Release 1.0.41

Without collect_other_fields, the visit_borrowed_str and
visit_borrowed_bytes implementations that were being generated were
identical to their default implementation of forwarding to visit_str and
visit_bytes.

README.md

@@ -1,9 +1,11 @@
-# Serde   [![Build Status]][travis] [![Latest Version]][crates.io]
+# Serde   [![Build Status]][travis] [![Latest Version]][crates.io] [![Rustc Version 1.13+]][rustc]
 
 [Build Status]: https://api.travis-ci.org/serde-rs/serde.svg?branch=master
 [travis]: https://travis-ci.org/serde-rs/serde
 [Latest Version]: https://img.shields.io/crates/v/serde.svg
 [crates.io]: https://crates.io/crates/serde
+[Rustc Version 1.13+]: https://img.shields.io/badge/rustc-1.13+-lightgray.svg
+[rustc]: https://blog.rust-lang.org/2016/11/10/Rust-1.13.html
 
 **Serde is a framework for *ser*ializing and *de*serializing Rust data structures efficiently and generically.**
 

rustfmt.toml

@@ -1,2 +1 @@
 error_on_line_overflow = false
-same_line_attributes = false

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.36" # remember to update html_root_url
+version = "1.0.41" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"

serde/src/de/from_primitive.rs

@@ -9,33 +9,33 @@
 use lib::*;
 
 macro_rules! int_to_int {
-    ($dst:ident, $n:ident) => (
+    ($dst:ident, $n:ident) => {
         if $dst::min_value() as i64 <= $n as i64 && $n as i64 <= $dst::max_value() as i64 {
             Some($n as $dst)
         } else {
             None
         }
-    )
+    };
 }
 
 macro_rules! int_to_uint {
-    ($dst:ident, $n:ident) => (
+    ($dst:ident, $n:ident) => {
         if 0 <= $n && $n as u64 <= $dst::max_value() as u64 {
             Some($n as $dst)
         } else {
             None
         }
-    )
+    };
 }
 
 macro_rules! uint_to {
-    ($dst:ident, $n:ident) => (
+    ($dst:ident, $n:ident) => {
         if $n as u64 <= $dst::max_value() as u64 {
             Some($n as $dst)
         } else {
             None
         }
-    )
+    };
 }
 
 pub trait FromPrimitive: Sized {
@@ -52,54 +52,144 @@ pub trait FromPrimitive: Sized {
 }
 
 macro_rules! impl_from_primitive_for_int {
-    ($t:ident) => (
+    ($t:ident) => {
         impl FromPrimitive for $t {
-            #[inline] fn from_isize(n: isize) -> Option<Self> { int_to_int!($t, n) }
+            #[inline]
-            #[inline] fn from_i8(n: i8) -> Option<Self> { int_to_int!($t, n) }
+            fn from_isize(n: isize) -> Option<Self> {
-            #[inline] fn from_i16(n: i16) -> Option<Self> { int_to_int!($t, n) }
+                int_to_int!($t, n)
-            #[inline] fn from_i32(n: i32) -> Option<Self> { int_to_int!($t, n) }
+            }
-            #[inline] fn from_i64(n: i64) -> Option<Self> { int_to_int!($t, n) }
+            #[inline]
-            #[inline] fn from_usize(n: usize) -> Option<Self> { uint_to!($t, n) }
+            fn from_i8(n: i8) -> Option<Self> {
-            #[inline] fn from_u8(n: u8) -> Option<Self> { uint_to!($t, n) }
+                int_to_int!($t, n)
-            #[inline] fn from_u16(n: u16) -> Option<Self> { uint_to!($t, n) }
+            }
-            #[inline] fn from_u32(n: u32) -> Option<Self> { uint_to!($t, n) }
+            #[inline]
-            #[inline] fn from_u64(n: u64) -> Option<Self> { uint_to!($t, n) }
+            fn from_i16(n: i16) -> Option<Self> {
+                int_to_int!($t, n)
+            }
+            #[inline]
+            fn from_i32(n: i32) -> Option<Self> {
+                int_to_int!($t, n)
+            }
+            #[inline]
+            fn from_i64(n: i64) -> Option<Self> {
+                int_to_int!($t, n)
+            }
+            #[inline]
+            fn from_usize(n: usize) -> Option<Self> {
+                uint_to!($t, n)
+            }
+            #[inline]
+            fn from_u8(n: u8) -> Option<Self> {
+                uint_to!($t, n)
+            }
+            #[inline]
+            fn from_u16(n: u16) -> Option<Self> {
+                uint_to!($t, n)
+            }
+            #[inline]
+            fn from_u32(n: u32) -> Option<Self> {
+                uint_to!($t, n)
+            }
+            #[inline]
+            fn from_u64(n: u64) -> Option<Self> {
+                uint_to!($t, n)
+            }
         }
-    )
+    };
 }
 
 macro_rules! impl_from_primitive_for_uint {
-    ($t:ident) => (
+    ($t:ident) => {
         impl FromPrimitive for $t {
-            #[inline] fn from_isize(n: isize) -> Option<Self> { int_to_uint!($t, n) }
+            #[inline]
-            #[inline] fn from_i8(n: i8) -> Option<Self> { int_to_uint!($t, n) }
+            fn from_isize(n: isize) -> Option<Self> {
-            #[inline] fn from_i16(n: i16) -> Option<Self> { int_to_uint!($t, n) }
+                int_to_uint!($t, n)
-            #[inline] fn from_i32(n: i32) -> Option<Self> { int_to_uint!($t, n) }
+            }
-            #[inline] fn from_i64(n: i64) -> Option<Self> { int_to_uint!($t, n) }
+            #[inline]
-            #[inline] fn from_usize(n: usize) -> Option<Self> { uint_to!($t, n) }
+            fn from_i8(n: i8) -> Option<Self> {
-            #[inline] fn from_u8(n: u8) -> Option<Self> { uint_to!($t, n) }
+                int_to_uint!($t, n)
-            #[inline] fn from_u16(n: u16) -> Option<Self> { uint_to!($t, n) }
+            }
-            #[inline] fn from_u32(n: u32) -> Option<Self> { uint_to!($t, n) }
+            #[inline]
-            #[inline] fn from_u64(n: u64) -> Option<Self> { uint_to!($t, n) }
+            fn from_i16(n: i16) -> Option<Self> {
+                int_to_uint!($t, n)
+            }
+            #[inline]
+            fn from_i32(n: i32) -> Option<Self> {
+                int_to_uint!($t, n)
+            }
+            #[inline]
+            fn from_i64(n: i64) -> Option<Self> {
+                int_to_uint!($t, n)
+            }
+            #[inline]
+            fn from_usize(n: usize) -> Option<Self> {
+                uint_to!($t, n)
+            }
+            #[inline]
+            fn from_u8(n: u8) -> Option<Self> {
+                uint_to!($t, n)
+            }
+            #[inline]
+            fn from_u16(n: u16) -> Option<Self> {
+                uint_to!($t, n)
+            }
+            #[inline]
+            fn from_u32(n: u32) -> Option<Self> {
+                uint_to!($t, n)
+            }
+            #[inline]
+            fn from_u64(n: u64) -> Option<Self> {
+                uint_to!($t, n)
+            }
         }
-    )
+    };
 }
 
 macro_rules! impl_from_primitive_for_float {
-    ($t:ident) => (
+    ($t:ident) => {
         impl FromPrimitive for $t {
-            #[inline] fn from_isize(n: isize) -> Option<Self> { Some(n as Self) }
+            #[inline]
-            #[inline] fn from_i8(n: i8) -> Option<Self> { Some(n as Self) }
+            fn from_isize(n: isize) -> Option<Self> {
-            #[inline] fn from_i16(n: i16) -> Option<Self> { Some(n as Self) }
+                Some(n as Self)
-            #[inline] fn from_i32(n: i32) -> Option<Self> { Some(n as Self) }
+            }
-            #[inline] fn from_i64(n: i64) -> Option<Self> { Some(n as Self) }
+            #[inline]
-            #[inline] fn from_usize(n: usize) -> Option<Self> { Some(n as Self) }
+            fn from_i8(n: i8) -> Option<Self> {
-            #[inline] fn from_u8(n: u8) -> Option<Self> { Some(n as Self) }
+                Some(n as Self)
-            #[inline] fn from_u16(n: u16) -> Option<Self> { Some(n as Self) }
+            }
-            #[inline] fn from_u32(n: u32) -> Option<Self> { Some(n as Self) }
+            #[inline]
-            #[inline] fn from_u64(n: u64) -> Option<Self> { Some(n as Self) }
+            fn from_i16(n: i16) -> Option<Self> {
+                Some(n as Self)
+            }
+            #[inline]
+            fn from_i32(n: i32) -> Option<Self> {
+                Some(n as Self)
+            }
+            #[inline]
+            fn from_i64(n: i64) -> Option<Self> {
+                Some(n as Self)
+            }
+            #[inline]
+            fn from_usize(n: usize) -> Option<Self> {
+                Some(n as Self)
+            }
+            #[inline]
+            fn from_u8(n: u8) -> Option<Self> {
+                Some(n as Self)
+            }
+            #[inline]
+            fn from_u16(n: u16) -> Option<Self> {
+                Some(n as Self)
+            }
+            #[inline]
+            fn from_u32(n: u32) -> Option<Self> {
+                Some(n as Self)
+            }
+            #[inline]
+            fn from_u64(n: u64) -> Option<Self> {
+                Some(n as Self)
+            }
         }
-    )
+    };
 }
 
 impl_from_primitive_for_int!(isize);

serde/src/de/impls.rs

@@ -470,7 +470,11 @@ impl<'de> Deserialize<'de> for CString {
 }
 
 macro_rules! forwarded_impl {
-    (( $($id: ident),* ), $ty: ty, $func: expr) => {
+    (
+        $(#[doc = $doc:tt])*
+        ( $($id: ident),* ), $ty: ty, $func: expr
+    ) => {
+        $(#[doc = $doc])*
         impl<'de $(, $id : Deserialize<'de>,)*> Deserialize<'de> for $ty {
             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
             where
@@ -1073,7 +1077,7 @@ map_impl!(
 
 #[cfg(feature = "std")]
 macro_rules! parse_ip_impl {
-    ($ty:ty; $size: expr) => {
+    ($ty:ty; $size:expr) => {
         impl<'de> Deserialize<'de> for $ty {
             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
             where
@@ -1087,7 +1091,7 @@ macro_rules! parse_ip_impl {
                 }
             }
         }
-    }
+    };
 }
 
 #[cfg(feature = "std")]
@@ -1230,7 +1234,7 @@ parse_ip_impl!(net::Ipv6Addr; 16);
 
 #[cfg(feature = "std")]
 macro_rules! parse_socket_impl {
-    ($ty:ty, $new: expr) => {
+    ($ty:ty, $new:expr) => {
         impl<'de> Deserialize<'de> for $ty {
             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
             where
@@ -1244,7 +1248,7 @@ macro_rules! parse_socket_impl {
                 }
             }
         }
-    }
+    };
 }
 
 #[cfg(feature = "std")]
@@ -1272,10 +1276,7 @@ parse_socket_impl!(net::SocketAddrV4, net::SocketAddrV4::new);
 
 #[cfg(feature = "std")]
 parse_socket_impl!(net::SocketAddrV6, |ip, port| net::SocketAddrV6::new(
-    ip,
+    ip, port, 0, 0
-    port,
-    0,
-    0
 ));
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1432,10 +1433,28 @@ forwarded_impl!((T), Box<[T]>, Vec::into_boxed_slice);
 forwarded_impl!((), Box<str>, String::into_boxed_str);
 
 #[cfg(all(not(feature = "unstable"), feature = "rc", any(feature = "std", feature = "alloc")))]
-forwarded_impl!((T), Arc<T>, Arc::new);
+forwarded_impl! {
+    /// This impl requires the [`"rc"`] Cargo feature of Serde.
+    ///
+    /// Deserializing a data structure containing `Arc` will not attempt to
+    /// deduplicate `Arc` references to the same data. Every deserialized `Arc`
+    /// will end up with a strong count of 1.
+    ///
+    /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
+    (T), Arc<T>, Arc::new
+}
 
 #[cfg(all(not(feature = "unstable"), feature = "rc", any(feature = "std", feature = "alloc")))]
-forwarded_impl!((T), Rc<T>, Rc::new);
+forwarded_impl! {
+    /// This impl requires the [`"rc"`] Cargo feature of Serde.
+    ///
+    /// Deserializing a data structure containing `Rc` will not attempt to
+    /// deduplicate `Rc` references to the same data. Every deserialized `Rc`
+    /// will end up with a strong count of 1.
+    ///
+    /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
+    (T), Rc<T>, Rc::new
+}
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'de, 'a, T: ?Sized> Deserialize<'de> for Cow<'a, T>
@@ -1456,7 +1475,11 @@ where
 
 #[cfg(all(feature = "unstable", feature = "rc", any(feature = "std", feature = "alloc")))]
 macro_rules! box_forwarded_impl {
-    ($t:ident) => {
+    (
+        $(#[doc = $doc:tt])*
+        $t:ident
+    ) => {
+        $(#[doc = $doc])*
         impl<'de, T: ?Sized> Deserialize<'de> for $t<T>
         where
             Box<T>: Deserialize<'de>,
@@ -1468,14 +1491,32 @@ macro_rules! box_forwarded_impl {
                 Box::deserialize(deserializer).map(Into::into)
             }
         }
-    }
+    };
 }
 
 #[cfg(all(feature = "unstable", feature = "rc", any(feature = "std", feature = "alloc")))]
-box_forwarded_impl!(Rc);
+box_forwarded_impl! {
+    /// This impl requires the [`"rc"`] Cargo feature of Serde.
+    ///
+    /// Deserializing a data structure containing `Rc` will not attempt to
+    /// deduplicate `Rc` references to the same data. Every deserialized `Rc`
+    /// will end up with a strong count of 1.
+    ///
+    /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
+    Rc
+}
 
 #[cfg(all(feature = "unstable", feature = "rc", any(feature = "std", feature = "alloc")))]
-box_forwarded_impl!(Arc);
+box_forwarded_impl! {
+    /// This impl requires the [`"rc"`] Cargo feature of Serde.
+    ///
+    /// Deserializing a data structure containing `Arc` will not attempt to
+    /// deduplicate `Arc` references to the same data. Every deserialized `Arc`
+    /// will end up with a strong count of 1.
+    ///
+    /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
+    Arc
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 

serde/src/de/value.rs

@@ -37,10 +37,10 @@
 
 use lib::*;
 
+use self::private::{First, Second};
 use de::{self, Expected, IntoDeserializer, SeqAccess};
 use private::de::size_hint;
 use ser;
-use self::private::{First, Second};
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -652,11 +652,8 @@ where
 {
     /// Check for remaining elements after passing a `SeqDeserializer` to
     /// `Visitor::visit_seq`.
-    pub fn end(mut self) -> Result<(), E> {
+    pub fn end(self) -> Result<(), E> {
-        let mut remaining = 0;
+        let remaining = self.iter.count();
-        while self.iter.next().is_some() {
-            remaining += 1;
-        }
         if remaining == 0 {
             Ok(())
         } else {
@@ -849,11 +846,8 @@ where
 {
     /// Check for remaining elements after passing a `MapDeserializer` to
     /// `Visitor::visit_map`.
-    pub fn end(mut self) -> Result<(), E> {
+    pub fn end(self) -> Result<(), E> {
-        let mut remaining = 0;
+        let remaining = self.iter.count();
-        while self.iter.next().is_some() {
-            remaining += 1;
-        }
         if remaining == 0 {
             Ok(())
         } else {

serde/src/lib.rs

@@ -79,7 +79,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.36")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.41")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // Unstable functionality only if the user asks for it. For tracking and
@@ -90,10 +90,13 @@
 #![cfg_attr(feature = "alloc", feature(alloc))]
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
 // Whitelisted clippy lints
-#![cfg_attr(feature = "cargo-clippy",
+#![cfg_attr(
-            allow(cast_lossless, const_static_lifetime, doc_markdown, linkedlist,
+    feature = "cargo-clippy",
-                  needless_pass_by_value, redundant_field_names, type_complexity,
+    allow(
-                  unreadable_literal, zero_prefixed_literal))]
+        cast_lossless, const_static_lifetime, doc_markdown, linkedlist, needless_pass_by_value,
+        redundant_field_names, type_complexity, unreadable_literal, zero_prefixed_literal
+    )
+)]
 // Whitelisted clippy_pedantic lints
 #![cfg_attr(feature = "cargo-clippy", allow(
 // integer and float ser/de requires these sorts of casts
@@ -135,16 +138,16 @@ extern crate core;
 /// module.
 mod lib {
     mod core {
-        #[cfg(feature = "std")]
-        pub use std::*;
         #[cfg(not(feature = "std"))]
         pub use core::*;
+        #[cfg(feature = "std")]
+        pub use std::*;
     }
 
     pub use self::core::{cmp, iter, mem, ops, slice, str};
-    pub use self::core::{isize, i16, i32, i64, i8};
-    pub use self::core::{usize, u16, u32, u64, u8};
     pub use self::core::{f32, f64};
+    pub use self::core::{i16, i32, i64, i8, isize};
+    pub use self::core::{u16, u32, u64, u8, usize};
 
     pub use self::core::cell::{Cell, RefCell};
     pub use self::core::clone::{self, Clone};
@@ -155,40 +158,40 @@ mod lib {
     pub use self::core::option::{self, Option};
     pub use self::core::result::{self, Result};
 
