Release 1.0.35

impl Serialize and Deserialize for std::num::NonZero*

appveyor.yml

@@ -5,7 +5,7 @@ environment:
 
 install:
   # Install rust, x86_64-pc-windows-msvc host
-  - appveyor DownloadFile https://win.rustup.rs/ -FileName rustup-init.exe
+  - curl -sSf -o rustup-init.exe https://win.rustup.rs/
   - rustup-init.exe -y --default-host x86_64-pc-windows-msvc --default-toolchain %APPVEYOR_RUST_CHANNEL%
   - set PATH=C:\msys64\usr\bin;%PATH%;C:\Users\appveyor\.cargo\bin
   - rustc -vV

rustfmt.toml

@@ -1,5 +1,2 @@
-fn_args_layout = "Block"
-array_layout = "Block"
-where_style = "Rfc"
-generics_indent = "Block"
-fn_call_style = "Block"
+error_on_line_overflow = false
+same_line_attributes = false

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.23" # remember to update html_root_url
+version = "1.0.35" # 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

@@ -10,7 +10,7 @@ use lib::*;
 
 macro_rules! int_to_int {
     ($dst:ident, $n:ident) => (
-        if $dst::MIN as i64 <= $n as i64 && $n as i64 <= $dst::MAX as i64 {
+        if $dst::min_value() as i64 <= $n as i64 && $n as i64 <= $dst::max_value() as i64 {
             Some($n as $dst)
         } else {
             None
@@ -20,7 +20,7 @@ macro_rules! int_to_int {
 
 macro_rules! int_to_uint {
     ($dst:ident, $n:ident) => (
-        if 0 <= $n && $n as u64 <= $dst::MAX as u64 {
+        if 0 <= $n && $n as u64 <= $dst::max_value() as u64 {
             Some($n as $dst)
         } else {
             None
@@ -30,7 +30,7 @@ macro_rules! int_to_uint {
 
 macro_rules! uint_to {
     ($dst:ident, $n:ident) => (
-        if $n as u64 <= $dst::MAX as u64 {
+        if $n as u64 <= $dst::max_value() as u64 {
             Some($n as $dst)
         } else {
             None

serde/src/de/ignored_any.rs

@@ -8,7 +8,7 @@
 
 use lib::*;
 
-use de::{Deserialize, Deserializer, Visitor, SeqAccess, MapAccess, Error};
+use de::{Deserialize, Deserializer, Error, MapAccess, SeqAccess, Visitor};
 
 /// An efficient way of discarding data from a deserializer.
 ///

serde/src/de/impls.rs

@@ -15,6 +15,7 @@ use de::{Deserialize, Deserializer, EnumAccess, Error, SeqAccess, Unexpected, Va
 use de::MapAccess;
 
 use de::from_primitive::FromPrimitive;
+use private::de::InPlaceSeed;
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 use private::de::size_hint;
@@ -210,6 +211,8 @@ impl<'de> Deserialize<'de> for char {
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 struct StringVisitor;
+#[cfg(any(feature = "std", feature = "alloc"))]
+struct StringInPlaceVisitor<'a>(&'a mut String);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 impl<'de> Visitor<'de> for StringVisitor {
@@ -249,7 +252,66 @@ impl<'de> Visitor<'de> for StringVisitor {
     {
         match String::from_utf8(v) {
             Ok(s) => Ok(s),
-            Err(e) => Err(Error::invalid_value(Unexpected::Bytes(&e.into_bytes()), &self),),
+            Err(e) => Err(Error::invalid_value(
+                Unexpected::Bytes(&e.into_bytes()),
+                &self,
+            )),
+        }
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, 'de> Visitor<'de> for StringInPlaceVisitor<'a> {
+    type Value = ();
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("a string")
+    }
+
+    fn visit_str<E>(self, v: &str) -> Result<(), E>
+    where
+        E: Error,
+    {
+        self.0.clear();
+        self.0.push_str(v);
+        Ok(())
+    }
+
+    fn visit_string<E>(self, v: String) -> Result<(), E>
+    where
+        E: Error,
+    {
+        *self.0 = v;
+        Ok(())
+    }
+
+    fn visit_bytes<E>(self, v: &[u8]) -> Result<(), E>
+    where
+        E: Error,
+    {
+        match str::from_utf8(v) {
+            Ok(s) => {
+                self.0.clear();
+                self.0.push_str(s);
+                Ok(())
+            }
+            Err(_) => Err(Error::invalid_value(Unexpected::Bytes(v), &self)),
+        }
+    }
+
+    fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<(), E>
+    where
+        E: Error,
+    {
+        match String::from_utf8(v) {
+            Ok(s) => {
+                *self.0 = s;
+                Ok(())
+            }
+            Err(e) => Err(Error::invalid_value(
+                Unexpected::Bytes(&e.into_bytes()),
+                &self,
+            )),
         }
     }
 }
@@ -262,6 +324,13 @@ impl<'de> Deserialize<'de> for String {
     {
         deserializer.deserialize_string(StringVisitor)
     }
+
+    fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        deserializer.deserialize_string(StringInPlaceVisitor(place))
+    }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -465,17 +534,25 @@ where
     where
         D: Deserializer<'de>,
     {
-        deserializer.deserialize_option(OptionVisitor { marker: PhantomData })
+        deserializer.deserialize_option(OptionVisitor {
+            marker: PhantomData,
+        })
     }
+
+    // The Some variant's repr is opaque, so we can't play cute tricks with its
+    // tag to have deserialize_in_place build the content in place unconditionally.
+    //
+    // FIXME: investigate whether branching on the old value being Some to
+    // deserialize_in_place the value is profitable (probably data-dependent?)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
-struct PhantomDataVisitor<T> {
+struct PhantomDataVisitor<T: ?Sized> {
     marker: PhantomData<T>,
 }
 
-impl<'de, T> Visitor<'de> for PhantomDataVisitor<T> {
+impl<'de, T: ?Sized> Visitor<'de> for PhantomDataVisitor<T> {
     type Value = PhantomData<T>;
 
     fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
@@ -491,12 +568,14 @@ impl<'de, T> Visitor<'de> for PhantomDataVisitor<T> {
     }
 }
 
-impl<'de, T> Deserialize<'de> for PhantomData<T> {
+impl<'de, T: ?Sized> Deserialize<'de> for PhantomData<T> {
     fn deserialize<D>(deserializer: D) -> Result<PhantomData<T>, D::Error>
     where
         D: Deserializer<'de>,
     {
-        let visitor = PhantomDataVisitor { marker: PhantomData };
+        let visitor = PhantomDataVisitor {
+            marker: PhantomData,
+        };
         deserializer.deserialize_unit_struct("PhantomData", visitor)
     }
 }
@@ -509,7 +588,9 @@ macro_rules! seq_impl {
         $ty:ident < T $(: $tbound1:ident $(+ $tbound2:ident)*)* $(, $typaram:ident : $bound1:ident $(+ $bound2:ident)*)* >,
         $access:ident,
         $ctor:expr,
+        $clear:expr,
         $with_capacity:expr,
+        $reserve:expr,
         $insert:expr
     ) => {
         impl<'de, T $(, $typaram)*> Deserialize<'de> for $ty<T $(, $typaram)*>
@@ -554,16 +635,59 @@ macro_rules! seq_impl {
                 let visitor = SeqVisitor { marker: PhantomData };
                 deserializer.deserialize_seq(visitor)
             }
+
+            fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error>
+            where
+                D: Deserializer<'de>,
+            {
+                struct SeqInPlaceVisitor<'a, T: 'a $(, $typaram: 'a)*>(&'a mut $ty<T $(, $typaram)*>);
+
+                impl<'a, 'de, T $(, $typaram)*> Visitor<'de> for SeqInPlaceVisitor<'a, T $(, $typaram)*>
+                where
+                    T: Deserialize<'de> $(+ $tbound1 $(+ $tbound2)*)*,
+                    $($typaram: $bound1 $(+ $bound2)*,)*
+                {
+                    type Value = ();
+
+                    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                        formatter.write_str("a sequence")
+                    }
+
+                    #[inline]
+                    fn visit_seq<A>(mut self, mut $access: A) -> Result<(), A::Error>
+                    where
+                        A: SeqAccess<'de>,
+                    {
+                        $clear(&mut self.0);
+                        $reserve(&mut self.0, size_hint::cautious($access.size_hint()));
+
+                        // FIXME: try to overwrite old values here? (Vec, VecDeque, LinkedList)
+                        while let Some(value) = try!($access.next_element()) {
+                            $insert(&mut self.0, value);
+                        }
+
+                        Ok(())
+                    }
+                }
+
+                deserializer.deserialize_seq(SeqInPlaceVisitor(place))
+            }
         }
     }
 }
 
+// Dummy impl of reserve
+#[cfg(any(feature = "std", feature = "alloc"))]
+fn nop_reserve<T>(_seq: T, _n: usize) {}
+
 #[cfg(any(feature = "std", feature = "alloc"))]
 seq_impl!(
     BinaryHeap<T: Ord>,
     seq,
     BinaryHeap::new(),
+    BinaryHeap::clear,
     BinaryHeap::with_capacity(size_hint::cautious(seq.size_hint())),
+    BinaryHeap::reserve,
     BinaryHeap::push);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
@@ -571,7 +695,9 @@ seq_impl!(
     BTreeSet<T: Eq + Ord>,
     seq,
     BTreeSet::new(),
+    BTreeSet::clear,
     BTreeSet::new(),
+    nop_reserve,
     BTreeSet::insert);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
@@ -579,15 +705,20 @@ seq_impl!(
     LinkedList<T>,
     seq,
     LinkedList::new(),
+    LinkedList::clear,
     LinkedList::new(),
-    LinkedList::push_back);
+    nop_reserve,
+    LinkedList::push_back
+);
 
 #[cfg(feature = "std")]
 seq_impl!(
     HashSet<T: Eq + Hash, S: BuildHasher + Default>,
     seq,
     HashSet::with_hasher(S::default()),
+    HashSet::clear,
     HashSet::with_capacity_and_hasher(size_hint::cautious(seq.size_hint()), S::default()),
+    HashSet::reserve,
     HashSet::insert);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
@@ -595,26 +726,35 @@ seq_impl!(
     Vec<T>,
     seq,
     Vec::new(),
+    Vec::clear,
     Vec::with_capacity(size_hint::cautious(seq.size_hint())),
-    Vec::push);
+    Vec::reserve,
+    Vec::push
+);
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 seq_impl!(
     VecDeque<T>,
     seq,
     VecDeque::new(),
+    VecDeque::clear,
     VecDeque::with_capacity(size_hint::cautious(seq.size_hint())),
-    VecDeque::push_back);
+    VecDeque::reserve,
+    VecDeque::push_back
+);
 
 ////////////////////////////////////////////////////////////////////////////////
 
 struct ArrayVisitor<A> {
     marker: PhantomData<A>,
 }
+struct ArrayInPlaceVisitor<'a, A: 'a>(&'a mut A);
 
 impl<A> ArrayVisitor<A> {
     fn new() -> Self {
-        ArrayVisitor { marker: PhantomData }
+        ArrayVisitor {
+            marker: PhantomData,
+        }
     }
 }
 
@@ -673,6 +813,35 @@ macro_rules! array_impls {
                 }
             }
 
+            impl<'a, 'de, T> Visitor<'de> for ArrayInPlaceVisitor<'a, [T; $len]>
+            where
+                T: Deserialize<'de>,
+            {
+                type Value = ();
+
+                fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                    formatter.write_str(concat!("an array of length ", $len))
+                }
+
+                #[inline]
+                fn visit_seq<A>(self, mut seq: A) -> Result<(), A::Error>
+                where
+                    A: SeqAccess<'de>,
+                {
+                    let mut fail_idx = None;
+                    for (idx, dest) in self.0[..].iter_mut().enumerate() {
+                        if try!(seq.next_element_seed(InPlaceSeed(dest))).is_none() {
+                            fail_idx = Some(idx);
+                            break;
+                        }
+                    }
+                    if let Some(idx) = fail_idx {
+                        return Err(Error::invalid_length(idx, &self));
+                    }
+                    Ok(())
+                }
+            }
+
             impl<'de, T> Deserialize<'de> for [T; $len]
             where
                 T: Deserialize<'de>,
@@ -683,6 +852,13 @@ macro_rules! array_impls {
                 {
                     deserializer.deserialize_tuple($len, ArrayVisitor::<[T; $len]>::new())
                 }
+
+                fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error>
+                where
+                    D: Deserializer<'de>,
+                {
+                    deserializer.deserialize_tuple($len, ArrayInPlaceVisitor(place))
+                }
             }
         )+
     }
@@ -726,49 +902,76 @@ array_impls! {
 ////////////////////////////////////////////////////////////////////////////////
 
 macro_rules! tuple_impls {
-    ($($len:tt $visitor:ident => ($($n:tt $name:ident)+))+) => {
+    ($($len:tt => ($($n:tt $name:ident)+))+) => {
         $(
-            struct $visitor<$($name,)+> {
-                marker: PhantomData<($($name,)+)>,
-            }
-
-            impl<$($name,)+> $visitor<$($name,)+> {
-                fn new() -> Self {
-                    $visitor { marker: PhantomData }
-                }
-            }
-
-            impl<'de, $($name: Deserialize<'de>),+> Visitor<'de> for $visitor<$($name,)+> {
-                type Value = ($($name,)+);
-
-                fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                    formatter.write_str(concat!("a tuple of size ", $len))
-                }
-
-                #[inline]
-                #[allow(non_snake_case)]
-                fn visit_seq<A>(self, mut seq: A) -> Result<($($name,)+), A::Error>
-                where
-                    A: SeqAccess<'de>,
-                {
-                    $(
-                        let $name = match try!(seq.next_element()) {
-                            Some(value) => value,
-                            None => return Err(Error::invalid_length($n, &self)),
-                        };
-                    )+
-
-                    Ok(($($name,)+))
-                }
-            }
-
             impl<'de, $($name: Deserialize<'de>),+> Deserialize<'de> for ($($name,)+) {
                 #[inline]
                 fn deserialize<D>(deserializer: D) -> Result<($($name,)+), D::Error>
                 where
                     D: Deserializer<'de>,
                 {
-                    deserializer.deserialize_tuple($len, $visitor::new())
+                    struct TupleVisitor<$($name,)+> {
+                        marker: PhantomData<($($name,)+)>,
+                    }
+
+                    impl<'de, $($name: Deserialize<'de>),+> Visitor<'de> for TupleVisitor<$($name,)+> {
+                        type Value = ($($name,)+);
+
+                        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str(concat!("a tuple of size ", $len))
+                        }
+
+                        #[inline]
+                        #[allow(non_snake_case)]
+                        fn visit_seq<A>(self, mut seq: A) -> Result<($($name,)+), A::Error>
+                        where
+                            A: SeqAccess<'de>,
+                        {
+                            $(
+                                let $name = match try!(seq.next_element()) {
+                                    Some(value) => value,
+                                    None => return Err(Error::invalid_length($n, &self)),
+                                };
+                            )+
+
+                            Ok(($($name,)+))
+                        }
+                    }
+
+                    deserializer.deserialize_tuple($len, TupleVisitor { marker: PhantomData })
+                }
+
+                #[inline]
+                fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error>
+                where
+                    D: Deserializer<'de>,
+                {
+                    struct TupleInPlaceVisitor<'a, $($name: 'a,)+>(&'a mut ($($name,)+));
+
+                    impl<'a, 'de, $($name: Deserialize<'de>),+> Visitor<'de> for TupleInPlaceVisitor<'a, $($name,)+> {
+                        type Value = ();
+
+                        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                            formatter.write_str(concat!("a tuple of size ", $len))
+                        }
+
+                        #[inline]
+                        #[allow(non_snake_case)]
+                        fn visit_seq<A>(self, mut seq:                                                                      A) -> Result<(), A::Error>
+                        where
+                            A: SeqAccess<'de>,
+                        {
+                            $(
+                                if try!(seq.next_element_seed(InPlaceSeed(&mut (self.0).$n))).is_none() {
+                                    return Err(Error::invalid_length($n, &self));
+                                }
+                            )+
+
+                            Ok(())
+                        }
+                    }
+
+                    deserializer.deserialize_tuple($len, TupleInPlaceVisitor(place))
                 }
             }
         )+
@@ -776,22 +979,22 @@ macro_rules! tuple_impls {
 }
 
 tuple_impls! {
-    1 TupleVisitor1 => (0 T0)
-    2 TupleVisitor2 => (0 T0 1 T1)
-    3 TupleVisitor3 => (0 T0 1 T1 2 T2)
-    4 TupleVisitor4 => (0 T0 1 T1 2 T2 3 T3)
-    5 TupleVisitor5 => (0 T0 1 T1 2 T2 3 T3 4 T4)
-    6 TupleVisitor6 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5)
-    7 TupleVisitor7 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6)
-    8 TupleVisitor8 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7)
-    9 TupleVisitor9 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8)
-    10 TupleVisitor10 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9)
-    11 TupleVisitor11 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10)
-    12 TupleVisitor12 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11)
-    13 TupleVisitor13 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12)
-    14 TupleVisitor14 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13)
-    15 TupleVisitor15 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13 14 T14)
-    16 TupleVisitor16 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13 14 T14 15 T15)
+    1  => (0 T0)
+    2  => (0 T0 1 T1)
+    3  => (0 T0 1 T1 2 T2)
+    4  => (0 T0 1 T1 2 T2 3 T3)
+    5  => (0 T0 1 T1 2 T2 3 T3 4 T4)
+    6  => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5)
+    7  => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6)
+    8  => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7)
+    9  => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8)
+    10 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9)
+    11 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10)
+    12 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11)
+    13 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12)
+    14 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13)
+    15 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13 14 T14)
+    16 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13 14 T14 15 T15)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1068,7 +1271,12 @@ impl<'de> Deserialize<'de> for net::SocketAddr {
 parse_socket_impl!(net::SocketAddrV4, net::SocketAddrV4::new);
 
 #[cfg(feature = "std")]
-parse_socket_impl!(net::SocketAddrV6, |ip, port| net::SocketAddrV6::new(ip, port, 0, 0));
+parse_socket_impl!(net::SocketAddrV6, |ip, port| net::SocketAddrV6::new(
+    ip,
+    port,
+    0,
+    0
+));
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -1179,7 +1387,9 @@ impl<'de> Visitor<'de> for OsStringVisitor {
 
         match try!(data.variant()) {
             (OsStringKind::Unix, v) => v.newtype_variant().map(OsString::from_vec),
-            (OsStringKind::Windows, _) => Err(Error::custom("cannot deserialize Windows OS string on Unix",),),
+            (OsStringKind::Windows, _) => Err(Error::custom(
+                "cannot deserialize Windows OS string on Unix",
+            )),
         }
     }
 
@@ -1191,11 +1401,11 @@ impl<'de> Visitor<'de> for OsStringVisitor {
         use std::os::windows::ffi::OsStringExt;
 
         match try!(data.variant()) {
-            (OsStringKind::Windows, v) => {
-                v.newtype_variant::<Vec<u16>>()
-                    .map(|vec| OsString::from_wide(&vec))
-            }
-            (OsStringKind::Unix, _) => Err(Error::custom("cannot deserialize Unix OS string on Windows",),),
+            (OsStringKind::Windows, v) => v.newtype_variant::<Vec<u16>>()
+                .map(|vec| OsString::from_wide(&vec)),
+            (OsStringKind::Unix, _) => Err(Error::custom(
+                "cannot deserialize Unix OS string on Windows",
+            )),
         }
     }
 }
@@ -1521,13 +1731,17 @@ impl<'de> Deserialize<'de> for SystemTime {
                     match key {
                         Field::Secs => {
                             if secs.is_some() {
-                                return Err(<A::Error as Error>::duplicate_field("secs_since_epoch"));
+                                return Err(<A::Error as Error>::duplicate_field(
+                                    "secs_since_epoch",
+                                ));
                             }
                             secs = Some(try!(map.next_value()));
                         }
                         Field::Nanos => {
                             if nanos.is_some() {
-                                return Err(<A::Error as Error>::duplicate_field("nanos_since_epoch"));
+                                return Err(<A::Error as Error>::duplicate_field(
+                                    "nanos_since_epoch",
+                                ));
                             }
                             nanos = Some(try!(map.next_value()));
                         }
@@ -1691,13 +1905,20 @@ where
         }
 
         const FIELDS: &'static [&'static str] = &["start", "end"];
-        deserializer.deserialize_struct("Range", FIELDS, RangeVisitor { phantom: PhantomData })
+        deserializer.deserialize_struct(
+            "Range",
+            FIELDS,
+            RangeVisitor {
+                phantom: PhantomData,
+            },
+        )
     }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(feature = "unstable")]
+#[allow(deprecated)]
 impl<'de, T> Deserialize<'de> for NonZero<T>
 where
     T: Deserialize<'de> + Zeroable,
@@ -1714,6 +1935,36 @@ where
     }
 }
 
+macro_rules! nonzero_integers {
+    ( $( $T: ty, )+ ) => {
+        $(
+            #[cfg(feature = "unstable")]
+            impl<'de> Deserialize<'de> for $T {
+                fn deserialize<D>(deserializer: D) -> Result<$T, D::Error>
+                where
+                    D: Deserializer<'de>,
+                {
+                    let value = try!(Deserialize::deserialize(deserializer));
+                    match <$T>::new(value) {
+                        Some(nonzero) => Ok(nonzero),
+                        None => Err(Error::custom("expected a non-zero value")),
+                    }
+                }
+            }
+        )+
+    };
+}
+
+nonzero_integers! {
+    // Not including signed NonZeroI* since they might be removed
+    NonZeroU8,
+    NonZeroU16,
+    NonZeroU32,
+    NonZeroU64,
+    // FIXME: https://github.com/serde-rs/serde/issues/1136 NonZeroU128,
+    NonZeroUsize,
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 impl<'de, T, E> Deserialize<'de> for Result<T, E>
@@ -1756,9 +2007,10 @@ where
                         match value {
                             0 => Ok(Field::Ok),
                             1 => Ok(Field::Err),
-                            _ => {
-                                Err(Error::invalid_value(Unexpected::Unsigned(value as u64), &self),)
-                            }
+                            _ => Err(Error::invalid_value(
+                                Unexpected::Unsigned(value as u64),
+                                &self,
+                            )),
                         }
                     }
 
