Release 0.9.7

Playground feature to get serde_derive picked up by integer32 playground

.travis.yml

@@ -1,5 +1,6 @@
 sudo: false
 language: rust
+cache: cargo
 
 # run builds for all the trains (and more)
 rust:
@@ -8,21 +9,9 @@ rust:
   - beta
   - nightly
 
-before_script:
-  - pip install 'travis-cargo<0.2' --user
-  - export PATH=$HOME/.local/bin:$PATH
+matrix:
+  include:
+    - rust: nightly
+      env: CLIPPY=true
 
-script:
-  - (cd serde && travis-cargo build)
-  - (cd serde && travis-cargo --only beta test)
-  - (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 test_suite && travis-cargo --only beta test)
-  - (cd test_suite/deps && travis-cargo --only nightly build && cd .. && travis-cargo --only nightly test -- --features unstable-testing)
-  - (cd test_suite/no_std && travis-cargo --only nightly build)
-
-env:
-  global:
-    - TRAVIS_CARGO_NIGHTLY_FEATURE=""
+script: ./travis.sh

Cargo.toml

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

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "0.9.2"
+version = "0.9.7"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"
@@ -8,7 +8,7 @@ homepage = "https://serde.rs"
 repository = "https://github.com/serde-rs/serde"
 documentation = "https://docs.serde.rs/serde/"
 readme = "../README.md"
-keywords = ["serde", "serialization"]
+keywords = ["serde", "serialization", "no_std"]
 categories = ["encoding"]
 include = ["Cargo.toml", "src/**/*.rs"]
 
@@ -22,10 +22,13 @@ std = []
 unstable = []
 alloc = ["unstable"]
 collections = ["alloc"]
-unstable-testing = ["clippy", "unstable", "std"]
+unstable-testing = ["unstable", "std"]
+
+# to get serde_derive picked up by play.integer32.com
+playground = ["serde_derive"]
 
 [dependencies]
-clippy = { version = "0.*", optional = true }
+serde_derive = { version = "0.9", optional = true }
 
 [dev-dependencies]
 serde_derive = "0.9"

serde/src/de/content.rs

@@ -0,0 +1,761 @@
+// 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 {
+    // Don't mind the PhantomData, just need to use E somewhere.
+    Bool(bool),
+
+    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>),
+
+    Unit,
+    Newtype(Box<Content>),
+    Seq(Vec<Content>),
+    Map(Vec<(Content, Content)>),
+}
+
+impl Deserialize for Content {
+    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)
+    }
+}
+
+struct ContentVisitor;
+
+impl Visitor for ContentVisitor {
+    type Value = Content;
+
+    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))
+    }
+
+    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 {
+    Tag,
+    Content(Content),
+}
+
+struct TagOrContentVisitor {
+    name: &'static str,
+}
+
+impl TagOrContentVisitor {
+    fn new(name: &'static str) -> Self {
+        TagOrContentVisitor {
+            name: name,
+        }
+    }
+}
+
+impl DeserializeSeed for TagOrContentVisitor {
+    type Value = TagOrContent;
+
+    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 Visitor for TagOrContentVisitor {
+    type Value = TagOrContent;
+
+    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.visit_bool(value).map(TagOrContent::Content)
+    }
+
+    fn visit_i8<F>(self, value: i8) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_i8(value).map(TagOrContent::Content)
+    }
+
+    fn visit_i16<F>(self, value: i16) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_i16(value).map(TagOrContent::Content)
+    }
+
+    fn visit_i32<F>(self, value: i32) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_i32(value).map(TagOrContent::Content)
+    }
+
+    fn visit_i64<F>(self, value: i64) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_i64(value).map(TagOrContent::Content)
+    }
+
+    fn visit_u8<F>(self, value: u8) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_u8(value).map(TagOrContent::Content)
+    }
+
+    fn visit_u16<F>(self, value: u16) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_u16(value).map(TagOrContent::Content)
+    }
+
+    fn visit_u32<F>(self, value: u32) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_u32(value).map(TagOrContent::Content)
+    }
+
+    fn visit_u64<F>(self, value: u64) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_u64(value).map(TagOrContent::Content)
+    }
+
+    fn visit_f32<F>(self, value: f32) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_f32(value).map(TagOrContent::Content)
+    }
+
+    fn visit_f64<F>(self, value: f64) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_f64(value).map(TagOrContent::Content)
+    }
+
+    fn visit_char<F>(self, value: char) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.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.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.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.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.visit_byte_buf(value).map(TagOrContent::Content)
+        }
+    }
+
+    fn visit_unit<F>(self) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_unit().map(TagOrContent::Content)
+    }
+
+    fn visit_none<F>(self) -> Result<Self::Value, F>
+        where F: de::Error
+    {
+        ContentVisitor.visit_none().map(TagOrContent::Content)
+    }
+
+    fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+        where D: Deserializer
+    {
+        ContentVisitor.visit_some(deserializer).map(TagOrContent::Content)
+    }
+
+    fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+        where D: Deserializer
+    {
+        ContentVisitor.visit_newtype_struct(deserializer).map(TagOrContent::Content)
+    }
+
+    fn visit_seq<V>(self, visitor: V) -> Result<Self::Value, V::Error>
+        where V: SeqVisitor
+    {
+        ContentVisitor.visit_seq(visitor).map(TagOrContent::Content)
+    }
+
+    fn visit_map<V>(self, visitor: V) -> Result<Self::Value, V::Error>
+        where V: MapVisitor
+    {
+        ContentVisitor.visit_map(visitor).map(TagOrContent::Content)
+    }
+
+    fn visit_enum<V>(self, visitor: V) -> Result<Self::Value, V::Error>
+        where V: EnumVisitor
+    {
+        ContentVisitor.visit_enum(visitor).map(TagOrContent::Content)
+    }
+}
+
+/// Used by generated code to deserialize an internally tagged enum.
+///
+/// Not public API.
+pub struct TaggedContent<T> {
+    pub tag: T,
+    pub content: Content,
+}
+
+/// Not public API.
+pub struct TaggedContentVisitor<T> {
+    tag_name: &'static str,
+    tag: PhantomData<T>,
+}
+
+impl<T> TaggedContentVisitor<T> {
+    /// 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,
+        }
+    }
+}
+
+impl<T> DeserializeSeed for TaggedContentVisitor<T>
+    where T: Deserialize
+{
+    type Value = TaggedContent<T>;
+
+    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> Visitor for TaggedContentVisitor<T>
+    where T: Deserialize
+{
+    type Value = TaggedContent<T>;
+
+    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),
+                })
+            }
+        }
+    }
+}
+
+/// Not public API
+pub struct ContentDeserializer<E> {
+    content: Content,
+    err: PhantomData<E>,
+}
+
+/// Used when deserializing an internally tagged enum because the content will
+/// be used exactly once.
+impl<E> Deserializer for ContentDeserializer<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 {
+            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(ContentDeserializer::new(*v)),
+            Content::Newtype(v) => visitor.visit_newtype_struct(ContentDeserializer::new(*v)),
+            Content::Seq(v) => {
+                let seq = v.into_iter().map(ContentDeserializer::new);
+                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().map(|(k, v)| (ContentDeserializer::new(k), ContentDeserializer::new(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(v) => visitor.visit_byte_buf(v),
+        }
+    }
+
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where V: Visitor
+    {
+        match self.content {
+            Content::None => visitor.visit_none(),
+            Content::Some(v) => visitor.visit_some(ContentDeserializer::new(*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> ContentDeserializer<E> {
+    /// private API, don't use
+    pub fn new(content: Content) -> Self {
+        ContentDeserializer {
+            content: content,
+            err: PhantomData,
+        }
+    }
+}
+
+/// Not public API.
+pub struct ContentRefDeserializer<'a, E> {
+    content: &'a Content,
+    err: PhantomData<E>,
+}
+
+/// Used when deserializing an untagged enum because the content may need to be
+/// used more than once.
+impl<'a, E> Deserializer for ContentRefDeserializer<'a, 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 {
+            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(ContentRefDeserializer::new(v)),
+            Content::Newtype(ref v) => visitor.visit_newtype_struct(ContentRefDeserializer::new(v)),
+            Content::Seq(ref v) => {
+                let seq = v.into_iter().map(ContentRefDeserializer::new);
+                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)| (ContentRefDeserializer::new(k), ContentRefDeserializer::new(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 {
+            Content::None => visitor.visit_none(),
+            Content::Some(ref v) => visitor.visit_some(ContentRefDeserializer::new(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> ContentRefDeserializer<'a, E> {
+    /// private API, don't use
+    pub fn new(content: &'a Content) -> Self {
+        ContentRefDeserializer {
+            content: content,
+            err: PhantomData,
+        }
+    }
+}
+
+impl<E> de::value::ValueDeserializer<E> for ContentDeserializer<E>
+    where E: de::Error
+{
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self {
+        self
+    }
+}
+
+impl<'a, E> de::value::ValueDeserializer<E> for ContentRefDeserializer<'a, 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