-    #[cfg(feature = "std")]
-    pub use std::borrow::{Cow, ToOwned};
     #[cfg(all(feature = "alloc", not(feature = "std")))]
     pub use alloc::borrow::{Cow, ToOwned};
-
     #[cfg(feature = "std")]
-    pub use std::string::String;
+    pub use std::borrow::{Cow, ToOwned};
+
     #[cfg(all(feature = "alloc", not(feature = "std")))]
     pub use alloc::string::{String, ToString};
-
     #[cfg(feature = "std")]
-    pub use std::vec::Vec;
+    pub use std::string::String;
+
     #[cfg(all(feature = "alloc", not(feature = "std")))]
     pub use alloc::vec::Vec;
-
     #[cfg(feature = "std")]
-    pub use std::boxed::Box;
+    pub use std::vec::Vec;
+
     #[cfg(all(feature = "alloc", not(feature = "std")))]
     pub use alloc::boxed::Box;
+    #[cfg(feature = "std")]
+    pub use std::boxed::Box;
 
-    #[cfg(all(feature = "rc", feature = "std"))]
-    pub use std::rc::Rc;
     #[cfg(all(feature = "rc", feature = "alloc", not(feature = "std")))]
     pub use alloc::rc::Rc;
-
     #[cfg(all(feature = "rc", feature = "std"))]
-    pub use std::sync::Arc;
+    pub use std::rc::Rc;
+
     #[cfg(all(feature = "rc", feature = "alloc", not(feature = "std")))]
     pub use alloc::arc::Arc;
+    #[cfg(all(feature = "rc", feature = "std"))]
+    pub use std::sync::Arc;
 
-    #[cfg(feature = "std")]
-    pub use std::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
     #[cfg(all(feature = "alloc", not(feature = "std")))]
     pub use alloc::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
+    #[cfg(feature = "std")]
+    pub use std::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
 
     #[cfg(feature = "std")]
     pub use std::{error, net};
@@ -206,16 +209,16 @@ mod lib {
     #[cfg(feature = "std")]
     pub use std::path::{Path, PathBuf};
     #[cfg(feature = "std")]
-    pub use std::time::{Duration, SystemTime, UNIX_EPOCH};
-    #[cfg(feature = "std")]
     pub use std::sync::{Mutex, RwLock};
+    #[cfg(feature = "std")]
+    pub use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
     #[cfg(feature = "unstable")]
     #[allow(deprecated)]
     pub use core::nonzero::{NonZero, Zeroable};
 
     #[cfg(feature = "unstable")]
-    pub use core::num::{NonZeroU8, NonZeroU16, NonZeroU32, NonZeroU64, NonZeroUsize};
+    pub use core::num::{NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU8, NonZeroUsize};
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -223,13 +226,13 @@ mod lib {
 #[macro_use]
 mod macros;
 
-pub mod ser;
 pub mod de;
+pub mod ser;
 
-#[doc(inline)]
-pub use ser::{Serialize, Serializer};
 #[doc(inline)]
 pub use de::{Deserialize, Deserializer};
+#[doc(inline)]
+pub use ser::{Serialize, Serializer};
 
 // Generated code uses these to support no_std. Not public API.
 #[doc(hidden)]

serde/src/private/de.rs

@@ -11,13 +11,13 @@ use lib::*;
 use de::{Deserialize, DeserializeSeed, Deserializer, Error, IntoDeserializer, Visitor};
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-use de::{Unexpected, MapAccess};
+use de::{MapAccess, Unexpected};
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-pub use self::content::{Content, ContentDeserializer, ContentRefDeserializer,
+pub use self::content::{Content, ContentDeserializer, ContentRefDeserializer, EnumDeserializer,
                         InternallyTaggedUnitVisitor, TagContentOtherField,
                         TagContentOtherFieldVisitor, TagOrContentField, TagOrContentFieldVisitor,
-                        TaggedContentVisitor, UntaggedUnitVisitor, EnumDeserializer};
+                        TaggedContentVisitor, UntaggedUnitVisitor};
 
 /// If the missing field is of type `Option<T>` then treat is as `None`,
 /// otherwise it is an error.
@@ -228,9 +228,9 @@ mod content {
 
     use lib::*;
 
-    use de::{self, Deserialize, DeserializeSeed, Deserializer, EnumAccess, MapAccess, SeqAccess,
-             Unexpected, Visitor};
     use super::size_hint;
+    use de::{self, Deserialize, DeserializeSeed, Deserializer, EnumAccess, Expected, MapAccess,
+             SeqAccess, Unexpected, Visitor};
 
     /// Used from generated code to buffer the contents of the Deserializer when
     /// deserializing untagged enums and internally tagged enums.
@@ -1013,6 +1013,62 @@ mod content {
         err: PhantomData<E>,
     }
 
+    impl<'de, E> ContentDeserializer<'de, E>
+    where
+        E: de::Error,
+    {
+        #[cold]
+        fn invalid_type(self, exp: &Expected) -> E {
+            de::Error::invalid_type(self.content.unexpected(), exp)
+        }
+
+        fn deserialize_integer<V>(self, visitor: V) -> Result<V::Value, E>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                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),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+    }
+
+    fn visit_content_seq<'de, V, E>(content: Vec<Content<'de>>, visitor: V) -> Result<V::Value, E>
+    where
+        V: Visitor<'de>,
+        E: de::Error,
+    {
+        let seq = content.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)
+    }
+
+    fn visit_content_map<'de, V, E>(
+        content: Vec<(Content<'de>, Content<'de>)>,
+        visitor: V,
+    ) -> Result<V::Value, E>
+    where
+        V: Visitor<'de>,
+        E: de::Error,
+    {
+        let map = content
+            .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)
+    }
+
     /// Used when deserializing an internally tagged enum because the content will
     /// be used exactly once.
     impl<'de, E> Deserializer<'de> for ContentDeserializer<'de, E>
@@ -1046,21 +1102,152 @@ mod content {
                 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) => {
+                Content::Seq(v) => visit_content_seq(v, visitor),
-                    let seq = v.into_iter().map(ContentDeserializer::new);
+                Content::Map(v) => visit_content_map(v, visitor),
-                    let mut seq_visitor = de::value::SeqDeserializer::new(seq);
+            }
-                    let value = try!(visitor.visit_seq(&mut seq_visitor));
+        }
-                    try!(seq_visitor.end());
+
-                    Ok(value)
+        fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error>
-                }
+        where
-                Content::Map(v) => {
+            V: Visitor<'de>,
-                    let map = v.into_iter()
+        {
-                        .map(|(k, v)| (ContentDeserializer::new(k), ContentDeserializer::new(v)));
+            match self.content {
-                    let mut map_visitor = de::value::MapDeserializer::new(map);
+                Content::Bool(v) => visitor.visit_bool(v),
-                    let value = try!(visitor.visit_map(&mut map_visitor));
+                _ => Err(self.invalid_type(&visitor)),
-                    try!(map_visitor.end());
+            }
-                    Ok(value)
+        }
-                }
+
+        fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                Content::F32(v) => visitor.visit_f32(v),
+                Content::F64(v) => visitor.visit_f64(v),
+                Content::U64(v) => visitor.visit_u64(v),
+                Content::I64(v) => visitor.visit_i64(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                Content::F64(v) => visitor.visit_f64(v),
+                Content::U64(v) => visitor.visit_u64(v),
+                Content::I64(v) => visitor.visit_i64(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                Content::Char(v) => visitor.visit_char(v),
+                Content::String(v) => visitor.visit_string(v),
+                Content::Str(v) => visitor.visit_borrowed_str(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_string(visitor)
+        }
+
+        fn deserialize_string<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                Content::String(v) => visitor.visit_string(v),
+                Content::Str(v) => visitor.visit_borrowed_str(v),
+                Content::ByteBuf(v) => visitor.visit_byte_buf(v),
+                Content::Bytes(v) => visitor.visit_borrowed_bytes(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_byte_buf(visitor)
+        }
+
+        fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                Content::String(v) => visitor.visit_string(v),
+                Content::Str(v) => visitor.visit_borrowed_str(v),
+                Content::ByteBuf(v) => visitor.visit_byte_buf(v),
+                Content::Bytes(v) => visitor.visit_borrowed_bytes(v),
+                Content::Seq(v) => visit_content_seq(v, visitor),
+                _ => Err(self.invalid_type(&visitor)),
             }
         }
 
@@ -1076,6 +1263,44 @@ mod content {
             }
         }
 
+        fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                Content::Unit => visitor.visit_unit(),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_unit_struct<V>(
+            self,
+            _name: &'static str,
+            visitor: V,
+        ) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                // As a special case, allow deserializing untagged newtype
+                // variant containing unit struct.
+                //
+                //     #[derive(Deserialize)]
+                //     struct Info;
+                //
+                //     #[derive(Deserialize)]
+                //     #[serde(tag = "topic")]
+                //     enum Message {
+                //         Info(Info),
+                //     }
+                //
+                // We want {"topic":"Info"} to deserialize even though
+                // ordinarily unit structs do not deserialize from empty map.
+                Content::Map(ref v) if v.is_empty() => visitor.visit_unit(),
+                _ => self.deserialize_any(visitor),
+            }
+        }
+
         fn deserialize_newtype_struct<V>(
             self,
             _name: &str,
@@ -1087,6 +1312,61 @@ mod content {
             visitor.visit_newtype_struct(self)
         }
 
+        fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                Content::Seq(v) => visit_content_seq(v, visitor),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_tuple<V>(self, _len: usize, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_seq(visitor)
+        }
+
+        fn deserialize_tuple_struct<V>(
+            self,
+            _name: &'static str,
+            _len: usize,
+            visitor: V,
+        ) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_seq(visitor)
+        }
+
+        fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                Content::Map(v) => visit_content_map(v, visitor),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_struct<V>(
+            self,
+            _name: &'static str,
+            _fields: &'static [&'static str],
+            visitor: V,
+        ) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                Content::Seq(v) => visit_content_seq(v, visitor),
+                Content::Map(v) => visit_content_map(v, visitor),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
         fn deserialize_enum<V>(
             self,
             _name: &str,
@@ -1129,38 +1409,23 @@ mod content {
             visitor.visit_enum(EnumDeserializer::new(variant, value))
         }
 
-        fn deserialize_unit_struct<V>(
+        fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, Self::Error>
-            self,
-            _name: &'static str,
-            visitor: V,
-        ) -> Result<V::Value, Self::Error>
         where
             V: Visitor<'de>,
         {
             match self.content {
-                // As a special case, allow deserializing untagged newtype
+                Content::String(v) => visitor.visit_string(v),
-                // variant containing unit struct.
+                Content::Str(v) => visitor.visit_borrowed_str(v),
-                //
+                _ => Err(self.invalid_type(&visitor)),
-                //     #[derive(Deserialize)]
-                //     struct Info;
-                //
-                //     #[derive(Deserialize)]
-                //     #[serde(tag = "topic")]
-                //     enum Message {
-                //         Info(Info),
-                //     }
-                //
-                // We want {"topic":"Info"} to deserialize even though
-                // ordinarily unit structs do not deserialize from empty map.
-                Content::Map(ref v) if v.is_empty() => visitor.visit_unit(),
-                _ => self.deserialize_any(visitor),
             }
         }
 
-        forward_to_deserialize_any! {
+        fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
-            bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string bytes
+        where
-            byte_buf unit seq tuple tuple_struct map struct identifier
+            V: Visitor<'de>,
-            ignored_any
+        {
+            drop(self);
+            visitor.visit_unit()
         }
     }
 
@@ -1184,7 +1449,8 @@ mod content {
     }
 
     impl<'de, E> EnumDeserializer<'de, E>
-        where E: de::Error
+    where
+        E: de::Error,
     {
         pub fn new(variant: Content<'de>, value: Option<Content<'de>>) -> EnumDeserializer<'de, E> {
             EnumDeserializer {
@@ -1451,6 +1717,68 @@ mod content {
         err: PhantomData<E>,
     }
 
+    impl<'a, 'de, E> ContentRefDeserializer<'a, 'de, E>
+    where
+        E: de::Error,
+    {
+        #[cold]
+        fn invalid_type(self, exp: &Expected) -> E {
+            de::Error::invalid_type(self.content.unexpected(), exp)
+        }
+
+        fn deserialize_integer<V>(self, visitor: V) -> Result<V::Value, E>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                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),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+    }
+
+    fn visit_content_seq_ref<'a, 'de, V, E>(
+        content: &'a [Content<'de>],
+        visitor: V,
+    ) -> Result<V::Value, E>
+    where
+        V: Visitor<'de>,
+        E: de::Error,
+    {
+        let seq = content.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)
+    }
+
+    fn visit_content_map_ref<'a, 'de, V, E>(
+        content: &'a [(Content<'de>, Content<'de>)],
+        visitor: V,
+    ) -> Result<V::Value, E>
+    where
+        V: Visitor<'de>,
+        E: de::Error,
+    {
+        let map = content.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)
+    }
+
     /// Used when deserializing an untagged enum because the content may need to be
     /// used more than once.
     impl<'de, 'a, E> Deserializer<'de> for ContentRefDeserializer<'a, 'de, E>
@@ -1486,28 +1814,155 @@ mod content {
                 Content::Newtype(ref v) => {
                     visitor.visit_newtype_struct(ContentRefDeserializer::new(v))
                 }
-                Content::Seq(ref v) => {
+                Content::Seq(ref v) => visit_content_seq_ref(v, visitor),
-                    let seq = v.into_iter().map(ContentRefDeserializer::new);
+                Content::Map(ref v) => visit_content_map_ref(v, visitor),
-                    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)
-                }
             }
         }
 
+        fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::Bool(v) => visitor.visit_bool(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_integer(visitor)
+        }
+
+        fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::F32(v) => visitor.visit_f32(v),
+                Content::F64(v) => visitor.visit_f64(v),
+                Content::U64(v) => visitor.visit_u64(v),
+                Content::I64(v) => visitor.visit_i64(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::F64(v) => visitor.visit_f64(v),
+                Content::U64(v) => visitor.visit_u64(v),
+                Content::I64(v) => visitor.visit_i64(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::Char(v) => visitor.visit_char(v),
+                Content::String(ref v) => visitor.visit_str(v),
+                Content::Str(v) => visitor.visit_borrowed_str(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::String(ref v) => visitor.visit_str(v),
+                Content::Str(v) => visitor.visit_borrowed_str(v),
+                Content::ByteBuf(ref v) => visitor.visit_bytes(v),
+                Content::Bytes(v) => visitor.visit_borrowed_bytes(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_string<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_str(visitor)
+        }
+
+        fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::String(ref v) => visitor.visit_str(v),
+                Content::Str(v) => visitor.visit_borrowed_str(v),
+                Content::ByteBuf(ref v) => visitor.visit_bytes(v),
+                Content::Bytes(v) => visitor.visit_borrowed_bytes(v),
+                Content::Seq(ref v) => visit_content_seq_ref(v, visitor),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_bytes(visitor)
+        }
+
         fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, E>
         where
             V: Visitor<'de>,
@@ -1520,6 +1975,27 @@ mod content {
             }
         }
 
+        fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::Unit => visitor.visit_unit(),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_unit_struct<V>(
+            self,
+            _name: &'static str,
+            visitor: V,
+        ) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_unit(visitor)
+        }
+
         fn deserialize_newtype_struct<V>(self, _name: &str, visitor: V) -> Result<V::Value, E>
         where
             V: Visitor<'de>,
@@ -1527,6 +2003,61 @@ mod content {
             visitor.visit_newtype_struct(self)
         }
 