@@ -1780,14 +2032,12 @@ where
                         match value {
                             b"Ok" => Ok(Field::Ok),
                             b"Err" => Ok(Field::Err),
-                            _ => {
-                                match str::from_utf8(value) {
-                                    Ok(value) => Err(Error::unknown_variant(value, VARIANTS)),
-                                    Err(_) => {
-                                        Err(Error::invalid_value(Unexpected::Bytes(value), &self))
-                                    }
+                            _ => match str::from_utf8(value) {
+                                Ok(value) => Err(Error::unknown_variant(value, VARIANTS)),
+                                Err(_) => {
+                                    Err(Error::invalid_value(Unexpected::Bytes(value), &self))
                                 }
-                            }
+                            },
                         }
                     }
                 }
@@ -1831,7 +2081,7 @@ where
 #[cfg(feature = "std")]
 impl<'de, T> Deserialize<'de> for Wrapping<T>
 where
-    T: Deserialize<'de>
+    T: Deserialize<'de>,
 {
     fn deserialize<D>(deserializer: D) -> Result<Wrapping<T>, D::Error>
     where

serde/src/de/mod.rs

@@ -98,7 +98,8 @@
 //!    - Path
 //!    - PathBuf
 //!    - Range\<T\>
-//!    - NonZero\<T\> (unstable)
+//!    - NonZero\<T\> (unstable, deprecated)
+//!    - num::NonZero* (unstable)
 //!  - **Net types**:
 //!    - IpAddr
 //!    - Ipv4Addr
@@ -504,6 +505,35 @@ pub trait Deserialize<'de>: Sized {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
         D: Deserializer<'de>;
+
+    /// Deserializes a value into `self` from the given Deserializer.
+    ///
+    /// The purpose of this method is to allow the deserializer to reuse
+    /// resources and avoid copies. As such, if this method returns an error,
+    /// `self` will be in an indeterminate state where some parts of the struct
+    /// have been overwritten. Although whatever state that is will be
+    /// memory-safe.
+    ///
+    /// This is generally useful when repeatedly deserializing values that
+    /// are processed one at a time, where the value of `self` doesn't matter
+    /// when the next deserialization occurs.
+    ///
+    /// If you manually implement this, your recursive deserializations should
+    /// use `deserialize_in_place`.
+    ///
+    /// This method is stable and an official public API, but hidden from the
+    /// documentation because it is almost never what newbies are looking for.
+    /// Showing it in rustdoc would cause it to be featured more prominently
+    /// than it deserves.
+    #[doc(hidden)]
+    fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        // Default implementation just delegates to `deserialize` impl.
+        *place = Deserialize::deserialize(deserializer)?;
+        Ok(())
+    }
 }
 
 /// A data structure that can be deserialized without borrowing any data from
@@ -1078,7 +1108,9 @@ pub trait Deserializer<'de>: Sized {
     /// change, as a value serialized in human-readable mode is not required to
     /// deserialize from the same data in compact mode.
     #[inline]
-    fn is_human_readable(&self) -> bool { true }
+    fn is_human_readable(&self) -> bool {
+        true
+    }
 }
 
 ////////////////////////////////////////////////////////////////////////////////

serde/src/de/value.rs

@@ -37,7 +37,7 @@
 
 use lib::*;
 
-use de::{self, IntoDeserializer, Expected, SeqAccess};
+use de::{self, Expected, IntoDeserializer, SeqAccess};
 use private::de::size_hint;
 use ser;
 use self::private::{First, Second};
@@ -62,7 +62,9 @@ impl de::Error for Error {
     where
         T: Display,
     {
-        Error { err: msg.to_string().into_boxed_str() }
+        Error {
+            err: msg.to_string().into_boxed_str(),
+        }
     }
 
     #[cfg(not(any(feature = "std", feature = "alloc")))]
@@ -112,7 +114,9 @@ where
     type Deserializer = UnitDeserializer<E>;
 
     fn into_deserializer(self) -> UnitDeserializer<E> {
-        UnitDeserializer { marker: PhantomData }
+        UnitDeserializer {
+            marker: PhantomData,
+        }
     }
 }
 
@@ -658,7 +662,10 @@ where
         } else {
             // First argument is the number of elements in the data, second
             // argument is the number of elements expected by the Deserialize.
-            Err(de::Error::invalid_length(self.count + remaining, &ExpectedInSeq(self.count)),)
+            Err(de::Error::invalid_length(
+                self.count + remaining,
+                &ExpectedInSeq(self.count),
+            ))
         }
     }
 }
@@ -852,7 +859,10 @@ where
         } else {
             // First argument is the number of elements in the data, second
             // argument is the number of elements expected by the Deserialize.
-            Err(de::Error::invalid_length(self.count + remaining, &ExpectedInMap(self.count)),)
+            Err(de::Error::invalid_length(
+                self.count + remaining,
+                &ExpectedInMap(self.count),
+            ))
         }
     }
 }
@@ -901,11 +911,7 @@ where
         Ok(value)
     }
 
-    fn deserialize_tuple<V>(
-        self,
-        len: usize,
-        visitor: V,
-    ) -> Result<V::Value, Self::Error>
+    fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error>
     where
         V: de::Visitor<'de>,
     {
@@ -1223,7 +1229,12 @@ mod private {
     }
 
     pub fn unit_only<T, E>(t: T) -> (T, UnitOnly<E>) {
-        (t, UnitOnly { marker: PhantomData })
+        (
+            t,
+            UnitOnly {
+                marker: PhantomData,
+            },
+        )
     }
 
     impl<'de, E> de::VariantAccess<'de> for UnitOnly<E>
@@ -1240,14 +1251,20 @@ mod private {
         where
             T: de::DeserializeSeed<'de>,
         {
-            Err(de::Error::invalid_type(Unexpected::UnitVariant, &"newtype variant"),)
+            Err(de::Error::invalid_type(
+                Unexpected::UnitVariant,
+                &"newtype variant",
+            ))
         }
 
         fn tuple_variant<V>(self, _len: usize, _visitor: V) -> Result<V::Value, Self::Error>
         where
             V: de::Visitor<'de>,
         {
-            Err(de::Error::invalid_type(Unexpected::UnitVariant, &"tuple variant"),)
+            Err(de::Error::invalid_type(
+                Unexpected::UnitVariant,
+                &"tuple variant",
+            ))
         }
 
         fn struct_variant<V>(
@@ -1258,7 +1275,10 @@ mod private {
         where
             V: de::Visitor<'de>,
         {
-            Err(de::Error::invalid_type(Unexpected::UnitVariant, &"struct variant"),)
+            Err(de::Error::invalid_type(
+                Unexpected::UnitVariant,
+                &"struct variant",
+            ))
         }
     }
 

serde/src/export.rs

@@ -12,7 +12,7 @@ pub use lib::default::Default;
 pub use lib::fmt::{self, Formatter};
 pub use lib::marker::PhantomData;
 pub use lib::option::Option::{self, None, Some};
-pub use lib::result::Result::{self, Ok, Err};
+pub use lib::result::Result::{self, Err, Ok};
 
 pub use self::string::from_utf8_lossy;
 

serde/src/lib.rs

@@ -79,30 +79,21 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.23")]
-
+#![doc(html_root_url = "https://docs.rs/serde/1.0.35")]
 // 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
 // discussion of these features please refer to this issue:
 //
 //    https://github.com/serde-rs/serde/issues/812
 #![cfg_attr(feature = "unstable", feature(nonzero, specialization))]
 #![cfg_attr(feature = "alloc", feature(alloc))]
-
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
 // Whitelisted clippy lints
-#![cfg_attr(feature = "cargo-clippy", allow(
-    cast_lossless,
-    const_static_lifetime,
-    doc_markdown,
-    linkedlist,
-    needless_pass_by_value,
-    type_complexity,
-    unreadable_literal,
-    zero_prefixed_literal,
-))]
+#![cfg_attr(feature = "cargo-clippy",
+            allow(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
@@ -113,6 +104,7 @@
 // simplifies some macros
     invalid_upcast_comparisons,
 // things are often more readable this way
+    decimal_literal_representation,
     option_unwrap_used,
     result_unwrap_used,
     shadow_reuse,
@@ -120,12 +112,13 @@
     stutter,
     use_self,
 // not practical
+    many_single_char_names,
     missing_docs_in_private_items,
+    similar_names,
 // alternative is not stable
     empty_enum,
     use_debug,
 ))]
-
 // Blacklisted Rust lints.
 #![deny(missing_docs, unused_imports)]
 
@@ -149,8 +142,8 @@ mod lib {
     }
 
     pub use self::core::{cmp, iter, mem, ops, slice, str};
-    pub use self::core::{i8, i16, i32, i64, isize};
-    pub use self::core::{u8, u16, u32, u64, usize};
+    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::cell::{Cell, RefCell};
@@ -193,9 +186,9 @@ mod lib {
     pub use alloc::arc::Arc;
 
     #[cfg(feature = "std")]
-    pub use std::collections::{BinaryHeap, BTreeMap, BTreeSet, LinkedList, VecDeque};
+    pub use std::collections::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
     #[cfg(all(feature = "alloc", not(feature = "std")))]
-    pub use alloc::{BinaryHeap, BTreeMap, BTreeSet, LinkedList, VecDeque};
+    pub use alloc::{BTreeMap, BTreeSet, BinaryHeap, LinkedList, VecDeque};
 
     #[cfg(feature = "std")]
     pub use std::{error, net};
@@ -203,9 +196,9 @@ mod lib {
     #[cfg(feature = "std")]
     pub use std::collections::{HashMap, HashSet};
     #[cfg(feature = "std")]
-    pub use std::ffi::{CString, CStr, OsString, OsStr};
+    pub use std::ffi::{CStr, CString, OsStr, OsString};
     #[cfg(feature = "std")]
-    pub use std::hash::{Hash, BuildHasher};
+    pub use std::hash::{BuildHasher, Hash};
     #[cfg(feature = "std")]
     pub use std::io::Write;
     #[cfg(feature = "std")]
@@ -218,7 +211,11 @@ mod lib {
     pub use std::sync::{Mutex, RwLock};
 
     #[cfg(feature = "unstable")]
+    #[allow(deprecated)]
     pub use core::nonzero::{NonZero, Zeroable};
+
+    #[cfg(feature = "unstable")]
+    pub use core::num::{NonZeroU8, NonZeroU16, NonZeroU32, NonZeroU64, NonZeroUsize};
 }
 
 ////////////////////////////////////////////////////////////////////////////////

serde/src/private/de.rs

@@ -8,16 +8,16 @@
 
 use lib::*;
 
-use de::{Deserialize, Deserializer, IntoDeserializer, Error, Visitor};
+use de::{Deserialize, DeserializeSeed, Deserializer, Error, IntoDeserializer, Visitor};
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-use de::Unexpected;
+use de::{Unexpected, MapAccess};
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-pub use self::content::{Content, ContentRefDeserializer, ContentDeserializer,
-                        TaggedContentVisitor, TagOrContentField, TagOrContentFieldVisitor,
-                        TagContentOtherField, TagContentOtherFieldVisitor,
-                        InternallyTaggedUnitVisitor, UntaggedUnitVisitor};
+pub use self::content::{Content, ContentDeserializer, ContentRefDeserializer,
+                        InternallyTaggedUnitVisitor, TagContentOtherField,
+                        TagContentOtherFieldVisitor, TagOrContentField, TagOrContentFieldVisitor,
+                        TaggedContentVisitor, UntaggedUnitVisitor, EnumDeserializer};
 
 /// If the missing field is of type `Option<T>` then treat is as `None`,
 /// otherwise it is an error.
@@ -120,7 +120,10 @@ where
         {
             match String::from_utf8(v) {
                 Ok(s) => Ok(Cow::Owned(s)),
-                Err(e) => Err(Error::invalid_value(Unexpected::Bytes(&e.into_bytes()), &self),),
+                Err(e) => Err(Error::invalid_value(
+                    Unexpected::Bytes(&e.into_bytes()),
+                    &self,
+                )),
             }
         }
     }
@@ -185,7 +188,7 @@ where
         }
     }
 
-    deserializer.deserialize_str(CowBytesVisitor)
+    deserializer.deserialize_bytes(CowBytesVisitor)
 }
 
 pub mod size_hint {
@@ -198,6 +201,7 @@ pub mod size_hint {
         helper(iter.size_hint())
     }
 
+    #[inline]
     pub fn cautious(hint: Option<usize>) -> usize {
         cmp::min(hint.unwrap_or(0), 4096)
     }
@@ -224,8 +228,8 @@ mod content {
 
     use lib::*;
 
-    use de::{self, Deserialize, DeserializeSeed, Deserializer, Visitor, SeqAccess, MapAccess,
-             EnumAccess, Unexpected};
+    use de::{self, Deserialize, DeserializeSeed, Deserializer, EnumAccess, MapAccess, SeqAccess,
+             Unexpected, Visitor};
     use super::size_hint;
 
     /// Used from generated code to buffer the contents of the Deserializer when
@@ -265,6 +269,14 @@ mod content {
     }
 
     impl<'de> Content<'de> {
+        pub fn as_str(&self) -> Option<&str> {
+            match *self {
+                Content::Str(x) => Some(x),
+                Content::String(ref x) => Some(x),
+                _ => None,
+            }
+        }
+
         fn unexpected(&self) -> Unexpected {
             match *self {
                 Content::Bool(b) => Unexpected::Bool(b),
@@ -501,7 +513,9 @@ mod content {
         where
             V: EnumAccess<'de>,
         {
-            Err(de::Error::custom("untagged and internally tagged enums do not support enum input",),)
+            Err(de::Error::custom(
+                "untagged and internally tagged enums do not support enum input",
+            ))
         }
     }
 
@@ -520,7 +534,10 @@ mod content {
 
     impl<'de> TagOrContentVisitor<'de> {
         fn new(name: &'static str) -> Self {
-            TagOrContentVisitor { name: name, value: PhantomData }
+            TagOrContentVisitor {
+                name: name,
+                value: PhantomData,
+            }
         }
     }
 
@@ -557,7 +574,9 @@ mod content {
         where
             F: de::Error,
         {
-            ContentVisitor::new().visit_i8(value).map(TagOrContent::Content)
+            ContentVisitor::new()
+                .visit_i8(value)
+                .map(TagOrContent::Content)
         }
 
         fn visit_i16<F>(self, value: i16) -> Result<Self::Value, F>
@@ -591,7 +610,9 @@ mod content {
         where
             F: de::Error,
         {
-            ContentVisitor::new().visit_u8(value).map(TagOrContent::Content)
+            ContentVisitor::new()
+                .visit_u8(value)
+                .map(TagOrContent::Content)
         }
 
         fn visit_u16<F>(self, value: u16) -> Result<Self::Value, F>
@@ -730,14 +751,18 @@ mod content {
         where
             F: de::Error,
         {
-            ContentVisitor::new().visit_unit().map(TagOrContent::Content)
+            ContentVisitor::new()
+                .visit_unit()
+                .map(TagOrContent::Content)
         }
 
         fn visit_none<F>(self) -> Result<Self::Value, F>
         where
             F: de::Error,
         {
-            ContentVisitor::new().visit_none().map(TagOrContent::Content)
+            ContentVisitor::new()
+                .visit_none()
+                .map(TagOrContent::Content)
         }
 
         fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
@@ -860,8 +885,7 @@ mod content {
         {
             let mut tag = None;
             let mut vec = Vec::with_capacity(size_hint::cautious(map.size_hint()));
-            while let Some(k) =
-                try!(map.next_key_seed(TagOrContentVisitor::new(self.tag_name))) {
+            while let Some(k) = try!(map.next_key_seed(TagOrContentVisitor::new(self.tag_name))) {
                 match k {
                     TagOrContent::Tag => {
                         if tag.is_some() {
@@ -877,14 +901,10 @@ mod content {
             }
             match tag {
                 None => Err(de::Error::missing_field(self.tag_name)),
-                Some(tag) => {
-                    Ok(
-                        TaggedContent {
-                            tag: tag,
-                            content: Content::Map(vec),
-                        },
-                    )
-                }
+                Some(tag) => Ok(TaggedContent {
+                    tag: tag,
+                    content: Content::Map(vec),
+                }),
             }
         }
     }
@@ -966,7 +986,11 @@ mod content {
         type Value = TagContentOtherField;
 
         fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-            write!(formatter, "{:?}, {:?}, or other ignored fields", self.tag, self.content)
+            write!(
+                formatter,
+                "{:?}, {:?}, or other ignored fields",
+                self.tag, self.content
+            )
         }
 
         fn visit_str<E>(self, field: &str) -> Result<Self::Value, E>
@@ -1030,10 +1054,8 @@ mod content {
                     Ok(value)
                 }
                 Content::Map(v) => {
-                    let map = v.into_iter().map(|(k, v)| {
-                                                    (ContentDeserializer::new(k),
-                                                    ContentDeserializer::new(v))
-                                                });
+                    let map = v.into_iter()
+                        .map(|(k, v)| (ContentDeserializer::new(k), ContentDeserializer::new(v)));
                     let mut map_visitor = de::value::MapDeserializer::new(map);
                     let value = try!(visitor.visit_map(&mut map_visitor));
                     try!(map_visitor.end());
@@ -1080,44 +1102,37 @@ mod content {
                     let (variant, value) = match iter.next() {
                         Some(v) => v,
                         None => {
-                            return Err(
-                                de::Error::invalid_value(
-                                    de::Unexpected::Map,
-                                    &"map with a single key",
-                                ),
-                            );
+                            return Err(de::Error::invalid_value(
+                                de::Unexpected::Map,
+                                &"map with a single key",
+                            ));
                         }
                     };
                     // enums are encoded in json as maps with a single key:value pair
                     if iter.next().is_some() {
-                        return Err(
-                            de::Error::invalid_value(
-                                de::Unexpected::Map,
-                                &"map with a single key",
-                            ),
-                        );
+                        return Err(de::Error::invalid_value(
+                            de::Unexpected::Map,
+                            &"map with a single key",
+                        ));
                     }
                     (variant, Some(value))
                 }
                 s @ Content::String(_) | s @ Content::Str(_) => (s, None),
                 other => {
-                    return Err(de::Error::invalid_type(other.unexpected(), &"string or map"),);
+                    return Err(de::Error::invalid_type(
+                        other.unexpected(),
+                        &"string or map",
+                    ));
                 }
             };
 
-            visitor.visit_enum(
-                EnumDeserializer {
-                    variant: variant,
-                    value: value,
-                    err: PhantomData,
-                },
-            )
+            visitor.visit_enum(EnumDeserializer::new(variant, value))
         }
 
         fn deserialize_unit_struct<V>(
             self,
             _name: &'static str,
-            visitor: V
+            visitor: V,
         ) -> Result<V::Value, Self::Error>
         where
             V: Visitor<'de>,
@@ -1159,7 +1174,7 @@ mod content {
         }
     }
 
-    struct EnumDeserializer<'de, E>
+    pub struct EnumDeserializer<'de, E>
     where
         E: de::Error,
     {
@@ -1168,6 +1183,18 @@ mod content {
         err: PhantomData<E>,
     }
 
+    impl<'de, E> EnumDeserializer<'de, E>
+        where E: de::Error
+    {
+        pub fn new(variant: Content<'de>, value: Option<Content<'de>>) -> EnumDeserializer<'de, E> {
+            EnumDeserializer {
+                variant: variant,
+                value: value,
+                err: PhantomData,
+            }
+        }
+    }
+
     impl<'de, E> de::EnumAccess<'de> for EnumDeserializer<'de, E>
     where
         E: de::Error,
@@ -1188,7 +1215,7 @@ mod content {
         }
     }
 
-    struct VariantDeserializer<'de, E>
+    pub struct VariantDeserializer<'de, E>
     where
         E: de::Error,
     {
@@ -1215,9 +1242,10 @@ mod content {
         {
             match self.value {
                 Some(value) => seed.deserialize(ContentDeserializer::new(value)),
-                None => {
-                    Err(de::Error::invalid_type(de::Unexpected::UnitVariant, &"newtype variant"),)
-                }
+                None => Err(de::Error::invalid_type(
+                    de::Unexpected::UnitVariant,
+                    &"newtype variant",
+                )),
             }
         }
 
@@ -1229,8 +1257,14 @@ mod content {
                 Some(Content::Seq(v)) => {
                     de::Deserializer::deserialize_any(SeqDeserializer::new(v), visitor)
                 }
-                Some(other) => Err(de::Error::invalid_type(other.unexpected(), &"tuple variant"),),
-                None => Err(de::Error::invalid_type(de::Unexpected::UnitVariant, &"tuple variant"),),
+                Some(other) => Err(de::Error::invalid_type(
+                    other.unexpected(),
+                    &"tuple variant",
+                )),
+                None => Err(de::Error::invalid_type(
+                    de::Unexpected::UnitVariant,
+                    &"tuple variant",
+                )),
             }
         }
 
@@ -1249,8 +1283,14 @@ mod content {
                 Some(Content::Seq(v)) => {
                     de::Deserializer::deserialize_any(SeqDeserializer::new(v), visitor)
                 }
-                Some(other) => Err(de::Error::invalid_type(other.unexpected(), &"struct variant"),),
-                _ => Err(de::Error::invalid_type(de::Unexpected::UnitVariant, &"struct variant"),),
+                Some(other) => Err(de::Error::invalid_type(
+                    other.unexpected(),
+                    &"struct variant",
+                )),
+                _ => Err(de::Error::invalid_type(
+                    de::Unexpected::UnitVariant,
+                    &"struct variant",
+                )),
             }
         }
     }
@@ -1318,10 +1358,7 @@ mod content {
             T: de::DeserializeSeed<'de>,
         {
             match self.iter.next() {
-                Some(value) => {
-                    seed.deserialize(ContentDeserializer::new(value))
-                        .map(Some)
-                }
+                Some(value) => seed.deserialize(ContentDeserializer::new(value)).map(Some),
                 None => Ok(None),
             }
         }
@@ -1457,12 +1494,12 @@ mod content {
                     Ok(value)
                 }
                 Content::Map(ref v) => {
-                    let map = v.into_iter()
-                        .map(
-                            |&(ref k, ref v)| {
-                                (ContentRefDeserializer::new(k), ContentRefDeserializer::new(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());
@@ -1505,38 +1542,35 @@ mod content {
                     let &(ref variant, ref value) = match iter.next() {
                         Some(v) => v,
                         None => {
-                            return Err(
-                                de::Error::invalid_value(
-                                    de::Unexpected::Map,
-                                    &"map with a single key",
-                                ),
-                            );
+                            return Err(de::Error::invalid_value(
+                                de::Unexpected::Map,
+                                &"map with a single key",
+                            ));
                         }
                     };
                     // enums are encoded in json as maps with a single key:value pair
                     if iter.next().is_some() {
-                        return Err(
-                            de::Error::invalid_value(
-                                de::Unexpected::Map,
-                                &"map with a single key",
-                            ),
-                        );
+                        return Err(de::Error::invalid_value(
+                            de::Unexpected::Map,
+                            &"map with a single key",
+                        ));
                     }
                     (variant, Some(value))
                 }
                 ref s @ Content::String(_) | ref s @ Content::Str(_) => (s, None),
                 ref other => {
-                    return Err(de::Error::invalid_type(other.unexpected(), &"string or map"),);
+                    return Err(de::Error::invalid_type(
+                        other.unexpected(),
+                        &"string or map",
+                    ));
                 }
             };
 
-            visitor.visit_enum(
-                EnumRefDeserializer {
-                    variant: variant,
-                    value: value,
-                    err: PhantomData,
-                },
-            )
+            visitor.visit_enum(EnumRefDeserializer {
+                variant: variant,
+                value: value,
+                err: PhantomData,
+            })
         }
 
         forward_to_deserialize_any! {
@@ -1612,9 +1646,10 @@ mod content {
         {
             match self.value {
                 Some(value) => seed.deserialize(ContentRefDeserializer::new(value)),
-                None => {
-                    Err(de::Error::invalid_type(de::Unexpected::UnitVariant, &"newtype variant"),)
-                }
+                None => Err(de::Error::invalid_type(
+                    de::Unexpected::UnitVariant,
+                    &"newtype variant",
+                )),
             }
         }
 
@@ -1626,8 +1661,14 @@ mod content {
                 Some(&Content::Seq(ref v)) => {
                     de::Deserializer::deserialize_any(SeqRefDeserializer::new(v), visitor)
                 }
-                Some(other) => Err(de::Error::invalid_type(other.unexpected(), &"tuple variant"),),
-                None => Err(de::Error::invalid_type(de::Unexpected::UnitVariant, &"tuple variant"),),
+                Some(other) => Err(de::Error::invalid_type(
+                    other.unexpected(),
+                    &"tuple variant",
+                )),
+                None => Err(de::Error::invalid_type(
+                    de::Unexpected::UnitVariant,
+                    &"tuple variant",
+                )),
             }
         }
 