@@ -27,8 +27,6 @@ use std::collections::{
     VecDeque,
 };
 
-#[cfg(feature = "collections")]
-use collections::enum_set::{CLike, EnumSet};
 #[cfg(feature = "collections")]
 use collections::borrow::ToOwned;
 
@@ -481,15 +479,6 @@ seq_impl!(
     BTreeSet::new(),
     BTreeSet::insert);
 
-#[cfg(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>,
@@ -574,7 +563,7 @@ 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];
@@ -590,7 +579,7 @@ macro_rules! array_impls {
                     $(
                         let $name = match try!(visitor.visit()) {
                             Some(val) => val,
-                            None => return Err(Error::invalid_length(0, &self)),
+                            None => return Err(Error::invalid_length($n, &self)),
                         };
                     )+
 
@@ -612,44 +601,44 @@ macro_rules! array_impls {
 }
 
 array_impls! {
-    1 => (a)
-    2 => (a b)
-    3 => (a b c)
-    4 => (a b c d)
-    5 => (a b c d e)
-    6 => (a b c d e f)
-    7 => (a b c d e f g)
-    8 => (a b c d e f g h)
-    9 => (a b c d e f g h i)
-    10 => (a b c d e f g h i j)
-    11 => (a b c d e f g h i j k)
-    12 => (a b c d e f g h i j k l)
-    13 => (a b c d e f g h i j k l m)
-    14 => (a b c d e f g h i j k l m n)
-    15 => (a b c d e f g h i j k l m n o)
-    16 => (a b c d e f g h i j k l m n o p)
-    17 => (a b c d e f g h i j k l m n o p q)
-    18 => (a b c d e f g h i j k l m n o p q r)
-    19 => (a b c d e f g h i j k l m n o p q r s)
-    20 => (a b c d e f g h i j k l m n o p q r s t)
-    21 => (a b c d e f g h i j k l m n o p q r s t u)
-    22 => (a b c d e f g h i j k l m n o p q r s t u 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)
-    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)
-    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)
-    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)
-    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)
-    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)
-    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)
-    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)
-    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)
-    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)
+    1 => (0 a)
+    2 => (0 a 1 b)
+    3 => (0 a 1 b 2 c)
+    4 => (0 a 1 b 2 c 3 d)
+    5 => (0 a 1 b 2 c 3 d 4 e)
+    6 => (0 a 1 b 2 c 3 d 4 e 5 f)
+    7 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g)
+    8 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h)
+    9 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i)
+    10 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j)
+    11 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k)
+    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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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 => (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,)+> {
@@ -678,7 +667,7 @@ macro_rules! tuple_impls {
                     $(
                         let $name = match try!(visitor.visit()) {
                             Some(value) => value,
-                            None => return Err(Error::invalid_length(0, &self)),
+                            None => return Err(Error::invalid_length($n, &self)),
                         };
                     )+
 
@@ -699,22 +688,22 @@ macro_rules! tuple_impls {
 }
 
 tuple_impls! {
-    1 => TupleVisitor1 => (T0)
-    2 => TupleVisitor2 => (T0 T1)
-    3 => TupleVisitor3 => (T0 T1 T2)
-    4 => TupleVisitor4 => (T0 T1 T2 T3)
-    5 => TupleVisitor5 => (T0 T1 T2 T3 T4)
-    6 => TupleVisitor6 => (T0 T1 T2 T3 T4 T5)
-    7 => TupleVisitor7 => (T0 T1 T2 T3 T4 T5 T6)
-    8 => TupleVisitor8 => (T0 T1 T2 T3 T4 T5 T6 T7)
-    9 => TupleVisitor9 => (T0 T1 T2 T3 T4 T5 T6 T7 T8)
-    10 => TupleVisitor10 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9)
-    11 => TupleVisitor11 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10)
-    12 => TupleVisitor12 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11)
-    13 => TupleVisitor13 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12)
-    14 => TupleVisitor14 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13)
-    15 => TupleVisitor15 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14)
-    16 => TupleVisitor16 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15)
+    1 => TupleVisitor1 => (0 T0)
+    2 => TupleVisitor2 => (0 T0 1 T1)
+    3 => TupleVisitor3 => (0 T0 1 T1 2 T2)
+    4 => TupleVisitor4 => (0 T0 1 T1 2 T2 3 T3)
+    5 => TupleVisitor5 => (0 T0 1 T1 2 T2 3 T3 4 T4)
+    6 => TupleVisitor6 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5)
+    7 => TupleVisitor7 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6)
+    8 => TupleVisitor8 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7)
+    9 => TupleVisitor9 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8)
+    10 => TupleVisitor10 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9)
+    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 => (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 => (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 => (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 => (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 => (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)
 }
 
 ///////////////////////////////////////////////////////////////////////////////

serde/src/de/mod.rs

@@ -115,6 +115,8 @@ mod from_primitive;
 // Helpers used by generated code. Not public API.
 #[doc(hidden)]
 pub mod private;
+#[cfg(any(feature = "std", feature = "collections"))]
+mod content;
 
 ///////////////////////////////////////////////////////////////////////////////
 
@@ -488,8 +490,8 @@ impl<'a> Display for Expected + 'a {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-/// An implementation of this trait is a **data structure** that can be
-/// deserialized from any data format supported by Serde.
+/// A **data structure** that can be deserialized from any data format supported
+/// by Serde.
 ///
 /// Serde provides `Deserialize` implementations for many Rust primitive and
 /// standard library types. The complete list is [here][de]. All of these can
@@ -687,8 +689,8 @@ impl<T> DeserializeSeed for PhantomData<T>
 
 ///////////////////////////////////////////////////////////////////////////////
 
-/// An implementation of this trait is a **data format** that can deserialize
-/// any data structure supported by Serde.
+/// A **data format** that can deserialize any data structure supported by
+/// Serde.
 ///
 /// The role of this trait is to define the deserialization half of the Serde
 /// data model, which is a way to categorize every Rust data type into one of 28
@@ -857,7 +859,7 @@ pub trait Deserializer: Sized {
     /// benefit from taking ownership of buffered data owned by the
     /// `Deserializer`.
     ///
-    /// If the `Visitor would benefit from taking ownership of `Vec<u8>` data,
+    /// If the `Visitor` would benefit from taking ownership of `Vec<u8>` data,
     /// indicate this to the `Deserializer` by using `deserialize_byte_buf`
     /// instead.
     fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value, Self::Error>

serde/src/de/private.rs

@@ -2,6 +2,16 @@ use core::marker::PhantomData;
 
 use de::{Deserialize, Deserializer, Error, Visitor};
 
+#[cfg(any(feature = "std", feature = "collections"))]
+pub use de::content::{
+    Content,
+    ContentRefDeserializer,
+    ContentDeserializer,
+    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>

serde/src/de/value.rs

@@ -51,7 +51,9 @@ use bytes;
 
 /// This represents all the possible errors that can occur using the `ValueDeserializer`.
 #[derive(Clone, Debug, PartialEq)]
-pub struct Error(ErrorImpl);
+pub struct Error {
+    err: ErrorImpl,
+}
 
 #[cfg(any(feature = "std", feature = "collections"))]
 type ErrorImpl = Box<str>;
@@ -61,19 +63,23 @@ type ErrorImpl = ();
 impl de::Error for Error {
     #[cfg(any(feature = "std", feature = "collections"))]
     fn custom<T: Display>(msg: T) -> Self {
-        Error(msg.to_string().into_boxed_str())
+        Error {
+            err: msg.to_string().into_boxed_str(),
+        }
     }
 
