     /// ```
     fn serialize_bytes(self, value: &[u8]) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes a `()` value. It's reasonable to just not serialize anything.
+    /// Serialize a `None` value.
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error>;
+
+    /// Serialize a `Some(T)` value.
+    fn serialize_some<T: ?Sized + Serialize>(
+        self,
+        value: &T,
+    ) -> Result<Self::Ok, Self::Error>;
+
+    /// Serialize a `()` value.
     fn serialize_unit(self) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes a unit struct value. A reasonable implementation would be to
+    /// Serialize a unit struct like `struct Unit` or `PhantomData<T>`.
-    /// forward to `serialize_unit`.
+    ///
+    /// A reasonable implementation would be to forward to `serialize_unit`.
     fn serialize_unit_struct(
         self,
         name: &'static str,
     ) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes a unit variant, otherwise known as a variant with no
+    /// Serialize a unit variant like `E::A` in `enum E { A, B }`.
-    /// arguments. A reasonable implementation would be to forward to
+    ///
-    /// `serialize_unit`.
+    /// The `name` is the name of the enum, the `variant_index` is the index of
+    /// this variant within the enum, and the `variant` is the name of the
+    /// variant.
+    ///
+    /// A reasonable implementation would be to forward to `serialize_unit`.
+    ///
+    /// ```rust,ignore
+    /// match *self {
+    ///     E::A => serializer.serialize_unit_variant("E", 0, "A"),
+    ///     E::B => serializer.serialize_unit_variant("E", 1, "B"),
+    /// }
+    /// ```
     fn serialize_unit_variant(
         self,
         name: &'static str,
@@ -209,74 +410,130 @@ pub trait Serializer {
         variant: &'static str,
     ) -> Result<Self::Ok, Self::Error>;
 
-    /// Allows a tuple struct with a single element, also known as a newtype
+    /// Serialize a newtype struct like `struct Millimeters(u8)`.
-    /// struct, to be more efficiently serialized than a tuple struct with
+    ///
-    /// multiple items. A reasonable implementation would be to forward to
+    /// Serializers are encouraged to treat newtype structs as insignificant
-    /// `serialize_tuple_struct` or to just serialize the inner value without wrapping.
+    /// wrappers around the data they contain. A reasonable implementation would
-    fn serialize_newtype_struct<T: Serialize>(
+    /// be to forward to `value.serialize(self)`.
+    ///
+    /// ```rust,ignore
+    /// serializer.serialize_newtype_struct("Millimeters", &self.0)
+    /// ```
+    fn serialize_newtype_struct<T: ?Sized + Serialize>(
         self,
         name: &'static str,
-        value: T,
+        value: &T,
     ) -> Result<Self::Ok, Self::Error>;
 
-    /// Allows a variant with a single item to be more efficiently serialized
+    /// Serialize a newtype variant like `E::N` in `enum E { N(u8) }`.
-    /// than a variant with multiple items. A reasonable implementation would be
+    ///
-    /// to forward to `serialize_tuple_variant`.
+    /// The `name` is the name of the enum, the `variant_index` is the index of
-    fn serialize_newtype_variant<T: Serialize>(
+    /// this variant within the enum, and the `variant` is the name of the
+    /// variant. The `value` is the data contained within this newtype variant.
+    ///
+    /// ```rust,ignore
+    /// match *self {
+    ///     E::N(ref n) => serializer.serialize_newtype_variant("E", 0, "N", n),
+    /// }
+    /// ```
+    fn serialize_newtype_variant<T: ?Sized + Serialize>(
         self,
         name: &'static str,
         variant_index: usize,
         variant: &'static str,
-        value: T,
+        value: &T,
     ) -> Result<Self::Ok, Self::Error>;
 
-    /// Serializes a `None` value.
+    /// Begin to serialize a dynamically sized sequence. This call must be
-    fn serialize_none(self) -> Result<Self::Ok, Self::Error>;
+    /// followed by zero or more calls to `serialize_element`, then a call to
-
+    /// `end`.
-    /// Serializes a `Some(...)` value.
+    ///
-    fn serialize_some<T: Serialize>(
+    /// The argument is the number of elements in the sequence, which may or may
-        self,
+    /// not be computable before the sequence is iterated. Some serializers only
-        value: T,
+    /// support sequences whose length is known up front.
-    ) -> Result<Self::Ok, Self::Error>;
+    ///
-
+    /// ```rust,ignore
-    /// Begins to serialize a sequence. This call must be followed by zero or
+    /// let mut seq = serializer.serialize_seq(Some(self.len()))?;
-    /// more calls to `serialize_seq_elt`, then a call to `serialize_seq_end`.
+    /// for element in self {
+    ///     seq.serialize_element(element)?;
+    /// }
+    /// seq.end()
+    /// ```
     fn serialize_seq(
         self,
         len: Option<usize>,
     ) -> Result<Self::SerializeSeq, Self::Error>;
 
-    /// Begins to serialize a sequence whose length will be known at
+    /// Begin to serialize a statically sized sequence whose length will be
-    /// deserialization time. This call must be followed by zero or more calls
+    /// known at deserialization time without looking at the serialized data.
-    /// to `serialize_seq_elt`, then a call to `serialize_seq_end`. A reasonable
+    /// This call must be followed by zero or more calls to `serialize_element`,
-    /// implementation would be to forward to `serialize_seq`.
+    /// then a call to `end`.
+    ///
+    /// ```rust,ignore
+    /// let mut seq = serializer.serialize_seq_fixed_size(self.len())?;
+    /// for element in self {
+    ///     seq.serialize_element(element)?;
+    /// }
+    /// seq.end()
+    /// ```
     fn serialize_seq_fixed_size(
         self,
         size: usize,
     ) -> Result<Self::SerializeSeq, Self::Error>;
 
-    /// Begins to serialize a tuple. This call must be followed by zero or more
+    /// Begin 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
+    /// calls to `serialize_field`, then a call to `end`.
-    /// reasonable implementation would be to forward to `serialize_seq`.
+    ///
+    /// ```rust,ignore
+    /// let mut tup = serializer.serialize_tuple(3)?;
+    /// tup.serialize_field(&self.0)?;
+    /// tup.serialize_field(&self.1)?;
+    /// tup.serialize_field(&self.2)?;
+    /// tup.end()
+    /// ```
     fn serialize_tuple(
         self,
         len: usize,
     ) -> Result<Self::SerializeTuple, Self::Error>;
 
-    /// Begins to serialize a tuple struct. This call must be followed by zero
+    /// Begin to serialize a tuple struct like `struct Rgb(u8, u8, u8)`. This
-    /// or more calls to `serialize_tuple_struct_elt`, then a call to
+    /// call must be followed by zero or more calls to `serialize_field`, then a
-    /// `serialize_tuple_struct_end`. A reasonable implementation would be to
+    /// call to `end`.
-    /// forward to `serialize_tuple`.
+    ///
+    /// The `name` is the name of the tuple struct and the `len` is the number
+    /// of data fields that will be serialized.
+    ///
+    /// ```rust,ignore
+    /// let mut ts = serializer.serialize_tuple_struct("Rgb", 3)?;
+    /// ts.serialize_field(&self.0)?;
+    /// ts.serialize_field(&self.1)?;
+    /// ts.serialize_field(&self.2)?;
+    /// ts.end()
+    /// ```
     fn serialize_tuple_struct(
         self,
         name: &'static str,
         len: usize,
     ) -> Result<Self::SerializeTupleStruct, Self::Error>;
 
-    /// Begins to serialize a tuple variant. This call must be followed by zero
+    /// Begin to serialize a tuple variant like `E::T` in `enum E { T(u8, u8)
-    /// or more calls to `serialize_tuple_variant_elt`, then a call to
+    /// }`. This call must be followed by zero or more calls to
-    /// `serialize_tuple_variant_end`. A reasonable implementation would be to
+    /// `serialize_field`, then a call to `end`.
-    /// forward to `serialize_tuple_struct`.
+    ///
+    /// The `name` is the name of the enum, the `variant_index` is the index of
+    /// this variant within the enum, the `variant` is the name of the variant,
+    /// and the `len` is the number of data fields that will be serialized.
+    ///
+    /// ```rust,ignore
+    /// match *self {
+    ///     E::T(ref a, ref b) => {
+    ///         let mut tv = serializer.serialize_tuple_variant("E", 0, "T", 2)?;
+    ///         tv.serialize_field(a)?;
+    ///         tv.serialize_field(b)?;
+    ///         tv.end()
+    ///     }
+    /// }
+    /// ```
     fn serialize_tuple_variant(
         self,
         name: &'static str,
@@ -285,25 +542,64 @@ pub trait Serializer {
         len: usize,
     ) -> Result<Self::SerializeTupleVariant, Self::Error>;
 
-    /// Begins to serialize a map. This call must be followed by zero or more
+    /// Begin 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
+    /// calls to `serialize_key` and `serialize_value`, then a call to `end`.
-    /// `serialize_map_end`.
+    ///
+    /// The argument is the number of elements in the map, which may or may not
+    /// be computable before the map is iterated. Some serializers only support
+    /// maps whose length is known up front.
+    ///
+    /// ```rust,ignore
+    /// let mut map = serializer.serialize_map(Some(self.len()))?;
+    /// for (k, v) in self {
+    ///     map.serialize_entry(k, v)?;
+    /// }
+    /// map.end()
+    /// ```
     fn serialize_map(
         self,
         len: Option<usize>,
     ) -> Result<Self::SerializeMap, Self::Error>;
 
-    /// Begins to serialize a struct. This call must be followed by zero or more
+    /// Begin to serialize a struct like `struct Rgb { r: u8, g: u8, b: u8 }`.
-    /// calls to `serialize_struct_elt`, then a call to `serialize_struct_end`.
+    /// This call must be followed by zero or more calls to `serialize_field`,
+    /// then a call to `end`.
+    ///
+    /// The `name` is the name of the struct and the `len` is the number of
+    /// data fields that will be serialized.
+    ///
+    /// ```rust,ignore
+    /// let mut struc = serializer.serialize_struct("Rgb", 3)?;
+    /// struc.serialize_field("r", &self.r)?;
+    /// struc.serialize_field("g", &self.g)?;
+    /// struc.serialize_field("b", &self.b)?;
+    /// struc.end()
+    /// ```
     fn serialize_struct(
         self,
         name: &'static str,
         len: usize,
     ) -> Result<Self::SerializeStruct, Self::Error>;
 
-    /// Begins to serialize a struct variant. This call must be followed by zero
+    /// Begin to serialize a struct variant like `E::S` in `enum E { S { r: u8,
-    /// or more calls to `serialize_struct_variant_elt`, then a call to
+    /// g: u8, b: u8 } }`. This call must be followed by zero or more calls to
-    /// `serialize_struct_variant_end`.
+    /// `serialize_field`, then a call to `end`.
+    ///
+    /// The `name` is the name of the enum, the `variant_index` is the index of
+    /// this variant within the enum, the `variant` is the name of the variant,
+    /// and the `len` is the number of data fields that will be serialized.
+    ///
+    /// ```rust,ignore
+    /// match *self {
+    ///     E::S { ref r, ref g, ref b } => {
+    ///         let mut sv = serializer.serialize_struct_variant("E", 0, "S", 3)?;
+    ///         sv.serialize_field("r", r)?;
+    ///         sv.serialize_field("g", g)?;
+    ///         sv.serialize_field("b", b)?;
+    ///         sv.end()
+    ///     }
+    /// }
+    /// ```
     fn serialize_struct_variant(
         self,
         name: &'static str,
@@ -315,134 +611,218 @@ pub trait Serializer {
 
 /// Returned from `Serializer::serialize_seq` and
 /// `Serializer::serialize_seq_fixed_size`.
+///
+/// ```rust,ignore
+/// let mut seq = serializer.serialize_seq(Some(self.len()))?;
+/// for element in self {
+///     seq.serialize_element(element)?;
+/// }
+/// seq.end()
+/// ```
 pub trait SerializeSeq {
-    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// Must match the `Ok` type of our `Serializer`.
-    /// `SerializeSeq` should set `Ok = ()`.
     type Ok;
 
-    /// The error type when some error occurs during serialization.
+    /// Must match the `Error` type of our `Serializer`.
     type Error: Error;
 
-    /// Serializes a sequence element.
+    /// Serialize a sequence element.
-    fn serialize_element<T: Serialize>(&mut self, value: T) -> Result<(), Self::Error>;
+    fn serialize_element<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error>;
 
-    /// Finishes serializing a sequence.
+    /// Finish serializing a sequence.
     fn end(self) -> Result<Self::Ok, Self::Error>;
 }
 
 /// Returned from `Serializer::serialize_tuple`.
+///
+/// ```rust,ignore
+/// let mut tup = serializer.serialize_tuple(3)?;
+/// tup.serialize_field(&self.0)?;
+/// tup.serialize_field(&self.1)?;
+/// tup.serialize_field(&self.2)?;
+/// tup.end()
+/// ```
 pub trait SerializeTuple {
-    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// Must match the `Ok` type of our `Serializer`.
-    /// `SerializeTuple` should set `Ok = ()`.
     type Ok;
 
-    /// The error type when some error occurs during serialization.
+    /// Must match the `Error` type of our `Serializer`.
     type Error: Error;
 
-    /// Serializes a tuple element.
+    /// Serialize a tuple element.
-    fn serialize_element<T: Serialize>(&mut self, value: T) -> Result<(), Self::Error>;
+    fn serialize_element<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error>;
 
-    /// Finishes serializing a tuple.
+    /// Finish serializing a tuple.
     fn end(self) -> Result<Self::Ok, Self::Error>;
 }
 
 /// Returned from `Serializer::serialize_tuple_struct`.
+///
+/// ```rust,ignore
+/// let mut ts = serializer.serialize_tuple_struct("Rgb", 3)?;
+/// ts.serialize_field(&self.0)?;
+/// ts.serialize_field(&self.1)?;
+/// ts.serialize_field(&self.2)?;
+/// ts.end()
+/// ```
 pub trait SerializeTupleStruct {
-    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// Must match the `Ok` type of our `Serializer`.
-    /// `SerializeTupleStruct` should set `Ok = ()`.
     type Ok;
 
-    /// The error type when some error occurs during serialization.
+    /// Must match the `Error` type of our `Serializer`.
     type Error: Error;
 
-    /// Serializes a tuple struct element.
+    /// Serialize a tuple struct field.
-    fn serialize_field<T: Serialize>(&mut self, value: T) -> Result<(), Self::Error>;
+    fn serialize_field<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error>;
 
-    /// Finishes serializing a tuple struct.
+    /// Finish serializing a tuple struct.
     fn end(self) -> Result<Self::Ok, Self::Error>;
 }
 
 /// Returned from `Serializer::serialize_tuple_variant`.
+///
+/// ```rust,ignore
+/// match *self {
+///     E::T(ref a, ref b) => {
+///         let mut tv = serializer.serialize_tuple_variant("E", 0, "T", 2)?;
+///         tv.serialize_field(a)?;
+///         tv.serialize_field(b)?;
+///         tv.end()
+///     }
+/// }
+/// ```
 pub trait SerializeTupleVariant {
-    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// Must match the `Ok` type of our `Serializer`.
-    /// `SerializeTupleVariant` should set `Ok = ()`.
     type Ok;
 
-    /// The error type when some error occurs during serialization.
+    /// Must match the `Error` type of our `Serializer`.
     type Error: Error;
 
-    /// Serializes a tuple variant element.
+    /// Serialize a tuple variant field.
-    fn serialize_field<T: Serialize>(&mut self, value: T) -> Result<(), Self::Error>;
+    fn serialize_field<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error>;
 
-    /// Finishes serializing a tuple variant.
+    /// Finish serializing a tuple variant.
     fn end(self) -> Result<Self::Ok, Self::Error>;
 }
 
 /// Returned from `Serializer::serialize_map`.
+///
+/// ```rust,ignore
+/// let mut map = serializer.serialize_map(Some(self.len()))?;
+/// for (k, v) in self {
+///     map.serialize_entry(k, v)?;
+/// }
+/// map.end()
+/// ```
 pub trait SerializeMap {
-    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// Must match the `Ok` type of our `Serializer`.
-    /// `SerializeMap` should set `Ok = ()`.
     type Ok;
 
-    /// The error type when some error occurs during serialization.
+    /// Must match the `Error` type of our `Serializer`.
     type Error: Error;
 
     /// Serialize a map key.
-    fn serialize_key<T: Serialize>(&mut self, key: T) -> Result<(), Self::Error>;
+    fn serialize_key<T: ?Sized + Serialize>(&mut self, key: &T) -> Result<(), Self::Error>;
 
     /// Serialize a map value.
-    fn serialize_value<T: Serialize>(&mut self, value: T) -> Result<(), Self::Error>;
+    fn serialize_value<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error>;
 
-    /// Finishes serializing a map.
+    /// Serialize a map entry consisting of a key and a value.
+    ///
+    /// Some `Serialize` types are not able to hold a key and value in memory at
+    /// the same time so `SerializeMap` implementations are required to support
+    /// `serialize_key` and `serialize_value` individually. The
+    /// `serialize_entry` method allows serializers to optimize for the case
+    /// where key and value are both available. `Serialize` implementations are
+    /// encouraged to use `serialize_entry` if possible.
+    ///
+    /// The default implementation delegates to `serialize_key` and
+    /// `serialize_value`. This is appropriate for serializers that do not care
+    /// about performance or are not able to optimize `serialize_entry` any
+    /// better than this.
+    fn serialize_entry<K: ?Sized + Serialize, V: ?Sized + Serialize>(
+        &mut self,
+        key: &K,
+        value: &V,
+    ) -> Result<(), Self::Error> {
+        try!(self.serialize_key(key));
+        self.serialize_value(value)
+    }
+
+    /// Finish serializing a map.
     fn end(self) -> Result<Self::Ok, Self::Error>;
 }
 