@@ -1646,8 +1687,14 @@ mod content {
                 Some(&Content::Seq(ref v)) => {
                     de::Deserializer::deserialize_any(SeqRefDeserializer::new(v), visitor)
                 }
-                Some(other) => Err(de::Error::invalid_type(other.unexpected(), &"struct variant"),),
-                _ => Err(de::Error::invalid_type(de::Unexpected::UnitVariant, &"struct variant"),),
+                Some(other) => Err(de::Error::invalid_type(
+                    other.unexpected(),
+                    &"struct variant",
+                )),
+                _ => Err(de::Error::invalid_type(
+                    de::Unexpected::UnitVariant,
+                    &"struct variant",
+                )),
             }
         }
     }
@@ -1715,10 +1762,8 @@ mod content {
             T: de::DeserializeSeed<'de>,
         {
             match self.iter.next() {
-                Some(value) => {
-                    seed.deserialize(ContentRefDeserializer::new(value))
-                        .map(Some)
-                }
+                Some(value) => seed.deserialize(ContentRefDeserializer::new(value))
+                    .map(Some),
                 None => Ok(None),
             }
         }
@@ -1763,8 +1808,7 @@ mod content {
             match self.iter.next() {
                 Some(&(ref key, ref value)) => {
                     self.value = Some(value);
-                    seed.deserialize(ContentRefDeserializer::new(key))
-                        .map(Some)
+                    seed.deserialize(ContentRefDeserializer::new(key)).map(Some)
                 }
                 None => Ok(None),
             }
@@ -1850,7 +1894,11 @@ mod content {
         type Value = ();
 
         fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-            write!(formatter, "unit variant {}::{}", self.type_name, self.variant_name)
+            write!(
+                formatter,
+                "unit variant {}::{}",
+                self.type_name, self.variant_name
+            )
         }
 
         fn visit_seq<S>(self, _: S) -> Result<(), S::Error>
@@ -1890,7 +1938,11 @@ mod content {
         type Value = ();
 
         fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-            write!(formatter, "unit variant {}::{}", self.type_name, self.variant_name)
+            write!(
+                formatter,
+                "unit variant {}::{}",
+                self.type_name, self.variant_name
+            )
         }
 
         fn visit_unit<E>(self) -> Result<(), E>
@@ -2008,3 +2060,180 @@ where
         map struct enum identifier ignored_any
     }
 }
+
+/// A DeserializeSeed helper for implementing deserialize_in_place Visitors.
+///
+/// Wraps a mutable reference and calls deserialize_in_place on it.
+pub struct InPlaceSeed<'a, T: 'a>(pub &'a mut T);
+
+impl<'a, 'de, T> DeserializeSeed<'de> for InPlaceSeed<'a, T>
+where
+    T: Deserialize<'de>,
+{
+    type Value = ();
+    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        T::deserialize_in_place(deserializer, self.0)
+    }
+}
+
+#[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>
+);
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, 'de, E> Deserializer<'de> for FlatMapDeserializer<'a, 'de, E>
+    where E: Error
+{
+    type Error = E;
+
+    fn deserialize_any<V>(self, _: V) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        Err(Error::custom("can only flatten structs and maps"))
+    }
+
+    fn deserialize_enum<V>(
+        self,
+        name: &'static str,
+        variants: &'static [&'static str],
+        visitor: V
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        for item in self.0.iter_mut() {
+            // items in the vector are nulled out when used.  So we can only use
+            // an item if it's still filled in and if the field is one we care
+            // about.
+            let use_item = match *item {
+                None => false,
+                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(
+                    key,
+                    Some(value)
+                ));
+            }
+        }
+
+        Err(Error::custom(format_args!(
+            "no variant of enum {} not found in flattened data",
+            name
+        )))
+    }
+
+    fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_map(FlatMapAccess::new(self.0.iter_mut(), None))
+    }
+
+    fn deserialize_struct<V>(
+        self,
+        _: &'static str,
+        fields: &'static [&'static str],
+        visitor: V
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_map(FlatMapAccess::new(self.0.iter_mut(), Some(fields)))
+    }
+
+    fn deserialize_newtype_struct<V>(
+        self,
+        _name: &str,
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_newtype_struct(self)
+    }
+
+    forward_to_deserialize_any! {
+        bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string bytes
+        byte_buf option unit unit_struct seq tuple tuple_struct identifier
+        ignored_any
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub struct FlatMapAccess<'a, 'de: 'a, E> {
+    iter: slice::IterMut<'a, Option<(Content<'de>, Content<'de>)>>,
+    pending_content: Option<Content<'de>>,
+    fields: Option<&'static [&'static str]>,
+    _marker: PhantomData<E>,
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, 'de, E> FlatMapAccess<'a, 'de, E> {
+    fn new(
+        iter: slice::IterMut<'a, Option<(Content<'de>, Content<'de>)>>,
+        fields: Option<&'static [&'static str]>
+    ) -> FlatMapAccess<'a, 'de, E> {
+        FlatMapAccess {
+            iter: iter,
+            pending_content: None,
+            fields: fields,
+            _marker: PhantomData,
+        }
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, 'de, E> MapAccess<'de> for FlatMapAccess<'a, 'de, E>
+    where E: Error
+{
+    type Error = E;
+
+    fn next_key_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error>
+    where
+        T: DeserializeSeed<'de>,
+    {
+        while let Some(item) = self.iter.next() {
+            // items in the vector are nulled out when used.  So we can only use
+            // an item if it's still filled in and if the field is one we care
+            // about.  In case we do not know which fields we want, we take them all.
+            let use_item = match *item {
+                None => false,
+                Some((ref c, _)) => {
+                    c.as_str().map_or(self.fields.is_none(), |key| {
+                        match self.fields {
+                            None => true,
+                            Some(fields) if fields.contains(&key) => true,
+                            _ => false
+                        }
+                    })
+                }
+            };
+
+            if use_item {
+                let (key, content) = item.take().unwrap();
+                self.pending_content = Some(content);
+                return seed.deserialize(ContentDeserializer::new(key)).map(Some);
+            }
+        }
+        Ok(None)
+    }
+
+    fn next_value_seed<T>(&mut self, seed: T) -> Result<T::Value, Self::Error>
+    where
+        T: DeserializeSeed<'de>,
+    {
+        match self.pending_content.take() {
+            Some(value) => seed.deserialize(ContentDeserializer::new(value)),
+            None => Err(Error::custom("value is missing")),
+        }
+    }
+}

serde/src/private/ser.rs

@@ -8,10 +8,15 @@
 
 use lib::*;
 
-use ser::{self, Serialize, Serializer, SerializeMap, SerializeStruct, Impossible};
+use ser::{self, Impossible, Serialize, SerializeMap, SerializeStruct, Serializer};
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-use self::content::{SerializeTupleVariantAsMapValue, SerializeStructVariantAsMapValue};
+use self::content::{
+    SerializeStructVariantAsMapValue,
+    SerializeTupleVariantAsMapValue,
+    ContentSerializer,
+    Content,
+};
 
 /// Used to check that serde(getter) attributes return the expected type.
 /// Not public API.
@@ -32,15 +37,13 @@ where
     S: Serializer,
     T: Serialize,
 {
-    value.serialize(
-        TaggedSerializer {
-            type_ident: type_ident,
-            variant_ident: variant_ident,
-            tag: tag,
-            variant_name: variant_name,
-            delegate: serializer,
-        },
-    )
+    value.serialize(TaggedSerializer {
+        type_ident: type_ident,
+        variant_ident: variant_ident,
+        tag: tag,
+        variant_name: variant_name,
+        delegate: serializer,
+    })
 }
 
 struct TaggedSerializer<S> {
@@ -60,10 +63,11 @@ enum Unsupported {
     ByteArray,
     Optional,
     Unit,
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    UnitStruct,
     Sequence,
     Tuple,
     TupleStruct,
-    #[cfg(not(any(feature = "std", feature = "alloc")))]
     Enum,
 }
 
@@ -78,10 +82,11 @@ impl Display for Unsupported {
             Unsupported::ByteArray => formatter.write_str("a byte array"),
             Unsupported::Optional => formatter.write_str("an optional"),
             Unsupported::Unit => formatter.write_str("unit"),
+            #[cfg(any(feature = "std", feature = "alloc"))]
+            Unsupported::UnitStruct => formatter.write_str("unit struct"),
             Unsupported::Sequence => formatter.write_str("a sequence"),
             Unsupported::Tuple => formatter.write_str("a tuple"),
             Unsupported::TupleStruct => formatter.write_str("a tuple struct"),
-            #[cfg(not(any(feature = "std", feature = "alloc")))]
             Unsupported::Enum => formatter.write_str("an enum"),
         }
     }
@@ -92,13 +97,10 @@ where
     S: Serializer,
 {
     fn bad_type(self, what: Unsupported) -> S::Error {
-        ser::Error::custom(
-            format_args!(
+        ser::Error::custom(format_args!(
             "cannot serialize tagged newtype variant {}::{} containing {}",
-            self.type_ident,
-            self.variant_ident,
-            what),
-        )
+            self.type_ident, self.variant_ident, what
+        ))
     }
 }
 
@@ -281,7 +283,11 @@ where
         let mut map = try!(self.delegate.serialize_map(Some(2)));
         try!(map.serialize_entry(self.tag, self.variant_name));
         try!(map.serialize_key(inner_variant));
-        Ok(SerializeTupleVariantAsMapValue::new(map, inner_variant, len),)
+        Ok(SerializeTupleVariantAsMapValue::new(
+            map,
+            inner_variant,
+            len,
+        ))
     }
 
     fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
@@ -324,7 +330,11 @@ where
         let mut map = try!(self.delegate.serialize_map(Some(2)));
         try!(map.serialize_entry(self.tag, self.variant_name));
         try!(map.serialize_key(inner_variant));
-        Ok(SerializeStructVariantAsMapValue::new(map, inner_variant, len),)
+        Ok(SerializeStructVariantAsMapValue::new(
+            map,
+            inner_variant,
+            len,
+        ))
     }
 
     #[cfg(not(any(feature = "std", feature = "alloc")))]
@@ -402,7 +412,10 @@ mod content {
         }
 
         fn end(mut self) -> Result<M::Ok, M::Error> {
-            try!(self.map.serialize_value(&Content::TupleStruct(self.name, self.fields)));
+            try!(
+                self.map
+                    .serialize_value(&Content::TupleStruct(self.name, self.fields))
+            );
             self.map.end()
         }
     }
@@ -444,13 +457,16 @@ mod content {
         }
 
         fn end(mut self) -> Result<M::Ok, M::Error> {
-            try!(self.map.serialize_value(&Content::Struct(self.name, self.fields)));
+            try!(
+                self.map
+                    .serialize_value(&Content::Struct(self.name, self.fields))
+            );
             self.map.end()
         }
     }
 
     #[derive(Debug)]
-    enum Content {
+    pub enum Content {
         Bool(bool),
 
         U8(u8),
@@ -485,7 +501,12 @@ mod content {
         TupleVariant(&'static str, u32, &'static str, Vec<Content>),
         Map(Vec<(Content, Content)>),
         Struct(&'static str, Vec<(&'static str, Content)>),
-        StructVariant(&'static str, u32, &'static str, Vec<(&'static str, Content)>),
+        StructVariant(
+            &'static str,
+            u32,
+            &'static str,
+            Vec<(&'static str, Content)>,
+        ),
     }
 
     impl Serialize for Content {
@@ -570,12 +591,12 @@ mod content {
         }
     }
 
-    struct ContentSerializer<E> {
+    pub struct ContentSerializer<E> {
         error: PhantomData<E>,
     }
 
     impl<E> ContentSerializer<E> {
-        fn new() -> Self {
+        pub fn new() -> Self {
             ContentSerializer { error: PhantomData }
         }
     }
@@ -687,7 +708,10 @@ mod content {
         where
             T: Serialize,
         {
-            Ok(Content::NewtypeStruct(name, Box::new(try!(value.serialize(self)))),)
+            Ok(Content::NewtypeStruct(
+                name,
+                Box::new(try!(value.serialize(self))),
+            ))
         }
 
         fn serialize_newtype_variant<T: ?Sized>(
@@ -700,32 +724,26 @@ mod content {
         where
             T: Serialize,
         {
-            Ok(
-                Content::NewtypeVariant(
-                    name,
-                    variant_index,
-                    variant,
-                    Box::new(try!(value.serialize(self))),
-                ),
-            )
+            Ok(Content::NewtypeVariant(
+                name,
+                variant_index,
+                variant,
+                Box::new(try!(value.serialize(self))),
+            ))
         }
 
         fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq, E> {
-            Ok(
-                SerializeSeq {
-                    elements: Vec::with_capacity(len.unwrap_or(0)),
-                    error: PhantomData,
-                },
-            )
+            Ok(SerializeSeq {
+                elements: Vec::with_capacity(len.unwrap_or(0)),
+                error: PhantomData,
+            })
         }
 
         fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple, E> {
-            Ok(
-                SerializeTuple {
-                    elements: Vec::with_capacity(len),
-                    error: PhantomData,
-                },
-            )
+            Ok(SerializeTuple {
+                elements: Vec::with_capacity(len),
+                error: PhantomData,
+            })
         }
 
         fn serialize_tuple_struct(
@@ -733,13 +751,11 @@ mod content {
             name: &'static str,
             len: usize,
         ) -> Result<Self::SerializeTupleStruct, E> {
-            Ok(
-                SerializeTupleStruct {
-                    name: name,
-                    fields: Vec::with_capacity(len),
-                    error: PhantomData,
-                },
-            )
+            Ok(SerializeTupleStruct {
+                name: name,
+                fields: Vec::with_capacity(len),
+                error: PhantomData,
+            })
         }
 
         fn serialize_tuple_variant(
@@ -749,25 +765,21 @@ mod content {
             variant: &'static str,
             len: usize,
         ) -> Result<Self::SerializeTupleVariant, E> {
-            Ok(
-                SerializeTupleVariant {
-                    name: name,
-                    variant_index: variant_index,
-                    variant: variant,
-                    fields: Vec::with_capacity(len),
-                    error: PhantomData,
-                },
-            )
+            Ok(SerializeTupleVariant {
+                name: name,
+                variant_index: variant_index,
+                variant: variant,
+                fields: Vec::with_capacity(len),
+                error: PhantomData,
+            })
         }
 
         fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, E> {
-            Ok(
-                SerializeMap {
-                    entries: Vec::with_capacity(len.unwrap_or(0)),
-                    key: None,
-                    error: PhantomData,
-                },
-            )
+            Ok(SerializeMap {
+                entries: Vec::with_capacity(len.unwrap_or(0)),
+                key: None,
+                error: PhantomData,
+            })
         }
 
         fn serialize_struct(
@@ -775,13 +787,11 @@ mod content {
             name: &'static str,
             len: usize,
         ) -> Result<Self::SerializeStruct, E> {
-            Ok(
-                SerializeStruct {
-                    name: name,
-                    fields: Vec::with_capacity(len),
-                    error: PhantomData,
-                },
-            )
+            Ok(SerializeStruct {
+                name: name,
+                fields: Vec::with_capacity(len),
+                error: PhantomData,
+            })
         }
 
         fn serialize_struct_variant(
@@ -791,19 +801,17 @@ mod content {
             variant: &'static str,
             len: usize,
         ) -> Result<Self::SerializeStructVariant, E> {
-            Ok(
-                SerializeStructVariant {
-                    name: name,
-                    variant_index: variant_index,
-                    variant: variant,
-                    fields: Vec::with_capacity(len),
-                    error: PhantomData,
-                },
-            )
+            Ok(SerializeStructVariant {
+                name: name,
+                variant_index: variant_index,
+                variant: variant,
+                fields: Vec::with_capacity(len),
+                error: PhantomData,
+            })
         }
     }
 
-    struct SerializeSeq<E> {
+    pub struct SerializeSeq<E> {
         elements: Vec<Content>,
         error: PhantomData<E>,
     }
@@ -829,7 +837,7 @@ mod content {
         }
     }
 
-    struct SerializeTuple<E> {
+    pub struct SerializeTuple<E> {
         elements: Vec<Content>,
         error: PhantomData<E>,
     }
@@ -855,7 +863,7 @@ mod content {
         }
     }
 
-    struct SerializeTupleStruct<E> {
+    pub struct SerializeTupleStruct<E> {
         name: &'static str,
         fields: Vec<Content>,
         error: PhantomData<E>,
@@ -882,7 +890,7 @@ mod content {
         }
     }
 
-    struct SerializeTupleVariant<E> {
+    pub struct SerializeTupleVariant<E> {
         name: &'static str,
         variant_index: u32,
         variant: &'static str,
@@ -907,11 +915,16 @@ mod content {
         }
 
         fn end(self) -> Result<Content, E> {
-            Ok(Content::TupleVariant(self.name, self.variant_index, self.variant, self.fields),)
+            Ok(Content::TupleVariant(
+                self.name,
+                self.variant_index,
+                self.variant,
+                self.fields,
+            ))
         }
     }
 
-    struct SerializeMap<E> {
+    pub struct SerializeMap<E> {
         entries: Vec<(Content, Content)>,
         key: Option<Content>,
         error: PhantomData<E>,
@@ -961,7 +974,7 @@ mod content {
         }
     }
 
-    struct SerializeStruct<E> {
+    pub struct SerializeStruct<E> {
         name: &'static str,
         fields: Vec<(&'static str, Content)>,
         error: PhantomData<E>,
@@ -988,7 +1001,7 @@ mod content {
         }
     }
 
-    struct SerializeStructVariant<E> {
+    pub struct SerializeStructVariant<E> {
         name: &'static str,
         variant_index: u32,
         variant: &'static str,
@@ -1013,7 +1026,292 @@ mod content {
         }
 
         fn end(self) -> Result<Content, E> {
-            Ok(Content::StructVariant(self.name, self.variant_index, self.variant, self.fields),)
+            Ok(Content::StructVariant(
+                self.name,
+                self.variant_index,
+                self.variant,
+                self.fields,
+            ))
         }
     }
 }
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+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
+{
+    fn bad_type(self, what: Unsupported) -> M::Error {
+        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
+{
+    type Ok = ();
+    type Error = M::Error;
+
+    type SerializeSeq = Impossible<Self::Ok, M::Error>;
+    type SerializeTuple = Impossible<Self::Ok, M::Error>;
+    type SerializeTupleStruct = Impossible<Self::Ok, M::Error>;
+    type SerializeMap = FlatMapSerializeMap<'a, M>;
+    type SerializeStruct = FlatMapSerializeStruct<'a, M>;
+    type SerializeTupleVariant = Impossible<Self::Ok, M::Error>;
+    type SerializeStructVariant = FlatMapSerializeStructVariantAsMapValue<'a, M>;
+
+    fn serialize_bool(self, _: bool) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Boolean))
+    }
+
+    fn serialize_i8(self, _: i8) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i16(self, _: i16) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i32(self, _: i32) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i64(self, _: i64) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u8(self, _: u8) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u16(self, _: u16) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u32(self, _: u32) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u64(self, _: u64) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_f32(self, _: f32) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Float))
+    }
+
+    fn serialize_f64(self, _: f64) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Float))
+    }
+
+    fn serialize_char(self, _: char) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Char))
+    }
+
+    fn serialize_str(self, _: &str) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::String))
+    }
+
+    fn serialize_bytes(self, _: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::ByteArray))
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Optional))
+    }
+
+    fn serialize_some<T: ?Sized>(self, _: &T) -> Result<Self::Ok, Self::Error>
+    where
+        T: Serialize,
+    {
+        Err(self.bad_type(Unsupported::Optional))
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Unit))
+    }
+
+    fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::UnitStruct))
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        _: &'static str,
+    ) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Enum))
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(
+        self,
+        _: &'static str,
+        value: &T,
+    ) -> Result<Self::Ok, Self::Error>
+    where
+        T: Serialize,
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _: &'static str,
+        _: u32,
+        variant: &'static str,
+        value: &T,
+    ) -> Result<Self::Ok, Self::Error>
+    where
+        T: Serialize,
+    {
+        try!(self.0.serialize_key(variant));
+        self.0.serialize_value(value)
+    }
+
+    fn serialize_seq(self, _: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(self.bad_type(Unsupported::Sequence))
+    }
+
+    fn serialize_tuple(self, _: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(self.bad_type(Unsupported::Tuple))
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeTupleStruct, Self::Error> {
+        Err(self.bad_type(Unsupported::TupleStruct))
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        _: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeTupleVariant, Self::Error> {
+        Err(self.bad_type(Unsupported::Enum))
+    }
+
+    fn serialize_map(self, _: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        Ok(FlatMapSerializeMap(self.0))
+    }
+
+    fn serialize_struct(
+        self,
+        _: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeStruct, Self::Error> {
+        Ok(FlatMapSerializeStruct(self.0))
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        inner_variant: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeStructVariant, Self::Error> {
+        try!(self.0.serialize_key(inner_variant));
+        Ok(FlatMapSerializeStructVariantAsMapValue::new(self.0, inner_variant))
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+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
+{
+    type Ok = ();
+    type Error = M::Error;
+
+    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    where
+        T: Serialize,
+    {
+        self.0.serialize_key(key)
+    }
+
+    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    where
+        T: Serialize,
+    {
+        self.0.serialize_value(value)
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+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
+{
+    type Ok = ();
+    type Error = M::Error;
+
+    fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Self::Error>
+    where
+        T: Serialize,
+    {
+        self.0.serialize_entry(key, value)
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub struct FlatMapSerializeStructVariantAsMapValue<'a, M: 'a> {
+    map: &'a mut M,
+    name: &'static str,
+    fields: Vec<(&'static str, Content)>,
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> FlatMapSerializeStructVariantAsMapValue<'a, M>
+    where M: SerializeMap + 'a
+{
+    fn new(map: &'a mut M, name: &'static str) -> FlatMapSerializeStructVariantAsMapValue<'a, M> {
+        FlatMapSerializeStructVariantAsMapValue {
+            map: map,
+            name: name,
+            fields: Vec::new(),
+        }
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> ser::SerializeStructVariant for FlatMapSerializeStructVariantAsMapValue<'a, M>
+    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>
+    where
+        T: Serialize,
+    {
+        let value = try!(value.serialize(ContentSerializer::<M::Error>::new()));
+        self.fields.push((key, value));
+        Ok(())
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        try!(self.map.serialize_value(&Content::Struct(self.name, self.fields)));
+        Ok(())
+    }
+}

serde/src/ser/impls.rs

@@ -111,7 +111,7 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-impl<T> Serialize for PhantomData<T> {
+impl<T: ?Sized> Serialize for PhantomData<T> {
     #[inline]
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -351,6 +351,7 @@ deref_impl!(<'a, T: ?Sized> Serialize for Cow<'a, T> where T: Serialize + ToOwne
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(feature = "unstable")]
+#[allow(deprecated)]
 impl<T> Serialize for NonZero<T>
 where
     T: Serialize + Zeroable + Clone,
@@ -363,6 +364,32 @@ where
     }
 }
 