     #[cfg(not(any(feature = "std", feature = "collections")))]
     fn custom<T: Display>(_msg: T) -> Self {
-        Error(())
+        Error {
+            err: (),
+        }
     }
 }
 
 impl Display for Error {
     #[cfg(any(feature = "std", feature = "collections"))]
     fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-        formatter.write_str(&self.0)
+        formatter.write_str(&self.err)
     }
 
     #[cfg(not(any(feature = "std", feature = "collections")))]
@@ -85,7 +91,7 @@ impl Display for Error {
 impl error::Error for Error {
     #[cfg(any(feature = "std", feature = "collections"))]
     fn description(&self) -> &str {
-        &self.0
+        &self.err
     }
 
     #[cfg(not(any(feature = "std", feature = "collections")))]
@@ -113,12 +119,16 @@ impl<E> ValueDeserializer<E> for ()
     type Deserializer = UnitDeserializer<E>;
 
     fn into_deserializer(self) -> UnitDeserializer<E> {
-        UnitDeserializer(PhantomData)
+        UnitDeserializer {
+            marker: PhantomData,
+        }
     }
 }
 
 /// A helper deserializer that deserializes a `()`.
-pub struct UnitDeserializer<E>(PhantomData<E>);
+pub struct UnitDeserializer<E> {
+    marker: PhantomData<E>,
+}
 
 impl<E> de::Deserializer for UnitDeserializer<E>
     where E: de::Error
@@ -149,7 +159,10 @@ impl<E> de::Deserializer for UnitDeserializer<E>
 macro_rules! primitive_deserializer {
     ($ty:ty, $name:ident, $method:ident $($cast:tt)*) => {
         /// A helper deserializer that deserializes a number.
-        pub struct $name<E>($ty, PhantomData<E>);
+        pub struct $name<E> {
+            value: $ty,
+            marker: PhantomData<E>
+        }
 
         impl<E> ValueDeserializer<E> for $ty
             where E: de::Error,
@@ -157,7 +170,10 @@ macro_rules! primitive_deserializer {
             type Deserializer = $name<E>;
 
             fn into_deserializer(self) -> $name<E> {
-                $name(self, PhantomData)
+                $name {
+                    value: self,
+                    marker: PhantomData,
+                }
             }
         }
 
@@ -175,7 +191,7 @@ macro_rules! primitive_deserializer {
             fn deserialize<V>(self, visitor: V) -> Result<V::Value, Self::Error>
                 where V: de::Visitor,
             {
-                visitor.$method(self.0 $($cast)*)
+                visitor.$method(self.value $($cast)*)
             }
         }
     }
@@ -199,7 +215,10 @@ primitive_deserializer!(char, CharDeserializer, visit_char);
 ///////////////////////////////////////////////////////////////////////////////
 
 /// A helper deserializer that deserializes a `&str`.
-pub struct StrDeserializer<'a, E>(&'a str, PhantomData<E>);
+pub struct StrDeserializer<'a, E> {
+    value: &'a str,
+    marker: PhantomData<E>,
+}
 
 impl<'a, E> ValueDeserializer<E> for &'a str
     where E: de::Error,
@@ -207,7 +226,10 @@ impl<'a, E> ValueDeserializer<E> for &'a str
     type Deserializer = StrDeserializer<'a, E>;
 
     fn into_deserializer(self) -> StrDeserializer<'a, E> {
-        StrDeserializer(self, PhantomData)
+        StrDeserializer {
+            value: self,
+            marker: PhantomData,
+        }
     }
 }
 
@@ -219,7 +241,7 @@ impl<'a, E> de::Deserializer for StrDeserializer<'a, E>
     fn deserialize<V>(self, visitor: V) -> Result<V::Value, Self::Error>
         where V: de::Visitor,
     {
-        visitor.visit_str(self.0)
+        visitor.visit_str(self.value)
     }
 
     fn deserialize_enum<V>(self,
@@ -255,7 +277,10 @@ impl<'a, E> de::EnumVisitor for StrDeserializer<'a, E>
 
 /// A helper deserializer that deserializes a `String`.
 #[cfg(any(feature = "std", feature = "collections"))]
-pub struct StringDeserializer<E>(String, PhantomData<E>);
+pub struct StringDeserializer<E> {
+    value: String,
+    marker: PhantomData<E>,
+}
 
 #[cfg(any(feature = "std", feature = "collections"))]
 impl<E> ValueDeserializer<E> for String
@@ -264,7 +289,10 @@ impl<E> ValueDeserializer<E> for String
     type Deserializer = StringDeserializer<E>;
 
     fn into_deserializer(self) -> StringDeserializer<E> {
-        StringDeserializer(self, PhantomData)
+        StringDeserializer {
+            value: self,
+            marker: PhantomData,
+        }
     }
 }
 
@@ -277,7 +305,7 @@ impl<E> de::Deserializer for StringDeserializer<E>
     fn deserialize<V>(self, visitor: V) -> Result<V::Value, Self::Error>
         where V: de::Visitor,
     {
-        visitor.visit_string(self.0)
+        visitor.visit_string(self.value)
     }
 
     fn deserialize_enum<V>(self,
@@ -314,7 +342,10 @@ impl<'a, E> de::EnumVisitor for StringDeserializer<E>
 
 /// A helper deserializer that deserializes a `String`.
 #[cfg(any(feature = "std", feature = "collections"))]
-pub struct CowStrDeserializer<'a, E>(Cow<'a, str>, PhantomData<E>);
+pub struct CowStrDeserializer<'a, E> {
+    value: Cow<'a, str>,
+    marker: PhantomData<E>,
+}
 
 #[cfg(any(feature = "std", feature = "collections"))]
 impl<'a, E> ValueDeserializer<E> for Cow<'a, str>
@@ -323,7 +354,10 @@ impl<'a, E> ValueDeserializer<E> for Cow<'a, str>
     type Deserializer = CowStrDeserializer<'a, E>;
 
     fn into_deserializer(self) -> CowStrDeserializer<'a, E> {
-        CowStrDeserializer(self, PhantomData)
+        CowStrDeserializer {
+            value: self,
+            marker: PhantomData,
+        }
     }
 }
 
@@ -336,7 +370,7 @@ impl<'a, E> de::Deserializer for CowStrDeserializer<'a, E>
     fn deserialize<V>(self, visitor: V) -> Result<V::Value, Self::Error>
         where V: de::Visitor,
     {
-        match self.0 {
+        match self.value {
             Cow::Borrowed(string) => visitor.visit_str(string),
             Cow::Owned(string) => visitor.visit_string(string),
         }
@@ -394,7 +428,9 @@ impl<I, E> SeqDeserializer<I, E>
         }
     }
 
-    fn end(&mut self) -> Result<(), E> {
+    /// Check for remaining elements after passing a `SeqDeserializer` to
+    /// `Visitor::visit_seq`.
+    pub fn end(mut self) -> Result<(), E> {
         let mut remaining = 0;
         while self.iter.next().is_some() {
             remaining += 1;
@@ -576,17 +612,9 @@ impl<I, E> MapDeserializer<I, E>
         }
     }
 
-    fn next_pair(&mut self) -> Option<(<I::Item as private::Pair>::First, <I::Item as private::Pair>::Second)> {
-        match self.iter.next() {
-            Some(kv) => {
-                self.count += 1;
-                Some(private::Pair::split(kv))
-            }
-            None => None,
-        }
-    }
-
-    fn end(&mut self) -> Result<(), E> {
+    /// Check for remaining elements after passing a `MapDeserializer` to
+    /// `Visitor::visit_map`.
+    pub fn end(mut self) -> Result<(), E> {
         let mut remaining = 0;
         while self.iter.next().is_some() {
             remaining += 1;
@@ -599,6 +627,16 @@ impl<I, E> MapDeserializer<I, E>
             Err(de::Error::invalid_length(self.count + remaining, &ExpectedInMap(self.count)))
         }
     }
+
+    fn next_pair(&mut self) -> Option<(<I::Item as private::Pair>::First, <I::Item as private::Pair>::Second)> {
+        match self.iter.next() {
+            Some(kv) => {
+                self.count += 1;
+                Some(private::Pair::split(kv))
+            }
+            None => None,
+        }
+    }
 }
 
 impl<I, E> de::Deserializer for MapDeserializer<I, E>
@@ -885,12 +923,18 @@ impl<'a, E> ValueDeserializer<E> for bytes::Bytes<'a>
     type Deserializer = BytesDeserializer<'a, E>;
 
     fn into_deserializer(self) -> BytesDeserializer<'a, E> {
-        BytesDeserializer(self.into(), PhantomData)
+        BytesDeserializer {
+            value: self.into(),
+            marker: PhantomData,
+        }
     }
 }
 