 /// Returned from `Serializer::serialize_struct`.
+///
+/// ```rust,ignore
+/// let mut struc = serializer.serialize_struct("Rgb", 3)?;
+/// struc.serialize_field("r", &self.r)?;
+/// struc.serialize_field("g", &self.g)?;
+/// struc.serialize_field("b", &self.b)?;
+/// struc.end()
+/// ```
 pub trait SerializeStruct {
-    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// Must match the `Ok` type of our `Serializer`.
-    /// `SerializeStruct` should set `Ok = ()`.
     type Ok;
 
-    /// The error type when some error occurs during serialization.
+    /// Must match the `Error` type of our `Serializer`.
     type Error: Error;
 
-    /// Serializes a struct field.
+    /// Serialize a struct field.
-    fn serialize_field<V: Serialize>(&mut self, key: &'static str, value: V) -> Result<(), Self::Error>;
+    fn serialize_field<T: ?Sized + Serialize>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>;
 
-    /// Finishes serializing a struct.
+    /// Finish serializing a struct.
     fn end(self) -> Result<Self::Ok, Self::Error>;
 }
 
 /// Returned from `Serializer::serialize_struct_variant`.
+///
+/// ```rust,ignore
+/// match *self {
+///     E::S { ref r, ref g, ref b } => {
+///         let mut sv = serializer.serialize_struct_variant("E", 0, "S", 3)?;
+///         sv.serialize_field("r", r)?;
+///         sv.serialize_field("g", g)?;
+///         sv.serialize_field("b", b)?;
+///         sv.end()
+///     }
+/// }
+/// ```
 pub trait SerializeStructVariant {
-    /// Trickery to enforce correct use of the `Serialize` trait. Every
+    /// Must match the `Ok` type of our `Serializer`.
-    /// `SerializeStructVariant` should set `Ok = ()`.
     type Ok;
 
-    /// The error type when some error occurs during serialization.
+    /// Must match the `Error` type of our `Serializer`.
     type Error: Error;
 
-    /// Serialize a struct variant element.
+    /// Serialize a struct variant field.
-    fn serialize_field<V: Serialize>(&mut self, key: &'static str, value: V) -> Result<(), Self::Error>;
+    fn serialize_field<T: ?Sized + Serialize>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>;
 
-    /// Finishes serializing a struct variant.
+    /// Finish serializing a struct variant.
     fn end(self) -> Result<Self::Ok, Self::Error>;
 }
 
-/// A wrapper type for iterators that implements `Serialize` for iterators whose items implement
+/// A wrapper type for iterators that implements `Serialize` for iterators whose
-/// `Serialize`. Don't use multiple times. Create new versions of this with the `iterator` function
+/// items implement `Serialize`. Don't use multiple times. Create new versions
-/// every time you want to serialize an iterator.
+/// of this with the `serde::ser::iterator` function every time you want to
+/// serialize an iterator.
 #[cfg(feature = "unstable")]
-pub struct Iterator<I>(RefCell<Option<I>>)
+pub struct Iterator<I>
     where <I as IntoIterator>::Item: Serialize,
-          I: IntoIterator;
+          I: IntoIterator
+{
+    data: RefCell<Option<I>>,
+}
 
-/// Creates a temporary type that can be passed to any function expecting a `Serialize` and will
+/// Create a wrapper type that can be passed to any function expecting a
-/// serialize the given iterator as a sequence
+/// `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)))
+    Iterator {
+        data: RefCell::new(Some(iter)),
+    }
 }

serde/src/ser/private.rs

@@ -0,0 +1,235 @@
+use core::fmt::{self, Display};
+
+use ser::{self, Serialize, Serializer, SerializeMap, SerializeStruct};
+
+/// Not public API.
+pub fn serialize_tagged_newtype<S, T>(
+    serializer: S,
+    type_ident: &'static str,
+    variant_ident: &'static str,
+    tag: &'static str,
+    variant_name: &'static str,
+    value: T,
+) -> Result<S::Ok, S::Error>
+    where S: Serializer,
+          T: Serialize
+{
+    value.serialize(TaggedSerializer {
+        type_ident: type_ident,
+        variant_ident: variant_ident,
+        tag: tag,
+        variant_name: variant_name,
+        delegate: serializer,
+    })
+}
+
+struct TaggedSerializer<S> {
+    type_ident: &'static str,
+    variant_ident: &'static str,
+    tag: &'static str,
+    variant_name: &'static str,
+    delegate: S,
+}
+
+enum Unsupported {
+    Boolean,
+    Integer,
+    Float,
+    Char,
+    String,
+    ByteArray,
+    Optional,
+    Unit,
+    UnitStruct,
+    Sequence,
+    Tuple,
+    TupleStruct,
+    Enum,
+}
+
+impl Display for Unsupported {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Unsupported::Boolean => formatter.write_str("a boolean"),
+            Unsupported::Integer => formatter.write_str("an integer"),
+            Unsupported::Float => formatter.write_str("a float"),
+            Unsupported::Char => formatter.write_str("a char"),
+            Unsupported::String => formatter.write_str("a string"),
+            Unsupported::ByteArray => formatter.write_str("a byte array"),
+            Unsupported::Optional => formatter.write_str("an optional"),
+            Unsupported::Unit => formatter.write_str("unit"),
+            Unsupported::UnitStruct => formatter.write_str("a unit struct"),
+            Unsupported::Sequence => formatter.write_str("a sequence"),
+            Unsupported::Tuple => formatter.write_str("a tuple"),
+            Unsupported::TupleStruct => formatter.write_str("a tuple struct"),
+            Unsupported::Enum => formatter.write_str("an enum"),
+        }
+    }
+}
+
+struct Error {
+    type_ident: &'static str,
+    variant_ident: &'static str,
+    ty: Unsupported,
+}
+
+impl Display for Error {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter,
+               "cannot serialize tagged newtype variant {}::{} containing {}",
+               self.type_ident, self.variant_ident, self.ty)
+    }
+}
+
+impl<S> TaggedSerializer<S>
+    where S: Serializer
+{
+    fn bad_type(self, what: Unsupported) -> S::Error {
+        ser::Error::custom(Error {
+            type_ident: self.type_ident,
+            variant_ident: self.variant_ident,
+            ty: what,
+        })
+    }
+}
+
+impl<S> Serializer for TaggedSerializer<S>
+    where S: Serializer
+{
+    type Ok = S::Ok;
+    type Error = S::Error;
+
+    type SerializeSeq = S::SerializeSeq;
+    type SerializeTuple = S::SerializeTuple;
+    type SerializeTupleStruct = S::SerializeTupleStruct;
+    type SerializeTupleVariant = S::SerializeTupleVariant;
+    type SerializeMap = S::SerializeMap;
+    type SerializeStruct = S::SerializeStruct;
+    type SerializeStructVariant = S::SerializeStructVariant;
+
+    fn serialize_bool(self, _: bool) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Boolean))
+    }
+
+    fn serialize_i8(self, _: i8) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i16(self, _: i16) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i32(self, _: i32) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i64(self, _: i64) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u8(self, _: u8) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u16(self, _: u16) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u32(self, _: u32) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u64(self, _: u64) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_f32(self, _: f32) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Float))
+    }
+
+    fn serialize_f64(self, _: f64) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Float))
+    }
+
+    fn serialize_char(self, _: char) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Char))
+    }
+
+    fn serialize_str(self, _: &str) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::String))
+    }
+
+    fn serialize_bytes(self, _: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::ByteArray))
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Optional))
+    }
+
+    fn serialize_some<T: ?Sized>(self, _: &T) -> Result<Self::Ok, Self::Error>
+        where T: Serialize
+    {
+        Err(self.bad_type(Unsupported::Optional))
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Unit))
+    }
+
+    fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::UnitStruct))
+    }
+
+    fn serialize_unit_variant(self, _: &'static str, _: usize, _: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Enum))
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(self, _: &'static str, value: &T) -> Result<Self::Ok, Self::Error>
+        where T: Serialize
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(self, _: &'static str, _: usize, _: &'static str, _: &T) -> Result<Self::Ok, Self::Error>
+        where T: Serialize
+    {
+        Err(self.bad_type(Unsupported::Enum))
+    }
+
+    fn serialize_seq(self, _: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(self.bad_type(Unsupported::Sequence))
+    }
+
+    fn serialize_seq_fixed_size(self, _: usize) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(self.bad_type(Unsupported::Sequence))
+    }
+
+    fn serialize_tuple(self, _: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(self.bad_type(Unsupported::Tuple))
+    }
+
+    fn serialize_tuple_struct(self, _: &'static str, _: usize) -> Result<Self::SerializeTupleStruct, Self::Error> {
+        Err(self.bad_type(Unsupported::TupleStruct))
+    }
+
+    fn serialize_tuple_variant(self, _: &'static str, _: usize, _: &'static str, _: usize) -> Result<Self::SerializeTupleVariant, Self::Error> {
+        Err(self.bad_type(Unsupported::Enum))
+    }
+
+    fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        let mut map = try!(self.delegate.serialize_map(len.map(|len| len + 1)));
+        try!(map.serialize_entry(self.tag, self.variant_name));
+        Ok(map)
+    }
+
+    fn serialize_struct(self, name: &'static str, len: usize) -> Result<Self::SerializeStruct, Self::Error> {
+        let mut state = try!(self.delegate.serialize_struct(name, len + 1));
+        try!(state.serialize_field(self.tag, self.variant_name));
+        Ok(state)
+    }
+
+    fn serialize_struct_variant(self, _: &'static str, _: usize, _: &'static str, _: usize) -> Result<Self::SerializeStructVariant, Self::Error> {
+        Err(self.bad_type(Unsupported::Enum))
+    }
+}

serde_codegen/Cargo.toml

@@ -1,29 +0,0 @@
-[package]
-name = "serde_codegen"
-version = "0.9.0-rc1"
-authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
-license = "MIT/Apache-2.0"
-description = "Macros to auto-generate implementations for the serde framework"
-homepage = "https://serde.rs"
-repository = "https://github.com/serde-rs/serde"
-documentation = "https://serde.rs/codegen.html"
-keywords = ["serde", "serialization"]
-include = ["Cargo.toml", "src/**/*.rs"]
-
-[features]
-default = ["with-syntex"]
-unstable = []
-unstable-testing = ["clippy"]
-with-syntex = [
-    "syntex",
-    "syntex_syntax",
-]
-with-syn = []
-
-[dependencies]
-clippy = { version = "^0.*", optional = true }
-quote = "0.3.8"
-serde_codegen_internals = { version = "=0.11.3", default-features = false, path = "../serde_codegen_internals" }
-syn = { version = "0.10", features = ["aster", "visit"] }
-syntex = { version = "^0.54.0", optional = true }
-syntex_syntax = { version = "^0.54.0", optional = true }

serde_codegen/src/lib.rs

@@ -1,172 +0,0 @@
-#![cfg_attr(feature = "clippy", plugin(clippy))]
-#![cfg_attr(feature = "clippy", feature(plugin))]
-#![cfg_attr(feature = "clippy", allow(too_many_arguments))]
-#![cfg_attr(feature = "clippy", allow(used_underscore_binding))]
-
-// The `quote!` macro requires deep recursion.
-#![recursion_limit = "192"]
-
-extern crate serde_codegen_internals as internals;
-
-#[cfg(feature = "with-syntex")]
-extern crate syntex;
-
-#[cfg(feature = "with-syntex")]
-#[macro_use]
-extern crate syntex_syntax as syntax;
-
-extern crate syn;
-#[macro_use]
-extern crate quote;
-
-#[cfg(feature = "with-syntex")]
-use std::path::Path;
-
-mod bound;
-mod de;
-mod ser;
-
-#[cfg(feature = "with-syntex")]
-fn syntex_registry() -> syntex::Registry {
-    use syntax::{ast, fold};
-
-    /// Strip the serde attributes from the crate.
-    #[cfg(feature = "with-syntex")]
-    fn strip_attributes(krate: ast::Crate) -> ast::Crate {
-        /// Helper folder that strips the serde attributes after the extensions have been expanded.
-        struct StripAttributeFolder;
-
-        impl fold::Folder for StripAttributeFolder {
-            fn fold_attribute(&mut self, attr: ast::Attribute) -> Option<ast::Attribute> {
-                if attr.value.name == "serde" {
-                    if let ast::MetaItemKind::List(..) = attr.value.node {
-                        return None;
-                    }
-                }
-                Some(attr)
-            }
-
-            fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
-                fold::noop_fold_mac(mac, self)
-            }
-        }
-
-        fold::Folder::fold_crate(&mut StripAttributeFolder, krate)
-    }
-
-    let mut reg = syntex::Registry::new();
-
-    reg.add_attr("feature(custom_derive)");
-    reg.add_attr("feature(custom_attribute)");
-
-    reg.add_decorator("derive_Serialize", shim::expand_derive_serialize);
-    reg.add_decorator("derive_Deserialize", shim::expand_derive_deserialize);
-
-    reg.add_post_expansion_pass(strip_attributes);
-
-    reg
-}
-
-#[cfg(feature = "with-syntex")]
-pub fn expand_str(src: &str) -> Result<String, syntex::Error> {
-    let src = src.to_owned();
-
-    let expand_thread = move || {
-        syntex_registry().expand_str("", "", &src)
-    };
-
-    syntex::with_extra_stack(expand_thread)
-}
-
-#[cfg(feature = "with-syntex")]
-pub fn expand<S, D>(src: S, dst: D) -> Result<(), syntex::Error>
-    where S: AsRef<Path>,
-          D: AsRef<Path>,
-{
-    let src = src.as_ref().to_owned();
-    let dst = dst.as_ref().to_owned();
-
-    let expand_thread = move || {
-        syntex_registry().expand("", src, dst)
-    };
-
-    syntex::with_extra_stack(expand_thread)
-}
-
-macro_rules! shim {
-    ($name:ident $pkg:ident :: $func:ident) => {
-        pub fn $func(
-            cx: &mut ::syntax::ext::base::ExtCtxt,
-            span: ::syntax::codemap::Span,
-            meta_item: &::syntax::ast::MetaItem,
-            annotatable: &::syntax::ext::base::Annotatable,
-            push: &mut FnMut(::syntax::ext::base::Annotatable)
-        ) {
-            let item = match *annotatable {
-                ::syntax::ext::base::Annotatable::Item(ref item) => item,
-                _ => {
-                    cx.span_err(
-                        meta_item.span,
-                        concat!("`#[derive(",
-                                stringify!($name),
-                                ")]` may only be applied to structs and enums"));
-                    return;
-                }
-            };
-
-            use syntax::{attr, ast, visit};
-            struct MarkSerdeAttributesUsed;
-            impl<'a> visit::Visitor<'a> for MarkSerdeAttributesUsed {
-                fn visit_attribute(&mut self, attr: &ast::Attribute) {
-                    if attr.value.name == "serde" {
-                        if let ast::MetaItemKind::List(..) = attr.value.node {
-                            attr::mark_used(attr);
-                        }
-                    }
-                }
-            }
-            visit::walk_item(&mut MarkSerdeAttributesUsed, item);
-
-            use syntax::print::pprust;
-            let s = pprust::item_to_string(item);
-
-            use {syn, $pkg};
-            let syn_item = syn::parse_macro_input(&s).unwrap();
-            let expanded = match $pkg::$func(&syn_item) {
-                Ok(expanded) => expanded.to_string(),
-                Err(msg) => {
-                    cx.span_err(span, &msg);
-                    return;
-                }
-            };
-
-            use syntax::parse;
-            let name = stringify!($name).to_string();
-            let sess = cx.parse_sess;
-            let impl_item = parse::parse_item_from_source_str(name, expanded, sess);
-            push(::syntax::ext::base::Annotatable::Item(impl_item.unwrap().unwrap()));
-        }
-    };
-}
-
-#[cfg(feature = "with-syntex")]
-mod shim {
-    shim!(Serialize ser::expand_derive_serialize);
-    shim!(Deserialize de::expand_derive_deserialize);
-}
-
-#[cfg(feature = "with-syn")]
-#[doc(hidden)]
-/// Not public API. Use the serde_derive crate.
-pub fn expand_derive_serialize(item: &str) -> Result<quote::Tokens, String> {
-    let syn_item = syn::parse_macro_input(item).unwrap();
-    ser::expand_derive_serialize(&syn_item)
-}
-
-#[cfg(feature = "with-syn")]
-#[doc(hidden)]
-/// Not public API. Use the serde_derive crate.
-pub fn expand_derive_deserialize(item: &str) -> Result<quote::Tokens, String> {
-    let syn_item = syn::parse_macro_input(item).unwrap();
-    de::expand_derive_deserialize(&syn_item)
-}

serde_codegen_internals/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_codegen_internals"
-version = "0.11.3"
+version = "0.13.0"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "AST representation used by Serde codegen. Unstable."
@@ -10,9 +10,8 @@ documentation = "https://docs.serde.rs/serde_codegen_internals/"
 keywords = ["serde", "serialization"]
 include = ["Cargo.toml", "src/**/*.rs"]
 
-[features]
-unstable-testing = ["clippy"]
-
 [dependencies]
-clippy = { version = "^0.*", optional = true }
+syn = "0.11"
-syn = "0.10"
+
+[badges]
+travis-ci = { repository = "serde-rs/serde" }

serde_codegen_internals/src/attr.rs

@@ -92,6 +92,32 @@ pub struct Item {
     deny_unknown_fields: bool,
     ser_bound: Option<Vec<syn::WherePredicate>>,
     de_bound: Option<Vec<syn::WherePredicate>>,
+    tag: EnumTag,
+}
+
+/// Styles of representing an enum.
+#[derive(Debug)]
+pub enum EnumTag {
+    /// The default.
+    ///
+    /// ```json
+    /// {"variant1": {"key1": "value1", "key2": "value2"}}
+    /// ```
+    External,
+
+    /// `#[serde(tag = "type")]`
+    ///
+    /// ```json
+    /// {"type": "variant1", "key1": "value1", "key2": "value2"}
+    /// ```
+    Internal(String),
+
+    /// `#[serde(untagged)]`
+    ///
+    /// ```json
+    /// {"key1": "value1", "key2": "value2"}
+    /// ```
+    None,
 }
 
 impl Item {
@@ -102,6 +128,8 @@ impl Item {
         let mut deny_unknown_fields = BoolAttr::none(cx, "deny_unknown_fields");
         let mut ser_bound = Attr::none(cx, "bound");
         let mut de_bound = Attr::none(cx, "bound");
+        let mut untagged = BoolAttr::none(cx, "untagged");
+        let mut internal_tag = Attr::none(cx, "tag");
 
         for meta_items in item.attrs.iter().filter_map(get_serde_meta_items) {
             for meta_item in meta_items {
@@ -143,18 +171,70 @@ impl Item {
                         }
                     }
 