+        fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::Seq(ref v) => visit_content_seq_ref(v, visitor),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_tuple<V>(self, _len: usize, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_seq(visitor)
+        }
+
+        fn deserialize_tuple_struct<V>(
+            self,
+            _name: &'static str,
+            _len: usize,
+            visitor: V,
+        ) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            self.deserialize_seq(visitor)
+        }
+
+        fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::Map(ref v) => visit_content_map_ref(v, visitor),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_struct<V>(
+            self,
+            _name: &'static str,
+            _fields: &'static [&'static str],
+            visitor: V,
+        ) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::Seq(ref v) => visit_content_seq_ref(v, visitor),
+                Content::Map(ref v) => visit_content_map_ref(v, visitor),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
         fn deserialize_enum<V>(
             self,
             _name: &str,
@@ -1573,10 +2104,22 @@ mod content {
             })
         }
 
-        forward_to_deserialize_any! {
+        fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, Self::Error>
-            bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string bytes
+        where
-            byte_buf unit unit_struct seq tuple tuple_struct map struct
+            V: Visitor<'de>,
-            identifier ignored_any
+        {
+            match *self.content {
+                Content::String(ref v) => visitor.visit_str(v),
+                Content::Str(v) => visitor.visit_borrowed_str(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
+
+        fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+        where
+            V: Visitor<'de>,
+        {
+            visitor.visit_unit()
         }
     }
 
@@ -2082,12 +2625,13 @@ where
 #[cfg(any(feature = "std", feature = "alloc"))]
 pub struct FlatMapDeserializer<'a, 'de: 'a, E>(
     pub &'a mut Vec<Option<(Content<'de>, Content<'de>)>>,
-    pub PhantomData<E>
+    pub PhantomData<E>,
 );
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'a, 'de, E> Deserializer<'de> for FlatMapDeserializer<'a, 'de, E>
-    where E: Error
+where
+    E: Error,
 {
     type Error = E;
 
@@ -2102,7 +2646,7 @@ impl<'a, 'de, E> Deserializer<'de> for FlatMapDeserializer<'a, 'de, E>
         self,
         name: &'static str,
         variants: &'static [&'static str],
-        visitor: V
+        visitor: V,
     ) -> Result<V::Value, Self::Error>
     where
         V: Visitor<'de>,
@@ -2113,15 +2657,12 @@ impl<'a, 'de, E> Deserializer<'de> for FlatMapDeserializer<'a, 'de, E>
             // about.
             let use_item = match *item {
                 None => false,
-                Some((ref c, _)) => c.as_str().map_or(false, |x| variants.contains(&x))
+                Some((ref c, _)) => c.as_str().map_or(false, |x| variants.contains(&x)),
             };
 
             if use_item {
                 let (key, value) = item.take().unwrap();
-                return visitor.visit_enum(EnumDeserializer::new(
+                return visitor.visit_enum(EnumDeserializer::new(key, Some(value)));
-                    key,
-                    Some(value)
-                ));
             }
         }
 
@@ -2142,7 +2683,7 @@ impl<'a, 'de, E> Deserializer<'de> for FlatMapDeserializer<'a, 'de, E>
         self,
         _: &'static str,
         fields: &'static [&'static str],
-        visitor: V
+        visitor: V,
     ) -> Result<V::Value, Self::Error>
     where
         V: Visitor<'de>,
@@ -2150,11 +2691,7 @@ impl<'a, 'de, E> Deserializer<'de> for FlatMapDeserializer<'a, 'de, E>
         visitor.visit_map(FlatMapAccess::new(self.0.iter_mut(), Some(fields)))
     }
 
-    fn deserialize_newtype_struct<V>(
+    fn deserialize_newtype_struct<V>(self, _name: &str, visitor: V) -> Result<V::Value, Self::Error>
-        self,
-        _name: &str,
-        visitor: V,
-    ) -> Result<V::Value, Self::Error>
     where
         V: Visitor<'de>,
     {
@@ -2180,7 +2717,7 @@ pub struct FlatMapAccess<'a, 'de: 'a, E> {
 impl<'a, 'de, E> FlatMapAccess<'a, 'de, E> {
     fn new(
         iter: slice::IterMut<'a, Option<(Content<'de>, Content<'de>)>>,
-        fields: Option<&'static [&'static str]>
+        fields: Option<&'static [&'static str]>,
     ) -> FlatMapAccess<'a, 'de, E> {
         FlatMapAccess {
             iter: iter,
@@ -2193,7 +2730,8 @@ impl<'a, 'de, E> FlatMapAccess<'a, 'de, E> {
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'a, 'de, E> MapAccess<'de> for FlatMapAccess<'a, 'de, E>
-    where E: Error
+where
+    E: Error,
 {
     type Error = E;
 
@@ -2208,13 +2746,12 @@ impl<'a, 'de, E> MapAccess<'de> for FlatMapAccess<'a, 'de, E>
             let use_item = match *item {
                 None => false,
                 Some((ref c, _)) => {
-                    c.as_str().map_or(self.fields.is_none(), |key| {
+                    c.as_str()
-                        match self.fields {
+                        .map_or(self.fields.is_none(), |key| match self.fields {
                             None => true,
                             Some(fields) if fields.contains(&key) => true,
-                            _ => false
+                            _ => false,
-                        }
+                        })
-                    })
                 }
             };
 

serde/src/private/mod.rs

@@ -8,5 +8,5 @@
 
 mod macros;
 
-pub mod ser;
 pub mod de;
+pub mod ser;

serde/src/private/ser.rs

@@ -11,12 +11,8 @@ use lib::*;
 use ser::{self, Impossible, Serialize, SerializeMap, SerializeStruct, Serializer};
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-use self::content::{
+use self::content::{Content, ContentSerializer, SerializeStructVariantAsMapValue,
-    SerializeStructVariantAsMapValue,
+                    SerializeTupleVariantAsMapValue};
-    SerializeTupleVariantAsMapValue,
-    ContentSerializer,
-    Content,
-};
 
 /// Used to check that serde(getter) attributes return the expected type.
 /// Not public API.
@@ -1042,16 +1038,20 @@ pub struct FlatMapSerializer<'a, M: 'a>(pub &'a mut M);
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'a, M> FlatMapSerializer<'a, M>
 where
-    M: SerializeMap + 'a
+    M: SerializeMap + 'a,
 {
     fn bad_type(self, what: Unsupported) -> M::Error {
-        ser::Error::custom(format_args!("can only flatten structs and maps (got {})", what))
+        ser::Error::custom(format_args!(
+            "can only flatten structs and maps (got {})",
+            what
+        ))
     }
 }
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'a, M> Serializer for FlatMapSerializer<'a, M>
-    where M: SerializeMap + 'a
+where
+    M: SerializeMap + 'a,
 {
     type Ok = ();
     type Error = M::Error;
@@ -1219,7 +1219,10 @@ impl<'a, M> Serializer for FlatMapSerializer<'a, M>
         _: usize,
     ) -> Result<Self::SerializeStructVariant, Self::Error> {
         try!(self.0.serialize_key(inner_variant));
-        Ok(FlatMapSerializeStructVariantAsMapValue::new(self.0, inner_variant))
+        Ok(FlatMapSerializeStructVariantAsMapValue::new(
+            self.0,
+            inner_variant,
+        ))
     }
 }
 
@@ -1228,7 +1231,8 @@ pub struct FlatMapSerializeMap<'a, M: 'a>(&'a mut M);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'a, M> ser::SerializeMap for FlatMapSerializeMap<'a, M>
-    where M: SerializeMap + 'a
+where
+    M: SerializeMap + 'a,
 {
     type Ok = ();
     type Error = M::Error;
@@ -1257,12 +1261,17 @@ pub struct FlatMapSerializeStruct<'a, M: 'a>(&'a mut M);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'a, M> ser::SerializeStruct for FlatMapSerializeStruct<'a, M>
-    where M: SerializeMap + 'a
+where
+    M: SerializeMap + 'a,
 {
     type Ok = ();
     type Error = M::Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
+    fn serialize_field<T: ?Sized>(
+        &mut self,
+        key: &'static str,
+        value: &T,
+    ) -> Result<(), Self::Error>
     where
         T: Serialize,
     {
@@ -1283,7 +1292,8 @@ pub struct FlatMapSerializeStructVariantAsMapValue<'a, M: 'a> {
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'a, M> FlatMapSerializeStructVariantAsMapValue<'a, M>
-    where M: SerializeMap + 'a
+where
+    M: SerializeMap + 'a,
 {
     fn new(map: &'a mut M, name: &'static str) -> FlatMapSerializeStructVariantAsMapValue<'a, M> {
         FlatMapSerializeStructVariantAsMapValue {
@@ -1296,12 +1306,17 @@ impl<'a, M> FlatMapSerializeStructVariantAsMapValue<'a, M>
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'a, M> ser::SerializeStructVariant for FlatMapSerializeStructVariantAsMapValue<'a, M>
-    where M: SerializeMap + 'a
+where
+    M: SerializeMap + 'a,
 {
     type Ok = ();
     type Error = M::Error;
 
-    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
+    fn serialize_field<T: ?Sized>(
+        &mut self,
+        key: &'static str,
+        value: &T,
+    ) -> Result<(), Self::Error>
     where
         T: Serialize,
     {
@@ -1311,7 +1326,10 @@ impl<'a, M> ser::SerializeStructVariant for FlatMapSerializeStructVariantAsMapVa
     }
 
     fn end(self) -> Result<(), Self::Error> {
-        try!(self.map.serialize_value(&Content::Struct(self.name, self.fields)));
+        try!(
+            self.map
+                .serialize_value(&Content::Struct(self.name, self.fields))
+        );
         Ok(())
     }
 }

serde/src/ser/impls.rs

@@ -320,8 +320,12 @@ map_impl!(HashMap<K: Eq + Hash, V, H: BuildHasher>);
 ////////////////////////////////////////////////////////////////////////////////
 
 macro_rules! deref_impl {
-    ($($desc:tt)+) => {
+    (
-        impl $($desc)+ {
+        $(#[doc = $doc:tt])*
+        <$($desc:tt)+
+    ) => {
+        $(#[doc = $doc])*
+        impl <$($desc)+ {
             #[inline]
             fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
             where
@@ -340,10 +344,30 @@ deref_impl!(<'a, T: ?Sized> Serialize for &'a mut T where T: Serialize);
 deref_impl!(<T: ?Sized> Serialize for Box<T> where T: Serialize);
 
 #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
-deref_impl!(<T: ?Sized> Serialize for Rc<T> where T: Serialize);
+deref_impl! {
+    /// This impl requires the [`"rc"`] Cargo feature of Serde.
+    ///
+    /// Serializing a data structure containing `Rc` will serialize a copy of
+    /// the contents of the `Rc` each time the `Rc` is referenced within the
+    /// data structure. Serialization will not attempt to deduplicate these
+    /// repeated data.
+    ///
+    /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
+    <T: ?Sized> Serialize for Rc<T> where T: Serialize
+}
 
 #[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))]
-deref_impl!(<T: ?Sized> Serialize for Arc<T> where T: Serialize);
+deref_impl! {
+    /// This impl requires the [`"rc"`] Cargo feature of Serde.
+    ///
+    /// Serializing a data structure containing `Arc` will serialize a copy of
+    /// the contents of the `Arc` each time the `Arc` is referenced within the
+    /// data structure. Serialization will not attempt to deduplicate these
+    /// repeated data.
+    ///
+    /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc
+    <T: ?Sized> Serialize for Arc<T> where T: Serialize
+}
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 deref_impl!(<'a, T: ?Sized> Serialize for Cow<'a, T> where T: Serialize + ToOwned);
@@ -521,11 +545,9 @@ macro_rules! serialize_display_bounded_length {
         // write! only provides fmt::Formatter to Display implementations, which
         // has methods write_str and write_char but no method to write arbitrary
         // bytes. Therefore `written` must be valid UTF-8.
-        let written_str = unsafe {
+        let written_str = unsafe { str::from_utf8_unchecked(written) };
-            str::from_utf8_unchecked(written)
-        };
         $serializer.serialize_str(written_str)
-    }}
+    }};
 }
 
 #[cfg(feature = "std")]

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "1.0.36" # remember to update html_root_url
+version = "1.0.41" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"
@@ -23,10 +23,10 @@ name = "serde_derive"
 proc-macro = true
 
 [dependencies]
-proc-macro2 = "0.2"
+proc-macro2 = "0.3"
-quote = "0.4"
+quote = "0.5"
-serde_derive_internals = { version = "=0.22.2", default-features = false, path = "../serde_derive_internals" }
+serde_derive_internals = { version = "=0.23.1", default-features = false, path = "../serde_derive_internals" }
-syn = { version = "0.12", features = ["visit"] }
+syn = { version = "0.13", features = ["visit"] }
 
 [dev-dependencies]
 serde = { version = "1.0", path = "../serde" }

serde_derive/src/bound.rs

@@ -8,13 +8,14 @@
 
 use std::collections::HashSet;
 
-use syn::{self, visit};
+use syn;
-use syn::punctuated::Punctuated;
+use syn::punctuated::{Pair, Punctuated};
+use syn::visit::{self, Visit};
 
-use internals::ast::{Data, Container};
+use internals::ast::{Container, Data};
 use internals::attr;
 
-use proc_macro2::{Span, Term};
+use proc_macro2::Span;
 
 // Remove the default from every type parameter because in the generated impls
 // they look like associated types: "error: associated type bindings are not
@@ -25,13 +26,11 @@ pub fn without_defaults(generics: &syn::Generics) -> syn::Generics {
             .params
             .iter()
             .map(|param| match *param {
-                syn::GenericParam::Type(ref param) => {
+                syn::GenericParam::Type(ref param) => syn::GenericParam::Type(syn::TypeParam {
-                    syn::GenericParam::Type(syn::TypeParam {
+                    eq_token: None,
-                        eq_token: None,
+                    default: None,
-                        default: None,
+                    ..param.clone()
-                        ..param.clone()
+                }),
-                    })
-                }
                 _ => param.clone(),
             })
             .collect(),
@@ -44,45 +43,25 @@ pub fn with_where_predicates(
     predicates: &[syn::WherePredicate],
 ) -> syn::Generics {
     let mut generics = generics.clone();
-    if generics.where_clause.is_none() {
+    generics
-        generics.where_clause = Some(syn::WhereClause {
+        .make_where_clause()
-            where_token: Default::default(),
-            predicates: Punctuated::new(),
-        });
-    }
-    generics.where_clause
-        .as_mut()
-        .unwrap()
         .predicates
         .extend(predicates.into_iter().cloned());
     generics
 }
 
-pub fn with_where_predicates_from_fields<F>(
+pub fn with_where_predicates_from_fields(
     cont: &Container,
     generics: &syn::Generics,
-    from_field: F,
+    from_field: fn(&attr::Field) -> Option<&[syn::WherePredicate]>,
-) -> syn::Generics
+) -> syn::Generics {
-where
-    F: Fn(&attr::Field) -> Option<&[syn::WherePredicate]>,
-{
     let predicates = cont.data
         .all_fields()
         .flat_map(|field| from_field(&field.attrs))
         .flat_map(|predicates| predicates.to_vec());
 
     let mut generics = generics.clone();
-    if generics.where_clause.is_none() {
+    generics.make_where_clause().predicates.extend(predicates);
-        generics.where_clause = Some(syn::WhereClause {
-            where_token: Default::default(),
-            predicates: Punctuated::new(),
-        });
-    }
-    generics.where_clause
-        .as_mut()
-        .unwrap()
-        .predicates
-        .extend(predicates);
     generics
 }
 