 /// A helper deserializer that deserializes a `&[u8]`.
-pub struct BytesDeserializer<'a, E>(&'a [u8], PhantomData<E>);
+pub struct BytesDeserializer<'a, E> {
+    value: &'a [u8],
+    marker: PhantomData<E>,
+}
 
 impl<'a, E> de::Deserializer for BytesDeserializer<'a, E>
     where E: de::Error
@@ -900,7 +944,7 @@ impl<'a, E> de::Deserializer for BytesDeserializer<'a, E>
     fn deserialize<V>(self, visitor: V) -> Result<V::Value, Self::Error>
         where V: de::Visitor,
     {
-        visitor.visit_bytes(self.0)
+        visitor.visit_bytes(self.value)
     }
 
     forward_to_deserialize! {
@@ -919,13 +963,19 @@ impl<E> ValueDeserializer<E> for bytes::ByteBuf
     type Deserializer = ByteBufDeserializer<E>;
 
     fn into_deserializer(self) -> Self::Deserializer {
-        ByteBufDeserializer(self.into(), PhantomData)
+        ByteBufDeserializer {
+            value: self.into(),
+            marker: PhantomData,
+        }
     }
 }
 
 /// A helper deserializer that deserializes a `Vec<u8>`.
 #[cfg(any(feature = "std", feature = "collections"))]
-pub struct ByteBufDeserializer<E>(Vec<u8>, PhantomData<E>);
+pub struct ByteBufDeserializer<E> {
+    value: Vec<u8>,
+    marker: PhantomData<E>,
+}
 
 #[cfg(any(feature = "std", feature = "collections"))]
 impl<E> de::Deserializer for ByteBufDeserializer<E>
@@ -936,7 +986,7 @@ impl<E> de::Deserializer for ByteBufDeserializer<E>
     fn deserialize<V>(self, visitor: V) -> Result<V::Value, Self::Error>
         where V: de::Visitor,
     {
-        visitor.visit_byte_buf(self.0)
+        visitor.visit_byte_buf(self.value)
     }
 
     forward_to_deserialize! {
@@ -952,10 +1002,12 @@ mod private {
     use de::{self, Unexpected};
     use core::marker::PhantomData;
 
-    pub struct UnitOnly<E>(PhantomData<E>);
+    pub struct UnitOnly<E> {
+        marker: PhantomData<E>,
+    }
 
     pub fn unit_only<T, E>(t: T) -> (T, UnitOnly<E>) {
-        (t, UnitOnly(PhantomData))
+        (t, UnitOnly { marker: PhantomData })
     }
 
     impl<E> de::VariantVisitor for UnitOnly<E>

serde/src/export.rs

@@ -9,7 +9,8 @@ use collections::borrow::Cow;
 pub use core::default::Default;
 pub use core::fmt;
 pub use core::marker::PhantomData;
-pub use core::result::Result;
+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> {

serde/src/lib.rs

@@ -61,12 +61,10 @@
 
 #![doc(html_root_url="https://docs.serde.rs")]
 #![cfg_attr(not(feature = "std"), no_std)]
-#![cfg_attr(feature = "unstable", feature(nonzero, inclusive_range, zero_one))]
+#![cfg_attr(feature = "unstable", feature(inclusive_range, nonzero, specialization, zero_one))]
 #![cfg_attr(feature = "alloc", feature(alloc))]
-#![cfg_attr(feature = "collections", feature(collections, enumset))]
-#![cfg_attr(feature = "clippy", feature(plugin))]
-#![cfg_attr(feature = "clippy", plugin(clippy))]
-#![cfg_attr(feature = "clippy", allow(linkedlist, type_complexity, doc_markdown))]
+#![cfg_attr(feature = "collections", feature(collections))]
+#![cfg_attr(feature = "cargo-clippy", allow(linkedlist, type_complexity, doc_markdown))]
 #![deny(missing_docs)]
 
 #[cfg(feature = "collections")]
@@ -81,12 +79,14 @@ 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, default, result};
+            usize, f32, f64, char, str, num, slice, iter, cell, default, result, option};
     #[cfg(feature = "unstable")]
     pub use actual_core::nonzero;
 }
 
+#[doc(inline)]
 pub use ser::{Serialize, Serializer};
+#[doc(inline)]
 pub use de::{Deserialize, Deserializer};
 
 #[macro_use]

serde/src/ser/impls.rs

@@ -24,8 +24,6 @@ use collections::{
     Vec,
 };
 
-#[cfg(feature = "collections")]
-use collections::enum_set::{CLike, EnumSet};
 #[cfg(feature = "collections")]
 use collections::borrow::ToOwned;
 
@@ -65,12 +63,9 @@ use super::{
     SerializeTuple,
     Serializer,
 };
-#[cfg(any(feature = "std", feature = "unstable"))]
+#[cfg(feature = "std")]
 use super::Error;
 
-#[cfg(feature = "unstable")]
-use super::Iterator;
-
 ///////////////////////////////////////////////////////////////////////////////
 
 macro_rules! impl_visit {
@@ -149,24 +144,6 @@ impl<T> Serialize for PhantomData<T> {
     }
 }
 
-
-///////////////////////////////////////////////////////////////////////////////
-
-impl<T> Serialize for [T]
-    where T: 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 {
-            try!(seq.serialize_element(e));
-        }
-        seq.end()
-    }
-}
-
 ///////////////////////////////////////////////////////////////////////////////
 
 macro_rules! array_impls {
@@ -222,48 +199,23 @@ array_impls!(32);
 
 ///////////////////////////////////////////////////////////////////////////////
 
-#[cfg(feature = "unstable")]
-impl<'a, I> Serialize for Iterator<I>
-    where I: IntoIterator, <I as IntoIterator>::Item: Serialize
-{
-    #[inline]
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-        where S: Serializer,
-    {
-        // FIXME: use specialization to prevent invalidating the object in case of clonable iterators?
-        let iter = match self.0.borrow_mut().take() {
-            Some(iter) => iter.into_iter(),
-            None => return Err(Error::custom("Iterator used twice")),
-        };
-        let size = match iter.size_hint() {
-            (lo, Some(hi)) if lo == hi => Some(lo),
-            _ => None,
-        };
-        let mut seq = try!(serializer.serialize_seq(size));
-        for e in iter {
-            try!(seq.serialize_element(&e));
-        }
-        seq.end()
-    }
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
 macro_rules! serialize_seq {
     () => {
         #[inline]
         fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
             where S: Serializer,
         {
-            let mut seq = try!(serializer.serialize_seq(Some(self.len())));
-            for e in self {
-                try!(seq.serialize_element(&e));
-            }
-            seq.end()
+            serializer.collect_seq(self)
         }
     }
 }
 
+impl<T> Serialize for [T]
+    where T: Serialize,
+{
+    serialize_seq!();
+}
+
 #[cfg(any(feature = "std", feature = "collections"))]
 impl<T> Serialize for BinaryHeap<T>
     where T: Serialize + Ord
@@ -278,13 +230,6 @@ impl<T> Serialize for BTreeSet<T>
     serialize_seq!();
 }
 
-#[cfg(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,
@@ -565,12 +510,7 @@ 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_entry(k, v));
-            }
-            map.end()
+            serializer.collect_map(self)
         }
     }
 }

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

@@ -98,12 +98,17 @@ use std::error;
 #[cfg(not(feature = "std"))]
 use error;
 