+macro_rules! nonzero_integers {
+    ( $( $T: ident, )+ ) => {
+        $(
+            #[cfg(feature = "unstable")]
+            impl Serialize for $T {
+                fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+                where
+                    S: Serializer,
+                {
+                    self.get().serialize(serializer)
+                }
+            }
+        )+
+    }
+}
+
+nonzero_integers! {
+    // Not including signed NonZeroI* since they might be removed
+    NonZeroU8,
+    NonZeroU16,
+    NonZeroU32,
+    NonZeroU64,
+    // FIXME: https://github.com/serde-rs/serde/issues/1136 NonZeroU128,
+    NonZeroUsize,
+}
+
 impl<T> Serialize for Cell<T>
 where
     T: Serialize + Copy,
@@ -464,7 +491,8 @@ impl Serialize for SystemTime {
         S: Serializer,
     {
         use super::SerializeStruct;
-        let duration_since_epoch = self.duration_since(UNIX_EPOCH).expect("SystemTime must be later than UNIX_EPOCH");
+        let duration_since_epoch = self.duration_since(UNIX_EPOCH)
+            .expect("SystemTime must be later than UNIX_EPOCH");
         let mut state = try!(serializer.serialize_struct("SystemTime", 2));
         try!(state.serialize_field("secs_since_epoch", &duration_since_epoch.as_secs()));
         try!(state.serialize_field("nanos_since_epoch", &duration_since_epoch.subsec_nanos()));
@@ -513,10 +541,12 @@ impl Serialize for net::IpAddr {
             }
         } else {
             match *self {
-                net::IpAddr::V4(ref a) =>
-                    serializer.serialize_newtype_variant("IpAddr", 0, "V4", a),
-                net::IpAddr::V6(ref a) =>
-                    serializer.serialize_newtype_variant("IpAddr", 1, "V6", a),
+                net::IpAddr::V4(ref a) => {
+                    serializer.serialize_newtype_variant("IpAddr", 0, "V4", a)
+                }
+                net::IpAddr::V6(ref a) => {
+                    serializer.serialize_newtype_variant("IpAddr", 1, "V6", a)
+                }
             }
         }
     }
@@ -567,10 +597,12 @@ impl Serialize for net::SocketAddr {
             }
         } else {
             match *self {
-                net::SocketAddr::V4(ref addr) =>
-                    serializer.serialize_newtype_variant("SocketAddr", 0, "V4", addr),
-                net::SocketAddr::V6(ref addr) =>
-                    serializer.serialize_newtype_variant("SocketAddr", 1, "V6", addr),
+                net::SocketAddr::V4(ref addr) => {
+                    serializer.serialize_newtype_variant("SocketAddr", 0, "V4", addr)
+                }
+                net::SocketAddr::V6(ref addr) => {
+                    serializer.serialize_newtype_variant("SocketAddr", 1, "V6", addr)
+                }
             }
         }
     }
@@ -600,7 +632,10 @@ impl Serialize for net::SocketAddrV6 {
     {
         if serializer.is_human_readable() {
             const MAX_LEN: usize = 47;
-            debug_assert_eq!(MAX_LEN, "[1001:1002:1003:1004:1005:1006:1007:1008]:65000".len());
+            debug_assert_eq!(
+                MAX_LEN,
+                "[1001:1002:1003:1004:1005:1006:1007:1008]:65000".len()
+            );
             serialize_display_bounded_length!(self, MAX_LEN, serializer)
         } else {
             (self.ip(), self.port()).serialize(serializer)

serde/src/ser/impossible.rs

@@ -10,8 +10,8 @@
 
 use lib::*;
 
-use ser::{self, Serialize, SerializeSeq, SerializeTuple, SerializeTupleStruct,
-          SerializeTupleVariant, SerializeMap, SerializeStruct, SerializeStructVariant};
+use ser::{self, Serialize, SerializeMap, SerializeSeq, SerializeStruct, SerializeStructVariant,
+          SerializeTuple, SerializeTupleStruct, SerializeTupleVariant};
 
 /// Helper type for implementing a `Serializer` that does not support
 /// serializing one of the compound types.

serde/src/ser/mod.rs

@@ -93,7 +93,8 @@
 //!    - Path
 //!    - PathBuf
 //!    - Range\<T\>
-//!    - NonZero\<T\> (unstable)
+//!    - NonZero\<T\> (unstable, deprecated)
+//!    - num::NonZero* (unstable)
 //!  - **Net types**:
 //!    - IpAddr
 //!    - Ipv4Addr
@@ -1412,7 +1413,9 @@ pub trait Serializer: Sized {
     /// change, as a value serialized in human-readable mode is not required to
     /// deserialize from the same data in compact mode.
     #[inline]
-    fn is_human_readable(&self) -> bool { true }
+    fn is_human_readable(&self) -> bool {
+        true
+    }
 }
 
 /// Returned from `Serializer::serialize_seq`.

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "1.0.23" # remember to update html_root_url
+version = "1.0.35" # 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)]"
@@ -14,14 +14,19 @@ include = ["Cargo.toml", "src/**/*.rs", "README.md", "LICENSE-APACHE", "LICENSE-
 [badges]
 travis-ci = { repository = "serde-rs/serde" }
 
+[features]
+default = []
+deserialize_in_place = []
+
 [lib]
 name = "serde_derive"
 proc-macro = true
 
 [dependencies]
-quote = "0.3.8"
-serde_derive_internals = { version = "=0.17.0", default-features = false, path = "../serde_derive_internals" }
-syn = { version = "0.11", features = ["visit"] }
+proc-macro2 = "0.2"
+quote = "0.4"
+serde_derive_internals = { version = "=0.22.1", default-features = false, path = "../serde_derive_internals" }
+syn = { version = "0.12", features = ["visit"] }
 
 [dev-dependencies]
 serde = { version = "1.0", path = "../serde" }

serde_derive/src/bound.rs

@@ -9,32 +9,31 @@
 use std::collections::HashSet;
 
 use syn::{self, visit};
+use syn::punctuated::Punctuated;
 
-use internals::ast::{Body, Container};
+use internals::ast::{Data, Container};
 use internals::attr;
 
-macro_rules! path {
-    ($($path:tt)+) => {
-        syn::parse_path(quote!($($path)+).as_str()).unwrap()
-    };
-}
+use proc_macro2::{Span, Term};
 
 // Remove the default from every type parameter because in the generated impls
 // they look like associated types: "error: associated type bindings are not
 // allowed here".
 pub fn without_defaults(generics: &syn::Generics) -> syn::Generics {
     syn::Generics {
-        ty_params: generics
-            .ty_params
+        params: generics
+            .params
             .iter()
-            .map(
-                |ty_param| {
-                    syn::TyParam {
+            .map(|param| match *param {
+                syn::GenericParam::Type(ref param) => {
+                    syn::GenericParam::Type(syn::TypeParam {
+                        eq_token: None,
                         default: None,
-                        ..ty_param.clone()
-                    }
-                },
-            )
+                        ..param.clone()
+                    })
+                }
+                _ => param.clone(),
+            })
             .collect(),
         ..generics.clone()
     }
@@ -45,10 +44,17 @@ pub fn with_where_predicates(
     predicates: &[syn::WherePredicate],
 ) -> syn::Generics {
     let mut generics = generics.clone();
-    generics
-        .where_clause
+    if generics.where_clause.is_none() {
+        generics.where_clause = Some(syn::WhereClause {
+            where_token: Default::default(),
+            predicates: Punctuated::new(),
+        });
+    }
+    generics.where_clause
+        .as_mut()
+        .unwrap()
         .predicates
-        .extend_from_slice(predicates);
+        .extend(predicates.into_iter().cloned());
     generics
 }
 
@@ -60,13 +66,23 @@ pub fn with_where_predicates_from_fields<F>(
 where
     F: Fn(&attr::Field) -> Option<&[syn::WherePredicate]>,
 {
-    let predicates = cont.body
+    let predicates = cont.data
         .all_fields()
         .flat_map(|field| from_field(&field.attrs))
         .flat_map(|predicates| predicates.to_vec());
 
     let mut generics = generics.clone();
-    generics.where_clause.predicates.extend(predicates);
+    if generics.where_clause.is_none() {
+        generics.where_clause = Some(syn::WhereClause {
+            where_token: Default::default(),
+            predicates: Punctuated::new(),
+        });
+    }
+    generics.where_clause
+        .as_mut()
+        .unwrap()
+        .predicates
+        .extend(predicates);
     generics
 }
 
@@ -99,22 +115,22 @@ where
         // them.
         relevant_ty_params: HashSet<syn::Ident>,
     }
-    impl visit::Visitor for FindTyParams {
+    impl<'ast> visit::Visit<'ast> for FindTyParams {
         fn visit_path(&mut self, path: &syn::Path) {
             if let Some(seg) = path.segments.last() {
-                if seg.ident == "PhantomData" {
+                if seg.into_value().ident == "PhantomData" {
                     // Hardcoded exception, because PhantomData<T> implements
                     // Serialize and Deserialize whether or not T implements it.
                     return;
                 }
             }
-            if !path.global && path.segments.len() == 1 {
-                let id = path.segments[0].ident.clone();
+            if path.leading_colon.is_none() && path.segments.len() == 1 {
+                let id = path.segments[0].ident;
                 if self.all_ty_params.contains(&id) {
                     self.relevant_ty_params.insert(id);
                 }
             }
-            visit::walk_path(self, path);
+            visit::visit_path(self, path);
         }
 
         // Type parameter should not be considered used by a macro path.
@@ -123,67 +139,79 @@ where
         //         mac: T!(),
         //         marker: PhantomData<T>,
         //     }
-        fn visit_mac(&mut self, _mac: &syn::Mac) {}
+        fn visit_macro(&mut self, _mac: &syn::Macro) {}
     }
 
     let all_ty_params: HashSet<_> = generics
-        .ty_params
+        .params
         .iter()
-        .map(|ty_param| ty_param.ident.clone())
+        .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,
         relevant_ty_params: HashSet::new(),
     };
-    match cont.body {
-        Body::Enum(ref variants) => {
-            for variant in variants.iter() {
-                let relevant_fields = variant
-                    .fields
-                    .iter()
-                    .filter(|field| filter(&field.attrs, Some(&variant.attrs)));
-                for field in relevant_fields {
-                    visit::walk_ty(&mut visitor, field.ty);
-                }
+    match cont.data {
+        Data::Enum(ref variants) => for variant in variants.iter() {
+            let relevant_fields = variant
+                .fields
+                .iter()
+                .filter(|field| filter(&field.attrs, Some(&variant.attrs)));
+            for field in relevant_fields {
+                visit::visit_type(&mut visitor, field.ty);
             }
-        }
-        Body::Struct(_, ref fields) => {
+        },
+        Data::Struct(_, ref fields) => {
             for field in fields.iter().filter(|field| filter(&field.attrs, None)) {
-                visit::walk_ty(&mut visitor, field.ty);
+                visit::visit_type(&mut visitor, field.ty);
             }
         }
     }
 
     let new_predicates = generics
-        .ty_params
+        .params
         .iter()
-        .map(|ty_param| ty_param.ident.clone())
+        .filter_map(|param| match *param {
+            syn::GenericParam::Type(ref param) => Some(param.ident),
+            _ => None,
+        })
         .filter(|id| visitor.relevant_ty_params.contains(id))
-        .map(
-            |id| {
-                syn::WherePredicate::BoundPredicate(
-                    syn::WhereBoundPredicate {
-                        bound_lifetimes: Vec::new(),
-                        // the type parameter that is being bounded e.g. T
-                        bounded_ty: syn::Ty::Path(None, id.into()),
-                        // the bound e.g. Serialize
-                        bounds: vec![
-                            syn::TyParamBound::Trait(
-                                syn::PolyTraitRef {
-                                    bound_lifetimes: Vec::new(),
-                                    trait_ref: bound.clone(),
-                                },
-                                syn::TraitBoundModifier::None,
-                            ),
-                        ],
-                    },
-                )
-            },
-        );
+        .map(|id| {
+            syn::WherePredicate::Type(syn::PredicateType {
+                lifetimes: None,
+                // the type parameter that is being bounded e.g. T
+                bounded_ty: syn::Type::Path(syn::TypePath {
+                    qself: None,
+                    path: id.into(),
+                }),
+                colon_token: Default::default(),
+                // the bound e.g. Serialize
+                bounds: vec![
+                    syn::TypeParamBound::Trait(syn::TraitBound {
+                        modifier: syn::TraitBoundModifier::None,
+                        lifetimes: None,
+                        path: bound.clone(),
+                    }),
+                ].into_iter().collect(),
+            })
+        });
 
     let mut generics = generics.clone();
-    generics.where_clause.predicates.extend(new_predicates);
+    if generics.where_clause.is_none() {
+        generics.where_clause = Some(syn::WhereClause {
+            where_token: Default::default(),
+            predicates: Punctuated::new(),
+        });
+    }
+    generics.where_clause
+        .as_mut()
+        .unwrap()
+        .predicates
+        .extend(new_predicates);
     generics
 }
 
@@ -193,82 +221,102 @@ pub fn with_self_bound(
     bound: &syn::Path,
 ) -> syn::Generics {
     let mut generics = generics.clone();
-    generics
-        .where_clause
+    if generics.where_clause.is_none() {
+        generics.where_clause = Some(syn::WhereClause {
+            where_token: Default::default(),
+            predicates: Punctuated::new(),
+        });
+    }
+    generics.where_clause
+        .as_mut()
+        .unwrap()
         .predicates
-        .push(
-            syn::WherePredicate::BoundPredicate(
-                syn::WhereBoundPredicate {
-                    bound_lifetimes: Vec::new(),
-                    // the type that is being bounded e.g. MyStruct<'a, T>
-                    bounded_ty: type_of_item(cont),
-                    // the bound e.g. Default
-                    bounds: vec![
-                        syn::TyParamBound::Trait(
-                            syn::PolyTraitRef {
-                                bound_lifetimes: Vec::new(),
-                                trait_ref: bound.clone(),
-                            },
-                            syn::TraitBoundModifier::None,
-                        ),
-                    ],
-                },
-            ),
-        );
+        .push(syn::WherePredicate::Type(syn::PredicateType {
+            lifetimes: None,
+            // the type that is being bounded e.g. MyStruct<'a, T>
+            bounded_ty: type_of_item(cont),
+            colon_token: Default::default(),
+            // the bound e.g. Default
+            bounds: vec![
+                syn::TypeParamBound::Trait(syn::TraitBound {
+                    modifier: syn::TraitBoundModifier::None,
+                    lifetimes: None,
+                    path: bound.clone(),
+                }),
+            ].into_iter().collect(),
+        }));
     generics
 }
 
 pub fn with_lifetime_bound(generics: &syn::Generics, lifetime: &str) -> syn::Generics {
-    let mut generics = generics.clone();
+    let bound = syn::Lifetime::new(Term::intern(lifetime), Span::def_site());
+    let def = syn::LifetimeDef {
+        attrs: Vec::new(),
+        lifetime: bound,
+        colon_token: None,
+        bounds: Punctuated::new(),
+    };
 
-    for lifetime_def in &mut generics.lifetimes {
-        lifetime_def.bounds.push(syn::Lifetime::new(lifetime));
+    let params = Some(syn::GenericParam::Lifetime(def))
+        .into_iter()
+        .chain(generics.params
+            .iter()
+            .cloned()
+            .map(|mut param| {
+                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
+            }))
+        .collect();
+
+    syn::Generics {
+        params: params,
+        ..generics.clone()
     }
-
-    for ty_param in &mut generics.ty_params {
-        ty_param
-            .bounds
-            .push(syn::TyParamBound::Region(syn::Lifetime::new(lifetime)));
-    }
-
-    generics
-        .lifetimes
-        .push(
-            syn::LifetimeDef {
-                attrs: Vec::new(),
-                lifetime: syn::Lifetime::new(lifetime),
-                bounds: Vec::new(),
-            },
-        );
-
-    generics
 }
 
-fn type_of_item(cont: &Container) -> syn::Ty {
-    syn::Ty::Path(
-        None,
-        syn::Path {
-            global: false,
+fn type_of_item(cont: &Container) -> syn::Type {
+    syn::Type::Path(syn::TypePath {
+        qself: None,
+        path: syn::Path {
+            leading_colon: None,
             segments: vec![
                 syn::PathSegment {
-                    ident: cont.ident.clone(),
-                    parameters: syn::PathParameters::AngleBracketed(
-                        syn::AngleBracketedParameterData {
-                            lifetimes: cont.generics
-                                .lifetimes
+                    ident: cont.ident,
+                    arguments: syn::PathArguments::AngleBracketed(
+                        syn::AngleBracketedGenericArguments {
+                            colon2_token: None,
+                            lt_token: Default::default(),
+                            args: cont.generics
+                                .params
                                 .iter()
-                                .map(|def| def.lifetime.clone())
+                                .map(|param| match *param {
+                                    syn::GenericParam::Type(ref param) => {
+                                        syn::GenericArgument::Type(syn::Type::Path(syn::TypePath {
+                                            qself: None,
+                                            path: param.ident.into(),
+                                        }))
+                                    }
+                                    syn::GenericParam::Lifetime(ref param) => {
+                                        syn::GenericArgument::Lifetime(param.lifetime)
+                                    }
+                                    syn::GenericParam::Const(_) => {
+                                        panic!("Serde does not support const generics yet");
+                                    }
+                                })
                                 .collect(),
-                            types: cont.generics
-                                .ty_params
-                                .iter()
-                                .map(|param| syn::Ty::Path(None, param.ident.clone().into()))
-                                .collect(),
-                            bindings: Vec::new(),
+                            gt_token: Default::default(),
                         },
                     ),
                 },
-            ],
+            ].into_iter().collect(),
         },
-    )
+    })
 }

serde_derive/src/fragment.rs

@@ -6,7 +6,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use quote::{Tokens, ToTokens};
+use quote::{ToTokens, Tokens};
+use syn::token;
 
 pub enum Fragment {
     /// Tokens that can be used as an expression.
@@ -36,9 +37,7 @@ impl ToTokens for Expr {
         match self.0 {
             Fragment::Expr(ref expr) => expr.to_tokens(out),
             Fragment::Block(ref block) => {
-                out.append("{");
-                block.to_tokens(out);
-                out.append("}");
+                token::Brace::default().surround(out, |out| block.to_tokens(out));
             }
         }
     }
@@ -63,13 +62,20 @@ impl ToTokens for Match {
         match self.0 {
             Fragment::Expr(ref expr) => {
                 expr.to_tokens(out);
-                out.append(",");
+                <Token![,]>::default().to_tokens(out);
             }
             Fragment::Block(ref block) => {
-                out.append("{");
-                block.to_tokens(out);
-                out.append("}");
+                token::Brace::default().surround(out, |out| block.to_tokens(out));
             }
         }
     }
 }
+
+impl AsRef<Tokens> for Fragment {
+    fn as_ref(&self) -> &Tokens {
+        match *self {
+            Fragment::Expr(ref expr) => expr,
+            Fragment::Block(ref block) => block,
+        }
+    }
+}

serde_derive/src/lib.rs

@@ -22,22 +22,24 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.23")]
-
-#![cfg_attr(feature = "cargo-clippy", allow(too_many_arguments))]
-#![cfg_attr(feature = "cargo-clippy", allow(used_underscore_binding))]
-
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.35")]
+#![cfg_attr(feature = "cargo-clippy", allow(enum_variant_names, redundant_field_names,
+                                            too_many_arguments, used_underscore_binding))]
 // The `quote!` macro requires deep recursion.
-#![recursion_limit = "192"]
+#![recursion_limit = "512"]
 
-extern crate syn;
 #[macro_use]
 extern crate quote;
+#[macro_use]
+extern crate syn;
 
 extern crate serde_derive_internals as internals;
 
 extern crate proc_macro;
+extern crate proc_macro2;
+
 use proc_macro::TokenStream;
+use syn::DeriveInput;
 
 #[macro_use]
 mod bound;
@@ -49,18 +51,18 @@ mod de;
 
 #[proc_macro_derive(Serialize, attributes(serde))]
 pub fn derive_serialize(input: TokenStream) -> TokenStream {
-    let input = syn::parse_derive_input(&input.to_string()).unwrap();
+    let input: DeriveInput = syn::parse(input).unwrap();
     match ser::expand_derive_serialize(&input) {
-        Ok(expanded) => expanded.parse().unwrap(),
+        Ok(expanded) => expanded.into(),
         Err(msg) => panic!(msg),
     }
 }
 
 #[proc_macro_derive(Deserialize, attributes(serde))]
 pub fn derive_deserialize(input: TokenStream) -> TokenStream {
-    let input = syn::parse_derive_input(&input.to_string()).unwrap();
+    let input: DeriveInput = syn::parse(input).unwrap();
     match de::expand_derive_deserialize(&input) {
-        Ok(expanded) => expanded.parse().unwrap(),
+        Ok(expanded) => expanded.into(),
         Err(msg) => panic!(msg),
     }
 }

serde_derive/src/ser.rs

@@ -6,12 +6,14 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use syn::{self, Ident};
+use syn::{self, Ident, Index, Member};
+use syn::spanned::Spanned;
 use quote::Tokens;
+use proc_macro2::Span;
 
 use bound;
-use fragment::{Fragment, Stmts, Match};
-use internals::ast::{Body, Container, Field, Style, Variant};
+use fragment::{Fragment, Match, Stmts};
+use internals::ast::{Data, Container, Field, Style, Variant};
 use internals::{attr, Ctxt};
 
 use std::u32;
@@ -25,14 +27,15 @@ 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));
+    let dummy_const = Ident::new(&format!("_IMPL_SERIALIZE_FOR_{}", ident), Span::def_site());
     let body = Stmts(serialize_body(&cont, &params));
 
     let impl_block = if let Some(remote) = cont.attrs.remote() {
         let vis = &input.vis;
+        let fun = quote_spanned!(Span::call_site()=> serialize);
         quote! {
             impl #impl_generics #ident #ty_generics #where_clause {
-                #vis fn serialize<__S>(__self: &#remote #ty_generics, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+                #vis fn #fun<__S>(__self: &#remote #ty_generics, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
                     where __S: _serde::Serializer
                 {
                     #body
@@ -95,14 +98,14 @@ impl Parameters {
     fn new(cont: &Container) -> Self {
         let is_remote = cont.attrs.remote().is_some();
         let self_var = if is_remote {
-            Ident::new("__self")
+            Ident::new("__self", Span::def_site())
         } else {
-            Ident::new("self")
+            Ident::new("self", Span::def_site())
         };
 
         let this = match cont.attrs.remote() {
             Some(remote) => remote.clone(),
-            None => cont.ident.clone().into(),
+            None => cont.ident.into(),
         };
 
         let generics = build_generics(cont);
@@ -118,7 +121,7 @@ impl Parameters {
     /// Type name to use in error messages and `&'static str` arguments to
     /// various Serializer methods.
     fn type_name(&self) -> &str {
-        self.this.segments.last().unwrap().ident.as_ref()
+        self.this.segments.last().unwrap().value().ident.as_ref()
     }
 }
 
@@ -132,14 +135,12 @@ fn build_generics(cont: &Container) -> syn::Generics {
 
     match cont.attrs.ser_bound() {
         Some(predicates) => bound::with_where_predicates(&generics, predicates),
-        None => {
-            bound::with_bound(
-                cont,
-                &generics,
-                needs_serialize_bound,
-                &path!(_serde::Serialize),
-            )
-        }
+        None => bound::with_bound(
+            cont,
+            &generics,
+            needs_serialize_bound,
+            &parse_quote!(_serde::Serialize),
+        ),
     }
 }
 