@@ -97,26 +76,39 @@ where
 //         #[serde(skip_serializing)]
 //         c: C,
 //     }
-pub fn with_bound<F>(
+pub fn with_bound(
     cont: &Container,
     generics: &syn::Generics,
-    filter: F,
+    filter: fn(&attr::Field, Option<&attr::Variant>) -> bool,
     bound: &syn::Path,
-) -> syn::Generics
+) -> syn::Generics {
-where
+    struct FindTyParams<'ast> {
-    F: Fn(&attr::Field, Option<&attr::Variant>) -> bool,
-{
-    struct FindTyParams {
         // Set of all generic type parameters on the current struct (A, B, C in
         // the example). Initialized up front.
-        all_ty_params: HashSet<syn::Ident>,
+        all_type_params: HashSet<syn::Ident>,
+
         // Set of generic type parameters used in fields for which filter
         // returns true (A and B in the example). Filled in as the visitor sees
         // them.
-        relevant_ty_params: HashSet<syn::Ident>,
+        relevant_type_params: HashSet<syn::Ident>,
+
+        // Fields whose type is an associated type of one of the generic type
+        // parameters.
+        associated_type_usage: Vec<&'ast syn::TypePath>,
     }
-    impl<'ast> visit::Visit<'ast> for FindTyParams {
+    impl<'ast> Visit<'ast> for FindTyParams<'ast> {
-        fn visit_path(&mut self, path: &syn::Path) {
+        fn visit_field(&mut self, field: &'ast syn::Field) {
+            if let syn::Type::Path(ref ty) = field.ty {
+                if let Some(Pair::Punctuated(ref t, _)) = ty.path.segments.first() {
+                    if self.all_type_params.contains(&t.ident) {
+                        self.associated_type_usage.push(ty);
+                    }
+                }
+            }
+            self.visit_type(&field.ty);
+        }
+
+        fn visit_path(&mut self, path: &'ast syn::Path) {
             if let Some(seg) = path.segments.last() {
                 if seg.into_value().ident == "PhantomData" {
                     // Hardcoded exception, because PhantomData<T> implements
@@ -126,8 +118,8 @@ where
             }
             if path.leading_colon.is_none() && path.segments.len() == 1 {
                 let id = path.segments[0].ident;
-                if self.all_ty_params.contains(&id) {
+                if self.all_type_params.contains(&id) {
-                    self.relevant_ty_params.insert(id);
+                    self.relevant_type_params.insert(id);
                 }
             }
             visit::visit_path(self, path);
@@ -139,21 +131,15 @@ where
         //         mac: T!(),
         //         marker: PhantomData<T>,
         //     }
-        fn visit_macro(&mut self, _mac: &syn::Macro) {}
+        fn visit_macro(&mut self, _mac: &'ast syn::Macro) {}
     }
 
-    let all_ty_params: HashSet<_> = generics
+    let all_type_params = generics.type_params().map(|param| param.ident).collect();
-        .params
-        .iter()
-        .filter_map(|param| match *param {
-            syn::GenericParam::Type(ref param) => Some(param.ident),
-            _ => None,
-        })
-        .collect();
 
     let mut visitor = FindTyParams {
-        all_ty_params: all_ty_params,
+        all_type_params: all_type_params,
-        relevant_ty_params: HashSet::new(),
+        relevant_type_params: HashSet::new(),
+        associated_type_usage: Vec::new(),
     };
     match cont.data {
         Data::Enum(ref variants) => for variant in variants.iter() {
@@ -162,54 +148,47 @@ where
                 .iter()
                 .filter(|field| filter(&field.attrs, Some(&variant.attrs)));
             for field in relevant_fields {
-                visit::visit_type(&mut visitor, field.ty);
+                visitor.visit_field(field.original);
             }
         },
         Data::Struct(_, ref fields) => {
             for field in fields.iter().filter(|field| filter(&field.attrs, None)) {
-                visit::visit_type(&mut visitor, field.ty);
+                visitor.visit_field(field.original);
             }
         }
     }
 
+    let relevant_type_params = visitor.relevant_type_params;
+    let associated_type_usage = visitor.associated_type_usage;
     let new_predicates = generics
-        .params
+        .type_params()
-        .iter()
+        .map(|param| param.ident)
-        .filter_map(|param| match *param {
+        .filter(|id| relevant_type_params.contains(id))
-            syn::GenericParam::Type(ref param) => Some(param.ident),
+        .map(|id| syn::TypePath {
-            _ => None,
+            qself: None,
+            path: id.into(),
         })
-        .filter(|id| visitor.relevant_ty_params.contains(id))
+        .chain(associated_type_usage.into_iter().cloned())
-        .map(|id| {
+        .map(|bounded_ty| {
             syn::WherePredicate::Type(syn::PredicateType {
                 lifetimes: None,
                 // the type parameter that is being bounded e.g. T
-                bounded_ty: syn::Type::Path(syn::TypePath {
+                bounded_ty: syn::Type::Path(bounded_ty),
-                    qself: None,
-                    path: id.into(),
-                }),
                 colon_token: Default::default(),
                 // the bound e.g. Serialize
-                bounds: vec![
+                bounds: vec![syn::TypeParamBound::Trait(syn::TraitBound {
-                    syn::TypeParamBound::Trait(syn::TraitBound {
+                    paren_token: None,
-                        modifier: syn::TraitBoundModifier::None,
+                    modifier: syn::TraitBoundModifier::None,
-                        lifetimes: None,
+                    lifetimes: None,
-                        path: bound.clone(),
+                    path: bound.clone(),
-                    }),
+                })].into_iter()
-                ].into_iter().collect(),
+                    .collect(),
             })
         });
 
     let mut generics = generics.clone();
-    if generics.where_clause.is_none() {
+    generics
-        generics.where_clause = Some(syn::WhereClause {
+        .make_where_clause()
-            where_token: Default::default(),
-            predicates: Punctuated::new(),
-        });
-    }
-    generics.where_clause
-        .as_mut()
-        .unwrap()
         .predicates
         .extend(new_predicates);
     generics
@@ -221,15 +200,8 @@ pub fn with_self_bound(
     bound: &syn::Path,
 ) -> syn::Generics {
     let mut generics = generics.clone();
-    if generics.where_clause.is_none() {
+    generics
-        generics.where_clause = Some(syn::WhereClause {
+        .make_where_clause()
-            where_token: Default::default(),
-            predicates: Punctuated::new(),
-        });
-    }
-    generics.where_clause
-        .as_mut()
-        .unwrap()
         .predicates
         .push(syn::WherePredicate::Type(syn::PredicateType {
             lifetimes: None,
@@ -237,19 +209,19 @@ pub fn with_self_bound(
             bounded_ty: type_of_item(cont),
             colon_token: Default::default(),
             // the bound e.g. Default
-            bounds: vec![
+            bounds: vec![syn::TypeParamBound::Trait(syn::TraitBound {
-                syn::TypeParamBound::Trait(syn::TraitBound {
+                paren_token: None,
-                    modifier: syn::TraitBoundModifier::None,
+                modifier: syn::TraitBoundModifier::None,
-                    lifetimes: None,
+                lifetimes: None,
-                    path: bound.clone(),
+                path: bound.clone(),
-                }),
+            })].into_iter()
-            ].into_iter().collect(),
+                .collect(),
         }));
     generics
 }
 
 pub fn with_lifetime_bound(generics: &syn::Generics, lifetime: &str) -> syn::Generics {
-    let bound = syn::Lifetime::new(Term::intern(lifetime), Span::def_site());
+    let bound = syn::Lifetime::new(lifetime, Span::call_site());
     let def = syn::LifetimeDef {
         attrs: Vec::new(),
         lifetime: bound,
@@ -259,21 +231,18 @@ pub fn with_lifetime_bound(generics: &syn::Generics, lifetime: &str) -> syn::Gen
 
     let params = Some(syn::GenericParam::Lifetime(def))
         .into_iter()
-        .chain(generics.params
+        .chain(generics.params.iter().cloned().map(|mut param| {
-            .iter()
+            match param {
-            .cloned()
+                syn::GenericParam::Lifetime(ref mut param) => {
-            .map(|mut param| {
+                    param.bounds.push(bound);
-                match param {
-                    syn::GenericParam::Lifetime(ref mut param) => {
-                        param.bounds.push(bound);
-                    }
-                    syn::GenericParam::Type(ref mut param) => {
-                        param.bounds.push(syn::TypeParamBound::Lifetime(bound));
-                    }
-                    syn::GenericParam::Const(_) => {}
                 }
-                param
+                syn::GenericParam::Type(ref mut param) => {
-            }))
+                    param.bounds.push(syn::TypeParamBound::Lifetime(bound));
+                }
+                syn::GenericParam::Const(_) => {}
+            }
+            param
+        }))
         .collect();
 
     syn::Generics {
@@ -287,36 +256,35 @@ fn type_of_item(cont: &Container) -> syn::Type {
         qself: None,
         path: syn::Path {
             leading_colon: None,
-            segments: vec![
+            segments: vec![syn::PathSegment {
-                syn::PathSegment {
+                ident: cont.ident,
-                    ident: cont.ident,
+                arguments: syn::PathArguments::AngleBracketed(
-                    arguments: syn::PathArguments::AngleBracketed(
+                    syn::AngleBracketedGenericArguments {
-                        syn::AngleBracketedGenericArguments {
+                        colon2_token: None,
-                            colon2_token: None,
+                        lt_token: Default::default(),
-                            lt_token: Default::default(),
+                        args: cont.generics
-                            args: cont.generics
+                            .params
-                                .params
+                            .iter()
-                                .iter()
+                            .map(|param| match *param {
-                                .map(|param| match *param {
+                                syn::GenericParam::Type(ref param) => {
-                                    syn::GenericParam::Type(ref param) => {
+                                    syn::GenericArgument::Type(syn::Type::Path(syn::TypePath {
-                                        syn::GenericArgument::Type(syn::Type::Path(syn::TypePath {
+                                        qself: None,
-                                            qself: None,
+                                        path: param.ident.into(),
-                                            path: param.ident.into(),
+                                    }))
-                                        }))
+                                }
-                                    }
+                                syn::GenericParam::Lifetime(ref param) => {
-                                    syn::GenericParam::Lifetime(ref param) => {
+                                    syn::GenericArgument::Lifetime(param.lifetime)
-                                        syn::GenericArgument::Lifetime(param.lifetime)
+                                }
-                                    }
+                                syn::GenericParam::Const(_) => {
-                                    syn::GenericParam::Const(_) => {
+                                    panic!("Serde does not support const generics yet");
-                                        panic!("Serde does not support const generics yet");
+                                }
-                                    }
+                            })
-                                })
+                            .collect(),
-                                .collect(),
+                        gt_token: Default::default(),
-                            gt_token: Default::default(),
+                    },
-                        },
+                ),
-                    ),
+            }].into_iter()
-                },
+                .collect(),
-            ].into_iter().collect(),
         },
     })
 }

serde_derive/src/de.rs

@@ -6,15 +6,15 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use syn::{self, Ident, Index, Member};
+use proc_macro2::{Literal, Span};
+use quote::{ToTokens, Tokens};
 use syn::punctuated::Punctuated;
 use syn::spanned::Spanned;
-use quote::{ToTokens, Tokens};
+use syn::{self, Ident, Index, Member};
-use proc_macro2::{Literal, Span, Term};
 
 use bound;
 use fragment::{Expr, Fragment, Match, Stmts};
-use internals::ast::{Data, Container, Field, Style, Variant};
+use internals::ast::{Container, Data, Field, Style, Variant};
 use internals::{self, attr};
 
 use std::collections::BTreeSet;
@@ -27,7 +27,10 @@ pub fn expand_derive_deserialize(input: &syn::DeriveInput) -> Result<Tokens, Str
     let ident = &cont.ident;
     let params = Parameters::new(&cont);
     let (de_impl_generics, _, ty_generics, where_clause) = split_with_de_lifetime(&params);
-    let dummy_const = Ident::new(&format!("_IMPL_DESERIALIZE_FOR_{}", ident), Span::def_site());
+    let dummy_const = Ident::new(
+        &format!("_IMPL_DESERIALIZE_FOR_{}", ident),
+        Span::call_site(),
+    );
     let body = Stmts(deserialize_body(&cont, &params));
     let delife = params.borrowed.de_lifetime();
 
@@ -181,8 +184,8 @@ enum BorrowedLifetimes {
 impl BorrowedLifetimes {
     fn de_lifetime(&self) -> syn::Lifetime {
         match *self {
-            BorrowedLifetimes::Borrowed(_) => syn::Lifetime::new(Term::intern("'de"), Span::def_site()),
+            BorrowedLifetimes::Borrowed(_) => syn::Lifetime::new("'de", Span::call_site()),
-            BorrowedLifetimes::Static => syn::Lifetime::new(Term::intern("'static"), Span::def_site()),
+            BorrowedLifetimes::Static => syn::Lifetime::new("'static", Span::call_site()),
         }
     }
 
@@ -190,7 +193,7 @@ impl BorrowedLifetimes {
         match *self {
             BorrowedLifetimes::Borrowed(ref bounds) => Some(syn::LifetimeDef {
                 attrs: Vec::new(),
-                lifetime: syn::Lifetime::new(Term::intern("'de"), Span::def_site()),
+                lifetime: syn::Lifetime::new("'de", Span::call_site()),
                 colon_token: None,
                 bounds: bounds.iter().cloned().collect(),
             }),
@@ -268,7 +271,8 @@ fn deserialize_in_place_body(cont: &Container, params: &Parameters) -> Option<St
 
     let code = match cont.data {
         Data::Struct(Style::Struct, ref fields) => {
-            if let Some(code) = deserialize_struct_in_place(None, params, fields, &cont.attrs, None) {
+            if let Some(code) = deserialize_struct_in_place(None, params, fields, &cont.attrs, None)
+            {
                 code
             } else {
                 return None;
@@ -321,8 +325,8 @@ fn deserialize_unit_struct(params: &Parameters, cattrs: &attr::Container) -> Fra
         impl<'de> _serde::de::Visitor<'de> for __Visitor {
             type Value = #this;
 
-            fn expecting(&self, formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
+            fn expecting(&self, __formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
-                _serde::export::Formatter::write_str(formatter, #expecting)
+                _serde::export::Formatter::write_str(__formatter, #expecting)
             }
 
             #[inline]
@@ -415,8 +419,8 @@ fn deserialize_tuple(
         impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause {
             type Value = #this #ty_generics;
 
-            fn expecting(&self, formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
+            fn expecting(&self, __formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
-                _serde::export::Formatter::write_str(formatter, #expecting)
+                _serde::export::Formatter::write_str(__formatter, #expecting)
             }
 
             #visit_newtype_struct
@@ -503,8 +507,8 @@ fn deserialize_tuple_in_place(
         impl #in_place_impl_generics _serde::de::Visitor<#delife> for __Visitor #in_place_ty_generics #where_clause {
             type Value = ();
 
-            fn expecting(&self, formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
+            fn expecting(&self, __formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
-                _serde::export::Formatter::write_str(formatter, #expecting)
+                _serde::export::Formatter::write_str(__formatter, #expecting)
             }
 
             #visit_newtype_struct
@@ -549,8 +553,9 @@ fn deserialize_seq(
             let visit = match field.attrs.deserialize_with() {
                 None => {
                     let field_ty = &field.ty;
-                    let span = Span::def_site().located_at(field.original.span());
+                    let span = field.original.span();
-                    let func = quote_spanned!(span=> _serde::de::SeqAccess::next_element::<#field_ty>);
+                    let func =
+                        quote_spanned!(span=> _serde::de::SeqAccess::next_element::<#field_ty>);
                     quote!(try!(#func(&mut __seq)))
                 }
                 Some(path) => {
@@ -637,13 +642,12 @@ fn deserialize_seq_in_place(
         .enumerate()
         .map(|(field_index, (_, field))| {
             // If there's no field name, assume we're a tuple-struct and use a numeric index
-            let field_name = field
+            let field_name = field.ident.map(Member::Named).unwrap_or_else(|| {
-                .ident
+                Member::Unnamed(Index {
-                .map(Member::Named)
-                .unwrap_or_else(|| Member::Unnamed(Index {
                     index: field_index as u32,
                     span: Span::call_site(),
-                }));
+                })
+            });
 
             let dot = quote_spanned!(Span::call_site()=> .);
             if field.attrs.skip_deserializing() {
@@ -871,8 +875,8 @@ fn deserialize_struct(
         impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause {
             type Value = #this #ty_generics;
 
-            fn expecting(&self, formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
+            fn expecting(&self, __formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
-                _serde::export::Formatter::write_str(formatter, #expecting)
+                _serde::export::Formatter::write_str(__formatter, #expecting)
             }
 
             #visit_seq
@@ -919,8 +923,8 @@ fn deserialize_struct_in_place(
 
     let visit_seq = Stmts(deserialize_seq_in_place(params, fields, cattrs));
 
-    let (field_visitor, fields_stmt, visit_map) = deserialize_struct_as_struct_in_place_visitor(
+    let (field_visitor, fields_stmt, visit_map) =
-        params, fields, cattrs);
+        deserialize_struct_as_struct_in_place_visitor(params, fields, cattrs);
 
     let field_visitor = Stmts(field_visitor);
     let fields_stmt = Stmts(fields_stmt);
@@ -978,8 +982,8 @@ fn deserialize_struct_in_place(
         impl #in_place_impl_generics _serde::de::Visitor<#delife> for __Visitor #in_place_ty_generics #where_clause {
             type Value = ();
 