-#[cfg(feature = "unstable")]
-use core::cell::RefCell;
-
 use core::fmt::Display;
+use core::iter::IntoIterator;
 
 mod impls;
+mod impossible;
+
+// Helpers used by generated code. Not public API.
+#[doc(hidden)]
+pub mod private;
+
+pub use self::impossible::Impossible;
 
 ///////////////////////////////////////////////////////////////////////////////
 
@@ -138,8 +143,8 @@ pub trait Error: Sized + error::Error {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-/// An implementation of this trait is a **data structure** that can be
-/// serialized into any data format supported by Serde.
+/// 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
@@ -175,8 +180,7 @@ pub trait Serialize {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-/// An implementation of this trait is a **data format** that can serialize any
-/// data structure supported by Serde.
+/// A **data format** that can serialize any data structure supported by Serde.
 ///
 /// The role of this trait is to define the serialization half of the Serde data
 /// model, which is a way to categorize every Rust data structure into one of 28
@@ -236,7 +240,7 @@ pub trait Serialize {
 /// 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 {
+pub trait Serializer: Sized {
     /// The output type produced by this `Serializer` during successful
     /// serialization. Most serializers that produce text or binary output
     /// should set `Ok = ()` and serialize into an `io::Write` or buffer
@@ -601,6 +605,41 @@ pub trait Serializer {
         variant: &'static str,
         len: usize,
     ) -> Result<Self::SerializeStructVariant, Self::Error>;
+
+    /// Collect an iterator as a sequence.
+    ///
+    /// The default implementation serializes each item yielded by the iterator
+    /// using `Self::SerializeSeq`. Implementors should not need to override
+    /// this method.
+    fn collect_seq<I>(self, iter: I) -> Result<Self::Ok, Self::Error>
+        where I: IntoIterator,
+              <I as IntoIterator>::Item: Serialize,
+    {
+        let iter = iter.into_iter();
+        let mut serializer = try!(self.serialize_seq(iter.len_hint()));
+        for item in iter {
+            try!(serializer.serialize_element(&item));
+        }
+        serializer.end()
+    }
+
+    /// Collect an iterator as a map.
+    ///
+    /// The default implementation serializes each pair yielded by the iterator
+    /// using `Self::SerializeMap`. Implementors should not need to override
+    /// this method.
+    fn collect_map<K, V, I>(self, iter: I) -> Result<Self::Ok, Self::Error>
+        where K: Serialize,
+              V: Serialize,
+              I: IntoIterator<Item = (K, V)>,
+    {
+        let iter = iter.into_iter();
+        let mut serializer = try!(self.serialize_map(iter.len_hint()));
+        for (key, value) in iter {
+            try!(serializer.serialize_entry(&key, &value));
+        }
+        serializer.end()
+    }
 }
 
 /// Returned from `Serializer::serialize_seq` and
@@ -797,21 +836,32 @@ pub trait SerializeStructVariant {
     fn end(self) -> Result<Self::Ok, Self::Error>;
 }
 
-/// A wrapper type for iterators that implements `Serialize` for iterators whose
-/// items implement `Serialize`. Don't use multiple times. Create new versions
-/// of this with the `serde::ser::iterator` function every time you want to
-/// serialize an iterator.
-#[cfg(feature = "unstable")]
-pub struct Iterator<I>(RefCell<Option<I>>)
-    where <I as IntoIterator>::Item: Serialize,
-          I: IntoIterator;
-
-/// Create a wrapper type that can be passed to any function expecting a
-/// `Serialize` and will serialize the given iterator as a sequence.
-#[cfg(feature = "unstable")]
-pub fn iterator<I>(iter: I) -> Iterator<I>
-    where <I as IntoIterator>::Item: Serialize,
-          I: IntoIterator
-{
-    Iterator(RefCell::new(Some(iter)))
+trait LenHint: Iterator {
+    fn len_hint(&self) -> Option<usize>;
+}
+
+impl<I: Iterator> LenHint for I {
+    #[cfg(not(feature = "unstable"))]
+    fn len_hint(&self) -> Option<usize> {
+        iterator_len_hint(self)
+    }
+
+    #[cfg(feature = "unstable")]
+    default fn len_hint(&self) -> Option<usize> {
+        iterator_len_hint(self)
+    }
+}
+
+#[cfg(feature = "unstable")]
+impl<I: ExactSizeIterator> LenHint for I {
+    fn len_hint(&self) -> Option<usize> {
+        Some(self.len())
+    }
+}
+
+fn iterator_len_hint<I: Iterator>(iter: &I) -> Option<usize> {
+    match iter.size_hint() {
+        (lo, Some(hi)) if lo == hi => Some(lo),
+        _ => None,
+    }
 }

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_internals/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_codegen_internals"
-version = "0.12.0"
+version = "0.13.0"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "AST representation used by Serde codegen. Unstable."
@@ -10,11 +10,7 @@ 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"
 
 [badges]

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 {
@@ -143,6 +171,32 @@ 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()));
@@ -155,6 +209,32 @@ impl Item {
             }
         }
 
+        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

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

@@ -1,18 +1,17 @@
 [package]
 name = "serde_derive"
-version = "0.9.2"
+version = "0.9.7"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"
 homepage = "https://serde.rs"
 repository = "https://github.com/serde-rs/serde"
 documentation = "https://serde.rs/codegen.html"
-keywords = ["serde", "serialization"]
+keywords = ["serde", "serialization", "no_std"]
 include = ["Cargo.toml", "src/**/*.rs"]
 
 [features]
 unstable = []
-unstable-testing = ["clippy", "serde_codegen_internals/unstable-testing"]
 
 [badges]
 travis-ci = { repository = "serde-rs/serde" }
@@ -22,7 +21,6 @@ name = "serde_derive"
 proc-macro = true
 
 [dependencies]
-clippy = { version = "0.*", optional = true }
 quote = "0.3.8"
-serde_codegen_internals = { version = "=0.12.0", default-features = false, path = "../serde_codegen_internals" }
+serde_codegen_internals = { version = "=0.13.0", default-features = false, path = "../serde_codegen_internals" }
 syn = { version = "0.11", features = ["aster", "visit"] }

serde_derive/src/de.rs

@@ -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(
@@ -209,21 +211,21 @@ fn deserialize_unit_struct(
             type Value = #type_ident;
 
             fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
-                formatter.write_str(#expecting)
+                _serde::export::fmt::Formatter::write_str(formatter, #expecting)
             }
 
             #[inline]
             fn visit_unit<__E>(self) -> _serde::export::Result<#type_ident, __E>
                 where __E: _serde::de::Error,
             {
-                Ok(#type_ident)
+                _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)
             }
         }
 
@@ -238,6 +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;
 
@@ -274,14 +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());
@@ -298,7 +303,7 @@ fn deserialize_tuple(
             type Value = #ty;
 
             fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
-                formatter.write_str(#expecting)
+                _serde::export::fmt::Formatter::write_str(formatter, #expecting)
             }
 
             #visit_newtype_struct
@@ -341,7 +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(
@@ -349,7 +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)
                         })
                     }
                 };
@@ -357,7 +363,7 @@ fn deserialize_seq(
                     let #var = match #visit {
                         Some(value) => { value },
                         None => {
-                            return Err(_serde::de::Error::invalid_length(#index_in_seq, &#expecting));
+                            return _serde::export::Err(_serde::de::Error::invalid_length(#index_in_seq, &#expecting));
                         }
                     };
                 };
@@ -379,7 +385,7 @@ fn deserialize_seq(
 
     quote! {
         #(#let_values)*
-        Ok(#result)
+        _serde::export::Ok(#result)
     }
 }
 
@@ -411,7 +417,7 @@ fn deserialize_newtype_struct(
         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))
         }
     }
 }
@@ -423,7 +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);
@@ -453,15 +463,18 @@ fn deserialize_struct(
         item_attrs,
     );
 
-    let is_enum = variant_ident.is_some();
-    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_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)
         }
     };
 
@@ -472,6 +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
 
@@ -481,15 +508,10 @@ fn deserialize_struct(
             type Value = #ty;
 
             fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
-                formatter.write_str(#expecting)
+                _serde::export::fmt::Formatter::write_str(formatter, #expecting)
             }
 