@@ -149,43 +150,41 @@ fn build_generics(cont: &Container) -> syn::Generics {
 // their own bound so we do not generate one. All other fields may need a `T:
 // Serialize` bound where T is the type of the field.
 fn needs_serialize_bound(field: &attr::Field, variant: Option<&attr::Variant>) -> bool {
-    !field.skip_serializing() &&
-    field.serialize_with().is_none() &&
-    field.ser_bound().is_none() &&
-    variant.map_or(true, |variant| variant.serialize_with().is_none())
+    !field.skip_serializing() && field.serialize_with().is_none() && field.ser_bound().is_none()
+        && variant.map_or(true, |variant| variant.serialize_with().is_none())
 }
 
 fn serialize_body(cont: &Container, params: &Parameters) -> Fragment {
-    if let Some(into_type) = cont.attrs.into_type() {
-        serialize_into(params, into_type)
+    if let Some(type_into) = cont.attrs.type_into() {
+        serialize_into(params, type_into)
     } else {
-        match cont.body {
-            Body::Enum(ref variants) => serialize_enum(params, variants, &cont.attrs),
-            Body::Struct(Style::Struct, ref fields) => {
+        match cont.data {
+            Data::Enum(ref variants) => serialize_enum(params, variants, &cont.attrs),
+            Data::Struct(Style::Struct, ref fields) => {
                 if fields.iter().any(|field| field.ident.is_none()) {
                     panic!("struct has unnamed fields");
                 }
                 serialize_struct(params, fields, &cont.attrs)
             }
-            Body::Struct(Style::Tuple, ref fields) => {
+            Data::Struct(Style::Tuple, ref fields) => {
                 if fields.iter().any(|field| field.ident.is_some()) {
                     panic!("tuple struct has named fields");
                 }
                 serialize_tuple_struct(params, fields, &cont.attrs)
             }
-            Body::Struct(Style::Newtype, ref fields) => {
+            Data::Struct(Style::Newtype, ref fields) => {
                 serialize_newtype_struct(params, &fields[0], &cont.attrs)
             }
-            Body::Struct(Style::Unit, _) => serialize_unit_struct(&cont.attrs),
+            Data::Struct(Style::Unit, _) => serialize_unit_struct(&cont.attrs),
         }
     }
 }
 
-fn serialize_into(params: &Parameters, into_type: &syn::Ty) -> Fragment {
+fn serialize_into(params: &Parameters, type_into: &syn::Type) -> Fragment {
     let self_var = &params.self_var;
     quote_block! {
         _serde::Serialize::serialize(
-            &_serde::export::Into::<#into_type>::into(_serde::export::Clone::clone(#self_var)),
+            &_serde::export::Into::<#type_into>::into(_serde::export::Clone::clone(#self_var)),
             __serializer)
     }
 }
@@ -205,13 +204,18 @@ fn serialize_newtype_struct(
 ) -> Fragment {
     let type_name = cattrs.name().serialize_name();
 
-    let mut field_expr = get_field(params, field, 0);
+    let mut field_expr = get_member(params, 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);
+        field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
     }
 
+    let span = Span::def_site().located_at(field.original.span());
+    let func = quote_spanned!(span=> _serde::Serializer::serialize_newtype_struct);
     quote_expr! {
-        _serde::Serializer::serialize_newtype_struct(__serializer, #type_name, #field_expr)
+        #func(__serializer, #type_name, #field_expr)
     }
 }
 
@@ -224,7 +228,7 @@ fn serialize_tuple_struct(
         fields,
         params,
         false,
-        quote!(_serde::ser::SerializeTupleStruct::serialize_field),
+        &TupleTrait::SerializeTupleStruct,
     );
 
     let type_name = cattrs.name().serialize_name();
@@ -239,14 +243,21 @@ fn serialize_tuple_struct(
 }
 
 fn serialize_struct(params: &Parameters, fields: &[Field], cattrs: &attr::Container) -> Fragment {
-    assert!(fields.len() as u64 <= u32::MAX as u64);
+    assert!(fields.len() as u64 <= u64::from(u32::MAX));
 
+    if cattrs.has_flatten() {
+        serialize_struct_as_map(params, fields, cattrs)
+    } else {
+        serialize_struct_as_struct(params, fields, cattrs)
+    }
+}
+
+fn serialize_struct_as_struct(params: &Parameters, fields: &[Field], cattrs: &attr::Container) -> Fragment {
     let serialize_fields = serialize_struct_visitor(
         fields,
         params,
         false,
-        quote!(_serde::ser::SerializeStruct::serialize_field),
-        quote!(_serde::ser::SerializeStruct::skip_field),
+        &StructTrait::SerializeStruct,
     );
 
     let type_name = cattrs.name().serialize_name();
@@ -259,16 +270,14 @@ fn serialize_struct(params: &Parameters, fields: &[Field], cattrs: &attr::Contai
     let let_mut = mut_if(serialized_fields.peek().is_some());
 
     let len = serialized_fields
-        .map(
-            |field| match field.attrs.skip_serializing_if() {
-                None => quote!(1),
-                Some(path) => {
-                    let ident = field.ident.clone().expect("struct has unnamed fields");
-                    let field_expr = get_field(params, field, ident);
-                    quote!(if #path(#field_expr) { 0 } else { 1 })
-                }
-            },
-        )
+        .map(|field| match field.attrs.skip_serializing_if() {
+            None => quote!(1),
+            Some(path) => {
+                let ident = field.ident.expect("struct has unnamed fields");
+                let field_expr = get_member(params, field, &Member::Named(ident));
+                quote!(if #path(#field_expr) { 0 } else { 1 })
+            }
+        })
         .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
 
     quote_block! {
@@ -278,19 +287,55 @@ fn serialize_struct(params: &Parameters, fields: &[Field], cattrs: &attr::Contai
     }
 }
 
+fn serialize_struct_as_map(params: &Parameters, fields: &[Field], cattrs: &attr::Container) -> Fragment {
+    let serialize_fields = serialize_struct_visitor(
+        fields,
+        params,
+        false,
+        &StructTrait::SerializeMap,
+    );
+
+    let mut serialized_fields = fields
+        .iter()
+        .filter(|&field| !field.attrs.skip_serializing())
+        .peekable();
+
+    let let_mut = mut_if(serialized_fields.peek().is_some());
+
+    let len = if cattrs.has_flatten() {
+        quote!(_serde::export::None)
+    } else {
+        let len = serialized_fields
+            .map(|field| match field.attrs.skip_serializing_if() {
+                None => quote!(1),
+                Some(path) => {
+                    let ident = field.ident.expect("struct has unnamed fields");
+                    let field_expr = get_member(params, field, &Member::Named(ident));
+                    quote!(if #path(#field_expr) { 0 } else { 1 })
+                }
+            })
+            .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
+        quote!(_serde::export::Some(#len))
+    };
+
+    quote_block! {
+        let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(__serializer, #len));
+        #(#serialize_fields)*
+        _serde::ser::SerializeMap::end(__serde_state)
+    }
+}
+
 fn serialize_enum(params: &Parameters, variants: &[Variant], cattrs: &attr::Container) -> Fragment {
-    assert!(variants.len() as u64 <= u32::MAX as u64);
+    assert!(variants.len() as u64 <= u64::from(u32::MAX));
 
     let self_var = &params.self_var;
 
     let arms: Vec<_> = variants
         .iter()
         .enumerate()
-        .map(
-            |(variant_index, variant)| {
-                serialize_variant(params, variant, variant_index as u32, cattrs)
-            },
-        )
+        .map(|(variant_index, variant)| {
+            serialize_variant(params, variant, variant_index as u32, cattrs)
+        })
         .collect();
 
     quote_expr! {
@@ -307,7 +352,7 @@ fn serialize_variant(
     cattrs: &attr::Container,
 ) -> Tokens {
     let this = &params.this;
-    let variant_ident = variant.ident.clone();
+    let variant_ident = variant.ident;
 
     if variant.attrs.skip_serializing() {
         let skipped_msg = format!(
@@ -321,13 +366,7 @@ fn serialize_variant(
         let fields_pat = match variant.style {
             Style::Unit => quote!(),
             Style::Newtype | Style::Tuple => quote!((..)),
-            Style::Struct => {
-                quote!(
-                    {
-                        ..
-                    }
-                )
-            }
+            Style::Struct => quote!({ .. }),
         };
         quote! {
             #this::#variant_ident #fields_pat => #skipped_err,
@@ -347,7 +386,7 @@ fn serialize_variant(
             }
             Style::Tuple => {
                 let field_names =
-                    (0..variant.fields.len()).map(|i| Ident::new(format!("__field{}", i)));
+                    (0..variant.fields.len()).map(|i| Ident::new(&format!("__field{}", i), Span::def_site()));
                 quote! {
                     #this::#variant_ident(#(ref #field_names),*)
                 }
@@ -356,34 +395,26 @@ fn serialize_variant(
                 let fields = variant
                     .fields
                     .iter()
-                    .map(
-                        |f| {
-                            f.ident
-                                .clone()
-                                .expect("struct variant has unnamed fields")
-                        },
-                    );
+                    .map(|f| f.ident.expect("struct variant has unnamed fields"));
                 quote! {
                     #this::#variant_ident { #(ref #fields),* }
                 }
             }
         };
 
-        let body = Match(
-            match *cattrs.tag() {
-                attr::EnumTag::External => {
-                    serialize_externally_tagged_variant(params, variant, variant_index, cattrs)
-                }
-                attr::EnumTag::Internal { ref tag } => {
-                    serialize_internally_tagged_variant(params, variant, cattrs, tag)
-                }
-                attr::EnumTag::Adjacent {
-                    ref tag,
-                    ref content,
-                } => serialize_adjacently_tagged_variant(params, variant, cattrs, tag, content),
-                attr::EnumTag::None => serialize_untagged_variant(params, variant, cattrs),
-            },
-        );
+        let body = Match(match *cattrs.tag() {
+            attr::EnumTag::External => {
+                serialize_externally_tagged_variant(params, variant, variant_index, cattrs)
+            }
+            attr::EnumTag::Internal { ref tag } => {
+                serialize_internally_tagged_variant(params, variant, cattrs, tag)
+            }
+            attr::EnumTag::Adjacent {
+                ref tag,
+                ref content,
+            } => serialize_adjacently_tagged_variant(params, variant, cattrs, tag, content),
+            attr::EnumTag::None => serialize_untagged_variant(params, variant, cattrs),
+        });
 
         quote! {
             #case => #body
@@ -401,7 +432,7 @@ fn serialize_externally_tagged_variant(
     let variant_name = variant.attrs.name().serialize_name();
 
     if let Some(path) = variant.attrs.serialize_with() {
-        let ser = wrap_serialize_variant_with(params, path, &variant);
+        let ser = wrap_serialize_variant_with(params, path, variant);
         return quote_expr! {
             _serde::Serializer::serialize_newtype_variant(
                 __serializer,
@@ -428,7 +459,7 @@ fn serialize_externally_tagged_variant(
             let field = &variant.fields[0];
             let mut field_expr = quote!(__field0);
             if let Some(path) = field.attrs.serialize_with() {
-                field_expr = wrap_serialize_field_with(params, field.ty, path, field_expr);
+                field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
             }
 
             quote_expr! {
@@ -441,28 +472,24 @@ fn serialize_externally_tagged_variant(
                 )
             }
         }
-        Style::Tuple => {
-            serialize_tuple_variant(
-                TupleVariant::ExternallyTagged {
-                    type_name: type_name,
-                    variant_index: variant_index,
-                    variant_name: variant_name,
-                },
-                params,
-                &variant.fields,
-            )
-        }
-        Style::Struct => {
-            serialize_struct_variant(
-                StructVariant::ExternallyTagged {
-                    variant_index: variant_index,
-                    variant_name: variant_name,
-                },
-                params,
-                &variant.fields,
-                &type_name,
-            )
-        }
+        Style::Tuple => serialize_tuple_variant(
+            TupleVariant::ExternallyTagged {
+                type_name: type_name,
+                variant_index: variant_index,
+                variant_name: variant_name,
+            },
+            params,
+            &variant.fields,
+        ),
+        Style::Struct => serialize_struct_variant(
+            StructVariant::ExternallyTagged {
+                variant_index: variant_index,
+                variant_name: variant_name,
+            },
+            params,
+            &variant.fields,
+            &type_name,
+        ),
     }
 }
 
@@ -479,7 +506,7 @@ fn serialize_internally_tagged_variant(
     let variant_ident_str = variant.ident.as_ref();
 
     if let Some(path) = variant.attrs.serialize_with() {
-        let ser = wrap_serialize_variant_with(params, path, &variant);
+        let ser = wrap_serialize_variant_with(params, path, variant);
         return quote_expr! {
             _serde::private::ser::serialize_tagged_newtype(
                 __serializer,
@@ -506,7 +533,7 @@ fn serialize_internally_tagged_variant(
             let field = &variant.fields[0];
             let mut field_expr = quote!(__field0);
             if let Some(path) = field.attrs.serialize_with() {
-                field_expr = wrap_serialize_field_with(params, field.ty, path, field_expr);
+                field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
             }
 
             quote_expr! {
@@ -520,17 +547,15 @@ fn serialize_internally_tagged_variant(
                 )
             }
         }
-        Style::Struct => {
-            serialize_struct_variant(
-                StructVariant::InternallyTagged {
-                    tag: tag,
-                    variant_name: variant_name,
-                },
-                params,
-                &variant.fields,
-                &type_name,
-            )
-        }
+        Style::Struct => serialize_struct_variant(
+            StructVariant::InternallyTagged {
+                tag: tag,
+                variant_name: variant_name,
+            },
+            params,
+            &variant.fields,
+            &type_name,
+        ),
         Style::Tuple => unreachable!("checked in serde_derive_internals"),
     }
 }
@@ -546,51 +571,47 @@ fn serialize_adjacently_tagged_variant(
     let type_name = cattrs.name().serialize_name();
     let variant_name = variant.attrs.name().serialize_name();
 
-    let inner = Stmts(
-        if let Some(path) = variant.attrs.serialize_with() {
-            let ser = wrap_serialize_variant_with(params, path, &variant);
-            quote_expr! {
-                _serde::Serialize::serialize(#ser, __serializer)
+    let inner = Stmts(if let Some(path) = variant.attrs.serialize_with() {
+        let ser = wrap_serialize_variant_with(params, path, variant);
+        quote_expr! {
+            _serde::Serialize::serialize(#ser, __serializer)
+        }
+    } else {
+        match variant.style {
+            Style::Unit => {
+                return quote_block! {
+                    let mut __struct = try!(_serde::Serializer::serialize_struct(
+                        __serializer, #type_name, 1));
+                    try!(_serde::ser::SerializeStruct::serialize_field(
+                        &mut __struct, #tag, #variant_name));
+                    _serde::ser::SerializeStruct::end(__struct)
+                };
             }
-        } else {
-            match variant.style {
-                Style::Unit => {
-                    return quote_block! {
-                        let mut __struct = try!(_serde::Serializer::serialize_struct(
-                            __serializer, #type_name, 1));
-                        try!(_serde::ser::SerializeStruct::serialize_field(
-                            &mut __struct, #tag, #variant_name));
-                        _serde::ser::SerializeStruct::end(__struct)
-                    };
+            Style::Newtype => {
+                let field = &variant.fields[0];
+                let mut field_expr = quote!(__field0);
+                if let Some(path) = field.attrs.serialize_with() {
+                    field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
                 }
-                Style::Newtype => {
-                    let field = &variant.fields[0];
-                    let mut field_expr = quote!(__field0);
-                    if let Some(path) = field.attrs.serialize_with() {
-                        field_expr = wrap_serialize_field_with(params, field.ty, path, field_expr);
-                    }
 
-                    quote_expr! {
-                        _serde::Serialize::serialize(#field_expr, __serializer)
-                    }
-                }
-                Style::Tuple => {
-                    serialize_tuple_variant(TupleVariant::Untagged, params, &variant.fields)
-                }
-                Style::Struct => {
-                    serialize_struct_variant(
-                        StructVariant::Untagged,
-                        params,
-                        &variant.fields,
-                        &variant_name,
-                    )
+                quote_expr! {
+                    _serde::Serialize::serialize(#field_expr, __serializer)
                 }
             }
-        },
-    );
+            Style::Tuple => {
+                serialize_tuple_variant(TupleVariant::Untagged, params, &variant.fields)
+            }
+            Style::Struct => serialize_struct_variant(
+                StructVariant::Untagged,
+                params,
+                &variant.fields,
+                &variant_name,
+            ),
+        }
+    });
 
     let fields_ty = variant.fields.iter().map(|f| &f.ty);
-    let ref fields_ident: Vec<_> = match variant.style {
+    let fields_ident: &Vec<_> = &match variant.style {
         Style::Unit => {
             if variant.attrs.serialize_with().is_some() {
                 vec![]
@@ -598,25 +619,15 @@ fn serialize_adjacently_tagged_variant(
                 unreachable!()
             }
         }
-        Style::Newtype => vec![Ident::new("__field0")],
-        Style::Tuple => {
-            (0..variant.fields.len())
-                .map(|i| Ident::new(format!("__field{}", i)))
-                .collect()
-        }
-        Style::Struct => {
-            variant
-                .fields
-                .iter()
-                .map(
-                    |f| {
-                        f.ident
-                            .clone()
-                            .expect("struct variant has unnamed fields")
-                    },
-                )
-                .collect()
-        }
+        Style::Newtype => vec![Ident::new("__field0", Span::def_site())],
+        Style::Tuple => (0..variant.fields.len())
+            .map(|i| Ident::new(&format!("__field{}", i), Span::def_site()))
+            .collect(),
+        Style::Struct => variant
+            .fields
+            .iter()
+            .map(|f| f.ident.expect("struct variant has unnamed fields"))
+            .collect(),
     };
 
     let (_, ty_generics, where_clause) = params.generics.split_for_impl();
@@ -662,7 +673,7 @@ fn serialize_untagged_variant(
     cattrs: &attr::Container,
 ) -> Fragment {
     if let Some(path) = variant.attrs.serialize_with() {
-        let ser = wrap_serialize_variant_with(params, path, &variant);
+        let ser = wrap_serialize_variant_with(params, path, variant);
         return quote_expr! {
             _serde::Serialize::serialize(#ser, __serializer)
         };
@@ -678,7 +689,7 @@ fn serialize_untagged_variant(
             let field = &variant.fields[0];
             let mut field_expr = quote!(__field0);
             if let Some(path) = field.attrs.serialize_with() {
-                field_expr = wrap_serialize_field_with(params, field.ty, path, field_expr);
+                field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
             }
 
             quote_expr! {
@@ -707,14 +718,12 @@ fn serialize_tuple_variant(
     params: &Parameters,
     fields: &[Field],
 ) -> Fragment {
-    let method = match context {
-        TupleVariant::ExternallyTagged { .. } => {
-            quote!(_serde::ser::SerializeTupleVariant::serialize_field)
-        }
-        TupleVariant::Untagged => quote!(_serde::ser::SerializeTuple::serialize_element),
+    let tuple_trait = match context {
+        TupleVariant::ExternallyTagged { .. } => TupleTrait::SerializeTupleVariant,
+        TupleVariant::Untagged => TupleTrait::SerializeTuple,
     };
 
-    let serialize_stmts = serialize_tuple_struct_visitor(fields, params, true, method);
+    let serialize_stmts = serialize_tuple_struct_visitor(fields, params, true, &tuple_trait);
 
     let len = serialize_stmts.len();
     let let_mut = mut_if(len > 0);
@@ -753,7 +762,10 @@ enum StructVariant<'a> {
         variant_index: u32,
         variant_name: String,
     },
-    InternallyTagged { tag: &'a str, variant_name: String },
+    InternallyTagged {
+        tag: &'a str,
+        variant_name: String,
+    },
     Untagged,
 }
 
@@ -763,23 +775,16 @@ fn serialize_struct_variant<'a>(
     fields: &[Field],
     name: &str,
 ) -> Fragment {
-    let (method, skip_method) = match context {
-        StructVariant::ExternallyTagged { .. } => {
-            (
-                quote!(_serde::ser::SerializeStructVariant::serialize_field),
-                quote!(_serde::ser::SerializeStructVariant::skip_field),
-            )
-        }
-        StructVariant::InternallyTagged { .. } |
-        StructVariant::Untagged => {
-            (
-                quote!(_serde::ser::SerializeStruct::serialize_field),
-                quote!(_serde::ser::SerializeStruct::skip_field),
-            )
-        }
+    let struct_trait = match context {
+        StructVariant::ExternallyTagged { .. } => (
+            StructTrait::SerializeStructVariant
+        ),
+        StructVariant::InternallyTagged { .. } | StructVariant::Untagged => (
+            StructTrait::SerializeStruct
+        ),
     };
 
-    let serialize_fields = serialize_struct_visitor(fields, params, true, method, skip_method);
+    let serialize_fields = serialize_struct_visitor(fields, params, true, &struct_trait);
 
     let mut serialized_fields = fields
         .iter()
@@ -789,16 +794,14 @@ fn serialize_struct_variant<'a>(
     let let_mut = mut_if(serialized_fields.peek().is_some());
 
     let len = serialized_fields
-        .map(
-            |field| {
-                let ident = field.ident.clone().expect("struct has unnamed fields");
+        .map(|field| {
+            let ident = field.ident.expect("struct has unnamed fields");
 
-                match field.attrs.skip_serializing_if() {
-                    Some(path) => quote!(if #path(#ident) { 0 } else { 1 }),
-                    None => quote!(1),
-                }
-            },
-        )
+            match field.attrs.skip_serializing_if() {
+                Some(path) => quote!(if #path(#ident) { 0 } else { 1 }),
+                None => quote!(1),
+            }
+        })
         .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
 
     match context {
@@ -852,39 +855,42 @@ fn serialize_tuple_struct_visitor(
     fields: &[Field],
     params: &Parameters,
     is_enum: bool,
-    func: Tokens,
+    tuple_trait: &TupleTrait,
 ) -> Vec<Tokens> {
     fields
         .iter()
         .enumerate()
-        .map(
-            |(i, field)| {
-                let mut field_expr = if is_enum {
-                    let id = Ident::new(format!("__field{}", i));
-                    quote!(#id)
-                } else {
-                    get_field(params, field, i)
-                };
+        .map(|(i, field)| {
+            let mut field_expr = if is_enum {
+                let id = Ident::new(&format!("__field{}", i), Span::def_site());
+                quote!(#id)
+            } else {
+                get_member(params, field, &Member::Unnamed(Index {
+                    index: i as u32,
+                    span: Span::call_site(),
+                }))
+            };
 
-                let skip = field
-                    .attrs
-                    .skip_serializing_if()
-                    .map(|path| quote!(#path(#field_expr)));
+            let skip = field
+                .attrs
+                .skip_serializing_if()
+                .map(|path| quote!(#path(#field_expr)));
 
-                if let Some(path) = field.attrs.serialize_with() {
-                    field_expr = wrap_serialize_field_with(params, field.ty, path, field_expr);
-                }
+            if let Some(path) = field.attrs.serialize_with() {
+                field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
+            }
 
-                let ser = quote! {
-                    try!(#func(&mut __serde_state, #field_expr));
-                };
+            let span = Span::def_site().located_at(field.original.span());
+            let func = tuple_trait.serialize_element(span);
+            let ser = quote! {
+                try!(#func(&mut __serde_state, #field_expr));
+            };
 
-                match skip {
-                    None => ser,
-                    Some(skip) => quote!(if !#skip { #ser }),
-                }
-            },
-        )
+            match skip {
+                None => ser,
+                Some(skip) => quote!(if !#skip { #ser }),
+            }
+        })
         .collect()
 }
 