+                    // Parse `#[serde(untagged)]`
+                    MetaItem(Word(ref name)) if name == "untagged" => {
+                        match item.body {
+                            syn::Body::Enum(_) => {
+                                untagged.set_true();
+                            }
+                            syn::Body::Struct(_) => {
+                                cx.error("#[serde(untagged)] can only be used on enums")
+                            }
+                        }
+                    }
+
+                    // Parse `#[serde(tag = "type")]`
+                    MetaItem(NameValue(ref name, ref lit)) if name == "tag" => {
+                        if let Ok(s) = get_string_from_lit(cx, name.as_ref(), name.as_ref(), lit) {
+                            match item.body {
+                                syn::Body::Enum(_) => {
+                                    internal_tag.set(s);
+                                }
+                                syn::Body::Struct(_) => {
+                                    cx.error("#[serde(tag = \"...\")] can only be used on enums")
+                                }
+                            }
+                        }
+                    }
+
                     MetaItem(ref meta_item) => {
                         cx.error(format!("unknown serde container attribute `{}`",
                                          meta_item.name()));
                     }
 
                     Literal(_) => {
-                        cx.error(format!("unexpected literal in serde container attribute"));
+                        cx.error("unexpected literal in serde container attribute");
                     }
                 }
             }
         }
 
+        let tag = match (untagged.get(), internal_tag.get()) {
+            (false, None) => EnumTag::External,
+            (true, None) => EnumTag::None,
+            (false, Some(tag)) => {
+                // Check that there are no tuple variants.
+                if let syn::Body::Enum(ref variants) = item.body {
+                    for variant in variants {
+                        match variant.data {
+                            syn::VariantData::Struct(_) | syn::VariantData::Unit => {}
+                            syn::VariantData::Tuple(ref fields) => {
+                                if fields.len() != 1 {
+                                    cx.error("#[serde(tag = \"...\")] cannot be used with tuple variants");
+                                    break;
+                                }
+                            }
+                        }
+                    }
+                }
+                EnumTag::Internal(tag)
+            }
+            (true, Some(_)) => {
+                cx.error("enum cannot be both untagged and internally tagged");
+                EnumTag::External // doesn't matter, will error
+            }
+        };
+
         Item {
             name: Name {
                 serialize: ser_name.get().unwrap_or_else(|| item.ident.to_string()),
@@ -163,6 +243,7 @@ impl Item {
             deny_unknown_fields: deny_unknown_fields.get(),
             ser_bound: ser_bound.get(),
             de_bound: de_bound.get(),
+            tag: tag,
         }
     }
 
@@ -181,6 +262,10 @@ impl Item {
     pub fn de_bound(&self) -> Option<&[syn::WherePredicate]> {
         self.de_bound.as_ref().map(|vec| &vec[..])
     }
+
+    pub fn tag(&self) -> &EnumTag {
+        &self.tag
+    }
 }
 
 /// Represents variant attribute information
@@ -231,7 +316,7 @@ impl Variant {
                     }
 
                     Literal(_) => {
-                        cx.error(format!("unexpected literal in serde variant attribute"));
+                        cx.error("unexpected literal in serde variant attribute");
                     }
                 }
             }
@@ -390,7 +475,7 @@ impl Field {
                     }
 
                     Literal(_) => {
-                        cx.error(format!("unexpected literal in serde field attribute"));
+                        cx.error("unexpected literal in serde field attribute");
                     }
                 }
             }
@@ -404,7 +489,7 @@ impl Field {
 
         Field {
             name: Name {
-                serialize: ser_name.get().unwrap_or(ident.clone()),
+                serialize: ser_name.get().unwrap_or_else(|| ident.clone()),
                 deserialize: de_name.get().unwrap_or(ident),
             },
             skip_serializing: skip_serializing.get(),

serde_codegen_internals/src/lib.rs

@@ -1,6 +1,3 @@
-#![cfg_attr(feature = "clippy", plugin(clippy))]
-#![cfg_attr(feature = "clippy", feature(plugin))]
-
 extern crate syn;
 
 pub mod ast;

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "0.9.0-rc1"
+version = "0.9.6"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"
@@ -10,18 +10,17 @@ documentation = "https://serde.rs/codegen.html"
 keywords = ["serde", "serialization"]
 include = ["Cargo.toml", "src/**/*.rs"]
 
+[features]
+unstable = []
+
+[badges]
+travis-ci = { repository = "serde-rs/serde" }
+
 [lib]
 name = "serde_derive"
 proc-macro = true
 
-[dependencies.serde_codegen]
+[dependencies]
-version = "=0.9.0-rc1"
+quote = "0.3.8"
-path = "../serde_codegen"
+serde_codegen_internals = { version = "=0.13.0", default-features = false, path = "../serde_codegen_internals" }
-default-features = false
+syn = { version = "0.11", features = ["aster", "visit"] }
-features = ["with-syn"]
-
-[dev-dependencies]
-compiletest_rs = "^0.2.0"
-fnv = "1.0"
-serde = { version = "0.9.0-rc1", path = "../serde" }
-serde_test = { version = "0.9.0-rc1", path = "../serde_test" }

serde_derive/src/de.rs

@@ -1,5 +1,5 @@
 use syn::{self, aster, Ident};
-use quote::Tokens;
+use quote::{self, Tokens};
 
 use bound;
 use internals::ast::{Body, Field, Item, Style, Variant};
@@ -7,7 +7,7 @@ use internals::{self, attr};
 
 use std::iter;
 
-pub fn expand_derive_deserialize(item: &syn::MacroInput) -> Result<Tokens, String> {
+pub fn expand_derive_deserialize(item: &syn::DeriveInput) -> Result<Tokens, String> {
     let item = {
         let ctxt = internals::Ctxt::new();
         let item = Item::from_ast(&ctxt, item);
@@ -36,7 +36,7 @@ pub fn expand_derive_deserialize(item: &syn::MacroInput) -> Result<Tokens, Strin
             extern crate serde as _serde;
             #[automatically_derived]
             impl #impl_generics _serde::Deserialize for #ty #where_clause {
-                fn deserialize<__D>(deserializer: __D) -> ::std::result::Result<#ty, __D::Error>
+                fn deserialize<__D>(deserializer: __D) -> _serde::export::Result<#ty, __D::Error>
                     where __D: _serde::Deserializer
                 #body
             }
@@ -110,7 +110,8 @@ fn deserialize_body(
                 impl_generics,
                 ty,
                 fields,
-                &item.attrs)
+                &item.attrs,
+                None)
         }
         Body::Struct(Style::Tuple, ref fields) |
         Body::Struct(Style::Newtype, ref fields) => {
@@ -124,7 +125,8 @@ fn deserialize_body(
                 impl_generics,
                 ty,
                 fields,
-                &item.attrs)
+                &item.attrs,
+                None)
         }
         Body::Struct(Style::Unit, _) => {
             deserialize_unit_struct(
@@ -158,11 +160,11 @@ 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()
@@ -182,7 +184,7 @@ fn deserialize_visitor(generics: &syn::Generics) -> (Tokens, Tokens, Tokens) {
             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! {
@@ -200,24 +202,30 @@ 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;
 
-            #[inline]
+            fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
-            fn visit_unit<__E>(self) -> ::std::result::Result<#type_ident, __E>
+                _serde::export::fmt::Formatter::write_str(formatter, #expecting)
-                where __E: _serde::de::Error,
-            {
-                Ok(#type_ident)
             }
 
             #[inline]
-            fn visit_seq<__V>(self, _: __V) -> ::std::result::Result<#type_ident, __V::Error>
+            fn visit_unit<__E>(self) -> _serde::export::Result<#type_ident, __E>
+                where __E: _serde::de::Error,
+            {
+                _serde::export::Ok(#type_ident)
+            }
+
+            #[inline]
+            fn visit_seq<__V>(self, _: __V) -> _serde::export::Result<#type_ident, __V::Error>
                 where __V: _serde::de::SeqVisitor,
             {
-                Ok(#type_ident)
+                _serde::export::Ok(#type_ident)
             }
         }
 
@@ -232,6 +240,7 @@ fn deserialize_tuple(
     ty: syn::Ty,
     fields: &[Field],
     item_attrs: &attr::Item,
+    deserializer: Option<Tokens>,
 ) -> Tokens {
     let where_clause = &impl_generics.where_clause;
 
@@ -242,6 +251,10 @@ 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();
 
@@ -264,14 +277,16 @@ fn deserialize_tuple(
         false,
     );
 
-    let dispatch = if is_enum {
+    let dispatch = if let Some(deserializer) = deserializer {
+        quote!(_serde::Deserializer::deserialize(#deserializer, #visitor_expr))
+    } else if is_enum {
         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))
+        quote!(_serde::Deserializer::deserialize_newtype_struct(deserializer, #type_name, #visitor_expr))
     } else {
         let type_name = item_attrs.name().deserialize_name();
-        quote!(deserializer.deserialize_tuple_struct(#type_name, #nfields, #visitor_expr))
+        quote!(_serde::Deserializer::deserialize_tuple_struct(deserializer, #type_name, #nfields, #visitor_expr))
     };
 
     let all_skipped = fields.iter().all(|field| field.attrs.skip_deserializing());
@@ -287,10 +302,14 @@ fn deserialize_tuple(
         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 {
+                _serde::export::fmt::Formatter::write_str(formatter, #expecting)
+            }
+
             #visit_newtype_struct
 
             #[inline]
-            fn visit_seq<__V>(self, #visitor_var: __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
@@ -310,6 +329,11 @@ fn deserialize_seq(
 ) -> 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 = vars.clone().zip(fields)
         .map(|(var, field)| {
@@ -322,7 +346,7 @@ fn deserialize_seq(
                 let visit = match field.attrs.deserialize_with() {
                     None => {
                         let field_ty = &field.ty;
-                        quote!(try!(visitor.visit::<#field_ty>()))
+                        quote!(try!(_serde::de::SeqVisitor::visit::<#field_ty>(&mut visitor)))
                     }
                     Some(path) => {
                         let (wrapper, wrapper_impl, wrapper_ty) = wrap_deserialize_with(
@@ -330,7 +354,8 @@ fn deserialize_seq(
                         quote!({
                             #wrapper
                             #wrapper_impl
-                            try!(visitor.visit::<#wrapper_ty>()).map(|wrap| wrap.value)
+                            try!(_serde::de::SeqVisitor::visit::<#wrapper_ty>(&mut visitor))
+                                .map(|wrap| wrap.value)
                         })
                     }
                 };
@@ -338,7 +363,7 @@ fn deserialize_seq(
                     let #var = match #visit {
                         Some(value) => { value },
                         None => {
-                            return Err(_serde::de::Error::invalid_length(#index_in_seq));
+                            return _serde::export::Err(_serde::de::Error::invalid_length(#index_in_seq, &#expecting));
                         }
                     };
                 };
@@ -360,7 +385,7 @@ fn deserialize_seq(
 
     quote! {
         #(#let_values)*
-        Ok(#result)
+        _serde::export::Ok(#result)
     }
 }
 
@@ -389,10 +414,10 @@ fn deserialize_newtype_struct(
     };
     quote! {
         #[inline]
-        fn visit_newtype_struct<__E>(self, __e: __E) -> ::std::result::Result<Self::Value, __E::Error>
+        fn visit_newtype_struct<__E>(self, __e: __E) -> _serde::export::Result<Self::Value, __E::Error>
             where __E: _serde::Deserializer,
         {
-            Ok(#type_path(#value))
+            _serde::export::Ok(#type_path(#value))
         }
     }
 }
@@ -404,7 +429,11 @@ fn deserialize_struct(
     ty: syn::Ty,
     fields: &[Field],
     item_attrs: &attr::Item,
+    deserializer: Option<Tokens>,
 ) -> Tokens {
+    let is_enum = variant_ident.is_some();
+    let is_untagged = deserializer.is_some();
+
     let where_clause = &impl_generics.where_clause;
 
     let (visitor_item, visitor_ty, visitor_expr) = deserialize_visitor(impl_generics);
@@ -413,6 +442,10 @@ 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,
@@ -430,15 +463,18 @@ fn deserialize_struct(
         item_attrs,
     );
 
-    let is_enum = variant_ident.is_some();
+    let dispatch = if let Some(deserializer) = deserializer {
-    let dispatch = if is_enum {
+        quote! {
+            _serde::Deserializer::deserialize(#deserializer, #visitor_expr)
+        }
+    } else if is_enum {
         quote! {
             _serde::de::VariantVisitor::visit_struct(visitor, FIELDS, #visitor_expr)
         }
     } else {
         let type_name = item_attrs.name().deserialize_name();
         quote! {
-            deserializer.deserialize_struct(#type_name, FIELDS, #visitor_expr)
+            _serde::Deserializer::deserialize_struct(deserializer, #type_name, FIELDS, #visitor_expr)
         }
     };
 
@@ -449,6 +485,20 @@ fn deserialize_struct(
         quote!(mut visitor)
     };
 
+    let visit_seq = if is_untagged {
+        // untagged struct variants do not get a visit_seq method
+        None
+    } else {
+        Some(quote! {
+            #[inline]
+            fn visit_seq<__V>(self, #visitor_var: __V) -> _serde::export::Result<#ty, __V::Error>
+                where __V: _serde::de::SeqVisitor
+            {
+                #visit_seq
+            }
+        })
+    };
+
     quote!({
         #field_visitor
 
@@ -457,15 +507,14 @@ fn deserialize_struct(
         impl #impl_generics _serde::de::Visitor for #visitor_ty #where_clause {
             type Value = #ty;
 
-            #[inline]
+            fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
-            fn visit_seq<__V>(self, #visitor_var: __V) -> ::std::result::Result<#ty, __V::Error>
+                _serde::export::fmt::Formatter::write_str(formatter, #expecting)
-                where __V: _serde::de::SeqVisitor
-            {
-                #visit_seq
             }
 
+            #visit_seq
+
             #[inline]
-            fn visit_map<__V>(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
@@ -484,29 +533,71 @@ fn deserialize_item_enum(
     ty: syn::Ty,
     variants: &[Variant],
     item_attrs: &attr::Item
+) -> Tokens {
+    match *item_attrs.tag() {
+        attr::EnumTag::External => {
+            deserialize_externally_tagged_enum(
+                type_ident,
+                impl_generics,
+                ty,
+                variants,
+                item_attrs,
+            )
+        }
+        attr::EnumTag::Internal(ref tag) => {
+            deserialize_internally_tagged_enum(
+                type_ident,
+                impl_generics,
+                ty,
+                variants,
+                item_attrs,
+                tag,
+            )
+        }
+        attr::EnumTag::None => {
+            deserialize_untagged_enum(
+                type_ident,
+                impl_generics,
+                ty,
+                variants,
+                item_attrs,
+            )
+        }
+    }
+}
+
+fn deserialize_externally_tagged_enum(
+    type_ident: &syn::Ident,
+    impl_generics: &syn::Generics,
+    ty: syn::Ty,
+    variants: &[Variant],
+    item_attrs: &attr::Item,
 ) -> Tokens {
     let where_clause = &impl_generics.where_clause;
 
     let type_name = item_attrs.name().deserialize_name();
 
-    let variant_names_idents = variants.iter()
+    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(
         variant_names_idents,
         item_attrs,
         true,
     );
 
-    let variant_names = variants.iter().map(|variant| variant.attrs.name().deserialize_name());
-
-    let variants_stmt = quote! {
-        const VARIANTS: &'static [&'static str] = &[ #(#variant_names),* ];
-    };
-
     // Match arms to extract a variant from a string
     let variant_arms = variants.iter()
         .enumerate()
@@ -514,7 +605,7 @@ fn deserialize_item_enum(
         .map(|(i, variant)| {
             let variant_name = field_i(i);
 
-            let block = deserialize_variant(
+            let block = deserialize_externally_tagged_variant(
                 type_ident,
                 impl_generics,
                 ty.clone(),
@@ -533,13 +624,14 @@ fn deserialize_item_enum(
         // all variants have `#[serde(skip_deserializing)]`.
         quote! {
             // FIXME: Once we drop support for Rust 1.15:
-            // let Err(err) = visitor.visit_variant::<__Field>();
+            // let _serde::export::Err(err) = _serde::de::EnumVisitor::visit_variant::<__Field>(visitor);
-            // Err(err)
+            // _serde::export::Err(err)
-            visitor.visit_variant::<__Field>().map(|(impossible, _)| match impossible {})
+            _serde::de::EnumVisitor::visit_variant::<__Field>(visitor)
+                .map(|(impossible, _)| match impossible {})
         }
     } else {
         quote! {
-            match try!(visitor.visit_variant()) {
+            match try!(_serde::de::EnumVisitor::visit_variant(visitor)) {
                 #(#variant_arms)*
             }
         }
@@ -555,7 +647,11 @@ fn deserialize_item_enum(
         impl #impl_generics _serde::de::Visitor for #visitor_ty #where_clause {
             type Value = #ty;
 
-            fn visit_enum<__V>(self, visitor: __V) -> ::std::result::Result<#ty, __V::Error>
+            fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
+                _serde::export::fmt::Formatter::write_str(formatter, #expecting)
+            }
+
+            fn visit_enum<__V>(self, visitor: __V) -> _serde::export::Result<#ty, __V::Error>
                 where __V: _serde::de::EnumVisitor,
             {
                 #match_variant
@@ -564,11 +660,115 @@ fn deserialize_item_enum(
 