-            #[inline]
-            fn visit_seq<__V>(self, #visitor_var: __V) -> _serde::export::Result<#ty, __V::Error>
-                where __V: _serde::de::SeqVisitor
-            {
-                #visit_seq
-            }
+            #visit_seq
 
             #[inline]
             fn visit_map<__V>(self, mut visitor: __V) -> _serde::export::Result<#ty, __V::Error>
@@ -511,6 +533,45 @@ 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;
 
@@ -544,7 +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(),
@@ -563,13 +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>();
-            // Err(err)
-            visitor.visit_variant::<__Field>().map(|(impossible, _)| match impossible {})
+            // let _serde::export::Err(err) = _serde::de::EnumVisitor::visit_variant::<__Field>(visitor);
+            // _serde::export::Err(err)
+            _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)*
             }
         }
@@ -586,7 +648,7 @@ fn deserialize_item_enum(
             type Value = #ty;
 
             fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
-                formatter.write_str(#expecting)
+                _serde::export::fmt::Formatter::write_str(formatter, #expecting)
             }
 
             fn visit_enum<__V>(self, visitor: __V) -> _serde::export::Result<#ty, __V::Error>
@@ -598,11 +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!(_serde::de::private::ContentDeserializer::<__D::Error>::new(_tagged.content)),
+            );
+
+            quote! {
+                __Field::#variant_name => #block
+            }
+        });
+
+    quote!({
+        #variant_visitor
+
+        #variants_stmt
+
+        let _tagged = try!(_serde::Deserializer::deserialize(
+            deserializer,
+            _serde::de::private::TaggedContentVisitor::<__Field>::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!(_serde::de::private::ContentRefDeserializer::<__D::Error>::new(&_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 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,
@@ -615,11 +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,
@@ -634,6 +800,7 @@ fn deserialize_variant(
                 ty,
                 &variant.fields,
                 item_attrs,
+                None,
             )
         }
         Style::Struct => {
@@ -644,22 +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) => {
@@ -668,12 +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)),
     }
 }
 
@@ -701,9 +990,9 @@ fn deserialize_field_visitor(
             {
                 match value {
                     #(
-                        #variant_indices => Ok(__Field::#field_idents),
+                        #variant_indices => _serde::export::Ok(__Field::#field_idents),
                     )*
-                    _ => Err(_serde::de::Error::invalid_value(
+                    _ => _serde::export::Err(_serde::de::Error::invalid_value(
                                 _serde::de::Unexpected::Unsigned(value as u64),
                                 &#fallthrough_msg))
                 }
@@ -715,15 +1004,15 @@ fn deserialize_field_visitor(
 
     let fallthrough_arm = if is_variant {
         quote! {
-            Err(_serde::de::Error::unknown_variant(value, VARIANTS))
+            _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, FIELDS))
+            _serde::export::Err(_serde::de::Error::unknown_field(value, FIELDS))
         }
     } else {
         quote! {
-            Ok(__Field::__ignore)
+            _serde::export::Ok(__Field::__ignore)
         }
     };
 
@@ -755,7 +1044,7 @@ fn deserialize_field_visitor(
                     type Value = __Field;
 
                     fn expecting(&self, formatter: &mut _serde::export::fmt::Formatter) -> _serde::export::fmt::Result {
-                        formatter.write_str("field name")
+                        _serde::export::fmt::Formatter::write_str(formatter, "field name")
                     }
 
                     #visit_index
@@ -765,7 +1054,7 @@ fn deserialize_field_visitor(
                     {
                         match value {
                             #(
-                                #field_strs => Ok(__Field::#field_idents),
+                                #field_strs => _serde::export::Ok(__Field::#field_idents),
                             )*
                             _ => #fallthrough_arm
                         }
@@ -776,7 +1065,7 @@ fn deserialize_field_visitor(
                     {
                         match value {
                             #(
-                                #field_bytes => Ok(__Field::#field_idents),
+                                #field_bytes => _serde::export::Ok(__Field::#field_idents),
                             )*
                             _ => {
                                 #bytes_to_str
@@ -786,7 +1075,7 @@ fn deserialize_field_visitor(
                     }
                 }
 
-                deserializer.deserialize_struct_field(__FieldVisitor)
+                _serde::Deserializer::deserialize_struct_field(deserializer, __FieldVisitor)
             }
         }
     }
@@ -848,7 +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;
             }
         });
 
@@ -862,7 +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) => {
@@ -871,16 +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() {
-                        return Err(<__V::Error as _serde::de::Error>::duplicate_field(#deser_name));
+                    if _serde::export::Option::is_some(&#name) {
+                        return _serde::export::Err(<__V::Error as _serde::de::Error>::duplicate_field(#deser_name));
                     }
-                    #name = Some(#visit);
+                    #name = _serde::export::Some(#visit);
                 }
             }
         });
@@ -890,7 +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)); }
         })
     };
 
@@ -898,12 +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());
-            try!(visitor.visit_key::<__Field>()).map(|impossible| match impossible {});
+            // let _serde::export::None::<__Field> = try!(_serde::de::MapVisitor::visit_key(&mut visitor));
+            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
@@ -919,8 +1209,8 @@ fn deserialize_map(
 
             quote! {
                 let #name = match #name {
-                    Some(#name) => #name,
-                    None => #missing_expr
+                    _serde::export::Some(#name) => #name,
+                    _serde::export::None => #missing_expr
                 };
             }
         });
@@ -943,7 +1233,7 @@ fn deserialize_map(
 
         #(#extract_values)*
 
-        Ok(#struct_path { #(#result),* })
+        _serde::export::Ok(#struct_path { #(#result),* })
     }
 }
 
@@ -990,7 +1280,7 @@ fn wrap_deserialize_with(
                     where __D: _serde::Deserializer
                 {
                     let value = try!(#deserialize_with(__d));
-                    Ok(__SerdeDeserializeWithStruct {
+                    _serde::export::Ok(__SerdeDeserializeWithStruct {
                         value: value,
                         phantom: _serde::export::PhantomData,
                     })
@@ -1021,7 +1311,7 @@ fn expr_is_missing(attrs: &attr::Field) -> Tokens {
         }
         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

@@ -1,7 +1,5 @@
-#![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))]
+#![cfg_attr(feature = "cargo-clippy", allow(too_many_arguments))]
+#![cfg_attr(feature = "cargo-clippy", allow(used_underscore_binding))]
 
 // The `quote!` macro requires deep recursion.
 #![recursion_limit = "192"]

serde_derive/src/ser.rs

@@ -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",
-                                type_ident, variant_ident);
+                                  type_ident, variant_ident);
         let skipped_err = quote! {
-            Err(_serde::ser::Error::custom(#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 =>
-                        _serde::Serializer::serialize_unit_variant(
-                            _serializer,
-                            #type_name,
-                            #variant_index,
-                            #variant_name,
-                        ),
+                    #type_ident::#variant_ident
                 }
-            },
+            }
             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(
-                    variant_index,
-                    variant_name,
+        let body = match *item_attrs.tag() {
+            attr::EnumTag::External => {
+                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! {
-                    #type_ident::#variant_ident { #(ref #fields),* } => { #block }
-                }
+        quote! {
+            #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(
-    type_name: String,
-    variant_index: usize,
-    variant_name: String,
-    item_ty: syn::Ty,
+fn serialize_internally_tagged_variant(
+    type_ident: &str,
+    variant_ident: &str,
     generics: &syn::Generics,
-    field: &Field,
+    ty: syn::Ty,
+    variant: &Variant,
+    item_attrs: &attr::Item,
+    tag: &str,
 ) -> Tokens {
-    let mut field_expr = quote!(__simple_value);
-    if let Some(path) = field.attrs.serialize_with() {
-        field_expr = wrap_serialize_with(
-            &item_ty, generics, field.ty, path, field_expr);
-    }
+    let type_name = item_attrs.name().serialize_name();
+    let variant_name = variant.attrs.name().serialize_name();
 