@@ -892,39 +898,47 @@ fn serialize_struct_visitor(
     fields: &[Field],
     params: &Parameters,
     is_enum: bool,
-    func: Tokens,
-    skip_func: Tokens,
+    struct_trait: &StructTrait,
 ) -> Vec<Tokens> {
     fields
         .iter()
         .filter(|&field| !field.attrs.skip_serializing())
-        .map(
-            |field| {
-                let field_ident = field.ident.clone().expect("struct has unnamed field");
-                let mut field_expr = if is_enum {
-                    quote!(#field_ident)
-                } else {
-                    get_field(params, field, field_ident)
-                };
+        .map(|field| {
+            let field_ident = field.ident.expect("struct has unnamed field");
 
-                let key_expr = field.attrs.name().serialize_name();
+            let mut field_expr = if is_enum {
+                quote!(#field_ident)
+            } else {
+                get_member(params, field, &Member::Named(field_ident))
+            };
 
-                let skip = field
-                    .attrs
-                    .skip_serializing_if()
-                    .map(|path| quote!(#path(#field_expr)));
+            let key_expr = field.attrs.name().serialize_name();
 
-                if let Some(path) = field.attrs.serialize_with() {
-                    field_expr = wrap_serialize_field_with(params, field.ty, path, field_expr);
+            let skip = field
+                .attrs
+                .skip_serializing_if()
+                .map(|path| quote!(#path(#field_expr)));
+
+            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 ser = if field.attrs.flatten() {
+                quote! {
+                    try!(_serde::Serialize::serialize(&#field_expr, _serde::private::ser::FlatMapSerializer(&mut __serde_state)));
                 }
-
-                let ser = quote! {
+            } else {
+                let func = struct_trait.serialize_field(span);
+                quote! {
                     try!(#func(&mut __serde_state, #key_expr, #field_expr));
-                };
+                }
+            };
 
-                match skip {
-                    None => ser,
-                    Some(skip) => {
+            match skip {
+                None => ser,
+                Some(skip) => {
+                    if let Some(skip_func) = struct_trait.skip_field(span) {
                         quote! {
                             if !#skip {
                                 #ser
@@ -932,59 +946,73 @@ fn serialize_struct_visitor(
                                 try!(#skip_func(&mut __serde_state, #key_expr));
                             }
                         }
+                    } else {
+                        quote! {
+                            if !#skip {
+                                #ser
+                            }
+                        }
                     }
                 }
-            },
-        )
+            }
+        })
         .collect()
 }
 
 fn wrap_serialize_field_with(
     params: &Parameters,
-    field_ty: &syn::Ty,
-    serialize_with: &syn::Path,
-    field_expr: Tokens,
+    field_ty: &syn::Type,
+    serialize_with: &syn::ExprPath,
+    field_expr: &Tokens,
 ) -> Tokens {
-    wrap_serialize_with(params,
-                        serialize_with,
-                        &[field_ty],
-                        &[quote!(#field_expr)])
+    wrap_serialize_with(params, serialize_with, &[field_ty], &[quote!(#field_expr)])
 }
 
 fn wrap_serialize_variant_with(
     params: &Parameters,
-    serialize_with: &syn::Path,
+    serialize_with: &syn::ExprPath,
     variant: &Variant,
 ) -> Tokens {
     let field_tys: Vec<_> = variant.fields.iter().map(|field| field.ty).collect();
-    let field_exprs: Vec<_> = variant.fields.iter()
+    let field_exprs: Vec<_> = variant
+        .fields
+        .iter()
         .enumerate()
         .map(|(i, field)| {
-            let id = field.ident.as_ref().map_or_else(|| Ident::new(format!("__field{}", i)),
-                                                      |id| id.clone());
+            let id = field
+                .ident
+                .unwrap_or_else(|| Ident::new(&format!("__field{}", i), Span::def_site()));
             quote!(#id)
         })
         .collect();
-    wrap_serialize_with(params, serialize_with, field_tys.as_slice(), field_exprs.as_slice())
+    wrap_serialize_with(
+        params,
+        serialize_with,
+        field_tys.as_slice(),
+        field_exprs.as_slice(),
+    )
 }
 
 fn wrap_serialize_with(
     params: &Parameters,
-    serialize_with: &syn::Path,
-    field_tys: &[&syn::Ty],
+    serialize_with: &syn::ExprPath,
+    field_tys: &[&syn::Type],
     field_exprs: &[Tokens],
 ) -> Tokens {
     let this = &params.this;
     let (_, ty_generics, where_clause) = params.generics.split_for_impl();
 
-    let wrapper_generics = if field_exprs.len() == 0 {
+    let wrapper_generics = if field_exprs.is_empty() {
         params.generics.clone()
     } else {
         bound::with_lifetime_bound(&params.generics, "'__a")
     };
     let (wrapper_impl_generics, wrapper_ty_generics, _) = wrapper_generics.split_for_impl();
 
-    let field_access = (0..field_exprs.len()).map(|n| Ident::new(format!("{}", n)));
+    let field_access = (0..field_exprs.len()).map(|n| Member::Unnamed(Index {
+        index: n as u32,
+        span: Span::call_site(),
+    }));
 
     quote!({
         struct __SerializeWith #wrapper_impl_generics #where_clause {
@@ -1014,23 +1042,23 @@ fn wrap_serialize_with(
 //
 // where we want to omit the `mut` to avoid a warning.
 fn mut_if(is_mut: bool) -> Option<Tokens> {
-    if is_mut { Some(quote!(mut)) } else { None }
+    if is_mut {
+        Some(quote!(mut))
+    } else {
+        None
+    }
 }
 
-fn get_field<I>(params: &Parameters, field: &Field, ident: I) -> Tokens
-where
-    I: Into<Ident>,
-{
+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) => {
-            let ident = ident.into();
-            quote!(&#self_var.#ident)
+            quote_spanned!(Span::call_site()=> &#self_var.#member)
         }
         (true, None) => {
+            let inner = quote_spanned!(Span::call_site()=> &#self_var.#member);
             let ty = field.ty;
-            let ident = ident.into();
-            quote!(_serde::private::ser::constrain::<#ty>(&#self_var.#ident))
+            quote!(_serde::private::ser::constrain::<#ty>(#inner))
         }
         (true, Some(getter)) => {
             let ty = field.ty;
@@ -1041,3 +1069,59 @@ where
         }
     }
 }
+
+enum StructTrait {
+    SerializeMap,
+    SerializeStruct,
+    SerializeStructVariant,
+}
+
+impl StructTrait {
+    fn serialize_field(&self, span: Span) -> Tokens {
+        match *self {
+            StructTrait::SerializeMap => {
+                quote_spanned!(span=> _serde::ser::SerializeMap::serialize_entry)
+            }
+            StructTrait::SerializeStruct => {
+                quote_spanned!(span=> _serde::ser::SerializeStruct::serialize_field)
+            }
+            StructTrait::SerializeStructVariant => {
+                quote_spanned!(span=> _serde::ser::SerializeStructVariant::serialize_field)
+            }
+        }
+    }
+
+    fn skip_field(&self, span: Span) -> Option<Tokens> {
+        match *self {
+            StructTrait::SerializeMap => None,
+            StructTrait::SerializeStruct => Some({
+                quote_spanned!(span=> _serde::ser::SerializeStruct::skip_field)
+            }),
+            StructTrait::SerializeStructVariant => Some({
+                quote_spanned!(span=> _serde::ser::SerializeStructVariant::skip_field)
+            })
+        }
+    }
+}
+
+enum TupleTrait {
+    SerializeTuple,
+    SerializeTupleStruct,
+    SerializeTupleVariant,
+}
+
+impl TupleTrait {
+    fn serialize_element(&self, span: Span) -> Tokens {
+        match *self {
+            TupleTrait::SerializeTuple => {
+                quote_spanned!(span=> _serde::ser::SerializeTuple::serialize_element)
+            }
+            TupleTrait::SerializeTupleStruct => {
+                quote_spanned!(span=> _serde::ser::SerializeTupleStruct::serialize_field)
+            }
+            TupleTrait::SerializeTupleVariant => {
+                quote_spanned!(span=> _serde::ser::SerializeTupleVariant::serialize_field)
+            }
+        }
+    }
+}

serde_derive_internals/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive_internals"
-version = "0.17.0" # remember to update html_root_url
+version = "0.22.1" # 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]
-syn = { version = "0.11.10", default-features = false, features = ["parsing"] }
-synom = "0.11"
+proc-macro2 = "0.2"
+syn = { version = "0.12", default-features = false, features = ["derive", "parsing", "clone-impls"] }
 
 [badges]
 travis-ci = { repository = "serde-rs/serde" }

serde_derive_internals/src/ast.rs

@@ -10,15 +10,16 @@ use syn;
 use attr;
 use check;
 use Ctxt;
+use syn::punctuated::Punctuated;
 
 pub struct Container<'a> {
     pub ident: syn::Ident,
     pub attrs: attr::Container,
-    pub body: Body<'a>,
+    pub data: Data<'a>,
     pub generics: &'a syn::Generics,
 }
 
-pub enum Body<'a> {
+pub enum Data<'a> {
     Enum(Vec<Variant<'a>>),
     Struct(Style, Vec<Field<'a>>),
 }
@@ -33,7 +34,8 @@ pub struct Variant<'a> {
 pub struct Field<'a> {
     pub ident: Option<syn::Ident>,
     pub attrs: attr::Field,
-    pub ty: &'a syn::Ty,
+    pub ty: &'a syn::Type,
+    pub original: &'a syn::Field,
 }
 
 #[derive(Copy, Clone)]
@@ -46,36 +48,45 @@ pub enum Style {
 
 impl<'a> Container<'a> {
     pub fn from_ast(cx: &Ctxt, item: &'a syn::DeriveInput) -> Container<'a> {
-        let attrs = attr::Container::from_ast(cx, item);
+        let mut attrs = attr::Container::from_ast(cx, item);
 
-        let mut body = match item.body {
-            syn::Body::Enum(ref variants) => Body::Enum(enum_from_ast(cx, variants)),
-            syn::Body::Struct(ref variant_data) => {
-                let (style, fields) = struct_from_ast(cx, variant_data, None);
-                Body::Struct(style, fields)
+        let mut data = match item.data {
+            syn::Data::Enum(ref data) => {
+                Data::Enum(enum_from_ast(cx, &data.variants, attrs.default()))
+            }
+            syn::Data::Struct(ref data) => {
+                let (style, fields) = struct_from_ast(cx, &data.fields, None, attrs.default());
+                Data::Struct(style, fields)
+            }
+            syn::Data::Union(_) => {
+                panic!("Serde does not support derive for unions");
             }
         };
 
-        match body {
-            Body::Enum(ref mut variants) => {
-                for ref mut variant in variants {
-                    variant.attrs.rename_by_rule(attrs.rename_all());
-                    for ref mut field in &mut variant.fields {
-                        field.attrs.rename_by_rule(variant.attrs.rename_all());
-                    }
+        let mut has_flatten = false;
+        match data {
+            Data::Enum(ref mut variants) => for variant in variants {
+                variant.attrs.rename_by_rule(attrs.rename_all());
+                for field in &mut variant.fields {
+                    field.attrs.rename_by_rule(variant.attrs.rename_all());
                 }
-            }
-            Body::Struct(_, ref mut fields) => {
-                for field in fields {
-                    field.attrs.rename_by_rule(attrs.rename_all());
+            },
+            Data::Struct(_, ref mut fields) => for field in fields {
+                if field.attrs.flatten() {
+                    has_flatten = true;
                 }
-            }
+                field.attrs.rename_by_rule(attrs.rename_all());
+            },
+        }
+
+        if has_flatten {
+            attrs.mark_has_flatten();
         }
 
         let item = Container {
-            ident: item.ident.clone(),
+            ident: item.ident,
             attrs: attrs,
-            body: body,
+            data: data,
             generics: &item.generics,
         };
         check::check(cx, &item);
@@ -83,13 +94,13 @@ impl<'a> Container<'a> {
     }
 }
 
-impl<'a> Body<'a> {
+impl<'a> Data<'a> {
     pub fn all_fields(&'a self) -> Box<Iterator<Item = &'a Field<'a>> + 'a> {
         match *self {
-            Body::Enum(ref variants) => {
+            Data::Enum(ref variants) => {
                 Box::new(variants.iter().flat_map(|variant| variant.fields.iter()))
             }
-            Body::Struct(_, ref fields) => Box::new(fields.iter()),
+            Data::Struct(_, ref fields) => Box::new(fields.iter()),
         }
     }
 
@@ -98,47 +109,64 @@ impl<'a> Body<'a> {
     }
 }
 
-fn enum_from_ast<'a>(cx: &Ctxt, variants: &'a [syn::Variant]) -> Vec<Variant<'a>> {
+fn enum_from_ast<'a>(
+    cx: &Ctxt,
+    variants: &'a Punctuated<syn::Variant, Token![,]>,
+    container_default: &attr::Default,
+) -> Vec<Variant<'a>> {
     variants
         .iter()
-        .map(
-            |variant| {
-                let attrs = attr::Variant::from_ast(cx, variant);
-                let (style, fields) = struct_from_ast(cx, &variant.data, Some(&attrs));
-                Variant {
-                    ident: variant.ident.clone(),
-                    attrs: attrs,
-                    style: style,
-                    fields: fields,
-                }
-            },
-        )
+        .map(|variant| {
+            let attrs = attr::Variant::from_ast(cx, variant);
+            let (style, fields) =
+                struct_from_ast(cx, &variant.fields, Some(&attrs), container_default);
+            Variant {
+                ident: variant.ident,
+                attrs: attrs,
+                style: style,
+                fields: fields,
+            }
+        })
         .collect()
 }
 
-fn struct_from_ast<'a>(cx: &Ctxt, data: &'a syn::VariantData, attrs: Option<&attr::Variant>) -> (Style, Vec<Field<'a>>) {
-    match *data {
-        syn::VariantData::Struct(ref fields) => (Style::Struct, fields_from_ast(cx, fields, attrs)),
-        syn::VariantData::Tuple(ref fields) if fields.len() == 1 => {
-            (Style::Newtype, fields_from_ast(cx, fields, attrs))
-        }
-        syn::VariantData::Tuple(ref fields) => (Style::Tuple, fields_from_ast(cx, fields, attrs)),
-        syn::VariantData::Unit => (Style::Unit, Vec::new()),
+fn struct_from_ast<'a>(
+    cx: &Ctxt,
+    fields: &'a syn::Fields,
+    attrs: Option<&attr::Variant>,
+    container_default: &attr::Default,
+) -> (Style, Vec<Field<'a>>) {
+    match *fields {
+        syn::Fields::Named(ref fields) => (
+            Style::Struct,
+            fields_from_ast(cx, &fields.named, attrs, container_default),
+        ),
+        syn::Fields::Unnamed(ref fields) if fields.unnamed.len() == 1 => (
+            Style::Newtype,
+            fields_from_ast(cx, &fields.unnamed, attrs, container_default),
+        ),
+        syn::Fields::Unnamed(ref fields) => (
+            Style::Tuple,
+            fields_from_ast(cx, &fields.unnamed, attrs, container_default),
+        ),
+        syn::Fields::Unit => (Style::Unit, Vec::new()),
     }
 }
 
-fn fields_from_ast<'a>(cx: &Ctxt, fields: &'a [syn::Field], attrs: Option<&attr::Variant>) -> Vec<Field<'a>> {
+fn fields_from_ast<'a>(
+    cx: &Ctxt,
+    fields: &'a Punctuated<syn::Field, Token![,]>,
+    attrs: Option<&attr::Variant>,
+    container_default: &attr::Default,
+) -> Vec<Field<'a>> {
     fields
         .iter()
         .enumerate()
-        .map(
-            |(i, field)| {
-                Field {
-                    ident: field.ident.clone(),
-                    attrs: attr::Field::from_ast(cx, i, field, attrs),
-                    ty: &field.ty,
-                }
-            },
-        )
+        .map(|(i, field)| Field {
+            ident: field.ident,
+            attrs: attr::Field::from_ast(cx, i, field, attrs, container_default),
+            ty: &field.ty,
+            original: field,
+        })
         .collect()
 }

serde_derive_internals/src/case.rs

@@ -7,19 +7,21 @@
 // except according to those terms.
 
 // See https://users.rust-lang.org/t/psa-dealing-with-warning-unused-import-std-ascii-asciiext-in-today-s-nightly/13726
-#[allow(unused_imports)]
+#[allow(deprecated, unused_imports)]
 use std::ascii::AsciiExt;
 
 use std::str::FromStr;
 
 use self::RenameRule::*;
 
-#[derive(Debug, PartialEq)]
+#[derive(PartialEq)]
 pub enum RenameRule {
     /// Don't apply a default rename rule.
     None,
     /// Rename direct children to "lowercase" style.
     LowerCase,
+    /// Rename direct children to "UPPERCASE" style.
+    UPPERCASE,
     /// Rename direct children to "PascalCase" style, as typically used for enum variants.
     PascalCase,
     /// Rename direct children to "camelCase" style.
@@ -31,7 +33,7 @@ pub enum RenameRule {
     /// Rename direct children to "kebab-case" style.
     KebabCase,
     /// Rename direct children to "SCREAMING-KEBAB-CASE" style.
-    ScreamingKebabCase
+    ScreamingKebabCase,
 }
 
 impl RenameRule {
@@ -39,6 +41,7 @@ impl RenameRule {
         match *self {
             None | PascalCase => variant.to_owned(),
             LowerCase => variant.to_ascii_lowercase(),
+            UPPERCASE => variant.to_ascii_uppercase(),
             CamelCase => variant[..1].to_ascii_lowercase() + &variant[1..],
             SnakeCase => {
                 let mut snake = String::new();
@@ -52,13 +55,16 @@ impl RenameRule {
             }
             ScreamingSnakeCase => SnakeCase.apply_to_variant(variant).to_ascii_uppercase(),
             KebabCase => SnakeCase.apply_to_variant(variant).replace('_', "-"),
-            ScreamingKebabCase => ScreamingSnakeCase.apply_to_variant(variant).replace('_', "-")
+            ScreamingKebabCase => ScreamingSnakeCase
+                .apply_to_variant(variant)
+                .replace('_', "-"),
         }
     }
 
     pub fn apply_to_field(&self, field: &str) -> String {
         match *self {
             None | LowerCase | SnakeCase => field.to_owned(),
+            UPPERCASE => field.to_ascii_uppercase(),
             PascalCase => {
                 let mut pascal = String::new();
                 let mut capitalize = true;
@@ -80,7 +86,7 @@ impl RenameRule {
             }
             ScreamingSnakeCase => field.to_ascii_uppercase(),
             KebabCase => field.replace('_', "-"),
-            ScreamingKebabCase => ScreamingSnakeCase.apply_to_field(field).replace('_', "-")
+            ScreamingKebabCase => ScreamingSnakeCase.apply_to_field(field).replace('_', "-"),
         }
     }
 }
@@ -91,6 +97,7 @@ impl FromStr for RenameRule {
     fn from_str(rename_all_str: &str) -> Result<Self, Self::Err> {
         match rename_all_str {
             "lowercase" => Ok(LowerCase),
+            "UPPERCASE" => Ok(UPPERCASE),
             "PascalCase" => Ok(PascalCase),
             "camelCase" => Ok(CamelCase),
             "snake_case" => Ok(SnakeCase),
@@ -104,34 +111,71 @@ impl FromStr for RenameRule {
 
 #[test]
 fn rename_variants() {
-    for &(original, lower, camel, snake, screaming, kebab, screaming_kebab) in
-        &[
-            ("Outcome", "outcome", "outcome", "outcome", "OUTCOME", "outcome", "OUTCOME"),
-            ("VeryTasty", "verytasty", "veryTasty", "very_tasty", "VERY_TASTY", "very-tasty", "VERY-TASTY"),
-            ("A", "a", "a", "a", "A", "a", "A"),
-            ("Z42", "z42", "z42", "z42", "Z42", "z42", "Z42"),
-        ] {
+    for &(original, lower, upper, camel, snake, screaming, kebab, screaming_kebab) in &[
+        (
+            "Outcome",
+            "outcome",
+            "OUTCOME",
+            "outcome",
+            "outcome",
+            "OUTCOME",
+            "outcome",
+            "OUTCOME",
+        ),
+        (
+            "VeryTasty",
+            "verytasty",
+            "VERYTASTY",
+            "veryTasty",
+            "very_tasty",
+            "VERY_TASTY",
+            "very-tasty",
+            "VERY-TASTY",
+        ),
+        ("A", "a", "A", "a", "a", "A", "a", "A"),
+        ("Z42", "z42", "Z42", "z42", "z42", "Z42", "z42", "Z42"),
+    ] {
         assert_eq!(None.apply_to_variant(original), original);
         assert_eq!(LowerCase.apply_to_variant(original), lower);
+        assert_eq!(UPPERCASE.apply_to_variant(original), upper);
         assert_eq!(PascalCase.apply_to_variant(original), original);
         assert_eq!(CamelCase.apply_to_variant(original), camel);
         assert_eq!(SnakeCase.apply_to_variant(original), snake);
         assert_eq!(ScreamingSnakeCase.apply_to_variant(original), screaming);
         assert_eq!(KebabCase.apply_to_variant(original), kebab);
-        assert_eq!(ScreamingKebabCase.apply_to_variant(original), screaming_kebab);
+        assert_eq!(
+            ScreamingKebabCase.apply_to_variant(original),
+            screaming_kebab
+        );
     }
 }
 
 #[test]
 fn rename_fields() {
-    for &(original, pascal, camel, screaming, kebab, screaming_kebab) in
-        &[
-            ("outcome", "Outcome", "outcome", "OUTCOME", "outcome", "OUTCOME"),
-            ("very_tasty", "VeryTasty", "veryTasty", "VERY_TASTY", "very-tasty", "VERY-TASTY"),
-            ("a", "A", "a", "A", "a", "A"),
-            ("z42", "Z42", "z42", "Z42", "z42", "Z42"),
-        ] {
+    for &(original, upper, pascal, camel, screaming, kebab, screaming_kebab) in &[
+        (
+            "outcome",
+            "OUTCOME",
+            "Outcome",
+            "outcome",
+            "OUTCOME",
+            "outcome",
+            "OUTCOME",
+        ),
+        (
+            "very_tasty",
+            "VERY_TASTY",
+            "VeryTasty",
+            "veryTasty",
+            "VERY_TASTY",
+            "very-tasty",
+            "VERY-TASTY",
+        ),
+        ("a", "A", "A", "a", "A", "a", "A"),
+        ("z42", "Z42", "Z42", "z42", "Z42", "z42", "Z42"),
+    ] {
         assert_eq!(None.apply_to_field(original), original);
+        assert_eq!(UPPERCASE.apply_to_field(original), upper);
         assert_eq!(PascalCase.apply_to_field(original), pascal);
         assert_eq!(CamelCase.apply_to_field(original), camel);
         assert_eq!(SnakeCase.apply_to_field(original), original);

serde_derive_internals/src/check.rs

@@ -6,38 +6,73 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use ast::{Body, Container, Style};
-use attr::Identifier;
+use ast::{Data, Container, Style};
+use attr::{Identifier, EnumTag};
 use Ctxt;
 
 /// Cross-cutting checks that require looking at more than a single attrs
 /// object. Simpler checks should happen when parsing and building the attrs.
 pub fn check(cx: &Ctxt, cont: &Container) {
     check_getter(cx, cont);
+    check_flatten(cx, cont);
     check_identifier(cx, cont);
     check_variant_skip_attrs(cx, cont);
+    check_internal_tag_field_name_conflict(cx, cont);
+    check_adjacent_tag_conflict(cx, cont);
 }
 