         #variants_stmt
 
-        deserializer.deserialize_enum(#type_name, VARIANTS, #visitor_expr)
+        _serde::Deserializer::deserialize_enum(deserializer, #type_name, VARIANTS, #visitor_expr)
     })
 }
 
-fn deserialize_variant(
+fn deserialize_internally_tagged_enum(
+    type_ident: &syn::Ident,
+    impl_generics: &syn::Generics,
+    ty: syn::Ty,
+    variants: &[Variant],
+    item_attrs: &attr::Item,
+    tag: &str,
+) -> Tokens {
+    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(
+        variant_names_idents,
+        item_attrs,
+        true,
+    );
+
+    // Match arms to extract a variant from a string
+    let variant_arms = variants.iter()
+        .enumerate()
+        .filter(|&(_, variant)| !variant.attrs.skip_deserializing())
+        .map(|(i, variant)| {
+            let variant_name = field_i(i);
+
+            let block = deserialize_internally_tagged_variant(
+                type_ident,
+                impl_generics,
+                ty.clone(),
+                variant,
+                item_attrs,
+                quote!(_tagged.content),
+            );
+
+            quote! {
+                __Field::#variant_name => #block
+            }
+        });
+
+    quote!({
+        #variant_visitor
+
+        #variants_stmt
+
+        let _tagged = try!(_serde::Deserializer::deserialize(
+            deserializer,
+            _serde::de::private::TaggedContentVisitor::<__Field, __D::Error>::new(#tag)));
+
+        match _tagged.tag {
+            #(#variant_arms)*
+        }
+    })
+}
+
+fn deserialize_untagged_enum(
+    type_ident: &syn::Ident,
+    impl_generics: &syn::Generics,
+    ty: syn::Ty,
+    variants: &[Variant],
+    item_attrs: &attr::Item,
+) -> Tokens {
+    let attempts = variants.iter()
+        .filter(|variant| !variant.attrs.skip_deserializing())
+        .map(|variant| {
+            deserialize_untagged_variant(
+                type_ident,
+                impl_generics,
+                ty.clone(),
+                variant,
+                item_attrs,
+                quote!(&_content),
+            )
+        });
+
+    // TODO this message could be better by saving the errors from the failed
+    // attempts. The heuristic used by TOML was to count the number of fields
+    // processed before an error, and use the error that happened after the
+    // largest number of fields. I'm not sure I like that. Maybe it would be
+    // better to save all the errors and combine them into one message that
+    // explains why none of the variants matched.
+    let fallthrough_msg = format!("data did not match any variant of untagged enum {}", type_ident);
+
+    quote!({
+        let _content = try!(<_serde::de::private::Content<__D::Error> as _serde::Deserialize>::deserialize(deserializer));
+
+        #(
+            if let _serde::export::Ok(ok) = #attempts {
+                return _serde::export::Ok(ok);
+            }
+        )*
+
+        _serde::export::Err(_serde::de::Error::custom(#fallthrough_msg))
+    })
+}
+
+fn deserialize_externally_tagged_variant(
     type_ident: &syn::Ident,
     generics: &syn::Generics,
     ty: syn::Ty,
@@ -581,11 +781,11 @@ fn deserialize_variant(
         Style::Unit => {
             quote!({
                 try!(_serde::de::VariantVisitor::visit_unit(visitor));
-                Ok(#type_ident::#variant_ident)
+                _serde::export::Ok(#type_ident::#variant_ident)
             })
         }
         Style::Newtype => {
-            deserialize_newtype_variant(
+            deserialize_externally_tagged_newtype_variant(
                 type_ident,
                 variant_ident,
                 generics,
@@ -600,6 +800,7 @@ fn deserialize_variant(
                 ty,
                 &variant.fields,
                 item_attrs,
+                None,
             )
         }
         Style::Struct => {
@@ -610,22 +811,115 @@ fn deserialize_variant(
                 ty,
                 &variant.fields,
                 item_attrs,
+                None,
             )
         }
     }
 }
 
-fn deserialize_newtype_variant(
+fn deserialize_internally_tagged_variant(
+    type_ident: &syn::Ident,
+    generics: &syn::Generics,
+    ty: syn::Ty,
+    variant: &Variant,
+    item_attrs: &attr::Item,
+    deserializer: Tokens,
+) -> Tokens {
+    let variant_ident = &variant.ident;
+
+    match variant.style {
+        Style::Unit => {
+            let type_name = type_ident.as_ref();
+            let variant_name = variant.ident.as_ref();
+            quote!({
+                try!(_serde::Deserializer::deserialize(#deserializer, _serde::de::private::InternallyTaggedUnitVisitor::new(#type_name, #variant_name)));
+                _serde::export::Ok(#type_ident::#variant_ident)
+            })
+        }
+        Style::Newtype | Style::Struct => {
+            deserialize_untagged_variant(
+                type_ident,
+                generics,
+                ty,
+                variant,
+                item_attrs,
+                deserializer,
+            )
+        }
+        Style::Tuple => unreachable!("checked in serde_codegen_internals"),
+    }
+}
+
+fn deserialize_untagged_variant(
+    type_ident: &syn::Ident,
+    generics: &syn::Generics,
+    ty: syn::Ty,
+    variant: &Variant,
+    item_attrs: &attr::Item,
+    deserializer: Tokens,
+) -> Tokens {
+    let variant_ident = &variant.ident;
+
+    match variant.style {
+        Style::Unit => {
+            let type_name = type_ident.as_ref();
+            let variant_name = variant.ident.as_ref();
+            quote! {
+                _serde::export::Result::map(
+                    _serde::Deserializer::deserialize(
+                        #deserializer,
+                        _serde::de::private::UntaggedUnitVisitor::new(#type_name, #variant_name)
+                    ),
+                    |()| #type_ident::#variant_ident)
+            }
+        }
+        Style::Newtype => {
+            deserialize_untagged_newtype_variant(
+                type_ident,
+                variant_ident,
+                generics,
+                &variant.fields[0],
+                deserializer,
+            )
+        }
+        Style::Tuple => {
+            deserialize_tuple(
+                type_ident,
+                Some(variant_ident),
+                generics,
+                ty,
+                &variant.fields,
+                item_attrs,
+                Some(deserializer),
+            )
+        }
+        Style::Struct => {
+            deserialize_struct(
+                type_ident,
+                Some(variant_ident),
+                generics,
+                ty,
+                &variant.fields,
+                item_attrs,
+                Some(deserializer),
+            )
+        }
+    }
+}
+
+fn deserialize_externally_tagged_newtype_variant(
     type_ident: &syn::Ident,
     variant_ident: &syn::Ident,
     impl_generics: &syn::Generics,
     field: &Field,
 ) -> Tokens {
-    let visit = match field.attrs.deserialize_with() {
+    match field.attrs.deserialize_with() {
         None => {
             let field_ty = &field.ty;
             quote! {
-                try!(_serde::de::VariantVisitor::visit_newtype::<#field_ty>(visitor))
+                _serde::export::Result::map(
+                    _serde::de::VariantVisitor::visit_newtype::<#field_ty>(visitor),
+                    #type_ident::#variant_ident),
             }
         }
         Some(path) => {
@@ -634,12 +928,41 @@ fn deserialize_newtype_variant(
             quote!({
                 #wrapper
                 #wrapper_impl
-                try!(_serde::de::VariantVisitor::visit_newtype::<#wrapper_ty>(visitor)).value
+                _serde::export::Result::map(
+                    _serde::de::VariantVisitor::visit_newtype::<#wrapper_ty>(visitor),
+                    |_wrapper| #type_ident::#variant_ident(_wrapper.value))
+            })
+        }
+    }
+}
+
+fn deserialize_untagged_newtype_variant(
+    type_ident: &syn::Ident,
+    variant_ident: &syn::Ident,
+    impl_generics: &syn::Generics,
+    field: &Field,
+    deserializer: Tokens,
+) -> Tokens {
+    match field.attrs.deserialize_with() {
+        None => {
+            let field_ty = &field.ty;
+            quote!({
+                _serde::export::Result::map(
+                    <#field_ty as _serde::Deserialize>::deserialize(#deserializer),
+                    #type_ident::#variant_ident)
+            })
+        }
+        Some(path) => {
+            let (wrapper, wrapper_impl, wrapper_ty) = wrap_deserialize_with(
+                type_ident, impl_generics, field.ty, path);
+            quote!({
+                #wrapper
+                #wrapper_impl
+                _serde::export::Result::map(
+                    <#wrapper_ty as _serde::Deserialize>::deserialize(#deserializer),
+                    |_wrapper| #type_ident::#variant_ident(_wrapper.value))
             })
         }
-    };
-    quote! {
-        Ok(#type_ident::#variant_ident(#visit)),
     }
 }
 
@@ -648,7 +971,8 @@ fn deserialize_field_visitor(
     item_attrs: &attr::Item,
     is_variant: bool,
 ) -> Tokens {
-    let field_names = fields.iter().map(|&(ref name, _)| name);
+    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 is_variant || item_attrs.deny_unknown_fields() {
@@ -657,20 +981,51 @@ fn deserialize_field_visitor(
         Some(quote!(__ignore,))
     };
 
+    let visit_index = if is_variant {
+        let variant_indices = 0u32..;
+        let fallthrough_msg = format!("variant index 0 <= i < {}", fields.len());
+        Some(quote! {
+            fn visit_u32<__E>(self, value: u32) -> _serde::export::Result<__Field, __E>
+                where __E: _serde::de::Error
+            {
+                match value {
+                    #(
+                        #variant_indices => _serde::export::Ok(__Field::#field_idents),
+                    )*
+                    _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                                _serde::de::Unexpected::Unsigned(value as u64),
+                                &#fallthrough_msg))
+                }
+            }
+        })
+    } else {
+        None
+    };
+
     let fallthrough_arm = if is_variant {
         quote! {
-            Err(_serde::de::Error::unknown_variant(value))
+            _serde::export::Err(_serde::de::Error::unknown_variant(value, VARIANTS))
         }
     } else if item_attrs.deny_unknown_fields() {
         quote! {
-            Err(_serde::de::Error::unknown_field(value))
+            _serde::export::Err(_serde::de::Error::unknown_field(value, FIELDS))
         }
     } else {
         quote! {
-            Ok(__Field::__ignore)
+            _serde::export::Ok(__Field::__ignore)
         }
     };
 
+    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);
+        })
+    } else {
+        None
+    };
+
     quote! {
         #[allow(non_camel_case_types)]
         enum __Field {
@@ -680,7 +1035,7 @@ fn deserialize_field_visitor(
 
         impl _serde::Deserialize for __Field {
             #[inline]
-            fn deserialize<__D>(deserializer: __D) -> ::std::result::Result<__Field, __D::Error>
+            fn deserialize<__D>(deserializer: __D) -> _serde::export::Result<__Field, __D::Error>
                 where __D: _serde::Deserializer,
             {
                 struct __FieldVisitor;
@@ -688,19 +1043,39 @@ fn deserialize_field_visitor(
                 impl _serde::de::Visitor for __FieldVisitor {
                     type Value = __Field;
 
-                    fn visit_str<__E>(self, value: &str) -> ::std::result::Result<__Field, __E>
+                    fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
+                        _serde::export::fmt::Formatter::write_str(formatter, "field name")
+                    }
+
+                    #visit_index
+
+                    fn visit_str<__E>(self, value: &str) -> _serde::export::Result<__Field, __E>
                         where __E: _serde::de::Error
                     {
                         match value {
                             #(
-                                #field_names => Ok(__Field::#field_idents),
+                                #field_strs => _serde::export::Ok(__Field::#field_idents),
                             )*
                             _ => #fallthrough_arm
                         }
                     }
+
+                    fn visit_bytes<__E>(self, value: &[u8]) -> _serde::export::Result<__Field, __E>
+                        where __E: _serde::de::Error
+                    {
+                        match value {
+                            #(
+                                #field_bytes => _serde::export::Ok(__Field::#field_idents),
+                            )*
+                            _ => {
+                                #bytes_to_str
+                                #fallthrough_arm
+                            }
+                        }
+                    }
                 }
 
-                deserializer.deserialize_struct_field(__FieldVisitor)
+                _serde::Deserializer::deserialize_struct_field(deserializer, __FieldVisitor)
             }
         }
     }
@@ -713,12 +1088,19 @@ fn deserialize_struct_visitor(
     fields: &[Field],
     item_attrs: &attr::Item,
 ) -> (Tokens, Tokens, Tokens) {
-    let field_names_idents = fields.iter()
+    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_names_idents,
         item_attrs,
@@ -733,11 +1115,6 @@ fn deserialize_struct_visitor(
         item_attrs,
     );
 
-    let field_names = fields.iter().map(|field| field.attrs.name().deserialize_name());
-    let fields_stmt = quote! {
-        const FIELDS: &'static [&'static str] = &[ #(#field_names),* ];
-    };
-
     (field_visitor, fields_stmt, visit_map)
 }
 
@@ -760,7 +1137,7 @@ fn deserialize_map(
         .map(|&(field, ref name)| {
             let field_ty = &field.ty;
             quote! {
-                let mut #name: Option<#field_ty> = None;
+                let mut #name: _serde::export::Option<#field_ty> = _serde::export::None;
             }
         });
 
@@ -774,7 +1151,7 @@ fn deserialize_map(
                 None => {
                     let field_ty = &field.ty;
                     quote! {
-                        try!(visitor.visit_value::<#field_ty>())
+                        try!(_serde::de::MapVisitor::visit_value::<#field_ty>(&mut visitor))
                     }
                 }
                 Some(path) => {
@@ -783,16 +1160,16 @@ fn deserialize_map(
                     quote!({
                         #wrapper
                         #wrapper_impl
-                        try!(visitor.visit_value::<#wrapper_ty>()).value
+                        try!(_serde::de::MapVisitor::visit_value::<#wrapper_ty>(&mut visitor)).value
                     })
                 }
             };
             quote! {
                 __Field::#name => {
-                    if #name.is_some() {
+                    if _serde::export::Option::is_some(&#name) {
-                        return Err(<__V::Error as _serde::de::Error>::duplicate_field(#deser_name));
+                        return _serde::export::Err(<__V::Error as _serde::de::Error>::duplicate_field(#deser_name));
                     }
-                    #name = Some(#visit);
+                    #name = _serde::export::Some(#visit);
                 }
             }
         });
@@ -802,7 +1179,7 @@ fn deserialize_map(
         None
     } else {
         Some(quote! {
-            _ => { let _ = try!(visitor.visit_value::<_serde::de::impls::IgnoredAny>()); }
+            _ => { let _ = try!(_serde::de::MapVisitor::visit_value::<_serde::de::impls::IgnoredAny>(&mut visitor)); }
         })
     };
 
@@ -810,12 +1187,13 @@ fn deserialize_map(
     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());
+            // let _serde::export::None::<__Field> = try!(_serde::de::MapVisitor::visit_key(&mut visitor));
-            try!(visitor.visit_key::<__Field>()).map(|impossible| match impossible {});
+            try!(_serde::de::MapVisitor::visit_key::<__Field>(&mut visitor))
+                .map(|impossible| match impossible {});
         }
     } else {
         quote! {
-            while let Some(key) = try!(visitor.visit_key::<__Field>()) {
+            while let _serde::export::Some(key) = try!(_serde::de::MapVisitor::visit_key::<__Field>(&mut visitor)) {
                 match key {
                     #(#value_arms)*
                     #ignored_arm
@@ -831,8 +1209,8 @@ fn deserialize_map(
 
             quote! {
                 let #name = match #name {
-                    Some(#name) => #name,
+                    _serde::export::Some(#name) => #name,
-                    None => #missing_expr
+                    _serde::export::None => #missing_expr
                 };
             }
         });
@@ -855,7 +1233,7 @@ fn deserialize_map(
 
         #(#extract_values)*
 
-        Ok(#struct_path { #(#result),* })
+        _serde::export::Ok(#struct_path { #(#result),* })
     }
 }
 
@@ -893,18 +1271,18 @@ 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::Deserialize for #wrapper_ty #where_clause {
-                fn deserialize<__D>(__d: __D) -> ::std::result::Result<Self, __D::Error>
+                fn deserialize<__D>(__d: __D) -> _serde::export::Result<Self, __D::Error>
                     where __D: _serde::Deserializer
                 {
                     let value = try!(#deserialize_with(__d));
-                    Ok(__SerdeDeserializeWithStruct {
+                    _serde::export::Ok(__SerdeDeserializeWithStruct {
                         value: value,
-                        phantom: ::std::marker::PhantomData,
+                        phantom: _serde::export::PhantomData,
                     })
                 }
             }
@@ -916,7 +1294,7 @@ 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());
@@ -928,12 +1306,12 @@ 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(_) => {
             quote! {
-                return Err(<__V::Error as _serde::de::Error>::missing_field(#name))
+                return _serde::export::Err(<__V::Error as _serde::de::Error>::missing_field(#name))
             }
         }
     }

serde_derive/src/lib.rs

@@ -1,11 +1,26 @@
-extern crate proc_macro;
+#![cfg_attr(feature = "cargo-clippy", allow(too_many_arguments))]
-extern crate serde_codegen;
+#![cfg_attr(feature = "cargo-clippy", allow(used_underscore_binding))]
 
+// The `quote!` macro requires deep recursion.
+#![recursion_limit = "192"]
+
+extern crate syn;
+#[macro_use]
+extern crate quote;
+
+extern crate serde_codegen_internals as internals;
+
+extern crate proc_macro;
 use proc_macro::TokenStream;
 
+mod bound;
+mod de;
+mod ser;
+
 #[proc_macro_derive(Serialize, attributes(serde))]
 pub fn derive_serialize(input: TokenStream) -> TokenStream {
-    match serde_codegen::expand_derive_serialize(&input.to_string()) {
+    let input = syn::parse_derive_input(&input.to_string()).unwrap();
+    match ser::expand_derive_serialize(&input) {
         Ok(expanded) => expanded.parse().unwrap(),
         Err(msg) => panic!(msg),
     }
@@ -13,7 +28,8 @@ pub fn derive_serialize(input: TokenStream) -> TokenStream {
 