-    quote! {
-        _serde::Serializer::serialize_newtype_variant(
-            _serializer,
-            #type_name,
-            #variant_index,
-            #variant_name,
-            #field_expr,
-        )
+    match variant.style {
+        Style::Unit => {
+            quote!({
+                let mut __struct = try!(_serde::Serializer::serialize_struct(
+                    _serializer, #type_name, 1));
+                try!(_serde::ser::SerializeStruct::serialize_field(
+                    &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,
-    variant_index: usize,
-    variant_name: String,
+    context: TupleVariant,
     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! {
-        let #let_mut __serde_state = try!(_serializer.serialize_tuple_variant(
-            #type_name,
-            #variant_index,
-            #variant_name,
-            #len));
-        #(#serialize_stmts)*
-        _serde::ser::SerializeTupleVariant::end(__serde_state)
+    match context {
+        TupleVariant::ExternallyTagged { type_name, variant_index, variant_name } => {
+            quote! {
+                let #let_mut __serde_state = try!(_serde::Serializer::serialize_tuple_variant(
+                    _serializer,
+                    #type_name,
+                    #variant_index,
+                    #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(
-    variant_index: usize,
-    variant_name: String,
+enum StructVariant<'a> {
+    ExternallyTagged {
+        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! {
-        let #let_mut __serde_state = try!(_serializer.serialize_struct_variant(
-            #item_name,
-            #variant_index,
-            #variant_name,
-            #len,
-        ));
-        #(#serialize_fields)*
-        _serde::ser::SerializeStructVariant::end(__serde_state)
+    match context {
+        StructVariant::ExternallyTagged { variant_index, variant_name } => {
+            quote! {
+                let #let_mut __serde_state = try!(_serde::Serializer::serialize_struct_variant(
+                    _serializer,
+                    #item_name,
+                    #variant_index,
+                    #variant_name,
+                    #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)
+            }
+        }
     }
 }
 
@@ -537,7 +778,7 @@ 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 {
@@ -550,7 +791,7 @@ fn wrap_serialize_with(
 
         &__SerializeWith {
             value: #value,
-            phantom: ::std::marker::PhantomData::<#item_ty>,
+            phantom: _serde::export::PhantomData::<#item_ty>,
         }
     })
 }

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "0.9.2"
+version = "0.9.7"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Token De/Serializer for testing De/Serialize implementations"
@@ -11,11 +11,7 @@ readme = "../README.md"
 keywords = ["serde", "serialization"]
 include = ["Cargo.toml", "src/**/*.rs"]
 
-[features]
-unstable-testing = ["clippy"]
-
 [dependencies]
-clippy = { version = "0.*", optional = true }
 serde = { version = "0.9", path = "../serde" }
 
 [badges]

serde_test/src/de.rs

@@ -47,91 +47,29 @@ impl<I> Deserializer<I>
         }
     }
 
-    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>
-        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>
+    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_map(DeserializerMapVisitor {
             de: self,
             len: len,
+            sep: sep,
+            end: end.clone(),
         }));
-        try!(self.expect_token(Token::MapEnd));
-        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));
+        try!(self.expect_token(end));
         Ok(value)
     }
 }
@@ -141,89 +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>
-        where __V: de::Visitor {
-        self.deserialize(visitor)
-    }
-    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_byte_buf<__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)
+    forward_to_deserialize! {
+        bool u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string unit
+        seq bytes byte_buf map struct_field ignored_any
     }
 
     fn deserialize<V>(self, visitor: V) -> Result<V::Value, Error>
@@ -251,16 +109,22 @@ impl<'a, I> de::Deserializer for &'a mut Deserializer<I>
             Some(Token::Unit) => visitor.visit_unit(),
             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)) => {
-                self.visit_seq(Some(len), visitor)
+            Some(Token::SeqArrayStart(len)) => {
+                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::EndOfTokens),
@@ -360,7 +224,7 @@ 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::EndOfTokens),
@@ -379,19 +243,19 @@ 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(_, _)) => {
                 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::EndOfTokens),
@@ -419,20 +283,20 @@ 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))
                 }
@@ -452,14 +316,14 @@ 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::EndOfTokens),
@@ -472,6 +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>
@@ -482,158 +348,15 @@ impl<'a, I> SeqVisitor for DeserializerSeqVisitor<'a, I>
     fn visit_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
         where T: DeserializeSeed,
     {
-        match self.de.tokens.peek() {
-            Some(&Token::SeqSep) => {
-                self.de.tokens.next();
-                self.len = self.len.map(|len| len - 1);
-                seed.deserialize(&mut *self.de).map(Some)
-            }
-            Some(&Token::SeqEnd) => Ok(None),
-            Some(_) => {
-                let token = self.de.tokens.next().unwrap();
-                Err(Error::UnexpectedToken(token))
-            }
-            None => Err(Error::EndOfTokens),
+        if self.de.tokens.peek() == Some(&self.end) {
+            return Ok(None);
         }
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        let len = self.len.unwrap_or(0);
-        (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_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
-        where T: DeserializeSeed,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::SeqSep) => {
-                self.de.tokens.next();
-                self.len -= 1;
+        match self.de.tokens.next() {
+            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::SeqEnd) => Ok(None),
-            Some(_) => {
-                let token = self.de.tokens.next().unwrap();
-                Err(Error::UnexpectedToken(token))
-            }
-            None => Err(Error::EndOfTokens),
-        }
-    }
-
-    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_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
-        where T: DeserializeSeed,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::TupleSep) => {
-                self.de.tokens.next();
-                self.len -= 1;
-                seed.deserialize(&mut *self.de).map(Some)
-            }
-            Some(&Token::TupleEnd) => Ok(None),
-            Some(_) => {
-                let token = self.de.tokens.next().unwrap();
-                Err(Error::UnexpectedToken(token))
-            }
-            None => Err(Error::EndOfTokens),
-        }
-    }
-
-    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_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
-        where T: DeserializeSeed,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::TupleStructSep) => {
-                self.de.tokens.next();
-                self.len -= 1;
-                seed.deserialize(&mut *self.de).map(Some)
-            }
-            Some(&Token::TupleStructEnd) => Ok(None),
-            Some(_) => {
-                let token = self.de.tokens.next().unwrap();
-                Err(Error::UnexpectedToken(token))
-            }
-            None => Err(Error::EndOfTokens),
-        }
-    }
-
-    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_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
-        where T: DeserializeSeed,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::EnumSeqSep) => {
-                self.de.tokens.next();
-                self.len = self.len.map(|len| len - 1);
-                seed.deserialize(&mut *self.de).map(Some)
-            }
-            Some(&Token::EnumSeqEnd) => Ok(None),
-            Some(_) => {
-                let token = self.de.tokens.next().unwrap();
-                Err(Error::UnexpectedToken(token))
-            }
+            Some(other) => Err(Error::UnexpectedToken(other)),
             None => Err(Error::EndOfTokens),
         }
     }
@@ -649,6 +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>
@@ -659,17 +384,15 @@ impl<'a, I> MapVisitor for DeserializerMapVisitor<'a, I>
     fn visit_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
         where K: DeserializeSeed,
     {
-        match self.de.tokens.peek() {
-            Some(&Token::MapSep) => {
-                self.de.tokens.next();
-                self.len = self.len.map(|len| if len > 0 { len - 1} else { 0 });
+        if self.de.tokens.peek() == Some(&self.end) {
+            return Ok(None);
+        }
+        match self.de.tokens.next() {
+            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(_) => {
-                let token = self.de.tokens.next().unwrap();
-                Err(Error::UnexpectedToken(token))
-            }
+            Some(other) => Err(Error::UnexpectedToken(other)),
             None => Err(Error::EndOfTokens),
         }
     }
@@ -688,47 +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_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
-        where K: DeserializeSeed,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::StructSep) => {
-                self.de.tokens.next();
-                self.len = self.len.saturating_sub(1);
-                seed.deserialize(&mut *self.de).map(Some)
-            }
-            Some(&Token::StructEnd) => Ok(None),
-            Some(_) => {
-                let token = self.de.tokens.next().unwrap();
-                Err(Error::UnexpectedToken(token))
-            }
-            None => Err(Error::EndOfTokens),
-        }
-    }
-
-    fn visit_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
-        where V: DeserializeSeed,
-    {
-        seed.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>,
 }
@@ -803,7 +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))
                 }
@@ -812,7 +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))
                 }
@@ -834,7 +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))
                 }
@@ -843,7 +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))
                 }
@@ -855,45 +537,3 @@ impl<'a, I> VariantVisitor for DeserializerEnumVisitor<'a, I>
         }
     }
 }
-
-//////////////////////////////////////////////////////////////////////////
-
-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_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
-        where K: DeserializeSeed,
-    {
-        match self.de.tokens.peek() {
-            Some(&Token::EnumMapSep) => {
-                self.de.tokens.next();
-                self.len = self.len.map(|len| if len > 0 { len - 1} else { 0 });
-                seed.deserialize(&mut *self.de).map(Some)
-            }
-            Some(&Token::EnumMapEnd) => Ok(None),
-            Some(_) => {
-                let token = self.de.tokens.next().unwrap();
-                Err(Error::UnexpectedToken(token))
-            }
-            None => Err(Error::EndOfTokens),
-        }
-    }
-
-    fn visit_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
-        where V: DeserializeSeed,
-    {
-        seed.deserialize(&mut *self.de)
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        let len = self.len.unwrap_or(0);
-        (len, self.len)
-    }
-}