-            fn expecting(&self, formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
+            fn expecting(&self, __formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
-                _serde::export::Formatter::write_str(formatter, #expecting)
+                _serde::export::Formatter::write_str(__formatter, #expecting)
             }
 
             #visit_seq
@@ -1059,9 +1063,7 @@ fn deserialize_externally_tagged_enum(
             let variant_name = field_i(i);
 
             let block = Match(deserialize_externally_tagged_variant(
-                params,
+                params, variant, cattrs,
-                variant,
-                cattrs,
             ));
 
             quote! {
@@ -1102,8 +1104,8 @@ fn deserialize_externally_tagged_enum(
         impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause {
             type Value = #this #ty_generics;
 
-            fn expecting(&self, formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
+            fn expecting(&self, __formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
-                _serde::export::Formatter::write_str(formatter, #expecting)
+                _serde::export::Formatter::write_str(__formatter, #expecting)
             }
 
             fn visit_enum<__A>(self, __data: __A) -> _serde::export::Result<Self::Value, __A::Error>
@@ -1161,9 +1163,9 @@ fn deserialize_internally_tagged_enum(
                 params,
                 variant,
                 cattrs,
-                quote!(
+                quote! {
                     _serde::private::de::ContentDeserializer::<__D::Error>::new(__tagged.content)
-                ),
+                },
             ));
 
             quote! {
@@ -1373,8 +1375,8 @@ fn deserialize_adjacently_tagged_enum(
         impl #de_impl_generics _serde::de::Visitor<#delife> for __Visitor #de_ty_generics #where_clause {
             type Value = #this #ty_generics;
 
-            fn expecting(&self, formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
+            fn expecting(&self, __formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
-                _serde::export::Formatter::write_str(formatter, #expecting)
+                _serde::export::Formatter::write_str(__formatter, #expecting)
             }
 
             fn visit_map<__A>(self, mut __map: __A) -> _serde::export::Result<Self::Value, __A::Error>
@@ -1525,8 +1527,7 @@ fn deserialize_externally_tagged_variant(
     cattrs: &attr::Container,
 ) -> Fragment {
     if let Some(path) = variant.attrs.deserialize_with() {
-        let (wrapper, wrapper_ty, unwrap_fn) =
+        let (wrapper, wrapper_ty, unwrap_fn) = wrap_deserialize_variant_with(params, variant, path);
-            wrap_deserialize_variant_with(params, variant, path);
         return quote_block! {
             #wrapper
             _serde::export::Result::map(
@@ -1608,8 +1609,7 @@ fn deserialize_untagged_variant(
     deserializer: Tokens,
 ) -> Fragment {
     if let Some(path) = variant.attrs.deserialize_with() {
-        let (wrapper, wrapper_ty, unwrap_fn) =
+        let (wrapper, wrapper_ty, unwrap_fn) = wrap_deserialize_variant_with(params, variant, path);
-            wrap_deserialize_variant_with(params, variant, path);
         return quote_block! {
             #wrapper
             _serde::export::Result::map(
@@ -1715,7 +1715,7 @@ fn deserialize_untagged_newtype_variant(
 fn deserialize_generated_identifier(
     fields: &[(String, Ident)],
     cattrs: &attr::Container,
-    is_variant: bool
+    is_variant: bool,
 ) -> Fragment {
     let this = quote!(__Field);
     let field_idents: &Vec<_> = &fields.iter().map(|&(_, ref ident)| ident).collect();
@@ -1810,12 +1810,7 @@ fn deserialize_custom_identifier(
 
     let names_idents: Vec<_> = ordinary
         .iter()
-        .map(|variant| {
+        .map(|variant| (variant.attrs.name().deserialize_name(), variant.ident))
-            (
-                variant.attrs.name().deserialize_name(),
-                variant.ident,
-            )
-        })
         .collect();
 
     let names = names_idents.iter().map(|&(ref name, _)| name);
@@ -1872,12 +1867,16 @@ fn deserialize_identifier(
     fields: &[(String, Ident)],
     is_variant: bool,
     fallthrough: Option<Tokens>,
-    collect_other_fields: bool
+    collect_other_fields: bool,
 ) -> Fragment {
     let field_strs = fields.iter().map(|&(ref name, _)| name);
     let field_borrowed_strs = fields.iter().map(|&(ref name, _)| name);
-    let field_bytes = fields.iter().map(|&(ref name, _)| Literal::byte_string(name.as_bytes()));
+    let field_bytes = fields
-    let field_borrowed_bytes = fields.iter().map(|&(ref name, _)| Literal::byte_string(name.as_bytes()));
+        .iter()
+        .map(|&(ref name, _)| Literal::byte_string(name.as_bytes()));
+    let field_borrowed_bytes = fields
+        .iter()
+        .map(|&(ref name, _)| Literal::byte_string(name.as_bytes()));
 
     let constructors: &Vec<_> = &fields
         .iter()
@@ -1892,10 +1891,54 @@ fn deserialize_identifier(
 
     let index_expecting = if is_variant { "variant" } else { "field" };
 
+    let bytes_to_str = if fallthrough.is_some() || collect_other_fields {
+        None
+    } else {
+        Some(quote! {
+            let __value = &_serde::export::from_utf8_lossy(__value);
+        })
+    };
+
+    let (
+        value_as_str_content,
+        value_as_borrowed_str_content,
+        value_as_bytes_content,
+        value_as_borrowed_bytes_content,
+    ) = if !collect_other_fields {
+        (None, None, None, None)
+    } else {
+        (
+            Some(quote! {
+                let __value = _serde::private::de::Content::String(__value.to_string());
+            }),
+            Some(quote! {
+                let __value = _serde::private::de::Content::Str(__value);
+            }),
+            Some(quote! {
+                let __value = _serde::private::de::Content::ByteBuf(__value.to_vec());
+            }),
+            Some(quote! {
+                let __value = _serde::private::de::Content::Bytes(__value);
+            }),
+        )
+    };
+
+    let fallthrough_arm = if let Some(fallthrough) = fallthrough {
+        fallthrough
+    } else if is_variant {
+        quote! {
+            _serde::export::Err(_serde::de::Error::unknown_variant(__value, VARIANTS))
+        }
+    } else {
+        quote! {
+            _serde::export::Err(_serde::de::Error::unknown_field(__value, FIELDS))
+        }
+    };
+
     let variant_indices = 0u64..;
     let fallthrough_msg = format!("{} index 0 <= i < {}", index_expecting, fields.len());
     let visit_other = if collect_other_fields {
-        Some(quote! {
+        quote! {
             fn visit_bool<__E>(self, __value: bool) -> Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
@@ -1973,9 +2016,38 @@ fn deserialize_identifier(
             {
                 Ok(__Field::__other(_serde::private::de::Content::Unit))
             }
-        })
+
+            fn visit_borrowed_str<__E>(self, __value: &'de str) -> _serde::export::Result<Self::Value, __E>
+                where __E: _serde::de::Error
+            {
+                match __value {
+                    #(
+                        #field_borrowed_strs => _serde::export::Ok(#constructors),
+                    )*
+                    _ => {
+                        #value_as_borrowed_str_content
+                        #fallthrough_arm
+                    }
+                }
+            }
+
+            fn visit_borrowed_bytes<__E>(self, __value: &'de [u8]) -> _serde::export::Result<Self::Value, __E>
+                where __E: _serde::de::Error
+            {
+                match __value {
+                    #(
+                        #field_borrowed_bytes => _serde::export::Ok(#constructors),
+                    )*
+                    _ => {
+                        #bytes_to_str
+                        #value_as_borrowed_bytes_content
+                        #fallthrough_arm
+                    }
+                }
+            }
+        }
     } else {
-        Some(quote! {
+        quote! {
             fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
@@ -1988,52 +2060,12 @@ fn deserialize_identifier(
                                 &#fallthrough_msg))
                 }
             }
-        })
-    };
-
-    let bytes_to_str = if fallthrough.is_some() || collect_other_fields {
-        None
-    } else {
-        Some(quote! {
-            let __value = &_serde::export::from_utf8_lossy(__value);
-        })
-    };
-
-    let (value_as_str_content, value_as_borrowed_str_content,
-         value_as_bytes_content, value_as_borrowed_bytes_content) = if !collect_other_fields {
-        (None, None, None, None)
-    } else {
-        (
-            Some(quote! {
-                let __value = _serde::private::de::Content::String(__value.to_string());
-            }),
-            Some(quote! {
-                let __value = _serde::private::de::Content::Str(__value);
-            }),
-            Some(quote! {
-                let __value = _serde::private::de::Content::ByteBuf(__value.to_vec());
-            }),
-            Some(quote! {
-                let __value = _serde::private::de::Content::Bytes(__value);
-            })
-        )
-    };
-
-    let fallthrough_arm = if let Some(fallthrough) = fallthrough {
-        fallthrough
-    } else if is_variant {
-        quote! {
-            _serde::export::Err(_serde::de::Error::unknown_variant(__value, VARIANTS))
-        }
-    } else {
-        quote! {
-            _serde::export::Err(_serde::de::Error::unknown_field(__value, FIELDS))
         }
     };
 
     quote_block! {
-        fn expecting(&self, formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
+        fn expecting(&self, __formatter: &mut _serde::export::Formatter) -> _serde::export::fmt::Result {
-            _serde::export::Formatter::write_str(formatter, #expecting)
+            _serde::export::Formatter::write_str(__formatter, #expecting)
         }
 
         #visit_other
@@ -2052,35 +2084,6 @@ fn deserialize_identifier(
             }
         }
 
-        fn visit_borrowed_str<__E>(self, __value: &'de str) -> _serde::export::Result<Self::Value, __E>
-            where __E: _serde::de::Error
-        {
-            match __value {
-                #(
-                    #field_borrowed_strs => _serde::export::Ok(#constructors),
-                )*
-                _ => {
-                    #value_as_borrowed_str_content
-                    #fallthrough_arm
-                }
-            }
-        }
-
-        fn visit_borrowed_bytes<__E>(self, __value: &'de [u8]) -> _serde::export::Result<Self::Value, __E>
-            where __E: _serde::de::Error
-        {
-            match __value {
-                #(
-                    #field_borrowed_bytes => _serde::export::Ok(#constructors),
-                )*
-                _ => {
-                    #bytes_to_str
-                    #value_as_borrowed_bytes_content
-                    #fallthrough_arm
-                }
-            }
-        }
-
         fn visit_bytes<__E>(self, __value: &[u8]) -> _serde::export::Result<Self::Value, __E>
             where __E: _serde::de::Error
         {
@@ -2193,8 +2196,9 @@ fn deserialize_map(
             let visit = match field.attrs.deserialize_with() {
                 None => {
                     let field_ty = &field.ty;
-                    let span = Span::def_site().located_at(field.original.span());
+                    let span = field.original.span();
-                    let func = quote_spanned!(span=> _serde::de::MapAccess::next_value::<#field_ty>);
+                    let func =
+                        quote_spanned!(span=> _serde::de::MapAccess::next_value::<#field_ty>);
                     quote! {
                         try!(#func(&mut __map))
                     }
@@ -2473,7 +2477,12 @@ fn deserialize_map_in_place(
             // If missing_expr unconditionally returns an error, don't try
             // to assign its value to self.place. Maybe this could be handled
             // more elegantly.
-            if missing_expr.as_ref().into_tokens().to_string().starts_with("return ") {
+            if missing_expr
+                .as_ref()
+                .into_tokens()
+                .to_string()
+                .starts_with("return ")
+            {
                 let missing_expr = Stmts(missing_expr);
                 quote! {
                     if !#name {
@@ -2522,7 +2531,7 @@ fn deserialize_map_in_place(
 }
 
 fn field_i(i: usize) -> Ident {
-    Ident::new(&format!("__field{}", i), Span::def_site())
+    Ident::new(&format!("__field{}", i), Span::call_site())
 }
 
 /// This function wraps the expression in `#[serde(deserialize_with = "...")]`
@@ -2582,35 +2591,37 @@ fn wrap_deserialize_variant_with(
     let (wrapper, wrapper_ty) =
         wrap_deserialize_with(params, &quote!((#(#field_tys),*)), deserialize_with);
 
-    let field_access = (0..variant.fields.len()).map(|n| Member::Unnamed(Index {
+    let field_access = (0..variant.fields.len()).map(|n| {
-        index: n as u32,
+        Member::Unnamed(Index {
-        span: Span::call_site(),
+            index: n as u32,
-    }));
+            span: Span::call_site(),
+        })
+    });
     let unwrap_fn = match variant.style {
+        Style::Struct if variant.fields.len() == 1 => {
+            let field_ident = variant.fields[0].ident.unwrap();
+            quote! {
+                |__wrap| #this::#variant_ident { #field_ident: __wrap.value }
+            }
+        }
         Style::Struct => {
             let field_idents = variant
                 .fields
                 .iter()
                 .map(|field| field.ident.as_ref().unwrap());
-            quote!({
+            quote! {
-                |__wrap| {
+                |__wrap| #this::#variant_ident { #(#field_idents: __wrap.value.#field_access),* }
-                    #this::#variant_ident { #(#field_idents: __wrap.value.#field_access),* }
+            }
-                }
-            })
         }
-        Style::Tuple => quote!({
+        Style::Tuple => quote! {
-            |__wrap| {
+            |__wrap| #this::#variant_ident(#(__wrap.value.#field_access),*)
-                #this::#variant_ident(#(__wrap.value.#field_access),*)
+        },
-            }
+        Style::Newtype => quote! {
-        }),
+            |__wrap| #this::#variant_ident(__wrap.value)
-        Style::Newtype => quote!({
+        },
-            |__wrap| {
+        Style::Unit => quote! {
-                #this::#variant_ident(__wrap.value)
+            |__wrap| #this::#variant_ident
-            }
+        },
-        }),
-        Style::Unit => quote!({
-            |__wrap| { #this::#variant_ident }
-        }),
     };
 
     (wrapper, wrapper_ty, unwrap_fn)
@@ -2638,7 +2649,7 @@ fn expr_is_missing(field: &Field, cattrs: &attr::Container) -> Fragment {
     let name = field.attrs.name().deserialize_name();
     match field.attrs.deserialize_with() {
         None => {
-            let span = Span::def_site().located_at(field.original.span());
+            let span = field.original.span();
             let func = quote_spanned!(span=> _serde::private::de::missing_field);
             quote_expr! {
                 try!(#func(#name))
@@ -2683,7 +2694,8 @@ impl<'a> ToTokens for InPlaceImplGenerics<'a> {
                     param.bounds.push(place_lifetime.lifetime);
                 }
                 syn::GenericParam::Type(ref mut param) => {
-                    param.bounds
+                    param
+                        .bounds
                         .push(syn::TypeParamBound::Lifetime(place_lifetime.lifetime));
                 }
                 syn::GenericParam::Const(_) => {}
@@ -2721,7 +2733,7 @@ impl<'a> ToTokens for DeTypeGenerics<'a> {
         if self.0.borrowed.de_lifetime_def().is_some() {
             let def = syn::LifetimeDef {
                 attrs: Vec::new(),
-                lifetime: syn::Lifetime::new(Term::intern("'de"), Span::def_site()),
+                lifetime: syn::Lifetime::new("'de", Span::call_site()),
                 colon_token: None,
                 bounds: Punctuated::new(),
             };
@@ -2747,7 +2759,7 @@ impl<'a> ToTokens for InPlaceTypeGenerics<'a> {
         if self.0.borrowed.de_lifetime_def().is_some() {
             let def = syn::LifetimeDef {
                 attrs: Vec::new(),
-                lifetime: syn::Lifetime::new(Term::intern("'de"), Span::def_site()),
+                lifetime: syn::Lifetime::new("'de", Span::call_site()),
                 colon_token: None,
                 bounds: Punctuated::new(),
             };
@@ -2772,7 +2784,7 @@ impl<'a> DeTypeGenerics<'a> {
 fn place_lifetime() -> syn::LifetimeDef {
     syn::LifetimeDef {
         attrs: Vec::new(),
-        lifetime: syn::Lifetime::new(Term::intern("'place"), Span::def_site()),
+        lifetime: syn::Lifetime::new("'place", Span::call_site()),
         colon_token: None,
         bounds: Punctuated::new(),
     }

serde_derive/src/lib.rs

@@ -22,9 +22,11 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.36")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.41")]
-#![cfg_attr(feature = "cargo-clippy", allow(enum_variant_names, redundant_field_names,
+#![cfg_attr(
-                                            too_many_arguments, used_underscore_binding))]
+    feature = "cargo-clippy",
+    allow(enum_variant_names, redundant_field_names, too_many_arguments, used_underscore_binding)
+)]
 // The `quote!` macro requires deep recursion.
 #![recursion_limit = "512"]
 