 /// Getters are only allowed inside structs (not enums) with the `remote`
 /// attribute.
 fn check_getter(cx: &Ctxt, cont: &Container) {
-    match cont.body {
-        Body::Enum(_) => {
-            if cont.body.has_getter() {
+    match cont.data {
+        Data::Enum(_) => {
+            if cont.data.has_getter() {
                 cx.error("#[serde(getter = \"...\")] is not allowed in an enum");
             }
         }
-        Body::Struct(_, _) => {
-            if cont.body.has_getter() && cont.attrs.remote().is_none() {
+        Data::Struct(_, _) => {
+            if cont.data.has_getter() && cont.attrs.remote().is_none() {
                 cx.error(
                     "#[serde(getter = \"...\")] can only be used in structs \
-                          that have #[serde(remote = \"...\")]",
+                     that have #[serde(remote = \"...\")]",
                 );
             }
         }
     }
 }
 
+/// Flattening has some restrictions we can test.
+fn check_flatten(cx: &Ctxt, cont: &Container) {
+    match cont.data {
+        Data::Enum(_) => {
+            assert!(!cont.attrs.has_flatten());
+        }
+        Data::Struct(_, _) => {
+            for field in cont.data.all_fields() {
+                if !field.attrs.flatten() {
+                    continue;
+                }
+                if field.attrs.skip_serializing() {
+                    cx.error(
+                        "#[serde(flatten] can not be combined with \
+                         #[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 = \"...\")]"
+                    );
+                } else if field.attrs.skip_deserializing() {
+                    cx.error(
+                        "#[serde(flatten] can not be combined with \
+                         #[serde(skip_deserializing)]"
+                    );
+                }
+            }
+        }
+    }
+}
+
 /// The `other` attribute must be used at most once and it must be the last
 /// variant of an enum that has the `field_identifier` attribute.
 ///
@@ -45,18 +80,21 @@ fn check_getter(cx: &Ctxt, cont: &Container) {
 /// `field_identifier` all but possibly one variant must be unit variants. The
 /// last variant may be a newtype variant which is an implicit "other" case.
 fn check_identifier(cx: &Ctxt, cont: &Container) {
-    let variants = match cont.body {
-        Body::Enum(ref variants) => variants,
-        Body::Struct(_, _) => {
+    let variants = match cont.data {
+        Data::Enum(ref variants) => variants,
+        Data::Struct(_, _) => {
             return;
         }
     };
 
     for (i, variant) in variants.iter().enumerate() {
-        match (variant.style, cont.attrs.identifier(), variant.attrs.other()) {
+        match (
+            variant.style,
+            cont.attrs.identifier(),
+            variant.attrs.other(),
+        ) {
             // The `other` attribute may only be used in a field_identifier.
-            (_, Identifier::Variant, true) |
-            (_, Identifier::No, true) => {
+            (_, Identifier::Variant, true) | (_, Identifier::No, true) => {
                 cx.error("#[serde(other)] may only be used inside a field_identifier");
             }
 
@@ -99,9 +137,9 @@ fn check_identifier(cx: &Ctxt, cont: &Container) {
 /// Skip-(de)serializing attributes are not allowed on variants marked
 /// (de)serialize_with.
 fn check_variant_skip_attrs(cx: &Ctxt, cont: &Container) {
-    let variants = match cont.body {
-        Body::Enum(ref variants) => variants,
-        Body::Struct(_, _) => {
+    let variants = match cont.data {
+        Data::Enum(ref variants) => variants,
+        Data::Struct(_, _) => {
             return;
         }
     };
@@ -109,44 +147,124 @@ fn check_variant_skip_attrs(cx: &Ctxt, cont: &Container) {
     for variant in variants.iter() {
         if variant.attrs.serialize_with().is_some() {
             if variant.attrs.skip_serializing() {
-                cx.error(format!("variant `{}` cannot have both #[serde(serialize_with)] and \
-                                  #[serde(skip_serializing)]", variant.ident));
+                cx.error(format!(
+                    "variant `{}` cannot have both #[serde(serialize_with)] and \
+                     #[serde(skip_serializing)]",
+                    variant.ident
+                ));
             }
 
             for (i, field) in variant.fields.iter().enumerate() {
-                let ident = field.ident.as_ref().map_or_else(|| format!("{}", i),
-                                                             |ident| format!("`{}`", ident));
+                let ident = field
+                    .ident
+                    .as_ref()
+                    .map_or_else(|| format!("{}", i), |ident| format!("`{}`", ident));
 
                 if field.attrs.skip_serializing() {
-                    cx.error(format!("variant `{}` cannot have both #[serde(serialize_with)] and \
-                                      a field {} marked with #[serde(skip_serializing)]",
-                                     variant.ident, ident));
+                    cx.error(format!(
+                        "variant `{}` cannot have both #[serde(serialize_with)] and \
+                         a field {} marked with #[serde(skip_serializing)]",
+                        variant.ident, ident
+                    ));
                 }
 
                 if field.attrs.skip_serializing_if().is_some() {
-                    cx.error(format!("variant `{}` cannot have both #[serde(serialize_with)] and \
-                                      a field {} marked with #[serde(skip_serializing_if)]",
-                                     variant.ident, ident));
+                    cx.error(format!(
+                        "variant `{}` cannot have both #[serde(serialize_with)] and \
+                         a field {} marked with #[serde(skip_serializing_if)]",
+                        variant.ident, ident
+                    ));
                 }
             }
         }
 
         if variant.attrs.deserialize_with().is_some() {
             if variant.attrs.skip_deserializing() {
-                cx.error(format!("variant `{}` cannot have both #[serde(deserialize_with)] and \
-                                  #[serde(skip_deserializing)]", variant.ident));
+                cx.error(format!(
+                    "variant `{}` cannot have both #[serde(deserialize_with)] and \
+                     #[serde(skip_deserializing)]",
+                    variant.ident
+                ));
             }
 
             for (i, field) in variant.fields.iter().enumerate() {
                 if field.attrs.skip_deserializing() {
-                    let ident = field.ident.as_ref().map_or_else(|| format!("{}", i),
-                                                                 |ident| format!("`{}`", ident));
+                    let ident = field
+                        .ident
+                        .as_ref()
+                        .map_or_else(|| format!("{}", i), |ident| format!("`{}`", ident));
 
-                    cx.error(format!("variant `{}` cannot have both #[serde(deserialize_with)] \
-                                      and a field {} marked with #[serde(skip_deserializing)]",
-                                     variant.ident, ident));
+                    cx.error(format!(
+                        "variant `{}` cannot have both #[serde(deserialize_with)] \
+                         and a field {} marked with #[serde(skip_deserializing)]",
+                        variant.ident, ident
+                    ));
                 }
             }
         }
     }
 }
+
+/// The tag of an internally-tagged struct variant must not be
+/// 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(
+    cx: &Ctxt,
+    cont: &Container,
+) {
+    let variants = match cont.data {
+        Data::Enum(ref variants) => variants,
+        Data::Struct(_, _) => return,
+    };
+
+    let tag = match *cont.attrs.tag() {
+        EnumTag::Internal { ref tag } => tag.as_str(),
+        EnumTag::External | EnumTag::Adjacent { .. } | EnumTag::None => return,
+    };
+
+    let diagnose_conflict = || {
+        let message = format!(
+            "variant field name `{}` conflicts with internal tag",
+            tag
+        );
+        cx.error(message);
+    };
+
+    for variant in variants {
+        match variant.style {
+            Style::Struct => {
+                for field in &variant.fields {
+                    let check_ser = !field.attrs.skip_serializing();
+                    let check_de = !field.attrs.skip_deserializing();
+                    let name = field.attrs.name();
+                    let ser_name = name.serialize_name();
+                    let de_name = name.deserialize_name();
+
+                    if check_ser && ser_name == tag || check_de && de_name == tag {
+                        diagnose_conflict();
+                        return;
+                    }
+                }
+            },
+            Style::Unit | Style::Newtype | Style::Tuple => {},
+        }
+    }
+}
+
+/// In the case of adjacently-tagged enums, the type and the
+/// 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::Internal { .. } | EnumTag::External | EnumTag::None => return,
+    };
+
+    if type_tag == content_tag {
+        let message = format!(
+            "enum tags `{}` for type and content conflict with each other",
+            type_tag
+        );
+        cx.error(message);
+    }
+}

serde_derive_internals/src/ctxt.rs

@@ -8,6 +8,7 @@
 
 use std::fmt::Display;
 use std::cell::RefCell;
+use std::thread;
 
 #[derive(Default)]
 pub struct Ctxt {
@@ -16,7 +17,9 @@ pub struct Ctxt {
 
 impl Ctxt {
     pub fn new() -> Self {
-        Ctxt { errors: RefCell::new(Some(Vec::new())) }
+        Ctxt {
+            errors: RefCell::new(Some(Vec::new())),
+        }
     }
 
     pub fn error<T: Display>(&self, msg: T) {
@@ -46,7 +49,7 @@ impl Ctxt {
 
 impl Drop for Ctxt {
     fn drop(&mut self) {
-        if self.errors.borrow().is_some() {
+        if !thread::panicking() && self.errors.borrow().is_some() {
             panic!("forgot to check for errors");
         }
     }

serde_derive_internals/src/lib.rs

@@ -6,11 +6,14 @@
 // 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/0.17.0")]
+#![doc(html_root_url = "https://docs.rs/serde_derive_internals/0.22.1")]
+#![cfg_attr(feature = "cargo-clippy", allow(cyclomatic_complexity, doc_markdown, match_same_arms,
+                                            redundant_field_names))]
 
-extern crate syn;
 #[macro_use]
-extern crate synom;
+extern crate syn;
+
+extern crate proc_macro2;
 
 pub mod ast;
 pub mod attr;

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "1.0.23" # remember to update html_root_url
+version = "1.0.35" # 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/assert.rs

@@ -184,11 +184,27 @@ where
     T: Deserialize<'de> + PartialEq + Debug,
 {
     let mut de = Deserializer::new(tokens);
-    match T::deserialize(&mut de) {
-        Ok(v) => assert_eq!(v, *value),
+    let mut deserialized_val = match T::deserialize(&mut de) {
+        Ok(v) => {
+            assert_eq!(v, *value);
+            v
+        }
         Err(e) => panic!("tokens failed to deserialize: {}", e),
+    };
+    if de.remaining() > 0 {
+        panic!("{} remaining tokens", de.remaining());
     }
 
+    // Do the same thing for deserialize_in_place. This isn't *great* because a
+    // no-op impl of deserialize_in_place can technically succeed here. Still,
+    // this should catch a lot of junk.
+    let mut de = Deserializer::new(tokens);
+    match T::deserialize_in_place(&mut de, &mut deserialized_val) {
+        Ok(()) => {
+            assert_eq!(deserialized_val, *value);
+        }
+        Err(e) => panic!("tokens failed to deserialize_in_place: {}", e),
+    }
     if de.remaining() > 0 {
         panic!("{} remaining tokens", de.remaining());
     }

serde_test/src/configure.rs

@@ -11,17 +11,17 @@ pub struct Compact<T: ?Sized>(T);
 
 /// Trait to determine whether a value is represented in human-readable or
 /// compact form.
-/// 
+///
 /// ```
 /// extern crate serde;
 /// extern crate serde_test;
-/// 
+///
 /// use serde::{Deserialize, Deserializer, Serialize, Serializer};
 /// use serde_test::{Configure, Token, assert_tokens};
-/// 
+///
 /// #[derive(Debug, PartialEq)]
 /// struct Example(u8, u8);
-/// 
+///
 /// impl Serialize for Example {
 ///     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
 ///         where S: Serializer,
@@ -33,7 +33,7 @@ pub struct Compact<T: ?Sized>(T);
 ///         }
 ///     }
 /// }
-/// 
+///
 /// impl<'de> Deserialize<'de> for Example {
 ///     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
 ///         where D: Deserializer<'de>,
@@ -52,7 +52,7 @@ pub struct Compact<T: ?Sized>(T);
 ///         }
 ///     }
 /// }
-/// 
+///
 /// fn main() {
 ///     assert_tokens(
 ///         &Example(1, 0).compact(),
@@ -73,11 +73,17 @@ pub struct Compact<T: ?Sized>(T);
 /// ```
 pub trait Configure {
     /// Marks `self` as using `is_human_readable == true`
-    fn readable(self) -> Readable<Self> where Self: Sized {
+    fn readable(self) -> Readable<Self>
+    where
+        Self: Sized,
+    {
         Readable(self)
     }
     /// Marks `self` as using `is_human_readable == false`
-    fn compact(self) -> Compact<Self> where Self: Sized {
+    fn compact(self) -> Compact<Self>
+    where
+        Self: Sized,
+    {
         Compact(self)
     }
 }
@@ -158,7 +164,6 @@ where
     }
 }
 
-
 macro_rules! forward_method {
     ($name: ident (self $(, $arg: ident : $arg_type: ty)* ) -> $return_type: ty) => {
         fn $name (self $(, $arg : $arg_type)* ) -> $return_type {
@@ -455,8 +460,7 @@ macro_rules! impl_serializer {
 impl_serializer!(Readable, true);
 impl_serializer!(Compact, false);
 
-
-use serde::de::{Visitor, EnumAccess, VariantAccess, MapAccess, DeserializeSeed, SeqAccess, Error};
+use serde::de::{DeserializeSeed, EnumAccess, Error, MapAccess, SeqAccess, VariantAccess, Visitor};
 
 macro_rules! forward_deserialize_methods {
     ( $wrapper : ident ( $( $name: ident ),* ) ) => {
@@ -468,7 +472,6 @@ macro_rules! forward_deserialize_methods {
     };
 }
 
-
 macro_rules! impl_deserializer {
     ($wrapper : ident, $is_human_readable : expr) => {
     impl <'de, D> Deserializer<'de> for $wrapper<D> where D: Deserializer<'de> {

serde_test/src/de.rs

@@ -95,15 +95,11 @@ impl<'de> Deserializer<'de> {
     where
         V: Visitor<'de>,
     {
-        let value = try!(
-            visitor.visit_seq(
-                DeserializerSeqVisitor {
-                    de: self,
-                    len: len,
-                    end: end,
-                },
-            )
-        );
+        let value = try!(visitor.visit_seq(DeserializerSeqVisitor {
+            de: self,
+            len: len,
+            end: end,
+        },));
         assert_next_token!(self, end);
         Ok(value)
     }
@@ -117,15 +113,11 @@ impl<'de> Deserializer<'de> {
     where
         V: Visitor<'de>,
     {
-        let value = try!(
-            visitor.visit_map(
-                DeserializerMapVisitor {
-                    de: self,
-                    len: len,
-                    end: end,
-                },
-            )
-        );
+        let value = try!(visitor.visit_map(DeserializerMapVisitor {
+            de: self,
+            len: len,
+            end: end,
+        },));
         assert_next_token!(self, end);
         Ok(value)
     }
@@ -169,7 +161,9 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
             Token::NewtypeStruct { .. } => visitor.visit_newtype_struct(self),
             Token::Seq { len } => self.visit_seq(len, Token::SeqEnd, visitor),
             Token::Tuple { len } => self.visit_seq(Some(len), Token::TupleEnd, visitor),
-            Token::TupleStruct { len, .. } => self.visit_seq(Some(len), Token::TupleStructEnd, visitor),
+            Token::TupleStruct { len, .. } => {
+                self.visit_seq(Some(len), Token::TupleStructEnd, visitor)
+            }
             Token::Map { len } => self.visit_map(len, Token::MapEnd, visitor),
             Token::Struct { len, .. } => self.visit_map(Some(len), Token::StructEnd, visitor),
             Token::Enum { .. } => {
@@ -195,17 +189,28 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
                 }
             }
             Token::UnitVariant { variant, .. } => visitor.visit_str(variant),
-            Token::NewtypeVariant { variant, .. } => {
-                visitor.visit_map(EnumMapVisitor::new(self, Token::Str(variant), EnumFormat::Any),)
-            }
-            Token::TupleVariant { variant, .. } => {
-                visitor.visit_map(EnumMapVisitor::new(self, Token::Str(variant), EnumFormat::Seq),)
-            }
-            Token::StructVariant { variant, .. } => {
-                visitor.visit_map(EnumMapVisitor::new(self, Token::Str(variant), EnumFormat::Map),)
-            }
-            Token::SeqEnd | Token::TupleEnd | Token::TupleStructEnd | Token::MapEnd |
-            Token::StructEnd | Token::TupleVariantEnd | Token::StructVariantEnd => {
+            Token::NewtypeVariant { variant, .. } => visitor.visit_map(EnumMapVisitor::new(
+                self,
+                Token::Str(variant),
+                EnumFormat::Any,
+            )),
+            Token::TupleVariant { variant, .. } => visitor.visit_map(EnumMapVisitor::new(
+                self,
+                Token::Str(variant),
+                EnumFormat::Seq,
+            )),
+            Token::StructVariant { variant, .. } => visitor.visit_map(EnumMapVisitor::new(
+                self,
+                Token::Str(variant),
+                EnumFormat::Map,
+            )),
+            Token::SeqEnd
+            | Token::TupleEnd
+            | Token::TupleStructEnd
+            | Token::MapEnd
+            | Token::StructEnd
+            | Token::TupleVariantEnd
+            | Token::StructVariantEnd => {
                 unexpected!(token);
             }
         }
@@ -216,8 +221,7 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
         V: Visitor<'de>,
     {
         match self.peek_token() {
-            Token::Unit |
-            Token::None => {
+            Token::Unit | Token::None => {
                 self.next_token();
                 visitor.visit_none()
             }
@@ -244,10 +248,11 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
 
                 visitor.visit_enum(DeserializerEnumVisitor { de: self })
             }
-            Token::UnitVariant { name: n, .. } |
-            Token::NewtypeVariant { name: n, .. } |
-            Token::TupleVariant { name: n, .. } |
-            Token::StructVariant { name: n, .. } if name == n => {
+            Token::UnitVariant { name: n, .. }
+            | Token::NewtypeVariant { name: n, .. }
+            | Token::TupleVariant { name: n, .. }
+            | Token::StructVariant { name: n, .. } if name == n =>
+            {
                 visitor.visit_enum(DeserializerEnumVisitor { de: self })
             }
             _ => {
@@ -269,7 +274,11 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
         }
     }
 
-    fn deserialize_newtype_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value, Error>
+    fn deserialize_newtype_struct<V>(
+        self,
+        name: &'static str,
+        visitor: V,
+    ) -> Result<V::Value, Error>
     where
         V: Visitor<'de>,
     {
@@ -287,8 +296,7 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
         V: Visitor<'de>,
     {
         match self.peek_token() {
-            Token::Unit |
-            Token::UnitStruct { .. } => {
+            Token::Unit | Token::UnitStruct { .. } => {
                 self.next_token();
                 visitor.visit_unit()
             }
@@ -448,10 +456,10 @@ impl<'de, 'a> EnumAccess<'de> for DeserializerEnumVisitor<'a, 'de> {
         V: DeserializeSeed<'de>,
     {
         match self.de.peek_token() {
-            Token::UnitVariant { variant: v, .. } |
-            Token::NewtypeVariant { variant: v, .. } |
-            Token::TupleVariant { variant: v, .. } |
-            Token::StructVariant { variant: v, .. } => {
+            Token::UnitVariant { variant: v, .. }
+            | Token::NewtypeVariant { variant: v, .. }
+            | Token::TupleVariant { variant: v, .. }
+            | Token::StructVariant { variant: v, .. } => {
                 let de = v.into_deserializer();
                 let value = try!(seed.deserialize(de));
                 Ok((value, self))
@@ -505,7 +513,9 @@ impl<'de, 'a> VariantAccess<'de> for DeserializerEnumVisitor<'a, 'de> {
                     unexpected!(token);
                 }
             }
-            Token::Seq { len: Some(enum_len) } => {
+            Token::Seq {
+                len: Some(enum_len),
+            } => {
                 let token = self.de.next_token();
 
                 if len == enum_len {
@@ -518,7 +528,11 @@ impl<'de, 'a> VariantAccess<'de> for DeserializerEnumVisitor<'a, 'de> {
         }
     }
 
-    fn struct_variant<V>(self, fields: &'static [&'static str], visitor: V) -> Result<V::Value, Error>
+    fn struct_variant<V>(
+        self,
+        fields: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value, Error>
     where
         V: Visitor<'de>,
     {
@@ -533,7 +547,9 @@ impl<'de, 'a> VariantAccess<'de> for DeserializerEnumVisitor<'a, 'de> {
                     unexpected!(token);
                 }
             }
-            Token::Map { len: Some(enum_len) } => {
+            Token::Map {
+                len: Some(enum_len),
+            } => {
                 let token = self.de.next_token();
 
                 if fields.len() == enum_len {
@@ -581,10 +597,8 @@ impl<'de, 'a> MapAccess<'de> for EnumMapVisitor<'a, 'de> {
     {
         match self.variant.take() {
             Some(Token::Str(variant)) => seed.deserialize(variant.into_deserializer()).map(Some),
-            Some(Token::Bytes(variant)) => {
-                seed.deserialize(BytesDeserializer { value: variant })
-                    .map(Some)
-            }
+            Some(Token::Bytes(variant)) => seed.deserialize(BytesDeserializer { value: variant })
+                .map(Some),
             Some(Token::U32(variant)) => seed.deserialize(variant.into_deserializer()).map(Some),
             Some(other) => unexpected!(other),
             None => Ok(None),

serde_test/src/error.rs

@@ -9,7 +9,7 @@
 use std::error;
 use std::fmt::{self, Display};
 
-use serde::{ser, de};
+use serde::{de, ser};
 
 #[derive(Clone, Debug)]
 pub struct Error {
@@ -18,13 +18,17 @@ pub struct Error {
 
 impl ser::Error for Error {
     fn custom<T: Display>(msg: T) -> Self {
-        Error { msg: msg.to_string() }
+        Error {
+            msg: msg.to_string(),
+        }
     }
 }
 
 impl de::Error for Error {
     fn custom<T: Display>(msg: T) -> Self {
-        Error { msg: msg.to_string() }
+        Error {
+            msg: msg.to_string(),
+        }
     }
 }
 

serde_test/src/lib.rs

@@ -53,7 +53,7 @@
 //! # use serde::ser::{Serialize, Serializer, SerializeMap};
 //! # use serde::de::{Deserialize, Deserializer, Visitor, MapAccess};
 //! #
-//! # // Dumb immitation of LinkedHashMap.
+//! # // Dumb imitation of LinkedHashMap.
 //! # #[derive(PartialEq, Debug)]
 //! # struct LinkedHashMap<K, V>(Vec<(K, V)>);
 //! #
@@ -155,18 +155,14 @@
 //! # }
 //! ```
 
-#![doc(html_root_url = "https://docs.rs/serde_test/1.0.23")]
-
+#![doc(html_root_url = "https://docs.rs/serde_test/1.0.35")]
 #![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", allow(
-    missing_docs_in_private_items,
-    stutter,
-    use_debug,
-    use_self,
-))]
+#![cfg_attr(feature = "cargo-clippy",
+            allow(empty_line_after_outer_attr, missing_docs_in_private_items,
+                  redundant_field_names, stutter, use_debug, use_self))]
 
 #[macro_use]
 extern crate serde;

serde_test/src/token.rs

@@ -232,7 +232,10 @@ pub enum Token {
     /// assert_tokens(&a, &[Token::UnitVariant { name: "E", variant: "A" }]);
     /// # }
     /// ```
-    UnitVariant { name: &'static str, variant: &'static str },
+    UnitVariant {
+        name: &'static str,
+        variant: &'static str,
+    },
 