 #[proc_macro_derive(Deserialize, attributes(serde))]
 pub fn derive_deserialize(input: TokenStream) -> TokenStream {
-    match serde_codegen::expand_derive_deserialize(&input.to_string()) {
+    let input = syn::parse_derive_input(&input.to_string()).unwrap();
+    match de::expand_derive_deserialize(&input) {
         Ok(expanded) => expanded.parse().unwrap(),
         Err(msg) => panic!(msg),
     }

serde_derive/src/ser.rs

@@ -5,7 +5,7 @@ use bound;
 use internals::ast::{Body, Field, Item, Style, Variant};
 use internals::{self, attr};
 
-pub fn expand_derive_serialize(item: &syn::MacroInput) -> Result<Tokens, String> {
+pub fn expand_derive_serialize(item: &syn::DeriveInput) -> Result<Tokens, String> {
     let ctxt = internals::Ctxt::new();
     let item = Item::from_ast(&ctxt, item);
     try!(ctxt.check());
@@ -30,7 +30,7 @@ pub fn expand_derive_serialize(item: &syn::MacroInput) -> Result<Tokens, String>
             extern crate serde as _serde;
             #[automatically_derived]
             impl #impl_generics _serde::Serialize for #ty #where_clause {
-                fn serialize<__S>(&self, _serializer: __S) -> ::std::result::Result<__S::Ok, __S::Error>
+                fn serialize<__S>(&self, _serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
                     where __S: _serde::Serializer
                 {
                     #body
@@ -125,7 +125,7 @@ fn serialize_unit_struct(item_attrs: &attr::Item) -> Tokens {
     let type_name = item_attrs.name().serialize_name();
 
     quote! {
-        _serializer.serialize_unit_struct(#type_name)
+        _serde::Serializer::serialize_unit_struct(_serializer, #type_name)
     }
 }
 
@@ -144,7 +144,7 @@ fn serialize_newtype_struct(
     }
 
     quote! {
-        _serializer.serialize_newtype_struct(#type_name, #field_expr)
+        _serde::Serializer::serialize_newtype_struct(_serializer, #type_name, #field_expr)
     }
 }
 
@@ -167,7 +167,7 @@ fn serialize_tuple_struct(
     let let_mut = mut_if(len > 0);
 
     quote! {
-        let #let_mut __serde_state = try!(_serializer.serialize_tuple_struct(#type_name, #len));
+        let #let_mut __serde_state = try!(_serde::Serializer::serialize_tuple_struct(_serializer, #type_name, #len));
         #(#serialize_stmts)*
         _serde::ser::SerializeTupleStruct::end(__serde_state)
     }
@@ -208,7 +208,7 @@ fn serialize_struct(
         .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
 
     quote! {
-        let #let_mut __serde_state = try!(_serializer.serialize_struct(#type_name, #len));
+        let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct(_serializer, #type_name, #len));
         #(#serialize_fields)*
         _serde::ser::SerializeStruct::end(__serde_state)
     }
@@ -251,16 +251,13 @@ fn serialize_variant(
     variant_index: usize,
     item_attrs: &attr::Item,
 ) -> Tokens {
-    let type_name = item_attrs.name().serialize_name();
-
     let variant_ident = variant.ident.clone();
-    let variant_name = variant.attrs.name().serialize_name();
 
     if variant.attrs.skip_serializing() {
-        let skipped_msg = format!("The enum variant {}::{} cannot be serialized",
+        let skipped_msg = format!("the enum variant {}::{} cannot be serialized",
-                                type_ident, variant_ident);
+                                  type_ident, variant_ident);
         let skipped_err = quote! {
-            Err(_serde::ser::Error::invalid_value(#skipped_msg))
+            _serde::export::Err(_serde::ser::Error::custom(#skipped_msg))
         };
         let fields_pat = match variant.style {
             Style::Unit => quote!(),
@@ -271,139 +268,351 @@ fn serialize_variant(
             #type_ident::#variant_ident #fields_pat => #skipped_err,
         }
     } else { // variant wasn't skipped
-        match variant.style {
+        let case = match variant.style {
             Style::Unit => {
                 quote! {
-                    #type_ident::#variant_ident =>
+                    #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],
-                );
-
                 quote! {
-                    #type_ident::#variant_ident(ref __simple_value) => #block,
+                    #type_ident::#variant_ident(ref __simple_value)
                 }
-            },
+            }
             Style::Tuple => {
                 let field_names = (0 .. variant.fields.len())
                     .map(|i| Ident::new(format!("__field{}", i)));
-
-                let block = serialize_tuple_variant(
-                    type_name,
-                    variant_index,
-                    variant_name,
-                    generics,
-                    ty,
-                    &variant.fields,
-                );
-
                 quote! {
-                    #type_ident::#variant_ident(#(ref #field_names),*) => { #block }
+                    #type_ident::#variant_ident(#(ref #field_names),*)
                 }
             }
             Style::Struct => {
                 let fields = variant.fields.iter()
                     .map(|f| f.ident.clone().expect("struct variant has unnamed fields"));
+                quote! {
+                    #type_ident::#variant_ident { #(ref #fields),* }
+                }
+            }
+        };
 
-                let block = serialize_struct_variant(
+        let body = match *item_attrs.tag() {
-                    variant_index,
+            attr::EnumTag::External => {
-                    variant_name,
+                serialize_externally_tagged_variant(
                     generics,
                     ty,
-                    &variant.fields,
+                    variant,
+                    variant_index,
                     item_attrs,
-                );
+                )
+            }
+            attr::EnumTag::Internal(ref tag) => {
+                serialize_internally_tagged_variant(
+                    type_ident.as_ref(),
+                    variant_ident.as_ref(),
+                    generics,
+                    ty,
+                    variant,
+                    item_attrs,
+                    tag,
+                )
+            }
+            attr::EnumTag::None => {
+                serialize_untagged_variant(
+                    generics,
+                    ty,
+                    variant,
+                    item_attrs,
+                )
+            }
+        };
 
-                quote! {
+        quote! {
-                    #type_ident::#variant_ident { #(ref #fields),* } => { #block }
+            #case => #body
-                }
+        }
+    }
+}
+
+fn serialize_externally_tagged_variant(
+    generics: &syn::Generics,
+    ty: syn::Ty,
+    variant: &Variant,
+    variant_index: usize,
+    item_attrs: &attr::Item,
+) -> Tokens {
+    let type_name = item_attrs.name().serialize_name();
+    let variant_name = variant.attrs.name().serialize_name();
+
+    match variant.style {
+        Style::Unit => {
+            quote! {
+                _serde::Serializer::serialize_unit_variant(
+                    _serializer,
+                    #type_name,
+                    #variant_index,
+                    #variant_name,
+                ),
+            }
+        }
+        Style::Newtype => {
+            let field = &variant.fields[0];
+            let mut field_expr = quote!(__simple_value);
+            if let Some(path) = field.attrs.serialize_with() {
+                field_expr = wrap_serialize_with(
+                    &ty, generics, field.ty, path, field_expr);
+            }
+
+            quote! {
+                _serde::Serializer::serialize_newtype_variant(
+                    _serializer,
+                    #type_name,
+                    #variant_index,
+                    #variant_name,
+                    #field_expr,
+                ),
+            }
+        }
+        Style::Tuple => {
+            let block = serialize_tuple_variant(
+                TupleVariant::ExternallyTagged {
+                    type_name: type_name,
+                    variant_index: variant_index,
+                    variant_name: variant_name,
+                },
+                generics,
+                ty,
+                &variant.fields,
+            );
+
+            quote! {
+                { #block }
+            }
+        }
+        Style::Struct => {
+            let block = serialize_struct_variant(
+                StructVariant::ExternallyTagged {
+                    variant_index: variant_index,
+                    variant_name: variant_name,
+                },
+                generics,
+                ty,
+                &variant.fields,
+                item_attrs,
+            );
+
+            quote! {
+                { #block }
             }
         }
     }
 }
 
-fn serialize_newtype_variant(
+fn serialize_internally_tagged_variant(
-    type_name: String,
+    type_ident: &str,
-    variant_index: usize,
+    variant_ident: &str,
-    variant_name: String,
-    item_ty: syn::Ty,
     generics: &syn::Generics,
-    field: &Field,
+    ty: syn::Ty,
+    variant: &Variant,
+    item_attrs: &attr::Item,
+    tag: &str,
 ) -> Tokens {
-    let mut field_expr = quote!(__simple_value);
+    let type_name = item_attrs.name().serialize_name();
-    if let Some(path) = field.attrs.serialize_with() {
+    let variant_name = variant.attrs.name().serialize_name();
-        field_expr = wrap_serialize_with(
-            &item_ty, generics, field.ty, path, field_expr);
-    }
 
-    quote! {
+    match variant.style {
-        _serde::Serializer::serialize_newtype_variant(
+        Style::Unit => {
-            _serializer,
+            quote!({
-            #type_name,
+                let mut __struct = try!(_serde::Serializer::serialize_struct(
-            #variant_index,
+                    _serializer, #type_name, 1));
-            #variant_name,
+                try!(_serde::ser::SerializeStruct::serialize_field(
-            #field_expr,
+                    &mut __struct, #tag, #variant_name));
-        )
+                _serde::ser::SerializeStruct::end(__struct)
+            })
+        }
+        Style::Newtype => {
+            let field = &variant.fields[0];
+            let mut field_expr = quote!(__simple_value);
+            if let Some(path) = field.attrs.serialize_with() {
+                field_expr = wrap_serialize_with(
+                    &ty, generics, field.ty, path, field_expr);
+            }
+
+            quote! {
+                _serde::ser::private::serialize_tagged_newtype(
+                    _serializer,
+                    #type_ident,
+                    #variant_ident,
+                    #tag,
+                    #variant_name,
+                    #field_expr,
+                ),
+            }
+        }
+        Style::Struct => {
+            let block = serialize_struct_variant(
+                StructVariant::InternallyTagged {
+                    tag: tag,
+                    variant_name: variant_name,
+                },
+                generics,
+                ty,
+                &variant.fields,
+                item_attrs,
+            );
+
+            quote! {
+                { #block }
+            }
+        }
+        Style::Tuple => unreachable!("checked in serde_codegen_internals"),
     }
 }
 
+fn serialize_untagged_variant(
+    generics: &syn::Generics,
+    ty: syn::Ty,
+    variant: &Variant,
+    item_attrs: &attr::Item,
+) -> Tokens {
+    match variant.style {
+        Style::Unit => {
+            quote! {
+                _serde::Serializer::serialize_unit(_serializer),
+            }
+        }
+        Style::Newtype => {
+            let field = &variant.fields[0];
+            let mut field_expr = quote!(__simple_value);
+            if let Some(path) = field.attrs.serialize_with() {
+                field_expr = wrap_serialize_with(
+                    &ty, generics, field.ty, path, field_expr);
+            }
+
+            quote! {
+                _serde::Serialize::serialize(#field_expr, _serializer),
+            }
+        }
+        Style::Tuple => {
+            let block = serialize_tuple_variant(
+                TupleVariant::Untagged,
+                generics,
+                ty,
+                &variant.fields,
+            );
+
+            quote! {
+                { #block }
+            }
+        }
+        Style::Struct => {
+            let block = serialize_struct_variant(
+                StructVariant::Untagged,
+                generics,
+                ty,
+                &variant.fields,
+                item_attrs,
+            );
+
+            quote! {
+                { #block }
+            }
+        }
+    }
+}
+
+enum TupleVariant {
+    ExternallyTagged {
+        type_name: String,
+        variant_index: usize,
+        variant_name: String,
+    },
+    Untagged,
+}
+
 fn serialize_tuple_variant(
-    type_name: String,
+    context: TupleVariant,
-    variant_index: usize,
-    variant_name: String,
     generics: &syn::Generics,
     structure_ty: syn::Ty,
     fields: &[Field],
 ) -> Tokens {
+    let method = match context {
+        TupleVariant::ExternallyTagged{..} => {
+            quote!(_serde::ser::SerializeTupleVariant::serialize_field)
+        }
+        TupleVariant::Untagged => {
+            quote!(_serde::ser::SerializeTuple::serialize_element)
+        }
+    };
+
     let serialize_stmts = serialize_tuple_struct_visitor(
         structure_ty,
         fields,
         generics,
         true,
-        quote!(_serde::ser::SerializeTupleVariant::serialize_field),
+        method,
     );
 
     let len = serialize_stmts.len();
     let let_mut = mut_if(len > 0);
 
-    quote! {
+    match context {
-        let #let_mut __serde_state = try!(_serializer.serialize_tuple_variant(
+        TupleVariant::ExternallyTagged { type_name, variant_index, variant_name } => {
-            #type_name,
+            quote! {
-            #variant_index,
+                let #let_mut __serde_state = try!(_serde::Serializer::serialize_tuple_variant(
-            #variant_name,
+                    _serializer,
-            #len));
+                    #type_name,
-        #(#serialize_stmts)*
+                    #variant_index,
-        _serde::ser::SerializeTupleVariant::end(__serde_state)
+                    #variant_name,
+                    #len));
+                #(#serialize_stmts)*
+                _serde::ser::SerializeTupleVariant::end(__serde_state)
+            }
+        }
+        TupleVariant::Untagged => {
+            quote! {
+                let #let_mut __serde_state = try!(_serde::Serializer::serialize_tuple(
+                    _serializer,
+                    #len));
+                #(#serialize_stmts)*
+                _serde::ser::SerializeTuple::end(__serde_state)
+            }
+        }
     }
 }
 
-fn serialize_struct_variant(
+enum StructVariant<'a> {
-    variant_index: usize,
+    ExternallyTagged {
-    variant_name: String,
+        variant_index: usize,
+        variant_name: String,
+    },
+    InternallyTagged {
+        tag: &'a str,
+        variant_name: String,
+    },
+    Untagged,
+}
+
+fn serialize_struct_variant<'a>(
+    context: StructVariant<'a>,
     generics: &syn::Generics,
     ty: syn::Ty,
     fields: &[Field],
     item_attrs: &attr::Item,
 ) -> Tokens {
+    let method = match context {
+        StructVariant::ExternallyTagged{..} => {
+            quote!(_serde::ser::SerializeStructVariant::serialize_field)
+        }
+        StructVariant::InternallyTagged{..} | StructVariant::Untagged => {
+            quote!(_serde::ser::SerializeStruct::serialize_field)
+        }
+    };
+
     let serialize_fields = serialize_struct_visitor(
         ty.clone(),
         fields,
         generics,
         true,
-        quote!(_serde::ser::SerializeStructVariant::serialize_field),
+        method,
     );
 
     let item_name = item_attrs.name().serialize_name();
@@ -425,15 +634,47 @@ fn serialize_struct_variant(
          })
         .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
 
-    quote! {
+    match context {
-        let #let_mut __serde_state = try!(_serializer.serialize_struct_variant(
+        StructVariant::ExternallyTagged { variant_index, variant_name } => {
-            #item_name,
+            quote! {
-            #variant_index,
+                let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct_variant(
-            #variant_name,
+                    _serializer,
-            #len,
+                    #item_name,
-        ));
+                    #variant_index,
-        #(#serialize_fields)*
+                    #variant_name,
-        _serde::ser::SerializeStructVariant::end(__serde_state)
+                    #len,
+                ));
+                #(#serialize_fields)*
+                _serde::ser::SerializeStructVariant::end(__serde_state)
+            }
+        }
+        StructVariant::InternallyTagged { tag, variant_name } => {
+            quote! {
+                let mut __serde_state = try!(_serde::Serializer::serialize_struct(
+                    _serializer,
+                    #item_name,
+                    #len + 1,
+                ));
+                try!(_serde::ser::SerializeStruct::serialize_field(
+                    &mut __serde_state,
+                    #tag,
+                    #variant_name,
+                ));
+                #(#serialize_fields)*
+                _serde::ser::SerializeStruct::end(__serde_state)
+            }
+        }
+        StructVariant::Untagged => {
+            quote! {
+                let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct(
+                    _serializer,
+                    #item_name,
+                    #len,
+                ));
+                #(#serialize_fields)*
+                _serde::ser::SerializeStruct::end(__serde_state)
+            }
+        }
     }
 }
 
@@ -537,20 +778,20 @@ fn wrap_serialize_with(
     quote!({
         struct __SerializeWith #wrapper_generics #where_clause {
             value: &'__a #field_ty,
-            phantom: ::std::marker::PhantomData<#item_ty>,
+            phantom: _serde::export::PhantomData<#item_ty>,
         }
 
         impl #wrapper_generics _serde::Serialize for #wrapper_ty #where_clause {
-            fn serialize<__S>(&self, __s: __S) -> ::std::result::Result<__S::Ok, __S::Error>
+            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>,
+            phantom: _serde::export::PhantomData::<#item_ty>,
         }
     })
 }

serde_derive/tests/compile_tests.rs

@@ -1,30 +0,0 @@
-extern crate compiletest_rs as compiletest;
-
-use std::path::PathBuf;
-use std::env::var;
-
-fn run_mode(mode: &'static str) {
-    let mut config = compiletest::default_config();
-
-    let cfg_mode = mode.parse().ok().expect("Invalid mode");
-
-    config.target_rustcflags = Some("-L target/debug/ -L target/debug/deps/".to_owned());
-    if let Ok(name) = var::<&str>("TESTNAME") {
-        let s : String = name.to_owned();
-        config.filter = Some(s)
-    }
-    config.mode = cfg_mode;
-    config.src_base = PathBuf::from(format!("tests/{}", mode));
-
-    compiletest::run_tests(&config);
-}
-
-#[test]
-fn compile_fail() {
-    run_mode("compile-fail");
-}
-
-#[test]
-fn run_pass() {
-    run_mode("run-pass");
-}

serde_derive/tests/test.rs

@@ -1,10 +0,0 @@
-#![feature(test)]
-
-#[macro_use]
-extern crate serde_derive;
-
-extern crate test;
-
-include!("../../testing/tests/test.rs.in");
-
-mod compile_tests;