@@ -41,13 +43,21 @@ extern crate proc_macro2;
 use proc_macro::TokenStream;
 use syn::DeriveInput;
 
+// Quote's default is def_site but it appears call_site is likely to stabilize
+// before def_site. Thus we try to use only call_site.
+macro_rules! quote {
+    ($($tt:tt)*) => {
+        quote_spanned!($crate::proc_macro2::Span::call_site()=> $($tt)*)
+    }
+}
+
 #[macro_use]
 mod bound;
 #[macro_use]
 mod fragment;
 
-mod ser;
 mod de;
+mod ser;
 
 #[proc_macro_derive(Serialize, attributes(serde))]
 pub fn derive_serialize(input: TokenStream) -> TokenStream {

serde_derive/src/ser.rs

@@ -6,14 +6,14 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use syn::{self, Ident, Index, Member};
-use syn::spanned::Spanned;
-use quote::Tokens;
 use proc_macro2::Span;
+use quote::Tokens;
+use syn::spanned::Spanned;
+use syn::{self, Ident, Index, Member};
 
 use bound;
 use fragment::{Fragment, Match, Stmts};
-use internals::ast::{Data, Container, Field, Style, Variant};
+use internals::ast::{Container, Data, Field, Style, Variant};
 use internals::{attr, Ctxt};
 
 use std::u32;
@@ -27,7 +27,7 @@ pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<Tokens, Strin
     let ident = &cont.ident;
     let params = Parameters::new(&cont);
     let (impl_generics, ty_generics, where_clause) = params.generics.split_for_impl();
-    let dummy_const = Ident::new(&format!("_IMPL_SERIALIZE_FOR_{}", ident), Span::def_site());
+    let dummy_const = Ident::new(&format!("_IMPL_SERIALIZE_FOR_{}", ident), Span::call_site());
     let body = Stmts(serialize_body(&cont, &params));
 
     let impl_block = if let Some(remote) = cont.attrs.remote() {
@@ -98,9 +98,9 @@ impl Parameters {
     fn new(cont: &Container) -> Self {
         let is_remote = cont.attrs.remote().is_some();
         let self_var = if is_remote {
-            Ident::new("__self", Span::def_site())
+            Ident::new("__self", Span::call_site())
         } else {
-            Ident::new("self", Span::def_site())
+            Ident::new("self", Span::call_site())
         };
 
         let this = match cont.attrs.remote() {
@@ -204,15 +204,19 @@ fn serialize_newtype_struct(
 ) -> Fragment {
     let type_name = cattrs.name().serialize_name();
 
-    let mut field_expr = get_member(params, field, &Member::Unnamed(Index {
+    let mut field_expr = get_member(
-        index: 0,
+        params,
-        span: Span::call_site(),
+        field,
-    }));
+        &Member::Unnamed(Index {
+            index: 0,
+            span: Span::call_site(),
+        }),
+    );
     if let Some(path) = field.attrs.serialize_with() {
         field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
     }
 
-    let span = Span::def_site().located_at(field.original.span());
+    let span = field.original.span();
     let func = quote_spanned!(span=> _serde::Serializer::serialize_newtype_struct);
     quote_expr! {
         #func(__serializer, #type_name, #field_expr)
@@ -224,12 +228,8 @@ fn serialize_tuple_struct(
     fields: &[Field],
     cattrs: &attr::Container,
 ) -> Fragment {
-    let serialize_stmts = serialize_tuple_struct_visitor(
+    let serialize_stmts =
-        fields,
+        serialize_tuple_struct_visitor(fields, params, false, &TupleTrait::SerializeTupleStruct);
-        params,
-        false,
-        &TupleTrait::SerializeTupleStruct,
-    );
 
     let type_name = cattrs.name().serialize_name();
     let len = serialize_stmts.len();
@@ -252,13 +252,13 @@ fn serialize_struct(params: &Parameters, fields: &[Field], cattrs: &attr::Contai
     }
 }
 
-fn serialize_struct_as_struct(params: &Parameters, fields: &[Field], cattrs: &attr::Container) -> Fragment {
+fn serialize_struct_as_struct(
-    let serialize_fields = serialize_struct_visitor(
+    params: &Parameters,
-        fields,
+    fields: &[Field],
-        params,
+    cattrs: &attr::Container,
-        false,
+) -> Fragment {
-        &StructTrait::SerializeStruct,
+    let serialize_fields =
-    );
+        serialize_struct_visitor(fields, params, false, &StructTrait::SerializeStruct);
 
     let type_name = cattrs.name().serialize_name();
 
@@ -287,13 +287,13 @@ fn serialize_struct_as_struct(params: &Parameters, fields: &[Field], cattrs: &at
     }
 }
 
-fn serialize_struct_as_map(params: &Parameters, fields: &[Field], cattrs: &attr::Container) -> Fragment {
+fn serialize_struct_as_map(
-    let serialize_fields = serialize_struct_visitor(
+    params: &Parameters,
-        fields,
+    fields: &[Field],
-        params,
+    cattrs: &attr::Container,
-        false,
+) -> Fragment {
-        &StructTrait::SerializeMap,
+    let serialize_fields =
-    );
+        serialize_struct_visitor(fields, params, false, &StructTrait::SerializeMap);
 
     let mut serialized_fields = fields
         .iter()
@@ -385,8 +385,8 @@ fn serialize_variant(
                 }
             }
             Style::Tuple => {
-                let field_names =
+                let field_names = (0..variant.fields.len())
-                    (0..variant.fields.len()).map(|i| Ident::new(&format!("__field{}", i), Span::def_site()));
+                    .map(|i| Ident::new(&format!("__field{}", i), Span::call_site()));
                 quote! {
                     #this::#variant_ident(#(ref #field_names),*)
                 }
@@ -619,9 +619,9 @@ fn serialize_adjacently_tagged_variant(
                 unreachable!()
             }
         }
-        Style::Newtype => vec![Ident::new("__field0", Span::def_site())],
+        Style::Newtype => vec![Ident::new("__field0", Span::call_site())],
         Style::Tuple => (0..variant.fields.len())
-            .map(|i| Ident::new(&format!("__field{}", i), Span::def_site()))
+            .map(|i| Ident::new(&format!("__field{}", i), Span::call_site()))
             .collect(),
         Style::Struct => variant
             .fields
@@ -776,12 +776,10 @@ fn serialize_struct_variant<'a>(
     name: &str,
 ) -> Fragment {
     let struct_trait = match context {
-        StructVariant::ExternallyTagged { .. } => (
+        StructVariant::ExternallyTagged { .. } => (StructTrait::SerializeStructVariant),
-            StructTrait::SerializeStructVariant
+        StructVariant::InternallyTagged { .. } | StructVariant::Untagged => {
-        ),
+            (StructTrait::SerializeStruct)
-        StructVariant::InternallyTagged { .. } | StructVariant::Untagged => (
+        }
-            StructTrait::SerializeStruct
-        ),
     };
 
     let serialize_fields = serialize_struct_visitor(fields, params, true, &struct_trait);
@@ -862,13 +860,17 @@ fn serialize_tuple_struct_visitor(
         .enumerate()
         .map(|(i, field)| {
             let mut field_expr = if is_enum {
-                let id = Ident::new(&format!("__field{}", i), Span::def_site());
+                let id = Ident::new(&format!("__field{}", i), Span::call_site());
                 quote!(#id)
             } else {
-                get_member(params, field, &Member::Unnamed(Index {
+                get_member(
-                    index: i as u32,
+                    params,
-                    span: Span::call_site(),
+                    field,
-                }))
+                    &Member::Unnamed(Index {
+                        index: i as u32,
+                        span: Span::call_site(),
+                    }),
+                )
             };
 
             let skip = field
@@ -880,7 +882,7 @@ fn serialize_tuple_struct_visitor(
                 field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
             }
 
-            let span = Span::def_site().located_at(field.original.span());
+            let span = field.original.span();
             let func = tuple_trait.serialize_element(span);
             let ser = quote! {
                 try!(#func(&mut __serde_state, #field_expr));
@@ -923,7 +925,7 @@ fn serialize_struct_visitor(
                 field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
             }
 
-            let span = Span::def_site().located_at(field.original.span());
+            let span = field.original.span();
             let ser = if field.attrs.flatten() {
                 quote! {
                     try!(_serde::Serialize::serialize(&#field_expr, _serde::private::ser::FlatMapSerializer(&mut __serde_state)));
@@ -981,7 +983,7 @@ fn wrap_serialize_variant_with(
         .map(|(i, field)| {
             let id = field
                 .ident
-                .unwrap_or_else(|| Ident::new(&format!("__field{}", i), Span::def_site()));
+                .unwrap_or_else(|| Ident::new(&format!("__field{}", i), Span::call_site()));
             quote!(#id)
         })
         .collect();
@@ -1009,10 +1011,12 @@ fn wrap_serialize_with(
     };
     let (wrapper_impl_generics, wrapper_ty_generics, _) = wrapper_generics.split_for_impl();
 
-    let field_access = (0..field_exprs.len()).map(|n| Member::Unnamed(Index {
+    let field_access = (0..field_exprs.len()).map(|n| {
-        index: n as u32,
+        Member::Unnamed(Index {
-        span: Span::call_site(),
+            index: n as u32,
-    }));
+            span: Span::call_site(),
+        })
+    });
 
     quote!({
         struct __SerializeWith #wrapper_impl_generics #where_clause {
@@ -1052,9 +1056,7 @@ fn mut_if(is_mut: bool) -> Option<Tokens> {
 fn get_member(params: &Parameters, field: &Field, member: &Member) -> Tokens {
     let self_var = &params.self_var;
     match (params.is_remote, field.attrs.getter()) {
-        (false, None) => {
+        (false, None) => quote_spanned!(Span::call_site()=> &#self_var.#member),
-            quote_spanned!(Span::call_site()=> &#self_var.#member)
-        }
         (true, None) => {
             let inner = quote_spanned!(Span::call_site()=> &#self_var.#member);
             let ty = field.ty;
@@ -1094,12 +1096,12 @@ impl StructTrait {
     fn skip_field(&self, span: Span) -> Option<Tokens> {
         match *self {
             StructTrait::SerializeMap => None,
-            StructTrait::SerializeStruct => Some({
+            StructTrait::SerializeStruct => {
-                quote_spanned!(span=> _serde::ser::SerializeStruct::skip_field)
+                Some(quote_spanned!(span=> _serde::ser::SerializeStruct::skip_field))
-            }),
+            }
-            StructTrait::SerializeStructVariant => Some({
+            StructTrait::SerializeStructVariant => {
-                quote_spanned!(span=> _serde::ser::SerializeStructVariant::skip_field)
+                Some(quote_spanned!(span=> _serde::ser::SerializeStructVariant::skip_field))
-            })
+            }
         }
     }
 }

serde_derive_internals/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive_internals"
-version = "0.22.2" # remember to update html_root_url
+version = "0.23.1" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "AST representation used by Serde derive macros. Unstable."
@@ -12,8 +12,8 @@ readme = "README.md"
 include = ["Cargo.toml", "src/**/*.rs", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
 
 [dependencies]
-proc-macro2 = "0.2"
+proc-macro2 = "0.3"
-syn = { version = "0.12", default-features = false, features = ["derive", "parsing", "clone-impls"] }
+syn = { version = "0.13", default-features = false, features = ["derive", "parsing", "clone-impls"] }
 
 [badges]
 travis-ci = { repository = "serde-rs/serde" }

serde_derive_internals/src/ast.rs

@@ -6,11 +6,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use syn;
 use attr;
 use check;
-use Ctxt;
+use syn;
 use syn::punctuated::Punctuated;
+use Ctxt;
 
 pub struct Container<'a> {
     pub ident: syn::Ident,
@@ -68,6 +68,9 @@ impl<'a> Container<'a> {
             Data::Enum(ref mut variants) => for variant in variants {
                 variant.attrs.rename_by_rule(attrs.rename_all());
                 for field in &mut variant.fields {
+                    if field.attrs.flatten() {
+                        has_flatten = true;
+                    }
                     field.attrs.rename_by_rule(variant.attrs.rename_all());
                 }
             },

serde_derive_internals/src/attr.rs

@@ -6,16 +6,16 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use Ctxt;
+use proc_macro2::{Group, Span, TokenStream, TokenTree};
+use std::collections::BTreeSet;
+use std::str::FromStr;
 use syn;
+use syn::punctuated::Punctuated;
+use syn::synom::{ParseError, Synom};
 use syn::Ident;
 use syn::Meta::{List, NameValue, Word};
 use syn::NestedMeta::{Literal, Meta};
-use syn::punctuated::Punctuated;
+use Ctxt;
-use syn::synom::{Synom, ParseError};
-use std::collections::BTreeSet;
-use std::str::FromStr;
-use proc_macro2::{Span, TokenStream, TokenNode, TokenTree};
 
 // This module handles parsing of `#[serde(...)]` attributes. The entrypoints
 // are `attr::Container::from_ast`, `attr::Variant::from_ast`, and
@@ -234,7 +234,10 @@ impl Container {
 
                     // Parse `#[serde(default)]`
                     Meta(Word(word)) if word == "default" => match item.data {
-                        syn::Data::Struct(syn::DataStruct { fields: syn::Fields::Named(_), .. }) => {
+                        syn::Data::Struct(syn::DataStruct {
+                            fields: syn::Fields::Named(_),
+                            ..
+                        }) => {
                             default.set(Default::Default);
                         }
                         _ => cx.error(
@@ -247,7 +250,10 @@ impl Container {
                     Meta(NameValue(ref m)) if m.ident == "default" => {
                         if let Ok(path) = parse_lit_into_expr_path(cx, m.ident.as_ref(), &m.lit) {
                             match item.data {
-                                syn::Data::Struct(syn::DataStruct { fields: syn::Fields::Named(_), .. }) => {
+                                syn::Data::Struct(syn::DataStruct {
+                                    fields: syn::Fields::Named(_),
+                                    ..
+                                }) => {
                                     default.set(Default::Path(path));
                                 }
                                 _ => cx.error(
@@ -503,13 +509,11 @@ fn decide_identifier(
         }
         (&syn::Data::Enum(_), true, false) => Identifier::Field,
         (&syn::Data::Enum(_), false, true) => Identifier::Variant,
-        (&syn::Data::Struct(_), true, false)
+        (&syn::Data::Struct(_), true, false) | (&syn::Data::Union(_), true, false) => {
-        | (&syn::Data::Union(_), true, false) => {
             cx.error("`field_identifier` can only be used on an enum");
             Identifier::No
         }
-        (&syn::Data::Struct(_), false, true)
+        (&syn::Data::Struct(_), false, true) | (&syn::Data::Union(_), false, true) => {
-        | (&syn::Data::Union(_), false, true) => {
             cx.error("`variant_identifier` can only be used on an enum");
             Identifier::No
         }
@@ -594,10 +598,16 @@ impl Variant {
                     Meta(NameValue(ref m)) if m.ident == "with" => {
                         if let Ok(path) = parse_lit_into_expr_path(cx, m.ident.as_ref(), &m.lit) {
                             let mut ser_path = path.clone();
-                            ser_path.path.segments.push(Ident::new("serialize", Span::call_site()).into());
+                            ser_path
+                                .path
+                                .segments
+                                .push(Ident::new("serialize", Span::call_site()).into());
                             serialize_with.set(ser_path);
                             let mut de_path = path;
-                            de_path.path.segments.push(Ident::new("deserialize", Span::call_site()).into());
+                            de_path
+                                .path
+                                .segments
+                                .push(Ident::new("deserialize", Span::call_site()).into());
                             deserialize_with.set(de_path);
                         }
                     }
@@ -838,10 +848,16 @@ impl Field {
                     Meta(NameValue(ref m)) if m.ident == "with" => {
                         if let Ok(path) = parse_lit_into_expr_path(cx, m.ident.as_ref(), &m.lit) {
                             let mut ser_path = path.clone();
-                            ser_path.path.segments.push(Ident::new("serialize", Span::call_site()).into());
+                            ser_path
+                                .path
+                                .segments
+                                .push(Ident::new("serialize", Span::call_site()).into());
                             serialize_with.set(ser_path);
                             let mut de_path = path;
-                            de_path.path.segments.push(Ident::new("deserialize", Span::call_site()).into());
+                            de_path
+                                .path
+                                .segments
+                                .push(Ident::new("deserialize", Span::call_site()).into());
                             deserialize_with.set(de_path);
                         }
                     }
@@ -873,7 +889,9 @@ impl Field {
 