serde_test/src/lib.rs

@@ -1,6 +1,4 @@
-#![cfg_attr(feature = "clippy", feature(plugin))]
-#![cfg_attr(feature = "clippy", plugin(clippy))]
-
+#[macro_use]
 extern crate serde;
 
 mod assert;

test_suite/Cargo.toml

@@ -13,11 +13,8 @@ publish = false
 
 [features]
 unstable-testing = [
-    "clippy",
     "compiletest_rs",
     "serde/unstable-testing",
-    "serde_derive/unstable-testing",
-    "serde_test/unstable-testing",
 ]
 
 [dev-dependencies]
@@ -28,7 +25,6 @@ serde_derive = { path = "../serde_derive" }
 serde_test = { path = "../serde_test" }
 
 [dependencies]
-clippy = { version = "0.*", optional = true }
 compiletest_rs = { version = "0.2", optional = true }
 
 [[test]]

test_suite/deps/Cargo.toml

@@ -4,6 +4,8 @@ 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/src/main.rs

@@ -21,7 +21,9 @@ pub extern fn rust_eh_unwind_resume() {}
 pub extern fn rust_begin_panic(_msg: core::fmt::Arguments,
                                _file: &'static str,
                                _line: u32) -> ! {
-    loop {}
+    unsafe {
+        libc::abort()
+    }
 }
 
 //////////////////////////////////////////////////////////////////////////////

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

@@ -1,7 +1,7 @@
 #[macro_use]
 extern crate serde_derive;
 
-#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
 struct S {
     #[serde(rename="x", serialize="y")] //~^^ HELP: unknown serde field attribute `serialize`
     x: (),

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

@@ -1,7 +1,7 @@
 #[macro_use]
 extern crate serde_derive;
 
-#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
 struct S {
     #[serde(rename="x")]
     #[serde(rename(deserialize="y"))] //~^^^ HELP: duplicate serde attribute `rename`

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

@@ -1,7 +1,7 @@
 #[macro_use]
 extern crate serde_derive;
 
-#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
 struct S {
     #[serde(rename(serialize="x"), rename(serialize="y"))] //~^^ HELP: duplicate serde attribute `rename`
     x: (),

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

@@ -1,7 +1,7 @@
 #[macro_use]
 extern crate serde_derive;
 
-#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
 struct S {
     #[serde(rename(serialize="x"))]
     #[serde(rename="y")] //~^^^ HELP: duplicate serde attribute `rename`

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

@@ -1,7 +1,7 @@
 #[macro_use]
 extern crate serde_derive;
 
-#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
 struct S {
     #[serde(rename(serialize="x", serialize="y"))] //~^^ HELP: duplicate serde attribute `rename`
     x: (),

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

@@ -1,7 +1,7 @@
 #[macro_use]
 extern crate serde_derive;
 
-#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
 struct S {
     #[serde(rename(serialize="x"))]
     #[serde(rename(serialize="y"))] //~^^^ HELP: duplicate serde attribute `rename`

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

@@ -0,0 +1,10 @@
+#[macro_use]
+extern crate serde_derive;
+
+#[derive(Serialize)] //~ ERROR: proc-macro derive 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: proc-macro derive 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: proc-macro derive 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: proc-macro derive panicked
+#[serde(untagged)] //~^ HELP: #[serde(untagged)] can only be used on enums
+struct S;
+
+fn main() {}

test_suite/tests/compile-fail/str_ref_deser.rs

@@ -1,7 +1,7 @@
 #[macro_use]
 extern crate serde_derive;
 
-#[derive(Serialize, Deserialize)] //~ ERROR: custom derive attribute panicked
+#[derive(Serialize, Deserialize)] //~ ERROR: proc-macro derive panicked
 struct Test<'a> {
     s: &'a str, //~^^ HELP: Serde does not support deserializing fields of type &str
 }

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

@@ -1,7 +1,7 @@
 #[macro_use]
 extern crate serde_derive;
 
-#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
 #[serde(abc="xyz")] //~^ HELP: unknown serde container attribute `abc`
 struct A {
     x: u32,

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

@@ -1,7 +1,7 @@
 #[macro_use]
 extern crate serde_derive;
 
-#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
 struct C {
     #[serde(abc="xyz")] //~^^ HELP: unknown serde field attribute `abc`
     x: u32,

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

@@ -1,7 +1,7 @@
 #[macro_use]
 extern crate serde_derive;
 
-#[derive(Serialize)] //~ ERROR: custom derive attribute panicked
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
 enum E {
     #[serde(abc="xyz")] //~^^ HELP: unknown serde variant attribute `abc`
     V,

test_suite/tests/test.rs

@@ -1,6 +1,3 @@
-#![cfg_attr(feature = "clippy", feature(plugin))]
-#![cfg_attr(feature = "clippy", plugin(clippy))]
-
 #![cfg_attr(feature = "unstable-testing", feature(test, non_ascii_idents))]
 
 #[cfg(feature = "unstable-testing")]

test_suite/tests/test_de.rs

@@ -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() {
@@ -225,7 +225,7 @@ declare_tests! {
         ],
         () => &[
             Token::TupleStructStart("Anything", 0),
-            Token::SeqEnd,
+            Token::TupleStructEnd,
         ],
     }
     test_unit_struct {
@@ -330,7 +330,7 @@ declare_tests! {
         ],
         BTreeSet::<isize>::new() => &[
             Token::TupleStructStart("Anything", 0),
-            Token::SeqEnd,
+            Token::TupleStructEnd,
         ],
     }
     test_hashset {
@@ -358,7 +358,7 @@ declare_tests! {
         ],
         HashSet::<isize>::new() => &[
             Token::TupleStructStart("Anything", 0),
-            Token::SeqEnd,
+            Token::TupleStructEnd,
         ],
         hashset![FnvHasher @ 1, 2, 3] => &[
             Token::SeqStart(Some(3)),
@@ -408,7 +408,7 @@ declare_tests! {
         ],
         Vec::<isize>::new() => &[
             Token::TupleStructStart("Anything", 0),
-            Token::SeqEnd,
+            Token::TupleStructEnd,
         ],
     }
     test_array {
@@ -472,7 +472,7 @@ declare_tests! {
         ],
         [0; 0] => &[
             Token::TupleStructStart("Anything", 0),
-            Token::SeqEnd,
+            Token::TupleStructEnd,
         ],
     }
     test_tuple {
@@ -564,7 +564,7 @@ declare_tests! {
         ],
         BTreeMap::<isize, isize>::new() => &[
             Token::StructStart("Anything", 0),
-            Token::MapEnd,
+            Token::StructEnd,
         ],
     }
     test_hashmap {
@@ -618,7 +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)),
@@ -936,4 +936,22 @@ declare_error_tests! {
         ],
         Error::Message("invalid value: integer `4`, expected variant index 0 <= i < 4".into()),
     }
+    test_short_tuple<(u8, u8, u8)> {
+        &[
+            Token::TupleStart(1),
+            Token::TupleSep,
+            Token::U8(1),
+            Token::TupleEnd,
+        ],
+        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()),
+    );
+}

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