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "0.9.0-rc1"
+version = "0.9.6"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Token De/Serializer for testing De/Serialize implementations"
@@ -12,4 +12,7 @@ keywords = ["serde", "serialization"]
 include = ["Cargo.toml", "src/**/*.rs"]
 
 [dependencies]
-serde = { version = "0.9.0-rc1", path = "../serde" }
+serde = { version = "0.9", path = "../serde" }
+
+[badges]
+travis-ci = { repository = "serde-rs/serde" }

serde_test/src/de.rs

@@ -3,6 +3,7 @@ use std::iter;
 use serde::de::{
     self,
     Deserialize,
+    DeserializeSeed,
     EnumVisitor,
     MapVisitor,
     SeqVisitor,
@@ -42,95 +43,33 @@ impl<I> Deserializer<I>
                     Err(Error::UnexpectedToken(token))
                 }
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn visit_seq<V>(&mut self, len: Option<usize>, visitor: V) -> Result<V::Value, Error>
+    fn visit_seq<V>(&mut self, len: Option<usize>, sep: Token<'static>, end: Token<'static>, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
         let value = try!(visitor.visit_seq(DeserializerSeqVisitor {
             de: self,
             len: len,
+            sep: sep,
+            end: end.clone(),
         }));
-        try!(self.expect_token(Token::SeqEnd));
+        try!(self.expect_token(end));
         Ok(value)
     }
 
-    fn visit_array<V>(&mut self, len: usize, visitor: V) -> Result<V::Value, Error>
+    fn visit_map<V>(&mut self, len: Option<usize>, sep: Token<'static>, end: Token<'static>, visitor: V) -> Result<V::Value, Error>
-        where V: Visitor,
-    {
-        let value = try!(visitor.visit_seq(DeserializerArrayVisitor {
-            de: self,
-            len: len,
-        }));
-        try!(self.expect_token(Token::SeqEnd));
-        Ok(value)
-    }
-
-    fn visit_tuple<V>(&mut self, len: usize, visitor: V) -> Result<V::Value, Error>
-        where V: Visitor,
-    {
-        let value = try!(visitor.visit_seq(DeserializerTupleVisitor {
-            de: self,
-            len: len,
-        }));
-        try!(self.expect_token(Token::TupleEnd));
-        Ok(value)
-    }
-
-    fn visit_tuple_struct<V>(&mut self, len: usize, visitor: V) -> Result<V::Value, Error>
-        where V: Visitor,
-    {
-        let value = try!(visitor.visit_seq(DeserializerTupleStructVisitor {
-            de: self,
-            len: len,
-        }));
-        try!(self.expect_token(Token::TupleStructEnd));
-        Ok(value)
-    }
-
-    fn visit_variant_seq<V>(&mut self, len: Option<usize>, visitor: V) -> Result<V::Value, Error>
-        where V: Visitor,
-    {
-        let value = try!(visitor.visit_seq(DeserializerVariantSeqVisitor {
-            de: self,
-            len: len,
-        }));
-        try!(self.expect_token(Token::EnumSeqEnd));
-        Ok(value)
-    }
-
-    fn visit_map<V>(&mut self, len: Option<usize>, visitor: V) -> Result<V::Value, Error>
         where V: Visitor,
     {
         let value = try!(visitor.visit_map(DeserializerMapVisitor {
             de: self,
             len: len,
+            sep: sep,
+            end: end.clone(),
         }));
-        try!(self.expect_token(Token::MapEnd));
+        try!(self.expect_token(end));
-        Ok(value)
-    }
-
-    fn visit_struct<V>(&mut self, fields: &'static [&'static str], visitor: V) -> Result<V::Value, Error>
-        where V: Visitor,
-    {
-        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)
     }
 }
@@ -140,93 +79,9 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
 {
     type Error = Error;
 
-    fn deserialize_seq<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
+    forward_to_deserialize! {
-        where __V: de::Visitor {
+        bool u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string unit
-        self.deserialize(visitor)
+        seq bytes byte_buf map struct_field ignored_any
-    }
-    fn deserialize_struct_field<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_map<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_unit<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_bytes<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_ignored_any<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_string<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_str<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_char<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_i64<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_i32<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_i16<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_i8<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_u64<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_u32<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_u16<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_u8<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_f32<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_f64<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    fn deserialize_bool<__V>(self, visitor: __V) -> Result<__V::Value, Self::Error>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    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>(self, visitor: V) -> Result<V::Value, Error>
@@ -234,12 +89,10 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
     {
         match self.tokens.next() {
             Some(Token::Bool(v)) => visitor.visit_bool(v),
-            Some(Token::Isize(v)) => visitor.visit_isize(v),
             Some(Token::I8(v)) => visitor.visit_i8(v),
             Some(Token::I16(v)) => visitor.visit_i16(v),
             Some(Token::I32(v)) => visitor.visit_i32(v),
             Some(Token::I64(v)) => visitor.visit_i64(v),
-            Some(Token::Usize(v)) => visitor.visit_usize(v),
             Some(Token::U8(v)) => visitor.visit_u8(v),
             Some(Token::U16(v)) => visitor.visit_u16(v),
             Some(Token::U32(v)) => visitor.visit_u32(v),
@@ -250,24 +103,31 @@ impl<'a, I> de::Deserializer for &'a mut 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)
+                self.visit_seq(len, Token::SeqSep, Token::SeqEnd, visitor)
             }
-            Some(Token::SeqArrayStart(len))| Some(Token::TupleStructStart(_, len)) => {
+            Some(Token::SeqArrayStart(len)) => {
-                self.visit_seq(Some(len), visitor)
+                self.visit_seq(Some(len), Token::SeqSep, Token::SeqEnd, visitor)
+            }
+            Some(Token::TupleStart(len)) => {
+                self.visit_seq(Some(len), Token::TupleSep, Token::TupleEnd, visitor)
+            }
+            Some(Token::TupleStructStart(_, len)) => {
+                self.visit_seq(Some(len), Token::TupleStructSep, Token::TupleStructEnd, visitor)
             }
             Some(Token::MapStart(len)) => {
-                self.visit_map(len, visitor)
+                self.visit_map(len, Token::MapSep, Token::MapEnd, visitor)
             }
             Some(Token::StructStart(_, len)) => {
-                self.visit_map(Some(len), visitor)
+                self.visit_map(Some(len), Token::StructSep, Token::StructEnd, visitor)
             }
             Some(token) => Err(Error::UnexpectedToken(token)),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -277,7 +137,7 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
         where V: Visitor,
     {
         match self.tokens.peek() {
-            Some(&Token::Option(false)) => {
+            Some(&Token::Unit) | Some(&Token::Option(false)) => {
                 self.tokens.next();
                 visitor.visit_none()
             }
@@ -285,12 +145,8 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
                 self.tokens.next();
                 visitor.visit_some(self)
             }
-            Some(&Token::Unit) => {
-                self.tokens.next();
-                visitor.visit_none()
-            }
             Some(_) => visitor.visit_some(self),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -320,7 +176,7 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
                 let token = self.tokens.next().unwrap();
                 Err(Error::UnexpectedToken(token))
             }
-            None => { return Err(Error::EndOfStream); }
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -337,7 +193,7 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
                 }
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -356,7 +212,7 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
                 }
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -368,10 +224,10 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
         match self.tokens.peek() {
             Some(&Token::SeqArrayStart(_)) => {
                 self.tokens.next();
-                self.visit_array(len, visitor)
+                self.visit_seq(Some(len), Token::SeqSep, Token::SeqEnd, visitor)
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -381,32 +237,28 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
         where V: Visitor,
     {
         match self.tokens.peek() {
-            Some(&Token::Unit) => {
+            Some(&Token::Unit) | Some(&Token::UnitStruct(_)) => {
-                self.tokens.next();
-                visitor.visit_unit()
-            }
-            Some(&Token::UnitStruct(_)) => {
                 self.tokens.next();
                 visitor.visit_unit()
             }
             Some(&Token::SeqStart(_)) => {
                 self.tokens.next();
-                self.visit_seq(Some(len), visitor)
+                self.visit_seq(Some(len), Token::SeqSep, Token::SeqEnd, visitor)
             }
             Some(&Token::SeqArrayStart(_)) => {
                 self.tokens.next();
-                self.visit_array(len, visitor)
+                self.visit_seq(Some(len), Token::SeqSep, Token::SeqEnd, visitor)
             }
             Some(&Token::TupleStart(_)) => {
                 self.tokens.next();
-                self.visit_tuple(len, visitor)
+                self.visit_seq(Some(len), Token::TupleSep, Token::TupleEnd, visitor)
             }
             Some(&Token::TupleStructStart(_, _)) => {
                 self.tokens.next();
-                self.visit_tuple_struct(len, visitor)
+                self.visit_seq(Some(len), Token::TupleStructSep, Token::TupleStructEnd, visitor)
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -431,26 +283,26 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
             }
             Some(&Token::SeqStart(_)) => {
                 self.tokens.next();
-                self.visit_seq(Some(len), visitor)
+                self.visit_seq(Some(len), Token::SeqSep, Token::SeqEnd, visitor)
             }
             Some(&Token::SeqArrayStart(_)) => {
                 self.tokens.next();
-                self.visit_array(len, visitor)
+                self.visit_seq(Some(len), Token::SeqSep, Token::SeqEnd, visitor)
             }
             Some(&Token::TupleStart(_)) => {
                 self.tokens.next();
-                self.visit_tuple(len, visitor)
+                self.visit_seq(Some(len), Token::TupleSep, Token::TupleEnd, visitor)
             }
             Some(&Token::TupleStructStart(n, _)) => {
                 self.tokens.next();
                 if name == n {
-                    self.visit_tuple_struct(len, visitor)
+                    self.visit_seq(Some(len), Token::TupleStructSep, Token::TupleStructEnd, visitor)
                 } else {
                     Err(Error::InvalidName(n))
                 }
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -464,17 +316,17 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
             Some(&Token::StructStart(n, _)) => {
                 self.tokens.next();
                 if name == n {
-                    self.visit_struct(fields, visitor)
+                    self.visit_map(Some(fields.len()), Token::StructSep, Token::StructEnd, visitor)
                 } else {
                     Err(Error::InvalidName(n))
                 }
             }
             Some(&Token::MapStart(_)) => {
                 self.tokens.next();
-                self.visit_map(Some(fields.len()), visitor)
+                self.visit_map(Some(fields.len()), Token::MapSep, Token::MapEnd, visitor)
             }
             Some(_) => self.deserialize(visitor),
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 }
@@ -484,6 +336,8 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
 struct DeserializerSeqVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
     de: &'a mut Deserializer<I>,
     len: Option<usize>,
+    sep: Token<'static>,
+    end: Token<'static>,
 }
 
 impl<'a, I> SeqVisitor for DeserializerSeqVisitor<'a, I>
@@ -491,162 +345,19 @@ impl<'a, I> SeqVisitor for DeserializerSeqVisitor<'a, I>
 {
     type Error = Error;
 
-    fn visit<T>(&mut self) -> Result<Option<T>, Error>
+    fn visit_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
-        where T: Deserialize,
+        where T: DeserializeSeed,
     {
-        match self.de.tokens.peek() {
+        if self.de.tokens.peek() == Some(&self.end) {
-            Some(&Token::SeqSep) => {
+            return Ok(None);
-                self.de.tokens.next();
-                self.len = self.len.map(|len| len - 1);
-                Deserialize::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),
         }
-    }
+        match self.de.tokens.next() {
-
+            Some(ref token) if *token == self.sep => {
-    fn size_hint(&self) -> (usize, Option<usize>) {
+                self.len = self.len.map(|len| len.saturating_sub(1));
-        let len = self.len.unwrap_or(0);
+                seed.deserialize(&mut *self.de).map(Some)
-        (len, self.len)
-    }
-}
-
-//////////////////////////////////////////////////////////////////////////
-
-struct DeserializerArrayVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
-    de: &'a mut Deserializer<I>,
-    len: usize,
-}
-
-impl<'a, I> SeqVisitor for DeserializerArrayVisitor<'a, I>
-    where I: Iterator<Item=Token<'static>>,
-{
-    type Error = Error;
-
-    fn visit<T>(&mut self) -> Result<Option<T>, Error>
-        where T: Deserialize,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::SeqSep) => {
-                self.de.tokens.next();
-                self.len -= 1;
-                Deserialize::deserialize(&mut *self.de).map(Some)
             }
-            Some(&Token::SeqEnd) => Ok(None),
+            Some(other) => Err(Error::UnexpectedToken(other)),
-            Some(_) => {
+            None => Err(Error::EndOfTokens),
-                let token = self.de.tokens.next().unwrap();
-                Err(Error::UnexpectedToken(token))
-            }
-            None => Err(Error::EndOfStream),
-        }
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        (self.len, Some(self.len))
-    }
-}
-
-//////////////////////////////////////////////////////////////////////////
-
-struct DeserializerTupleVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
-    de: &'a mut Deserializer<I>,
-    len: usize,
-}
-
-impl<'a, I> SeqVisitor for DeserializerTupleVisitor<'a, I>
-    where I: Iterator<Item=Token<'static>>,
-{
-    type Error = Error;
-
-    fn visit<T>(&mut self) -> Result<Option<T>, Error>
-        where T: Deserialize,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::TupleSep) => {
-                self.de.tokens.next();
-                self.len -= 1;
-                Deserialize::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 size_hint(&self) -> (usize, Option<usize>) {
-        (self.len, Some(self.len))
-    }
-}
-
-//////////////////////////////////////////////////////////////////////////
-
-struct DeserializerTupleStructVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
-    de: &'a mut Deserializer<I>,
-    len: usize,
-}
-
-impl<'a, I> SeqVisitor for DeserializerTupleStructVisitor<'a, I>
-    where I: Iterator<Item=Token<'static>>,
-{
-    type Error = Error;
-
-    fn visit<T>(&mut self) -> Result<Option<T>, Error>
-        where T: Deserialize,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::TupleStructSep) => {
-                self.de.tokens.next();
-                self.len -= 1;
-                Deserialize::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 size_hint(&self) -> (usize, Option<usize>) {
-        (self.len, Some(self.len))
-    }
-}
-
-//////////////////////////////////////////////////////////////////////////
-
-struct DeserializerVariantSeqVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
-    de: &'a mut Deserializer<I>,
-    len: Option<usize>,
-}
-
-impl<'a, I> SeqVisitor for DeserializerVariantSeqVisitor<'a, I>
-    where I: Iterator<Item=Token<'static>>,
-{
-    type Error = Error;
-
-    fn visit<T>(&mut self) -> Result<Option<T>, Error>
-        where T: Deserialize,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::EnumSeqSep) => {
-                self.de.tokens.next();
-                self.len = self.len.map(|len| len - 1);
-                Deserialize::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),
         }
     }
 
@@ -661,6 +372,8 @@ impl<'a, I> SeqVisitor for DeserializerVariantSeqVisitor<'a, I>
 struct DeserializerMapVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
     de: &'a mut Deserializer<I>,
     len: Option<usize>,
+    sep: Token<'static>,
+    end: Token<'static>,
 }
 
 impl<'a, I> MapVisitor for DeserializerMapVisitor<'a, I>
@@ -668,28 +381,26 @@ impl<'a, I> MapVisitor for DeserializerMapVisitor<'a, I>
 {
     type Error = Error;
 
-    fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
+    fn visit_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
-        where K: Deserialize,
+        where K: DeserializeSeed,
     {
-        match self.de.tokens.peek() {
+        if self.de.tokens.peek() == Some(&self.end) {
-            Some(&Token::MapSep) => {
+            return Ok(None);
-                self.de.tokens.next();
+        }
-                self.len = self.len.map(|len| if len > 0 { len - 1} else { 0 });
+        match self.de.tokens.next() {
-                Deserialize::deserialize(&mut *self.de).map(Some)
+            Some(ref token) if *token == self.sep => {
+                self.len = self.len.map(|len| len.saturating_sub(1));
+                seed.deserialize(&mut *self.de).map(Some)
             }
-            Some(&Token::MapEnd) => Ok(None),
+            Some(other) => Err(Error::UnexpectedToken(other)),
-            Some(_) => {
+            None => Err(Error::EndOfTokens),
-                let token = self.de.tokens.next().unwrap();
-                Err(Error::UnexpectedToken(token))
-            }
-            None => Err(Error::EndOfStream),
         }
     }
 
-    fn visit_value<V>(&mut self) -> Result<V, Error>
+    fn visit_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
-        where V: Deserialize,
+        where V: DeserializeSeed,
     {
-        Deserialize::deserialize(&mut *self.de)
+        seed.deserialize(&mut *self.de)
     }
 
     fn size_hint(&self) -> (usize, Option<usize>) {
@@ -700,47 +411,6 @@ 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: usize,
-}
-
-impl<'a, I> MapVisitor for DeserializerStructVisitor<'a, I>
-    where I: Iterator<Item=Token<'static>>,
-{
-    type Error = Error;
-
-    fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
-        where K: Deserialize,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::StructSep) => {
-                self.de.tokens.next();
-                self.len = self.len.saturating_sub(1);
-                Deserialize::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),
-        }
-    }
-
-    fn visit_value<V>(&mut self) -> Result<V, Error>
-        where V: Deserialize,
-    {
-        Deserialize::deserialize(&mut *self.de)
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        (self.len, Some(self.len))
-    }
-}
-
-//////////////////////////////////////////////////////////////////////////
-
 struct DeserializerEnumVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
     de: &'a mut Deserializer<I>,
 }
@@ -751,8 +421,8 @@ impl<'a, I> EnumVisitor for DeserializerEnumVisitor<'a, I>
     type Error = Error;
     type Variant = Self;
 