     /// The header to a serialized newtype struct of the given name.
     ///
@@ -286,7 +289,10 @@ pub enum Token {
     /// ]);
     /// # }
     /// ```
-    NewtypeVariant { name: &'static str, variant: &'static str },
+    NewtypeVariant {
+        name: &'static str,
+        variant: &'static str,
+    },
 
     /// The header to a sequence.
     ///
@@ -391,7 +397,11 @@ pub enum Token {
     /// ]);
     /// # }
     /// ```
-    TupleVariant { name: &'static str, variant: &'static str, len: usize },
+    TupleVariant {
+        name: &'static str,
+        variant: &'static str,
+        len: usize,
+    },
 
     /// An indicator of the end of a tuple variant.
     TupleVariantEnd,
@@ -488,7 +498,11 @@ pub enum Token {
     /// ]);
     /// # }
     /// ```
-    StructVariant { name: &'static str, variant: &'static str, len: usize },
+    StructVariant {
+        name: &'static str,
+        variant: &'static str,
+        len: usize,
+    },
 
     /// An indicator of the end of a struct variant.
     StructVariantEnd,

test_suite/Cargo.toml

@@ -9,9 +9,10 @@ unstable = ["serde/unstable", "compiletest_rs"]
 
 [dev-dependencies]
 fnv = "1.0"
+proc-macro2 = "0.2"
 rustc-serialize = "0.3.16"
 serde = { path = "../serde", features = ["rc"] }
-serde_derive = { path = "../serde_derive" }
+serde_derive = { path = "../serde_derive", features = ["deserialize_in_place"] }
 serde_test = { path = "../serde_test" }
 
 [dependencies]

test_suite/tests/compile-fail/conflict/adjacent-tag.rs

@@ -0,0 +1,20 @@
+// 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
+#[serde(tag = "conflict", content = "conflict")]
+//~^^ HELP: enum tags `conflict` for type and content conflict with each other
+enum E {
+    A,
+    B,
+}
+
+fn main() {}

test_suite/tests/compile-fail/conflict/flatten-skip-deserializing.rs

@@ -0,0 +1,24 @@
+// 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(Deserialize)] //~ ERROR: proc-macro derive panicked
+//~^ HELP: #[serde(flatten] can not be combined with #[serde(skip_deserializing)]
+struct Foo {
+    #[serde(flatten, skip_deserializing)]
+    other: Other,
+}
+
+#[derive(Deserialize)]
+struct Other {
+    x: u32
+}
+
+fn main() {}

test_suite/tests/compile-fail/conflict/flatten-skip-serializing-if.rs

@@ -0,0 +1,24 @@
+// 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] can not be combined with #[serde(skip_serializing_if = "...")]
+struct Foo {
+    #[serde(flatten, skip_serializing_if="Option::is_none")]
+    other: Option<Other>,
+}
+
+#[derive(Serialize)]
+struct Other {
+    x: u32
+}
+
+fn main() {}

test_suite/tests/compile-fail/conflict/flatten-skip-serializing.rs

@@ -0,0 +1,24 @@
+// 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] can not be combined with #[serde(skip_serializing)]
+struct Foo {
+    #[serde(flatten, skip_serializing)]
+    other: Other,
+}
+
+#[derive(Serialize)]
+struct Other {
+    x: u32
+}
+
+fn main() {}

test_suite/tests/compile-fail/conflict/internal-tag.rs

@@ -0,0 +1,22 @@
+// 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
+#[serde(tag = "conflict")]
+//~^^ HELP: variant field name `conflict` conflicts with internal tag
+enum E {
+    A {
+        #[serde(rename = "conflict")]
+        x: (),
+    },
+}
+
+fn main() {}

test_suite/tests/test_borrow.rs

@@ -13,7 +13,7 @@ extern crate serde;
 use serde::{Deserialize, Deserializer};
 
 extern crate serde_test;
-use serde_test::{Token, assert_de_tokens, assert_de_tokens_error};
+use serde_test::{assert_de_tokens, assert_de_tokens_error, Token};
 
 use std::borrow::Cow;
 
@@ -87,18 +87,18 @@ fn test_struct() {
 
     assert_de_tokens(
         &Borrowing {
-             bs: "str",
-             bb: b"bytes",
-         },
+            bs: "str",
+            bb: b"bytes",
+        },
         &[
-            Token::Struct { name: "Borrowing", len: 2 },
-
+            Token::Struct {
+                name: "Borrowing",
+                len: 2,
+            },
             Token::BorrowedStr("bs"),
             Token::BorrowedStr("str"),
-
             Token::BorrowedStr("bb"),
             Token::BorrowedBytes(b"bytes"),
-
             Token::StructEnd,
         ],
     );
@@ -115,14 +115,14 @@ fn test_cow() {
     }
 
     let tokens = &[
-        Token::Struct { name: "Cows", len: 2 },
-
+        Token::Struct {
+            name: "Cows",
+            len: 2,
+        },
         Token::Str("copied"),
         Token::BorrowedStr("copied"),
-
         Token::Str("borrowed"),
         Token::BorrowedStr("borrowed"),
-
         Token::StructEnd,
     ];
 

test_suite/tests/test_de.rs

@@ -6,6 +6,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![cfg_attr(feature = "cargo-clippy", allow(decimal_literal_representation))]
+
 #[macro_use]
 extern crate serde_derive;
 
@@ -49,14 +51,16 @@ struct TupleStruct(i32, i32, i32);
 struct Struct {
     a: i32,
     b: i32,
-    #[serde(skip_deserializing)] c: i32,
+    #[serde(skip_deserializing)]
+    c: i32,
 }
 
 #[derive(PartialEq, Debug, Deserialize)]
 #[serde(deny_unknown_fields)]
 struct StructDenyUnknown {
     a: i32,
-    #[serde(skip_deserializing)] b: i32,
+    #[serde(skip_deserializing)]
+    b: i32,
 }
 
 #[derive(PartialEq, Debug, Deserialize)]
@@ -77,13 +81,35 @@ impl Default for StructDefault<String> {
 
 #[derive(PartialEq, Debug, Deserialize)]
 struct StructSkipAll {
-    #[serde(skip_deserializing)] a: i32,
+    #[serde(skip_deserializing)]
+    a: i32,
+}
+
+#[derive(PartialEq, Debug, Deserialize)]
+#[serde(default)]
+struct StructSkipDefault {
+    #[serde(skip_deserializing)]
+    a: i32,
+}
+
+#[derive(PartialEq, Debug, Deserialize)]
+#[serde(default)]
+struct StructSkipDefaultGeneric<T> {
+    #[serde(skip_deserializing)]
+    t: T,
+}
+
+impl Default for StructSkipDefault {
+    fn default() -> Self {
+        StructSkipDefault { a: 16 }
+    }
 }
 
 #[derive(PartialEq, Debug, Deserialize)]
 #[serde(deny_unknown_fields)]
 struct StructSkipAllDenyUnknown {
-    #[serde(skip_deserializing)] a: i32,
+    #[serde(skip_deserializing)]
+    a: i32,
 }
 
 #[derive(PartialEq, Debug, Deserialize)]
@@ -94,7 +120,11 @@ enum Enum {
     Unit,
     Simple(i32),
     Seq(i32, i32, i32),
-    Map { a: i32, b: i32, c: i32 },
+    Map {
+        a: i32,
+        b: i32,
+        c: i32,
+    },
 }
 
 #[derive(PartialEq, Debug, Deserialize)]
@@ -600,6 +630,12 @@ declare_tests! {
             Token::StructEnd,
         ],
     }
+    test_struct_skip_default {
+        StructSkipDefault { a: 16 } => &[
+            Token::Struct { name: "StructSkipDefault", len: 0 },
+            Token::StructEnd,
+        ],
+    }
     test_struct_skip_all_deny_unknown {
         StructSkipAllDenyUnknown { a: 0 } => &[
             Token::Struct { name: "StructSkipAllDenyUnknown", len: 0 },

test_suite/tests/test_gen.rs

@@ -11,7 +11,6 @@
 // types involved.
 
 #![deny(warnings)]
-
 #![cfg_attr(feature = "unstable", feature(non_ascii_idents))]
 
 #[macro_use]
@@ -47,7 +46,7 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     struct With<T> {
         t: T,
-        #[serde(serialize_with="ser_x", deserialize_with="de_x")]
+        #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
         x: X,
     }
     assert::<With<i32>>();
@@ -55,7 +54,7 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     struct WithTogether<T> {
         t: T,
-        #[serde(with="both_x")]
+        #[serde(with = "both_x")]
         x: X,
     }
     assert::<WithTogether<i32>>();
@@ -64,7 +63,7 @@ fn test_gen() {
     struct WithRef<'a, T: 'a> {
         #[serde(skip_deserializing)]
         t: StdOption<&'a T>,
-        #[serde(serialize_with="ser_x", deserialize_with="de_x")]
+        #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
         x: X,
     }
     assert::<WithRef<i32>>();
@@ -94,17 +93,17 @@ fn test_gen() {
     enum EnumWith<T> {
         Unit,
         Newtype(
-            #[serde(serialize_with="ser_x", deserialize_with="de_x")]
-            X
+            #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
+            X,
         ),
         Tuple(
             T,
-            #[serde(serialize_with="ser_x", deserialize_with="de_x")]
-            X
+            #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
+            X,
         ),
         Struct {
             t: T,
-            #[serde(serialize_with="ser_x", deserialize_with="de_x")]
+            #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
             x: X,
         },
     }
@@ -124,16 +123,16 @@ fn test_gen() {
 
     #[derive(Serialize, Deserialize)]
     struct Newtype(
-        #[serde(serialize_with="ser_x", deserialize_with="de_x")]
-        X
+        #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
+        X,
     );
     assert::<Newtype>();
 
     #[derive(Serialize, Deserialize)]
     struct Tuple<T>(
         T,
-        #[serde(serialize_with="ser_x", deserialize_with="de_x")]
-        X
+        #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
+        X,
     );
     assert::<Tuple<i32>>();
 
@@ -143,7 +142,9 @@ fn test_gen() {
             left: Box<TreeNode<D>>,
             right: Box<TreeNode<D>>,
         },
-        Leaf { data: D },
+        Leaf {
+            data: D,
+        },
     }
     assert::<TreeNode<i32>>();
 
@@ -188,29 +189,28 @@ fn test_gen() {
     assert_ser::<OptionStatic>();
 
     #[derive(Serialize, Deserialize)]
-    #[serde(bound="D: SerializeWith + DeserializeWith")]
+    #[serde(bound = "D: SerializeWith + DeserializeWith")]
     struct WithTraits1<D, E> {
-        #[serde(serialize_with="SerializeWith::serialize_with",
-                deserialize_with="DeserializeWith::deserialize_with")]
+        #[serde(serialize_with = "SerializeWith::serialize_with",
+                deserialize_with = "DeserializeWith::deserialize_with")]
         d: D,
-        #[serde(serialize_with="SerializeWith::serialize_with",
-                deserialize_with="DeserializeWith::deserialize_with",
-                bound="E: SerializeWith + DeserializeWith")]
+        #[serde(serialize_with = "SerializeWith::serialize_with",
+                deserialize_with = "DeserializeWith::deserialize_with",
+                bound = "E: SerializeWith + DeserializeWith")]
         e: E,
     }
     assert::<WithTraits1<X, X>>();
 
     #[derive(Serialize, Deserialize)]
-    #[serde(bound(serialize="D: SerializeWith",
-                deserialize="D: DeserializeWith"))]
+    #[serde(bound(serialize = "D: SerializeWith", deserialize = "D: DeserializeWith"))]
     struct WithTraits2<D, E> {
-        #[serde(serialize_with="SerializeWith::serialize_with",
-                deserialize_with="DeserializeWith::deserialize_with")]
+        #[serde(serialize_with = "SerializeWith::serialize_with",
+                deserialize_with = "DeserializeWith::deserialize_with")]
         d: D,
-        #[serde(serialize_with="SerializeWith::serialize_with",
-                bound(serialize="E: SerializeWith"))]
-        #[serde(deserialize_with="DeserializeWith::deserialize_with",
-                bound(deserialize="E: DeserializeWith"))]
+        #[serde(serialize_with = "SerializeWith::serialize_with",
+                bound(serialize = "E: SerializeWith"))]
+        #[serde(deserialize_with = "DeserializeWith::deserialize_with",
+                bound(deserialize = "E: DeserializeWith"))]
         e: E,
     }
     assert::<WithTraits2<X, X>>();
@@ -272,14 +272,14 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     struct TupleSkipAll(
         #[serde(skip_deserializing)]
-        u8
+        u8,
     );
 
     #[derive(Serialize, Deserialize)]
     #[serde(deny_unknown_fields)]
     struct TupleSkipAllDenyUnknown(
         #[serde(skip_deserializing)]
-        u8
+        u8,
     );
 
     #[derive(Serialize, Deserialize)]
@@ -307,7 +307,7 @@ fn test_gen() {
         },
         TupleSkip(
             #[serde(skip_deserializing)]
-            u8
+            u8,
         ),
     }
 
@@ -323,7 +323,7 @@ fn test_gen() {
         },
         TupleSkip(
             #[serde(skip_deserializing)]
-            u8
+            u8,
         ),
     }
 
@@ -403,10 +403,7 @@ fn test_gen() {
         #[serde(serialize_with = "serialize_some_other_variant")]
         #[serde(deserialize_with = "deserialize_some_other_variant")]
         #[allow(dead_code)]
-        Struct {
-            f1: String,
-            f2: u8,
-        },
+        Struct { f1: String, f2: u8 },
 
         #[serde(serialize_with = "serialize_some_unit_variant")]
         #[serde(deserialize_with = "deserialize_some_unit_variant")]
@@ -429,10 +426,7 @@ fn test_gen() {
         #[serde(serialize_with = "serialize_some_other_variant")]
         #[serde(deserialize_with = "deserialize_some_other_variant")]
         #[allow(dead_code)]
-        Struct {
-            f1: String,
-            f2: u8,
-        },
+        Struct { f1: String, f2: u8 },
 
         #[serde(serialize_with = "serialize_some_unit_variant")]
         #[serde(deserialize_with = "deserialize_some_unit_variant")]
@@ -460,10 +454,7 @@ fn test_gen() {
         #[serde(serialize_with = "serialize_some_other_variant")]
         #[serde(deserialize_with = "deserialize_some_other_variant")]
         #[allow(dead_code)]
-        Struct {
-            f1: String,
-            f2: u8,
-        },
+        Struct { f1: String, f2: u8 },
 
         #[serde(serialize_with = "serialize_some_unit_variant")]
         #[serde(deserialize_with = "deserialize_some_unit_variant")]
@@ -491,10 +482,7 @@ fn test_gen() {
         #[serde(serialize_with = "serialize_some_other_variant")]
         #[serde(deserialize_with = "deserialize_some_other_variant")]
         #[allow(dead_code)]
-        Struct {
-            f1: String,
-            f2: u8,
-        },
+        Struct { f1: String, f2: u8 },
 
         #[serde(serialize_with = "serialize_some_unit_variant")]
         #[serde(deserialize_with = "deserialize_some_unit_variant")]
@@ -517,10 +505,7 @@ fn test_gen() {
 
     #[derive(Serialize, Deserialize)]
     enum StaticStrEnum<'a> {
-        Struct {
-            a: &'a str,
-            b: &'static str,
-        },
+        Struct { a: &'a str, b: &'static str },
         Tuple(&'a str, &'static str),
         Newtype(&'static str),
     }
@@ -543,6 +528,13 @@ fn test_gen() {
         marker: PhantomData<T>,
     }
     assert::<TypeMacro<X>>();
+
+    #[derive(Serialize)]
+    struct BigArray {
+        #[serde(serialize_with = "<[_]>::serialize")]
+        array: [u8; 256],
+    }
+    assert_ser::<BigArray>();
 }
 
 //////////////////////////////////////////////////////////////////////////
@@ -570,7 +562,7 @@ pub fn de_x<'de, D: Deserializer<'de>>(_: D) -> StdResult<X, D::Error> {
 }
 
 mod both_x {
-    pub use super::{ser_x as serialize, de_x as deserialize};
+    pub use super::{de_x as deserialize, ser_x as serialize};
 }
 
 impl SerializeWith for X {
@@ -586,27 +578,33 @@ impl DeserializeWith for X {
 }
 
 pub fn serialize_some_unit_variant<S>(_: S) -> StdResult<S::Ok, S::Error>
-    where S: Serializer,
+where
+    S: Serializer,
 {
     unimplemented!()
 }
 
 pub fn deserialize_some_unit_variant<'de, D>(_: D) -> StdResult<(), D::Error>
-    where D: Deserializer<'de>,
+where
+    D: Deserializer<'de>,
 {
     unimplemented!()
 }
 
 pub fn serialize_some_other_variant<S>(_: &str, _: &u8, _: S) -> StdResult<S::Ok, S::Error>
-    where S: Serializer,
+where
+    S: Serializer,
 {
     unimplemented!()
 }
 
 pub fn deserialize_some_other_variant<'de, D>(_: D) -> StdResult<(String, u8), D::Error>
-    where D: Deserializer<'de>,
+where
+    D: Deserializer<'de>,
 {
     unimplemented!()
 }
 
-pub fn is_zero(n: &u8) -> bool { *n == 0 }
+pub fn is_zero(n: &u8) -> bool {
+    *n == 0
+}

test_suite/tests/test_identifier.rs

@@ -49,7 +49,8 @@ fn test_unit_fallthrough() {
     enum F {
         Aaa,
         Bbb,
-        #[serde(other)] Other,
+        #[serde(other)]
+        Other,
     }
 
     assert_de_tokens(&F::Other, &[Token::Str("x")]);

test_suite/tests/test_remote.rs

@@ -6,6 +6,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![cfg_attr(feature = "cargo-clippy", allow(redundant_field_names))]
+
 #[macro_use]
 extern crate serde_derive;
 
@@ -85,23 +87,32 @@ mod remote {
 
 #[derive(Serialize, Deserialize)]
 struct Test {
-    #[serde(with = "UnitDef")] unit: remote::Unit,
+    #[serde(with = "UnitDef")]
+    unit: remote::Unit,
 
-    #[serde(with = "PrimitivePrivDef")] primitive_priv: remote::PrimitivePriv,
+    #[serde(with = "PrimitivePrivDef")]
+    primitive_priv: remote::PrimitivePriv,
 
-    #[serde(with = "PrimitivePubDef")] primitive_pub: remote::PrimitivePub,
+    #[serde(with = "PrimitivePubDef")]
+    primitive_pub: remote::PrimitivePub,
 
-    #[serde(with = "NewtypePrivDef")] newtype_priv: remote::NewtypePriv,
+    #[serde(with = "NewtypePrivDef")]
+    newtype_priv: remote::NewtypePriv,
 
-    #[serde(with = "NewtypePubDef")] newtype_pub: remote::NewtypePub,
+    #[serde(with = "NewtypePubDef")]
+    newtype_pub: remote::NewtypePub,
 
-    #[serde(with = "TuplePrivDef")] tuple_priv: remote::TuplePriv,
+    #[serde(with = "TuplePrivDef")]
+    tuple_priv: remote::TuplePriv,
 
-    #[serde(with = "TuplePubDef")] tuple_pub: remote::TuplePub,
+    #[serde(with = "TuplePubDef")]
+    tuple_pub: remote::TuplePub,
 
-    #[serde(with = "StructPrivDef")] struct_priv: remote::StructPriv,
+    #[serde(with = "StructPrivDef")]
+    struct_priv: remote::StructPriv,
 
-    #[serde(with = "StructPubDef")] struct_pub: remote::StructPub,
+    #[serde(with = "StructPubDef")]
+    struct_pub: remote::StructPub,
 }
 
 #[derive(Serialize, Deserialize)]
@@ -110,7 +121,10 @@ struct UnitDef;
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::PrimitivePriv")]
-struct PrimitivePrivDef(#[serde(getter = "remote::PrimitivePriv::get")] u8);
+struct PrimitivePrivDef(
+    #[serde(getter = "remote::PrimitivePriv::get")]
+    u8,
+);
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::PrimitivePub")]
@@ -119,28 +133,39 @@ struct PrimitivePubDef(u8);
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::NewtypePriv")]
 struct NewtypePrivDef(
-    #[serde(getter = "remote::NewtypePriv::get", with = "UnitDef")] remote::Unit,
+    #[serde(getter = "remote::NewtypePriv::get", with = "UnitDef")]
+    remote::Unit,
 );
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::NewtypePub")]
-struct NewtypePubDef(#[serde(with = "UnitDef")] remote::Unit);
+struct NewtypePubDef(
+    #[serde(with = "UnitDef")]
+    remote::Unit,
+);
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::TuplePriv")]
 struct TuplePrivDef(
-    #[serde(getter = "remote::TuplePriv::first")] u8,
-    #[serde(getter = "remote::TuplePriv::second", with = "UnitDef")] remote::Unit,
+    #[serde(getter = "remote::TuplePriv::first")]
+    u8,
+    #[serde(getter = "remote::TuplePriv::second", with = "UnitDef")]
+    remote::Unit,
 );
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::TuplePub")]
-struct TuplePubDef(u8, #[serde(with = "UnitDef")] remote::Unit);
+struct TuplePubDef(
+    u8,
+    #[serde(with = "UnitDef")]
+    remote::Unit,
+);
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::StructPriv")]
 struct StructPrivDef {
-    #[serde(getter = "remote::StructPriv::a")] a: u8,
+    #[serde(getter = "remote::StructPriv::a")]
+    a: u8,
 
     #[serde(getter = "remote::StructPriv::b")]
     #[serde(with = "UnitDef")]
@@ -150,7 +175,8 @@ struct StructPrivDef {
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::StructPub")]
 struct StructPubDef {
-    #[allow(dead_code)] a: u8,
+    #[allow(dead_code)]
+    a: u8,
 
     #[allow(dead_code)]
     #[serde(with = "UnitDef")]

test_suite/tests/test_roundtrip.rs

@@ -30,7 +30,7 @@ fn ip_addr_roundtrip() {
 }
 
 #[test]
-fn socked_addr_roundtrip() {
+fn socket_addr_roundtrip() {
     assert_tokens(
         &net::SocketAddr::from((*b"1234567890123456", 1234)).compact(),
         &seq![

test_suite/tests/test_ser.rs

@@ -50,11 +50,21 @@ enum Enum {
     Unit,
     One(i32),
     Seq(i32, i32),
-    Map { a: i32, b: i32 },
-    #[serde(skip_serializing)] SkippedUnit,
-    #[serde(skip_serializing)] SkippedOne(i32),
-    #[serde(skip_serializing)] SkippedSeq(i32, i32),
-    #[serde(skip_serializing)] SkippedMap { _a: i32, _b: i32 },
+    Map {
+        a: i32,
+        b: i32,
+    },
+    #[serde(skip_serializing)]
+    SkippedUnit,
+    #[serde(skip_serializing)]
+    SkippedOne(i32),
+    #[serde(skip_serializing)]
+    SkippedSeq(i32, i32),
+    #[serde(skip_serializing)]
+    SkippedMap {
+        _a: i32,
+        _b: i32,
+    },
 }
 
 //////////////////////////////////////////////////////////////////////////

travis.sh

@@ -55,6 +55,7 @@ else
     channel build
     cd "$DIR/test_suite"
     channel test --features unstable
+    channel build --tests --features proc-macro2/nightly
     if [ -z "${APPVEYOR}" ]; then
         cd "$DIR/test_suite/no_std"
         channel build