                     // Parse `#[serde(borrow = "'a + 'b")]`
                     Meta(NameValue(ref m)) if m.ident == "borrow" => {
-                        if let Ok(lifetimes) = parse_lit_into_lifetimes(cx, m.ident.as_ref(), &m.lit) {
+                        if let Ok(lifetimes) =
+                            parse_lit_into_lifetimes(cx, m.ident.as_ref(), &m.lit)
+                        {
                             if let Ok(borrowable) = borrowable_lifetimes(cx, &ident, &field.ty) {
                                 for lifetime in &lifetimes {
                                     if !borrowable.contains(lifetime) {
@@ -939,10 +957,14 @@ impl Field {
                     leading_colon: None,
                     segments: Punctuated::new(),
                 };
-                path.segments.push(Ident::new("_serde", Span::def_site()).into());
+                path.segments
-                path.segments.push(Ident::new("private", Span::def_site()).into());
+                    .push(Ident::new("_serde", Span::call_site()).into());
-                path.segments.push(Ident::new("de", Span::def_site()).into());
+                path.segments
-                path.segments.push(Ident::new("borrow_cow_str", Span::def_site()).into());
+                    .push(Ident::new("private", Span::call_site()).into());
+                path.segments
+                    .push(Ident::new("de", Span::call_site()).into());
+                path.segments
+                    .push(Ident::new("borrow_cow_str", Span::call_site()).into());
                 let expr = syn::ExprPath {
                     attrs: Vec::new(),
                     qself: None,
@@ -954,10 +976,14 @@ impl Field {
                     leading_colon: None,
                     segments: Punctuated::new(),
                 };
-                path.segments.push(Ident::new("_serde", Span::def_site()).into());
+                path.segments
-                path.segments.push(Ident::new("private", Span::def_site()).into());
+                    .push(Ident::new("_serde", Span::call_site()).into());
-                path.segments.push(Ident::new("de", Span::def_site()).into());
+                path.segments
-                path.segments.push(Ident::new("borrow_cow_bytes", Span::def_site()).into());
+                    .push(Ident::new("private", Span::call_site()).into());
+                path.segments
+                    .push(Ident::new("de", Span::call_site()).into());
+                path.segments
+                    .push(Ident::new("borrow_cow_bytes", Span::call_site()).into());
                 let expr = syn::ExprPath {
                     attrs: Vec::new(),
                     qself: None,
@@ -1097,7 +1123,10 @@ where
     Ok((ser_meta.get(), de_meta.get()))
 }
 
-fn get_renames<'a>(cx: &Ctxt, items: &'a Punctuated<syn::NestedMeta, Token![,]>) -> Result<SerAndDe<&'a syn::LitStr>, ()> {
+fn get_renames<'a>(
+    cx: &Ctxt,
+    items: &'a Punctuated<syn::NestedMeta, Token![,]>,
+) -> Result<SerAndDe<&'a syn::LitStr>, ()> {
     get_ser_and_de(cx, "rename", items, get_lit_str)
 }
 
@@ -1141,12 +1170,18 @@ fn get_lit_str<'a>(
 
 fn parse_lit_into_path(cx: &Ctxt, attr_name: &str, lit: &syn::Lit) -> Result<syn::Path, ()> {
     let string = try!(get_lit_str(cx, attr_name, attr_name, lit));
-    parse_lit_str(string).map_err(|_| cx.error(format!("failed to parse path: {:?}", string.value())))
+    parse_lit_str(string)
+        .map_err(|_| cx.error(format!("failed to parse path: {:?}", string.value())))
 }
 
-fn parse_lit_into_expr_path(cx: &Ctxt, attr_name: &str, lit: &syn::Lit) -> Result<syn::ExprPath, ()> {
+fn parse_lit_into_expr_path(
+    cx: &Ctxt,
+    attr_name: &str,
+    lit: &syn::Lit,
+) -> Result<syn::ExprPath, ()> {
     let string = try!(get_lit_str(cx, attr_name, attr_name, lit));
-    parse_lit_str(string).map_err(|_| cx.error(format!("failed to parse path: {:?}", string.value())))
+    parse_lit_str(string)
+        .map_err(|_| cx.error(format!("failed to parse path: {:?}", string.value())))
 }
 
 fn parse_lit_into_where(
@@ -1160,7 +1195,7 @@ fn parse_lit_into_where(
         return Ok(Vec::new());
     }
 
-    let where_string = syn::LitStr::new(&format!("where {}", string.value()), string.span);
+    let where_string = syn::LitStr::new(&format!("where {}", string.value()), string.span());
 
     parse_lit_str::<syn::WhereClause>(&where_string)
         .map(|wh| wh.predicates.into_iter().collect())
@@ -1173,7 +1208,8 @@ fn parse_lit_into_ty(cx: &Ctxt, attr_name: &str, lit: &syn::Lit) -> Result<syn::
     parse_lit_str(string).map_err(|_| {
         cx.error(format!(
             "failed to parse type: {} = {:?}",
-            attr_name, string.value()
+            attr_name,
+            string.value()
         ))
     })
 }
@@ -1210,7 +1246,10 @@ fn parse_lit_into_lifetimes(
         return Ok(set);
     }
 
-    cx.error(format!("failed to parse borrowed lifetimes: {:?}", string.value()));
+    cx.error(format!(
+        "failed to parse borrowed lifetimes: {:?}",
+        string.value()
+    ));
     Err(())
 }
 
@@ -1255,14 +1294,10 @@ fn is_cow(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool {
             return false;
         }
     };
-    seg.ident == "Cow"
+    seg.ident == "Cow" && args.len() == 2 && match (&args[0], &args[1]) {
-        && args.len() == 2
+        (&syn::GenericArgument::Lifetime(_), &syn::GenericArgument::Type(ref arg)) => elem(arg),
-        && match (&args[0], &args[1]) {
+        _ => false,
-            (&syn::GenericArgument::Lifetime(_), &syn::GenericArgument::Type(ref arg)) => {
+    }
-                elem(arg)
-            }
-            _ => false,
-        }
 }
 
 // Whether the type looks like it might be `&T` where elem="T". This can have
@@ -1287,9 +1322,7 @@ fn is_cow(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool {
 //     }
 fn is_rptr(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool {
     match *ty {
-        syn::Type::Reference(ref ty) => {
+        syn::Type::Reference(ref ty) => ty.mutability.is_none() && elem(&ty.elem),
-            ty.mutability.is_none() && elem(&ty.elem)
-        }
         _ => false,
     }
 }
@@ -1307,17 +1340,13 @@ fn is_slice_u8(ty: &syn::Type) -> bool {
 
 fn is_primitive_type(ty: &syn::Type, primitive: &str) -> bool {
     match *ty {
-        syn::Type::Path(ref ty) => {
+        syn::Type::Path(ref ty) => ty.qself.is_none() && is_primitive_path(&ty.path, primitive),
-            ty.qself.is_none() && is_primitive_path(&ty.path, primitive)
-        }
         _ => false,
     }
 }
 
 fn is_primitive_path(path: &syn::Path, primitive: &str) -> bool {
-    path.leading_colon.is_none()
+    path.leading_colon.is_none() && path.segments.len() == 1 && path.segments[0].ident == primitive
-        && path.segments.len() == 1
-        && path.segments[0].ident == primitive
         && path.segments[0].arguments.is_empty()
 }
 
@@ -1410,21 +1439,20 @@ where
 
 fn spanned_tokens(s: &syn::LitStr) -> Result<TokenStream, ParseError> {
     let stream = try!(syn::parse_str(&s.value()));
-    Ok(respan_token_stream(stream, s.span))
+    Ok(respan_token_stream(stream, s.span()))
 }
 
 fn respan_token_stream(stream: TokenStream, span: Span) -> TokenStream {
-    stream.into_iter().map(|token| respan_token_tree(token, span)).collect()
+    stream
+        .into_iter()
+        .map(|token| respan_token_tree(token, span))
+        .collect()
 }
 
-fn respan_token_tree(token: TokenTree, span: Span) -> TokenTree {
+fn respan_token_tree(mut token: TokenTree, span: Span) -> TokenTree {
-    TokenTree {
+    if let TokenTree::Group(ref mut g) = token {
-        span: span,
+        *g = Group::new(g.delimiter(), respan_token_stream(g.stream().clone(), span));
-        kind: match token.kind {
-            TokenNode::Group(delimiter, nested) => {
-                TokenNode::Group(delimiter, respan_token_stream(nested, span))
-            }
-            other => other,
-        },
     }
+    token.set_span(span);
+    token
 }

serde_derive_internals/src/case.rs

@@ -113,14 +113,7 @@ impl FromStr for RenameRule {
 fn rename_variants() {
     for &(original, lower, upper, camel, snake, screaming, kebab, screaming_kebab) in &[
         (
-            "Outcome",
+            "Outcome", "outcome", "OUTCOME", "outcome", "outcome", "OUTCOME", "outcome", "OUTCOME",
-            "outcome",
-            "OUTCOME",
-            "outcome",
-            "outcome",
-            "OUTCOME",
-            "outcome",
-            "OUTCOME",
         ),
         (
             "VeryTasty",
@@ -154,13 +147,7 @@ fn rename_variants() {
 fn rename_fields() {
     for &(original, upper, pascal, camel, screaming, kebab, screaming_kebab) in &[
         (
-            "outcome",
+            "outcome", "OUTCOME", "Outcome", "outcome", "OUTCOME", "outcome", "OUTCOME",
-            "OUTCOME",
-            "Outcome",
-            "outcome",
-            "OUTCOME",
-            "outcome",
-            "OUTCOME",
         ),
         (
             "very_tasty",

serde_derive_internals/src/check.rs

@@ -6,8 +6,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use ast::{Data, Container, Style};
+use ast::{Container, Data, Style};
-use attr::{Identifier, EnumTag};
+use attr::{EnumTag, Identifier};
 use Ctxt;
 
 /// Cross-cutting checks that require looking at more than a single attrs
@@ -45,27 +45,38 @@ fn check_getter(cx: &Ctxt, cont: &Container) {
 fn check_flatten(cx: &Ctxt, cont: &Container) {
     match cont.data {
         Data::Enum(_) => {
-            assert!(!cont.attrs.has_flatten());
+            if cont.attrs.has_flatten() {
+                cx.error("#[serde(flatten)] cannot be used within enums");
+            }
         }
-        Data::Struct(_, _) => {
+        Data::Struct(style, _) => {
             for field in cont.data.all_fields() {
                 if !field.attrs.flatten() {
                     continue;
                 }
+                match style {
+                    Style::Tuple => {
+                        cx.error("#[serde(flatten)] cannot be used on tuple structs");
+                    }
+                    Style::Newtype => {
+                        cx.error("#[serde(flatten)] cannot be used on newtype structs");
+                    }
+                    _ => {}
+                }
                 if field.attrs.skip_serializing() {
                     cx.error(
                         "#[serde(flatten] can not be combined with \
-                         #[serde(skip_serializing)]"
+                         #[serde(skip_serializing)]",
                     );
                 } else if field.attrs.skip_serializing_if().is_some() {
                     cx.error(
                         "#[serde(flatten] can not be combined with \
-                         #[serde(skip_serializing_if = \"...\")]"
+                         #[serde(skip_serializing_if = \"...\")]",
                     );
                 } else if field.attrs.skip_deserializing() {
                     cx.error(
                         "#[serde(flatten] can not be combined with \
-                         #[serde(skip_deserializing)]"
+                         #[serde(skip_deserializing)]",
                     );
                 }
             }
@@ -209,10 +220,7 @@ fn check_variant_skip_attrs(cx: &Ctxt, cont: &Container) {
 /// the same as either one of its fields, as this would result in
 /// duplicate keys in the serialized output and/or ambiguity in
 /// the to-be-deserialized input.
-fn check_internal_tag_field_name_conflict(
+fn check_internal_tag_field_name_conflict(cx: &Ctxt, cont: &Container) {
-    cx: &Ctxt,
-    cont: &Container,
-) {
     let variants = match cont.data {
         Data::Enum(ref variants) => variants,
         Data::Struct(_, _) => return,
@@ -224,10 +232,7 @@ fn check_internal_tag_field_name_conflict(
     };
 
     let diagnose_conflict = || {
-        let message = format!(
+        let message = format!("variant field name `{}` conflicts with internal tag", tag);
-            "variant field name `{}` conflicts with internal tag",
-            tag
-        );
         cx.error(message);
     };
 
@@ -246,8 +251,8 @@ fn check_internal_tag_field_name_conflict(
                         return;
                     }
                 }
-            },
+            }
-            Style::Unit | Style::Newtype | Style::Tuple => {},
+            Style::Unit | Style::Newtype | Style::Tuple => {}
         }
     }
 }
@@ -256,7 +261,10 @@ fn check_internal_tag_field_name_conflict(
 /// contents tag must differ, for the same reason.
 fn check_adjacent_tag_conflict(cx: &Ctxt, cont: &Container) {
     let (type_tag, content_tag) = match *cont.attrs.tag() {
-        EnumTag::Adjacent { ref tag, ref content } => (tag, content),
+        EnumTag::Adjacent {
+            ref tag,
+            ref content,
+        } => (tag, content),
         EnumTag::Internal { .. } | EnumTag::External | EnumTag::None => return,
     };
 

serde_derive_internals/src/ctxt.rs

@@ -6,8 +6,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::fmt::Display;
 use std::cell::RefCell;
+use std::fmt::Display;
 use std::thread;
 
 #[derive(Default)]

serde_derive_internals/src/lib.rs

@@ -6,9 +6,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![doc(html_root_url = "https://docs.rs/serde_derive_internals/0.22.2")]
+#![doc(html_root_url = "https://docs.rs/serde_derive_internals/0.23.1")]
-#![cfg_attr(feature = "cargo-clippy", allow(cyclomatic_complexity, doc_markdown, match_same_arms,
+#![cfg_attr(
-                                            redundant_field_names))]
+    feature = "cargo-clippy",
+    allow(cyclomatic_complexity, doc_markdown, match_same_arms, redundant_field_names)
+)]
 
 #[macro_use]
 extern crate syn;

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "1.0.36" # remember to update html_root_url
+version = "1.0.41" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Token De/Serializer for testing De/Serialize implementations"

serde_test/src/de.rs

@@ -6,9 +6,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use serde::de::value::{MapAccessDeserializer, SeqAccessDeserializer};
 use serde::de::{self, Deserialize, DeserializeSeed, EnumAccess, IntoDeserializer, MapAccess,
                 SeqAccess, VariantAccess, Visitor};
-use serde::de::value::{MapAccessDeserializer, SeqAccessDeserializer};
 
 use error::Error;
 use token::Token;
@@ -22,28 +22,28 @@ macro_rules! assert_next_token {
     ($de:expr, $expected:expr) => {
         match $de.next_token_opt() {
             Some(token) if token == $expected => {}
-            Some(other) => {
+            Some(other) => panic!(
-                panic!("expected Token::{} but deserialization wants Token::{}",
+                "expected Token::{} but deserialization wants Token::{}",
-                       other, $expected)
+                other, $expected
-            }
+            ),
-            None => {
+            None => panic!(
-                panic!("end of tokens but deserialization wants Token::{}",
+                "end of tokens but deserialization wants Token::{}",
-                       $expected)
+                $expected
-            }
+            ),
         }
-    }
+    };
 }
 
 macro_rules! unexpected {
     ($token:expr) => {
         panic!("deserialization did not expect this token: {}", $token)
-    }
+    };
 }
 
 macro_rules! end_of_tokens {
     () => {
         panic!("ran out of tokens to deserialize")
-    }
+    };
 }
 
 impl<'de> Deserializer<'de> {

serde_test/src/lib.rs

@@ -155,29 +155,33 @@
 //! # }
 //! ```
 
-#![doc(html_root_url = "https://docs.rs/serde_test/1.0.36")]
+#![doc(html_root_url = "https://docs.rs/serde_test/1.0.41")]
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
 // Whitelisted clippy lints
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp))]
 // Whitelisted clippy_pedantic lints
-#![cfg_attr(feature = "cargo-clippy",
+#![cfg_attr(
-            allow(empty_line_after_outer_attr, missing_docs_in_private_items,
+    feature = "cargo-clippy",
-                  redundant_field_names, stutter, use_debug, use_self))]
+    allow(
+        empty_line_after_outer_attr, missing_docs_in_private_items, redundant_field_names, stutter,
+        use_debug, use_self
+    )
+)]
 