-    fn visit_variant<V>(self) -> Result<(V, Self), Error>
+    fn visit_variant_seed<V>(self, seed: V) -> Result<(V::Value, Self), Error>
-        where V: Deserialize,
+        where V: DeserializeSeed,
     {
         match self.de.tokens.peek() {
             Some(&Token::EnumUnit(_, v))
@@ -760,14 +430,14 @@ impl<'a, I> EnumVisitor for DeserializerEnumVisitor<'a, I>
             | Some(&Token::EnumSeqStart(_, v, _))
             | Some(&Token::EnumMapStart(_, v, _)) => {
                 let de = v.into_deserializer();
-                let value = try!(Deserialize::deserialize(de));
+                let value = try!(seed.deserialize(de));
                 Ok((value, self))
             }
             Some(_) => {
-                let value = try!(Deserialize::deserialize(&mut *self.de));
+                let value = try!(seed.deserialize(&mut *self.de));
                 Ok((value, self))
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 }
@@ -786,22 +456,22 @@ impl<'a, I> VariantVisitor for DeserializerEnumVisitor<'a, I>
             Some(_) => {
                 Deserialize::deserialize(self.de)
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
-    fn visit_newtype<T>(self) -> Result<T, Self::Error>
+    fn visit_newtype_seed<T>(self, seed: T) -> Result<T::Value, Self::Error>
-        where T: Deserialize,
+        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),
         }
     }
 
@@ -815,7 +485,7 @@ impl<'a, I> VariantVisitor for DeserializerEnumVisitor<'a, I>
                 let token = self.de.tokens.next().unwrap();
 
                 if len == enum_len {
-                    self.de.visit_variant_seq(Some(len), visitor)
+                    self.de.visit_seq(Some(len), Token::EnumSeqSep, Token::EnumSeqEnd, visitor)
                 } else {
                     Err(Error::UnexpectedToken(token))
                 }
@@ -824,7 +494,7 @@ impl<'a, I> VariantVisitor for DeserializerEnumVisitor<'a, I>
                 let token = self.de.tokens.next().unwrap();
 
                 if len == enum_len {
-                    self.de.visit_seq(Some(len), visitor)
+                    self.de.visit_seq(Some(len), Token::SeqSep, Token::SeqEnd, visitor)
                 } else {
                     Err(Error::UnexpectedToken(token))
                 }
@@ -832,7 +502,7 @@ impl<'a, I> VariantVisitor for DeserializerEnumVisitor<'a, I>
             Some(_) => {
                 de::Deserializer::deserialize(self.de, visitor)
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 
@@ -846,7 +516,7 @@ impl<'a, I> VariantVisitor for DeserializerEnumVisitor<'a, I>
                 let token = self.de.tokens.next().unwrap();
 
                 if fields.len() == enum_len {
-                    self.de.visit_variant_map(Some(fields.len()), visitor)
+                    self.de.visit_map(Some(fields.len()), Token::EnumMapSep, Token::EnumMapEnd, visitor)
                 } else {
                     Err(Error::UnexpectedToken(token))
                 }
@@ -855,7 +525,7 @@ impl<'a, I> VariantVisitor for DeserializerEnumVisitor<'a, I>
                 let token = self.de.tokens.next().unwrap();
 
                 if fields.len() == enum_len {
-                    self.de.visit_map(Some(fields.len()), visitor)
+                    self.de.visit_map(Some(fields.len()), Token::MapSep, Token::MapEnd, visitor)
                 } else {
                     Err(Error::UnexpectedToken(token))
                 }
@@ -863,49 +533,7 @@ impl<'a, I> VariantVisitor for DeserializerEnumVisitor<'a, I>
             Some(_) => {
                 de::Deserializer::deserialize(self.de, visitor)
             }
-            None => Err(Error::EndOfStream),
+            None => Err(Error::EndOfTokens),
         }
     }
 }
-
-//////////////////////////////////////////////////////////////////////////
-
-struct DeserializerVariantMapVisitor<'a, I: 'a> where I: Iterator<Item=Token<'static>> {
-    de: &'a mut Deserializer<I>,
-    len: Option<usize>,
-}
-
-impl<'a, I> MapVisitor for DeserializerVariantMapVisitor<'a, I>
-    where I: Iterator<Item=Token<'static>>,
-{
-    type Error = Error;
-
-    fn visit_key<K>(&mut self) -> Result<Option<K>, Error>
-        where K: Deserialize,
-    {
-        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 });
-                Deserialize::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),
-        }
-    }
-
-    fn visit_value<V>(&mut self) -> Result<V, Error>
-        where V: Deserialize,
-    {
-        Deserialize::deserialize(&mut *self.de)
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        let len = self.len.unwrap_or(0);
-        (len, self.len)
-    }
-}

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
+    Message(String),
-    Custom(String),
-    InvalidValue(String),
-
-    // De
-    EndOfStream,
-    InvalidType(de::Type),
-    InvalidLength(usize),
-    UnknownVariant(String),
-    UnknownField(String),
-    MissingField(&'static str),
-    DuplicateField(&'static str),
     InvalidName(&'static str),
     UnexpectedToken(Token<'static>),
+    EndOfTokens,
 }
 
 impl ser::Error for Error {
-    fn custom<T: Into<String>>(msg: T) -> Error {
+    fn custom<T: Display>(msg: T) -> Error {
-        Error::Custom(msg.into())
+        Error::Message(msg.to_string())
-    }
-
-    fn invalid_value(msg: &str) -> Error {
-        Error::InvalidValue(msg.to_owned())
     }
 }
 
 impl de::Error for Error {
-    fn custom<T: Into<String>>(msg: T) -> Error {
+    fn custom<T: Display>(msg: T) -> Error {
-        Error::Custom(msg.into())
+        Error::Message(msg.to_string())
-    }
-
-    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)
     }
 }
 
 impl fmt::Display for Error {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        formatter.write_str(format!("{:?}", self).as_ref())
+        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"
+        match *self {
-    }
+            Error::Message(ref msg) => msg,
-
+            Error::InvalidName(_) => "invalid name",
-    fn cause(&self) -> Option<&error::Error> {
+            Error::UnexpectedToken(_) => "unexpected token",
-        None
+            Error::EndOfTokens => "end of tokens",
+        }
     }
 }

serde_test/src/lib.rs

@@ -1,3 +1,4 @@
+#[macro_use]
 extern crate serde;
 
 mod assert;

serde_test/src/ser.rs

@@ -46,11 +46,6 @@ impl<'s, 'a, I> ser::Serializer for &'s mut Serializer<'a, I>
         Ok(())
     }
 
-    fn serialize_isize(self, v: isize) -> Result<(), Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::Isize(v)));
-        Ok(())
-    }
-
     fn serialize_i8(self, v: i8) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::I8(v)));
         Ok(())
@@ -71,11 +66,6 @@ impl<'s, 'a, I> ser::Serializer for &'s mut Serializer<'a, I>
         Ok(())
     }
 
-    fn serialize_usize(self, v: usize) -> Result<(), Error> {
-        assert_eq!(self.tokens.next(), Some(&Token::Usize(v)));
-        Ok(())
-    }
-
     fn serialize_u8(self, v: u8) -> Result<(), Error> {
         assert_eq!(self.tokens.next(), Some(&Token::U8(v)));
         Ok(())
@@ -139,20 +129,20 @@ impl<'s, 'a, I> ser::Serializer for &'s mut Serializer<'a, I>
         Ok(())
     }
 
-    fn serialize_newtype_struct<T>(self,
+    fn serialize_newtype_struct<T: ?Sized>(self,
-                                   name: &'static str,
+                                           name: &'static str,
-                                   value: T) -> Result<(), Error>
+                                           value: &T) -> Result<(), Error>
         where T: Serialize,
     {
         assert_eq!(self.tokens.next(), Some(&Token::StructNewType(name)));
         value.serialize(self)
     }
 
-    fn serialize_newtype_variant<T>(self,
+    fn serialize_newtype_variant<T: ?Sized>(self,
-                                    name: &str,
+                                            name: &str,
-                                    _variant_index: usize,
+                                            _variant_index: usize,
-                                    variant: &str,
+                                            variant: &str,
-                                    value: T) -> Result<(), Error>
+                                            value: &T) -> Result<(), Error>
         where T: Serialize,
     {
         assert_eq!(self.tokens.next(), Some(&Token::EnumNewType(name, variant)));
@@ -164,8 +154,8 @@ impl<'s, 'a, I> ser::Serializer for &'s mut Serializer<'a, I>
         Ok(())
     }
 
-    fn serialize_some<V>(self, value: V) -> Result<(), Error>
+    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<(), Error>
-        where V: Serialize,
+        where T: Serialize,
     {
         assert_eq!(self.tokens.next(), Some(&Token::Option(true)));
         value.serialize(self)
@@ -228,7 +218,7 @@ impl<'s, 'a, I> ser::SerializeSeq for &'s mut Serializer<'a, I>
     type Ok = ();
     type Error = Error;
 
-    fn serialize_element<T>(&mut self, value: T) -> Result<(), Error>
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
         where T: Serialize
     {
         assert_eq!(self.tokens.next(), Some(&Token::SeqSep));
@@ -247,7 +237,7 @@ impl<'s, 'a, I> ser::SerializeTuple for &'s mut Serializer<'a, I>
     type Ok = ();
     type Error = Error;
 
-    fn serialize_element<T>(&mut self, value: T) -> Result<(), Error>
+    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
         where T: Serialize
     {
         assert_eq!(self.tokens.next(), Some(&Token::TupleSep));
@@ -266,7 +256,7 @@ impl<'s, 'a, I> ser::SerializeTupleStruct for &'s mut Serializer<'a, I>
     type Ok = ();
     type Error = Error;
 
-    fn serialize_field<T>(&mut self, value: T) -> Result<(), Error>
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
         where T: Serialize
     {
         assert_eq!(self.tokens.next(), Some(&Token::TupleStructSep));
@@ -285,7 +275,7 @@ impl<'s, 'a, I> ser::SerializeTupleVariant for &'s mut Serializer<'a, I>
     type Ok = ();
     type Error = Error;
 
-    fn serialize_field<T>(&mut self, value: T) -> Result<(), Error>
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
         where T: Serialize
     {
         assert_eq!(self.tokens.next(), Some(&Token::EnumSeqSep));
@@ -304,12 +294,12 @@ impl<'s, 'a, I> ser::SerializeMap for &'s mut Serializer<'a, I>
     type Ok = ();
     type Error = Error;
 
-    fn serialize_key<T>(&mut self, key: T) -> Result<(), Self::Error> where T: Serialize {
+    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>(&mut self, value: T) -> Result<(), Self::Error> where T: Serialize {
+    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> where T: Serialize {
         value.serialize(&mut **self)
     }
 
@@ -325,7 +315,7 @@ impl<'s, 'a, I> ser::SerializeStruct for &'s mut Serializer<'a, I>
     type Ok = ();
     type Error = Error;
 
-    fn serialize_field<V>(&mut self, key: &'static str, value: V) -> Result<(), Self::Error> where V: Serialize {
+    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)
@@ -343,7 +333,7 @@ impl<'s, 'a, I> ser::SerializeStructVariant for &'s mut Serializer<'a, I>
     type Ok = ();
     type Error = Error;
 
-    fn serialize_field<V>(&mut self, key: &'static str, value: V) -> Result<(), Self::Error> where V: Serialize {
+    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)

serde_test/src/token.rs

@@ -1,12 +1,10 @@
 #[derive(Clone, PartialEq, Debug)]
 pub enum Token<'a> {
     Bool(bool),
-    Isize(isize),
     I8(i8),
     I16(i16),
     I32(i32),
     I64(i64),
-    Usize(usize),
     U8(u8),
     U16(u16),
     U32(u32),
@@ -17,6 +15,7 @@ pub enum Token<'a> {
     Str(&'a str),
     String(String),
     Bytes(&'a [u8]),
+    ByteBuf(Vec<u8>),
 
     Option(bool),
 

test_suite/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
-name = "serde_testing"
+name = "serde_test_suite"
-version = "0.9.0-rc1"
+version = "0.0.0"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"
@@ -9,23 +9,23 @@ repository = "https://github.com/serde-rs/serde"
 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"]
+unstable-testing = [
-
+    "compiletest_rs",
-[build-dependencies]
+    "serde/unstable-testing",
-serde_codegen = { path = "../serde_codegen", features = ["with-syntex"] }
+]
 
 [dev-dependencies]
 fnv = "1.0"
-rustc-serialize = "^0.3.16"
+rustc-serialize = "0.3.16"
 serde = { path = "../serde" }
+serde_derive = { path = "../serde_derive" }
 serde_test = { path = "../serde_test" }
 
 [dependencies]
-clippy = { version = "^0.*", optional = true }
+compiletest_rs = { version = "0.2", optional = true }
 
 [[test]]
 name = "test"

test_suite/deps/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "serde_test_suite_deps"
+version = "0.0.0"
+authors = ["David Tolnay <dtolnay@gmail.com>"]
+publish = false
+
+[workspace]
+
+[dependencies]
+serde = { path = "../../serde" }
+serde_derive = { path = "../../serde_derive" }

test_suite/no_std/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "serde_derive_tests_no_std"
+version = "0.0.0"
+publish = false
+
+[dependencies]
+serde = { path = "../../serde", default-features = false }
+serde_derive = { path = "../../serde_derive" }

test_suite/no_std/src/main.rs

@@ -0,0 +1,52 @@
+#![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) -> ! {
+    unsafe {
+        libc::abort()
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[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 },
+}

test_suite/tests/compile-fail/enum-representation/internal-tuple-variant.rs

@@ -0,0 +1,10 @@
+#[macro_use]
+extern crate serde_derive;
+
+#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[serde(tag = "type")] //~^ HELP: #[serde(tag = "...")] cannot be used with tuple variants
+enum E {
+    Tuple(u8, u8),
+}
+
+fn main() {}

test_suite/tests/compile-fail/enum-representation/internally-tagged-struct.rs

@@ -0,0 +1,8 @@
+#[macro_use]
+extern crate serde_derive;
+
+#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[serde(tag = "type")] //~^ HELP: #[serde(tag = "...")] can only be used on enums
+struct S;
+
+fn main() {}

test_suite/tests/compile-fail/enum-representation/untagged-and-internal.rs

@@ -0,0 +1,12 @@
+#[macro_use]
+extern crate serde_derive;
+
+#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[serde(untagged)]
+#[serde(tag = "type")] //~^^ HELP: enum cannot be both untagged and internally tagged
+enum E {
+    A(u8),
+    B(String),
+}
+
+fn main() {}

test_suite/tests/compile-fail/enum-representation/untagged-struct.rs

@@ -0,0 +1,8 @@
+#[macro_use]
+extern crate serde_derive;
+
+#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[serde(untagged)] //~^ HELP: #[serde(untagged)] can only be used on enums
+struct S;
+
+fn main() {}

test_suite/tests/compiletest.rs

@@ -0,0 +1,26 @@
+extern crate compiletest_rs as compiletest;
+
+use std::env;
+
+fn run_mode(mode: &'static str) {
+    let mut config = compiletest::default_config();
+
+    config.mode = mode.parse().expect("invalid mode");
+    config.target_rustcflags = Some("-L deps/target/debug/deps".to_owned());
+    if let Ok(name) = env::var("TESTNAME") {
+        config.filter = Some(name);
+    }
+    config.src_base = format!("tests/{}", mode).into();
+
+    compiletest::run_tests(&config);
+}
+
+#[test]
+fn compile_fail() {
+    run_mode("compile-fail");
+}
+
+#[test]
+fn run_pass() {
+    run_mode("run-pass");
+}

test_suite/tests/macros.rs

@@ -1,31 +1,3 @@
-#[macro_export]
-macro_rules! declare_ser_tests {
-    ($($name:ident { $($value:expr => $tokens:expr,)+ })+) => {
-        $(
-            #[test]
-            fn $name() {
-                $(
-                    assert_ser_tokens(&$value, $tokens);
-                )+
-            }
-        )+
-    }
-}
-
-#[macro_export]
-macro_rules! btreemap {
-    () => {
-        BTreeMap::new()
-    };
-    ($($key:expr => $value:expr),+) => {
-        {
-            let mut map = BTreeMap::new();
-            $(map.insert($key, $value);)+
-            map
-        }
-    }
-}
-
 macro_rules! btreeset {
     () => {
         BTreeSet::new()

test_suite/tests/test.rs

@@ -0,0 +1,23 @@
+#![cfg_attr(feature = "unstable-testing", feature(test, non_ascii_idents))]
+
+#[cfg(feature = "unstable-testing")]
+extern crate test;
+
+#[macro_use]
+extern crate serde_derive;
+
+extern crate serde;
+extern crate serde_test;
+
+#[macro_use]
+mod macros;
+
+mod test_annotations;
+mod test_bytes;
+mod test_de;
+mod test_gen;
+mod test_macros;
+mod test_ser;
+
+#[cfg(feature = "unstable-testing")]
+mod compiletest;

test_suite/tests/test_annotations.rs

@@ -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"),
@@ -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())
     );
 }
 
@@ -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()),
     );
 }

test_suite/tests/test_bytes.rs

@@ -15,6 +15,7 @@ fn test_bytes() {
 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, &[
@@ -28,6 +29,7 @@ fn test_byte_buf() {
 
     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, &[

test_suite/tests/test_de.rs

@@ -3,7 +3,7 @@ use std::net;
 use std::path::PathBuf;
 use std::time::Duration;
 