 #[macro_use]
 extern crate serde;
 
-mod ser;
 mod de;
 mod error;
+mod ser;
 
+mod assert;
 mod configure;
 mod token;
-mod assert;
 
-pub use token::Token;
 pub use assert::{assert_de_tokens, assert_de_tokens_error, assert_ser_tokens,
                  assert_ser_tokens_error, assert_tokens};
+pub use token::Token;
 
 pub use configure::{Compact, Configure, Readable};
 

serde_test/src/ser.rs

@@ -45,7 +45,7 @@ macro_rules! assert_next_token {
     ($ser:expr, $expected:ident($v:expr)) => {
         assert_next_token!(
             $ser,
-            format_args!("{}({:?})", stringify!($expected), $v),
+            format_args!(concat!(stringify!($expected), "({:?})"), $v),
             Token::$expected(v),
             v == $v
         );
@@ -56,13 +56,13 @@ macro_rules! assert_next_token {
             use std::fmt::Write;
             let mut buffer = String::new();
             $(
-                write!(&mut buffer, "{}: {:?}, ", stringify!($k), $k).unwrap();
+                write!(&mut buffer, concat!(stringify!($k), ": {:?}, "), $k).unwrap();
             )*
             buffer
         };
         assert_next_token!(
             $ser,
-            format_args!("{} {{ {}}}", stringify!($expected), field_format()),
+            format_args!(concat!(stringify!($expected), " {{ {}}}"), field_format()),
             Token::$expected { $($k),* },
             ($($k,)*) == compare
         );

test_suite/Cargo.toml

@@ -9,7 +9,7 @@ unstable = ["serde/unstable", "compiletest_rs"]
 
 [dev-dependencies]
 fnv = "1.0"
-proc-macro2 = "0.2"
+proc-macro2 = "0.3"
 rustc-serialize = "0.3.16"
 serde = { path = "../serde", features = ["rc"] }
 serde_derive = { path = "../serde_derive", features = ["deserialize_in_place"] }

test_suite/no_std/src/main.rs

@@ -6,11 +6,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(lang_items, start, compiler_builtins_lib)]
+#![feature(lang_items, start)]
 #![no_std]
 
 extern crate libc;
-extern crate compiler_builtins;
 
 #[start]
 fn start(_argc: isize, _argv: *const *const u8) -> isize {
@@ -19,19 +18,17 @@ fn start(_argc: isize, _argv: *const *const u8) -> isize {
 
 #[lang = "eh_personality"]
 #[no_mangle]
-pub extern fn rust_eh_personality() {}
+pub extern "C" fn rust_eh_personality() {}
-
-#[lang = "eh_unwind_resume"]
-#[no_mangle]
-pub extern fn rust_eh_unwind_resume() {}
 
 #[lang = "panic_fmt"]
 #[no_mangle]
-pub extern fn rust_begin_panic(_msg: core::fmt::Arguments,
+pub extern "C" fn rust_begin_panic(
-                               _file: &'static str,
+    _msg: core::fmt::Arguments,
-                               _line: u32) -> ! {
+    _file: &'static str,
+    _line: u32,
+) -> ! {
     unsafe {
-        libc::abort()
+        libc::abort();
     }
 }
 
@@ -50,7 +47,9 @@ struct Newtype(u8);
 struct Tuple(u8, u8);
 
 #[derive(Serialize, Deserialize)]
-struct Struct { f: u8 }
+struct Struct {
+    f: u8,
+}
 
 #[derive(Serialize, Deserialize)]
 enum Enum {

test_suite/tests/bytes/mod.rs

@@ -0,0 +1,52 @@
+use serde::de::{Deserializer, Visitor, SeqAccess, Error};
+use std::fmt;
+
+pub fn deserialize<'de, D>(deserializer: D) -> Result<Vec<u8>, D::Error>
+    where D: Deserializer<'de>
+{
+    deserializer.deserialize_byte_buf(ByteBufVisitor)
+}
+
+struct ByteBufVisitor;
+
+impl<'de> Visitor<'de> for ByteBufVisitor {
+    type Value = Vec<u8>;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("byte array")
+    }
+
+    fn visit_seq<V>(self, mut visitor: V) -> Result<Self::Value, V::Error>
+        where V: SeqAccess<'de>
+    {
+        let mut values = Vec::new();
+        while let Some(value) = try!(visitor.next_element()) {
+            values.push(value);
+        }
+        Ok(values)
+    }
+
+    fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
+        where E: Error
+    {
+        Ok(v.to_vec())
+    }
+
+    fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
+        where E: Error
+    {
+        Ok(v)
+    }
+
+    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+        where E: Error
+    {
+        Ok(v.as_bytes().to_vec())
+    }
+
+    fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
+        where E: Error
+    {
+        Ok(v.into_bytes())
+    }
+}

test_suite/tests/compile-fail/conflict/flatten-newtype-struct.rs

@@ -0,0 +1,16 @@
+// Copyright 2018 Serde Developers
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[macro_use]
+extern crate serde_derive;
+
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
+//~^ HELP: #[serde(flatten)] cannot be used on newtype structs
+struct Foo(#[serde(flatten)] HashMap<String, String>);
+
+fn main() {}

test_suite/tests/compile-fail/conflict/flatten-tuple-struct.rs

@@ -0,0 +1,16 @@
+// Copyright 2018 Serde Developers
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[macro_use]
+extern crate serde_derive;
+
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
+//~^ HELP: #[serde(flatten)] cannot be used on tuple structs
+struct Foo(u32, #[serde(flatten)] HashMap<String, String>);
+
+fn main() {}

test_suite/tests/compile-fail/conflict/flatten-within-enum.rs

@@ -0,0 +1,21 @@
+// Copyright 2018 Serde Developers
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[macro_use]
+extern crate serde_derive;
+
+#[derive(Serialize)] //~ ERROR: proc-macro derive panicked
+//~^ HELP: #[serde(flatten)] cannot be used within enums
+enum Foo {
+    A {
+        #[serde(flatten)]
+        fields: HashMap<String, String>,
+    }
+}
+
+fn main() {}

test_suite/tests/test_gen.rs

@@ -391,9 +391,6 @@ fn test_gen() {
 
     #[derive(Serialize, Deserialize)]
     enum ExternallyTaggedVariantWith {
-        #[allow(dead_code)]
-        Normal { f1: String },
-
         #[serde(serialize_with = "ser_x")]
         #[serde(deserialize_with = "de_x")]
         #[allow(dead_code)]
@@ -404,6 +401,11 @@ fn test_gen() {
         #[allow(dead_code)]
         Tuple(String, u8),
 
+        #[serde(serialize_with = "ser_x")]
+        #[serde(deserialize_with = "de_x")]
+        #[allow(dead_code)]
+        Struct1 { x: X },
+
         #[serde(serialize_with = "serialize_some_other_variant")]
         #[serde(deserialize_with = "deserialize_some_other_variant")]
         #[allow(dead_code)]
@@ -419,14 +421,16 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     #[serde(tag = "t")]
     enum InternallyTaggedVariantWith {
-        #[allow(dead_code)]
-        Normal { f1: String },
-
         #[serde(serialize_with = "ser_x")]
         #[serde(deserialize_with = "de_x")]
         #[allow(dead_code)]
         Newtype(X),
 
+        #[serde(serialize_with = "ser_x")]
+        #[serde(deserialize_with = "de_x")]
+        #[allow(dead_code)]
+        Struct1 { x: X },
+
         #[serde(serialize_with = "serialize_some_other_variant")]
         #[serde(deserialize_with = "deserialize_some_other_variant")]
         #[allow(dead_code)]
@@ -442,9 +446,6 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     #[serde(tag = "t", content = "c")]
     enum AdjacentlyTaggedVariantWith {
-        #[allow(dead_code)]
-        Normal { f1: String },
-
         #[serde(serialize_with = "ser_x")]
         #[serde(deserialize_with = "de_x")]
         #[allow(dead_code)]
@@ -455,6 +456,11 @@ fn test_gen() {
         #[allow(dead_code)]
         Tuple(String, u8),
 
+        #[serde(serialize_with = "ser_x")]
+        #[serde(deserialize_with = "de_x")]
+        #[allow(dead_code)]
+        Struct1 { x: X },
+
         #[serde(serialize_with = "serialize_some_other_variant")]
         #[serde(deserialize_with = "deserialize_some_other_variant")]
         #[allow(dead_code)]
@@ -470,9 +476,6 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     #[serde(untagged)]
     enum UntaggedVariantWith {
-        #[allow(dead_code)]
-        Normal { f1: String },
-
         #[serde(serialize_with = "ser_x")]
         #[serde(deserialize_with = "de_x")]
         #[allow(dead_code)]
@@ -483,6 +486,11 @@ fn test_gen() {
         #[allow(dead_code)]
         Tuple(String, u8),
 
+        #[serde(serialize_with = "ser_x")]
+        #[serde(deserialize_with = "de_x")]
+        #[allow(dead_code)]
+        Struct1 { x: X },
+
         #[serde(serialize_with = "serialize_some_other_variant")]
         #[serde(deserialize_with = "deserialize_some_other_variant")]
         #[allow(dead_code)]
@@ -539,6 +547,30 @@ fn test_gen() {
         array: [u8; 256],
     }
     assert_ser::<BigArray>();
+
+    trait AssocSerde {
+        type Assoc;
+    }
+
+    struct NoSerdeImpl;
+    impl AssocSerde for NoSerdeImpl {
+        type Assoc = u32;
+    }
+
+    #[derive(Serialize, Deserialize)]
+    struct AssocDerive<T: AssocSerde> {
+        assoc: T::Assoc
+    }
+
+    assert::<AssocDerive<NoSerdeImpl>>();
+
+    #[derive(Serialize, Deserialize)]
+    struct AssocDeriveMulti<S, T: AssocSerde> {
+        s: S,
+        assoc: T::Assoc,
+    }
+
+    assert::<AssocDeriveMulti<i32, NoSerdeImpl>>();
 }
 
 //////////////////////////////////////////////////////////////////////////

test_suite/tests/test_macros.rs

@@ -13,7 +13,11 @@
 #[macro_use]
 extern crate serde_derive;
 
+extern crate serde;
 extern crate serde_test;
+
+mod bytes;
+
 use self::serde_test::{assert_de_tokens, assert_de_tokens_error, assert_ser_tokens, assert_tokens,
                        Token};
 
@@ -779,6 +783,158 @@ fn test_internally_tagged_enum() {
     );
 }
 
+#[test]
+fn test_internally_tagged_bytes() {
+    #[derive(Debug, PartialEq, Deserialize)]
+    #[serde(tag = "type")]
+    enum InternallyTagged {
+        String {
+            string: String,
+        },
+        Bytes {
+            #[serde(with = "bytes")]
+            bytes: Vec<u8>,
+        },
+    }
+
+    assert_de_tokens(
+        &InternallyTagged::String { string: "\0".to_owned() },
+        &[
+            Token::Struct {
+                name: "String",
+                len: 2,
+            },
+            Token::Str("type"),
+            Token::Str("String"),
+            Token::Str("string"),
+            Token::Str("\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &InternallyTagged::String { string: "\0".to_owned() },
+        &[
+            Token::Struct {
+                name: "String",
+                len: 2,
+            },
+            Token::Str("type"),
+            Token::Str("String"),
+            Token::Str("string"),
+            Token::String("\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &InternallyTagged::String { string: "\0".to_owned() },
+        &[
+            Token::Struct {
+                name: "String",
+                len: 2,
+            },
+            Token::Str("type"),
+            Token::Str("String"),
+            Token::Str("string"),
+            Token::Bytes(b"\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &InternallyTagged::String { string: "\0".to_owned() },
+        &[
+            Token::Struct {
+                name: "String",
+                len: 2,
+            },
+            Token::Str("type"),
+            Token::Str("String"),
+            Token::Str("string"),
+            Token::ByteBuf(b"\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &InternallyTagged::Bytes { bytes: vec![0] },
+        &[
+            Token::Struct {
+                name: "Bytes",
+                len: 2,
+            },
+            Token::Str("type"),
+            Token::Str("Bytes"),
+            Token::Str("bytes"),
+            Token::Str("\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &InternallyTagged::Bytes { bytes: vec![0] },
+        &[
+            Token::Struct {
+                name: "Bytes",
+                len: 2,
+            },
+            Token::Str("type"),
+            Token::Str("Bytes"),
+            Token::Str("bytes"),
+            Token::String("\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &InternallyTagged::Bytes { bytes: vec![0] },
+        &[
+            Token::Struct {
+                name: "Bytes",
+                len: 2,
+            },
+            Token::Str("type"),
+            Token::Str("Bytes"),
+            Token::Str("bytes"),
+            Token::Bytes(b"\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &InternallyTagged::Bytes { bytes: vec![0] },
+        &[
+            Token::Struct {
+                name: "Bytes",
+                len: 2,
+            },
+            Token::Str("type"),
+            Token::Str("Bytes"),
+            Token::Str("bytes"),
+            Token::ByteBuf(b"\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &InternallyTagged::Bytes { bytes: vec![0] },
+        &[
+            Token::Struct {
+                name: "Bytes",
+                len: 2,
+            },
+            Token::Str("type"),
+            Token::Str("Bytes"),
+            Token::Str("bytes"),
+            Token::Seq { len: Some(1) },
+            Token::U8(0),
+            Token::SeqEnd,
+            Token::StructEnd,
+        ],
+    );
+}
+
 #[test]
 fn test_internally_tagged_struct_variant_containing_unit_variant() {
     #[derive(Debug, PartialEq, Serialize, Deserialize)]
@@ -1246,6 +1402,140 @@ fn test_enum_in_untagged_enum() {
     );
 }
 
+#[test]
+fn test_untagged_bytes() {
+    #[derive(Debug, PartialEq, Deserialize)]
+    #[serde(untagged)]
+    enum Untagged {
+        String {
+            string: String,
+        },
+        Bytes {
+            #[serde(with = "bytes")]
+            bytes: Vec<u8>,
+        },
+    }
+
+    assert_de_tokens(
+        &Untagged::String { string: "\0".to_owned() },
+        &[
+            Token::Struct {
+                name: "Untagged",
+                len: 1,
+            },
+            Token::Str("string"),
+            Token::Str("\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Untagged::String { string: "\0".to_owned() },
+        &[
+            Token::Struct {
+                name: "Untagged",
+                len: 1,
+            },
+            Token::Str("string"),
+            Token::String("\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Untagged::String { string: "\0".to_owned() },
+        &[
+            Token::Struct {
+                name: "Untagged",
+                len: 1,
+            },
+            Token::Str("string"),
+            Token::Bytes(b"\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Untagged::String { string: "\0".to_owned() },
+        &[
+            Token::Struct {
+                name: "Untagged",
+                len: 1,
+            },
+            Token::Str("string"),
+            Token::ByteBuf(b"\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Untagged::Bytes { bytes: vec![0] },
+        &[
+            Token::Struct {
+                name: "Untagged",
+                len: 1,
+            },
+            Token::Str("bytes"),
+            Token::Str("\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Untagged::Bytes { bytes: vec![0] },
+        &[
+            Token::Struct {
+                name: "Untagged",
+                len: 1,
+            },
+            Token::Str("bytes"),
+            Token::String("\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Untagged::Bytes { bytes: vec![0] },
+        &[
+            Token::Struct {
+                name: "Untagged",
+                len: 1,
+            },
+            Token::Str("bytes"),
+            Token::Bytes(b"\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Untagged::Bytes { bytes: vec![0] },
+        &[
+            Token::Struct {
+                name: "Untagged",
+                len: 1,
+            },
+            Token::Str("bytes"),
+            Token::ByteBuf(b"\0"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Untagged::Bytes { bytes: vec![0] },
+        &[
+            Token::Struct {
+                name: "Untagged",
+                len: 1,
+            },
+            Token::Str("bytes"),
+            Token::Seq { len: Some(1) },
+            Token::U8(0),
+            Token::SeqEnd,
+            Token::StructEnd,
+        ],
+    );
+}
+
 #[test]
 fn test_rename_all() {
     #[derive(Serialize, Deserialize, Debug, PartialEq)]