-use serde::de::{Deserialize, Type};
+use serde::Deserialize;
 
 extern crate fnv;
 use self::fnv::FnvHasher;
@@ -97,7 +97,7 @@ macro_rules! declare_tests {
 }
 
 macro_rules! declare_error_tests {
-    ($($name:ident<$target:ident> { $tokens:expr, $expected:expr, })+) => {
+    ($($name:ident<$target:ty> { $tokens:expr, $expected:expr, })+) => {
         $(
             #[test]
             fn $name() {
@@ -155,12 +155,10 @@ declare_tests! {
         false => &[Token::Bool(false)],
     }
     test_isize {
-        0isize => &[Token::Isize(0)],
         0isize => &[Token::I8(0)],
         0isize => &[Token::I16(0)],
         0isize => &[Token::I32(0)],
         0isize => &[Token::I64(0)],
-        0isize => &[Token::Usize(0)],
         0isize => &[Token::U8(0)],
         0isize => &[Token::U16(0)],
         0isize => &[Token::U32(0)],
@@ -169,14 +167,12 @@ declare_tests! {
         0isize => &[Token::F64(0.)],
     }
     test_ints {
-        0isize => &[Token::Isize(0)],
         0i8 => &[Token::I8(0)],
         0i16 => &[Token::I16(0)],
         0i32 => &[Token::I32(0)],
         0i64 => &[Token::I64(0)],
     }
     test_uints {
-        0usize => &[Token::Usize(0)],
         0u8 => &[Token::U8(0)],
         0u16 => &[Token::U16(0)],
         0u32 => &[Token::U32(0)],
@@ -229,7 +225,7 @@ declare_tests! {
         ],
         () => &[
             Token::TupleStructStart("Anything", 0),
-            Token::SeqEnd,
+            Token::TupleStructEnd,
         ],
     }
     test_unit_struct {
@@ -334,7 +330,7 @@ declare_tests! {
         ],
         BTreeSet::<isize>::new() => &[
             Token::TupleStructStart("Anything", 0),
-            Token::SeqEnd,
+            Token::TupleStructEnd,
         ],
     }
     test_hashset {
@@ -362,7 +358,7 @@ declare_tests! {
         ],
         HashSet::<isize>::new() => &[
             Token::TupleStructStart("Anything", 0),
-            Token::SeqEnd,
+            Token::TupleStructEnd,
         ],
         hashset![FnvHasher @ 1, 2, 3] => &[
             Token::SeqStart(Some(3)),
@@ -412,7 +408,7 @@ declare_tests! {
         ],
         Vec::<isize>::new() => &[
             Token::TupleStructStart("Anything", 0),
-            Token::SeqEnd,
+            Token::TupleStructEnd,
         ],
     }
     test_array {
@@ -476,7 +472,7 @@ declare_tests! {
         ],
         [0; 0] => &[
             Token::TupleStructStart("Anything", 0),
-            Token::SeqEnd,
+            Token::TupleStructEnd,
         ],
     }
     test_tuple {
@@ -568,7 +564,7 @@ declare_tests! {
         ],
         BTreeMap::<isize, isize>::new() => &[
             Token::StructStart("Anything", 0),
-            Token::MapEnd,
+            Token::StructEnd,
         ],
     }
     test_hashmap {
@@ -622,7 +618,7 @@ declare_tests! {
         ],
         HashMap::<isize, isize>::new() => &[
             Token::StructStart("Anything", 0),
-            Token::MapEnd,
+            Token::StructEnd,
         ],
         hashmap![FnvHasher @ 1 => 2, 3 => 4] => &[
             Token::MapStart(Some(2)),
@@ -774,6 +770,20 @@ declare_tests! {
             Token::EnumMapEnd,
         ],
     }
+    test_enum_unit_usize {
+        Enum::Unit => &[
+            Token::EnumStart("Enum"),
+            Token::U32(0),
+            Token::Unit,
+        ],
+    }
+    test_enum_unit_bytes {
+        Enum::Unit => &[
+            Token::EnumStart("Enum"),
+            Token::Bytes(b"Unit"),
+            Token::Unit,
+        ],
+    }
     test_box {
         Box::new(0i32) => &[Token::I32(0)],
     }
@@ -849,7 +859,7 @@ declare_error_tests! {
                 Token::StructSep,
                 Token::Str("d"),
         ],
-        Error::UnknownField("d".to_owned()),
+        Error::Message("unknown field `d`, expected `a`".to_owned()),
     }
     test_skipped_field_is_unknown<StructDenyUnknown> {
         &[
@@ -857,7 +867,7 @@ declare_error_tests! {
                 Token::StructSep,
                 Token::Str("b"),
         ],
-        Error::UnknownField("b".to_owned()),
+        Error::Message("unknown field `b`, expected `a`".to_owned()),
     }
     test_skip_all_deny_unknown<StructSkipAllDenyUnknown> {
         &[
@@ -865,25 +875,25 @@ declare_error_tests! {
                 Token::StructSep,
                 Token::Str("a"),
         ],
-        Error::UnknownField("a".to_owned()),
+        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::UnknownVariant("Skipped".to_owned()),
+        Error::Message("unknown variant `Skipped`, there are no variants".to_owned()),
     }
     test_struct_seq_too_long<Struct> {
         &[
@@ -904,7 +914,7 @@ declare_error_tests! {
                 Token::MapSep,
                 Token::Str("a"),
         ],
-        Error::DuplicateField("a"),
+        Error::Message("duplicate field `a`".to_owned()),
     }
     test_duplicate_field_enum<Enum> {
         &[
@@ -916,22 +926,32 @@ declare_error_tests! {
                 Token::EnumMapSep,
                 Token::Str("a"),
         ],
-        Error::DuplicateField("a"),
+        Error::Message("duplicate field `a`".to_owned()),
     }
-    test_enum_unit_usize<Enum> {
+    test_enum_out_of_range<Enum> {
         &[
             Token::EnumStart("Enum"),
-            Token::Usize(0),
+            Token::U32(4),
             Token::Unit,
         ],
-        Error::InvalidType(Type::U64),
+        Error::Message("invalid value: integer `4`, expected variant index 0 <= i < 4".into()),
     }
-    test_enum_unit_bytes<Enum> {
+    test_short_tuple<(u8, u8, u8)> {
         &[
-            Token::EnumStart("Enum"),
+            Token::TupleStart(1),
-            Token::Bytes(b"Unit"),
+            Token::TupleSep,
-            Token::Unit,
+            Token::U8(1),
+            Token::TupleEnd,
         ],
-        Error::InvalidType(Type::Bytes),
+        Error::Message("invalid length 1, expected a tuple of size 3".into()),
+    }
+    test_short_array<[u8; 3]> {
+        &[
+            Token::SeqStart(Some(1)),
+            Token::SeqSep,
+            Token::U8(1),
+            Token::SeqEnd,
+        ],
+        Error::Message("invalid length 1, expected an array of length 3".into()),
     }
 }

test_suite/tests/test_gen.rs

@@ -8,11 +8,15 @@ use self::serde::de::{Deserialize, Deserializer};
 
 use std::borrow::Cow;
 use std::marker::PhantomData;
+use std::result::Result as StdResult;
 
 // Try to trip up the generated code if it fails to use fully qualified paths.
 #[allow(dead_code)]
 struct Result;
-use std::result::Result as StdResult;
+#[allow(dead_code)]
+struct Ok;
+#[allow(dead_code)]
+struct Err;
 
 //////////////////////////////////////////////////////////////////////////
 

test_suite/tests/test_macros.rs

@@ -1,11 +1,14 @@
 extern crate serde_test;
 use self::serde_test::{
+    Error,
     Token,
     assert_tokens,
     assert_ser_tokens,
     assert_de_tokens,
+    assert_de_tokens_error,
 };
 
+use std::collections::BTreeMap;
 use std::marker::PhantomData;
 
 // That tests that the derived Serialize implementation doesn't trigger
@@ -625,3 +628,256 @@ fn test_enum_state_field() {
         ]
     );
 }
+
+#[test]
+fn test_untagged_enum() {
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    #[serde(untagged)]
+    enum Untagged {
+        A {
+            a: u8,
+        },
+        B {
+            b: u8,
+        },
+        C,
+        D(u8),
+        E(String),
+        F(u8, u8),
+    }
+
+    assert_tokens(
+        &Untagged::A { a: 1 },
+        &[
+            Token::StructStart("Untagged", 1),
+
+            Token::StructSep,
+            Token::Str("a"),
+            Token::U8(1),
+
+            Token::StructEnd,
+        ]
+    );
+
+    assert_tokens(
+        &Untagged::B { b: 2 },
+        &[
+            Token::StructStart("Untagged", 1),
+
+            Token::StructSep,
+            Token::Str("b"),
+            Token::U8(2),
+
+            Token::StructEnd,
+        ]
+    );
+
+    assert_tokens(
+        &Untagged::C,
+        &[
+            Token::Unit,
+        ]
+    );
+
+    assert_tokens(
+        &Untagged::D(4),
+        &[
+            Token::U8(4),
+        ]
+    );
+    assert_tokens(
+        &Untagged::E("e".to_owned()),
+        &[
+            Token::Str("e"),
+        ]
+    );
+
+    assert_tokens(
+        &Untagged::F(1, 2),
+        &[
+            Token::TupleStart(2),
+
+            Token::TupleSep,
+            Token::U8(1),
+
+            Token::TupleSep,
+            Token::U8(2),
+
+            Token::TupleEnd,
+        ]
+    );
+
+    assert_de_tokens_error::<Untagged>(
+        &[
+            Token::Option(false),
+        ],
+        Error::Message("data did not match any variant of untagged enum Untagged".to_owned()),
+    );
+
+    assert_de_tokens_error::<Untagged>(
+        &[
+            Token::TupleStart(1),
+
+            Token::TupleSep,
+            Token::U8(1),
+
+            Token::TupleEnd,
+        ],
+        Error::Message("data did not match any variant of untagged enum Untagged".to_owned()),
+    );
+
+    assert_de_tokens_error::<Untagged>(
+        &[
+            Token::TupleStart(3),
+
+            Token::TupleSep,
+            Token::U8(1),
+
+            Token::TupleSep,
+            Token::U8(2),
+
+            Token::TupleSep,
+            Token::U8(3),
+
+            Token::TupleEnd,
+        ],
+        Error::Message("data did not match any variant of untagged enum Untagged".to_owned()),
+    );
+}
+
+#[test]
+fn test_internally_tagged_enum() {
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    struct Newtype(BTreeMap<String, String>);
+
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    struct Struct {
+        f: u8,
+    }
+
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    #[serde(tag = "type")]
+    enum InternallyTagged {
+        A {
+            a: u8,
+        },
+        B {
+            b: u8,
+        },
+        C,
+        D(BTreeMap<String, String>),
+        E(Newtype),
+        F(Struct),
+    }
+
+    assert_tokens(
+        &InternallyTagged::A { a: 1 },
+        &[
+            Token::StructStart("InternallyTagged", 2),
+
+            Token::StructSep,
+            Token::Str("type"),
+            Token::Str("A"),
+
+            Token::StructSep,
+            Token::Str("a"),
+            Token::U8(1),
+
+            Token::StructEnd,
+        ]
+    );
+
+    assert_tokens(
+        &InternallyTagged::B { b: 2 },
+        &[
+            Token::StructStart("InternallyTagged", 2),
+
+            Token::StructSep,
+            Token::Str("type"),
+            Token::Str("B"),
+
+            Token::StructSep,
+            Token::Str("b"),
+            Token::U8(2),
+
+            Token::StructEnd,
+        ]
+    );
+
+    assert_tokens(
+        &InternallyTagged::C,
+        &[
+            Token::StructStart("InternallyTagged", 1),
+
+            Token::StructSep,
+            Token::Str("type"),
+            Token::Str("C"),
+
+            Token::StructEnd,
+        ]
+    );
+
+    assert_tokens(
+        &InternallyTagged::D(BTreeMap::new()),
+        &[
+            Token::MapStart(Some(1)),
+
+            Token::MapSep,
+            Token::Str("type"),
+            Token::Str("D"),
+
+            Token::MapEnd,
+        ]
+    );
+
+    assert_tokens(
+        &InternallyTagged::E(Newtype(BTreeMap::new())),
+        &[
+            Token::MapStart(Some(1)),
+
+            Token::MapSep,
+            Token::Str("type"),
+            Token::Str("E"),
+
+            Token::MapEnd,
+        ]
+    );
+
+    assert_tokens(
+        &InternallyTagged::F(Struct { f: 6 }),
+        &[
+            Token::StructStart("Struct", 2),
+
+            Token::StructSep,
+            Token::Str("type"),
+            Token::Str("F"),
+
+            Token::StructSep,
+            Token::Str("f"),
+            Token::U8(6),
+
+            Token::StructEnd,
+        ]
+    );
+
+    assert_de_tokens_error::<InternallyTagged>(
+        &[
+            Token::MapStart(Some(0)),
+            Token::MapEnd,
+        ],
+        Error::Message("missing field `type`".to_owned()),
+    );
+
+    assert_de_tokens_error::<InternallyTagged>(
+        &[
+            Token::MapStart(Some(1)),
+
+            Token::MapSep,
+            Token::Str("type"),
+            Token::Str("Z"),
+
+            Token::MapEnd,
+        ],
+        Error::Message("unknown variant `Z`, expected one of `A`, `B`, `C`, `D`, `E`, `F`".to_owned()),
+    );
+}

test_suite/tests/test_ser.rs

@@ -51,7 +51,20 @@ enum Enum {
 
 //////////////////////////////////////////////////////////////////////////
 
-declare_ser_tests! {
+macro_rules! declare_tests {
+    ($($name:ident { $($value:expr => $tokens:expr,)+ })+) => {
+        $(
+            #[test]
+            fn $name() {
+                $(
+                    assert_ser_tokens(&$value, $tokens);
+                )+
+            }
+        )+
+    }
+}
+
+declare_tests! {
     test_unit {
         () => &[Token::Unit],
     }
@@ -60,14 +73,12 @@ declare_ser_tests! {
         false => &[Token::Bool(false)],
     }
     test_isizes {
-        0isize => &[Token::Isize(0)],
         0i8 => &[Token::I8(0)],
         0i16 => &[Token::I16(0)],
         0i32 => &[Token::I32(0)],
         0i64 => &[Token::I64(0)],
     }
     test_usizes {
-        0usize => &[Token::Usize(0)],
         0u8 => &[Token::U8(0)],
         0u16 => &[Token::U16(0)],
         0u32 => &[Token::U32(0)],
@@ -432,7 +443,7 @@ 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);
@@ -440,7 +451,7 @@ 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]
@@ -448,17 +459,17 @@ fn test_enum_skipped() {
     assert_ser_tokens_error(
         &Enum::SkippedUnit,
         &[],
-        Error::InvalidValue("The enum variant Enum::SkippedUnit cannot be serialized".to_owned()));
+        Error::Message("the enum variant Enum::SkippedUnit cannot be serialized".to_owned()));
     assert_ser_tokens_error(
         &Enum::SkippedOne(42),
         &[],
-        Error::InvalidValue("The enum variant Enum::SkippedOne cannot be serialized".to_owned()));
+        Error::Message("the enum variant Enum::SkippedOne cannot be serialized".to_owned()));
     assert_ser_tokens_error(
         &Enum::SkippedSeq(1, 2),
         &[],
-        Error::InvalidValue("The enum variant Enum::SkippedSeq cannot be serialized".to_owned()));
+        Error::Message("the enum variant Enum::SkippedSeq cannot be serialized".to_owned()));
     assert_ser_tokens_error(
         &Enum::SkippedMap { _a: 1, _b: 2 },
         &[],
-        Error::InvalidValue("The enum variant Enum::SkippedMap cannot be serialized".to_owned()));
+        Error::Message("the enum variant Enum::SkippedMap cannot be serialized".to_owned()));
 }

testing/build.rs

@@ -1,11 +0,0 @@
-extern crate serde_codegen;
-
-use std::env;
-use std::path::Path;
-
-fn main() {
-    let out_dir = env::var_os("OUT_DIR").unwrap();
-    let src = Path::new("tests/test.rs.in");
-    let dst = Path::new(&out_dir).join("test.rs");
-    serde_codegen::expand(&src, &dst).unwrap();
-}

testing/tests/test.rs

@@ -1,6 +0,0 @@
-#![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

@@ -1,12 +0,0 @@
-extern crate serde;
-extern crate serde_test;
-
-#[macro_use]
-mod macros;
-
-mod test_annotations;
-mod test_bytes;
-mod test_de;
-mod test_gen;
-mod test_macros;
-mod test_ser;

travis.sh

@@ -0,0 +1,71 @@
+#!/bin/bash
+
+set -e
+
+DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+channel() {
+    if [ -n "${TRAVIS}" ]; then
+        if [ "${TRAVIS_RUST_VERSION}" = "${CHANNEL}" ]; then
+            pwd
+            (set -x; cargo "$@")
+        fi
+    else
+        pwd
+        (set -x; cargo "+${CHANNEL}" "$@")
+    fi
+}
+
+if [ -n "${CLIPPY}" ]; then
+    # cached installation will not work on a later nightly
+    if [ -n "${TRAVIS}" ] && ! cargo install clippy --debug --force; then
+        echo "COULD NOT COMPILE CLIPPY, IGNORING CLIPPY TESTS"
+        exit
+    fi
+
+    cd "$DIR/serde"
+    cargo clippy --features unstable-testing -- -Dclippy
+
+    cd "$DIR/serde_derive"
+    cargo clippy --features unstable-testing -- -Dclippy
+
+    cd "$DIR/test_suite"
+    cargo clippy --features unstable-testing -- -Dclippy
+
+    cd "$DIR/test_suite/no_std"
+    cargo clippy -- -Dclippy
+else
+    CHANNEL=nightly
+    cargo clean
+    cd "$DIR/serde"
+    channel build
+    channel build --no-default-features
+    channel build --no-default-features --features alloc
+    channel build --no-default-features --features collections
+    channel test --features unstable-testing
+    cd "$DIR/test_suite/deps"
+    channel build
+    cd "$DIR/test_suite"
+    channel test --features unstable-testing
+    cd "$DIR/test_suite/no_std"
+    channel build
+
+    CHANNEL=beta
+    cargo clean
+    cd "$DIR/serde"
+    channel build
+    cd "$DIR/test_suite"
+    channel test
+
+    CHANNEL=stable
+    cargo clean
+    cd "$DIR/serde"
+    channel build
+    channel build --no-default-features
+
+    CHANNEL=1.13.0
+    cargo clean
+    cd "$DIR/serde"
+    channel build
+    channel build --no-default-features
+fi