Release 1.0.26

Some of the serde_derive lines inside of quote!(...) are too long. Rustfmt
cannot fix these. Will need to follow up.

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 = "1.0.19" # remember to update html_root_url
+version = "1.0.26" # 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/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()));
                         }
@@ -1691,7 +1905,13 @@ where
         }
 
         const FIELDS: &'static [&'static str] = &["start", "end"];
-        deserializer.deserialize_struct("Range", FIELDS, RangeVisitor { phantom: PhantomData })
+        deserializer.deserialize_struct(
+            "Range",
+            FIELDS,
+            RangeVisitor {
+                phantom: PhantomData,
+            },
+        )
     }
 }
 
@@ -1756,9 +1976,10 @@ 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 +2001,12 @@ 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 +2050,7 @@ 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

@@ -504,6 +504,35 @@ 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 repeateadly 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 +1107,9 @@ 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/1.0.19")]
-
+#![doc(html_root_url = "https://docs.rs/serde/1.0.26")]
 // 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, 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
@@ -125,7 +116,6 @@
     empty_enum,
     use_debug,
 ))]
-
 // Blacklisted Rust lints.
 #![deny(missing_docs, unused_imports)]
 
@@ -149,8 +139,8 @@ 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 +183,9 @@ 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 +193,9 @@ 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")]

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;
 
 #[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};
 
 /// 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,
+                )),
             }
         }
     }
@@ -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
@@ -501,7 +505,9 @@ 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 +526,10 @@ mod content {
 
     impl<'de> TagOrContentVisitor<'de> {
         fn new(name: &'static str) -> Self {
-            TagOrContentVisitor { name: name, value: PhantomData }
+            TagOrContentVisitor {
+                name: name,
+                value: PhantomData,
+            }
         }
     }
 
@@ -557,7 +566,9 @@ 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 +602,9 @@ 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 +743,18 @@ 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 +877,7 @@ 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 +893,10 @@ 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 +978,11 @@ 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 +1046,8 @@ 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 +1094,41 @@ 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 {
+                variant: variant,
+                value: value,
+                err: PhantomData,
+            })
         }
 
         fn deserialize_unit_struct<V>(
             self,
             _name: &'static str,
-            visitor: V
+            visitor: V,
         ) -> Result<V::Value, Self::Error>
         where
             V: Visitor<'de>,
@@ -1215,9 +1226,10 @@ 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 +1241,14 @@ 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",
+                )),
             }
         }
 
@@ -1246,8 +1264,17 @@ mod content {
                 Some(Content::Map(v)) => {
                     de::Deserializer::deserialize_any(MapDeserializer::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(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",
+                )),
             }
         }
     }
@@ -1315,10 +1342,7 @@ 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),
             }
         }
@@ -1454,12 +1478,12 @@ 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());
@@ -1502,38 +1526,35 @@ 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! {
@@ -1609,9 +1630,10 @@ 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",
+                )),
             }
         }
 
@@ -1623,8 +1645,14 @@ 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",
+                )),
             }
         }
 
@@ -1640,8 +1668,17 @@ mod content {
                 Some(&Content::Map(ref v)) => {
                     de::Deserializer::deserialize_any(MapRefDeserializer::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(&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",
+                )),
             }
         }
     }
@@ -1709,10 +1746,8 @@ 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),
             }
         }
@@ -1757,8 +1792,7 @@ 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),
             }
@@ -1844,7 +1878,11 @@ 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>
@@ -1884,7 +1922,11 @@ 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>
@@ -2002,3 +2044,21 @@ 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)
+    }
+}

serde/src/private/ser.rs

@@ -8,10 +8,10 @@
 
 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};
 
 /// Used to check that serde(getter) attributes return the expected type.
 /// Not public API.
@@ -32,15 +32,13 @@ 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> {
@@ -92,13 +90,10 @@ 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 +276,11 @@ 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 +323,11 @@ 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 +405,10 @@ 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()
         }
     }
@@ -444,7 +450,10 @@ 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()
         }
     }
@@ -485,7 +494,12 @@ 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 {
@@ -687,7 +701,10 @@ 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 +717,26 @@ 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 +744,11 @@ 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 +758,21 @@ 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 +780,11 @@ 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(
@@ -791,15 +794,13 @@ 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,
+            })
         }
     }
 
@@ -907,7 +908,12 @@ 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,
+            ))
         }
     }
 
@@ -1013,7 +1019,12 @@ 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,
+            ))
         }
     }
 }

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
@@ -464,7 +464,8 @@ 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 +514,12 @@ 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 +570,12 @@ 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 +605,10 @@ 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

@@ -1412,7 +1412,9 @@ 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 = "1.0.19" # remember to update html_root_url
+version = "1.0.26" # 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)]"
@@ -14,13 +14,17 @@ 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" }
+serde_derive_internals = { version = "=0.18.1", default-features = false, path = "../serde_derive_internals" }
 syn = { version = "0.11", features = ["visit"] }
 
 [dev-dependencies]

serde_derive/src/bound.rs

@@ -27,14 +27,10 @@ pub fn without_defaults(generics: &syn::Generics) -> syn::Generics {
         ty_params: generics
             .ty_params
             .iter()
-            .map(
-                |ty_param| {
-                    syn::TyParam {
-                        default: None,
-                        ..ty_param.clone()
-                    }
-                },
-            )
+            .map(|ty_param| syn::TyParam {
+                default: None,
+                ..ty_param.clone()
+            })
             .collect(),
         ..generics.clone()
     }
@@ -137,17 +133,15 @@ where
         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);
-                }
+        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);
             }
-        }
+        },
         Body::Struct(_, ref fields) => {
             for field in fields.iter().filter(|field| filter(&field.attrs, None)) {
                 visit::walk_ty(&mut visitor, field.ty);
@@ -160,27 +154,23 @@ where
         .iter()
         .map(|ty_param| ty_param.ident.clone())
         .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::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,
+                    ),
+                ],
+            })
+        });
 
     let mut generics = generics.clone();
     generics.where_clause.predicates.extend(new_predicates);
@@ -196,25 +186,23 @@ pub fn with_self_bound(
     generics
         .where_clause
         .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::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,
+                    ),
+                ],
+            },
+        ));
     generics
 }
 
@@ -231,15 +219,11 @@ pub fn with_lifetime_bound(generics: &syn::Generics, lifetime: &str) -> syn::Gen
             .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.lifetimes.push(syn::LifetimeDef {
+        attrs: Vec::new(),
+        lifetime: syn::Lifetime::new(lifetime),
+        bounds: Vec::new(),
+    });
 
     generics
 }

serde_derive/src/fragment.rs

@@ -6,7 +6,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use quote::{Tokens, ToTokens};
+use quote::{ToTokens, Tokens};
 
 pub enum Fragment {
     /// Tokens that can be used as an expression.
@@ -73,3 +73,12 @@ impl ToTokens for Match {
         }
     }
 }
+
+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

@@ -22,17 +22,15 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.19")]
-
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.26")]
 #![cfg_attr(feature = "cargo-clippy", allow(too_many_arguments))]
 #![cfg_attr(feature = "cargo-clippy", allow(used_underscore_binding))]
-
 // The `quote!` macro requires deep recursion.
 #![recursion_limit = "192"]
 
-extern crate syn;
 #[macro_use]
 extern crate quote;
+extern crate syn;
 
 extern crate serde_derive_internals as internals;
 

serde_derive/src/ser.rs

@@ -10,7 +10,7 @@ use syn::{self, Ident};
 use quote::Tokens;
 
 use bound;
-use fragment::{Fragment, Stmts, Match};
+use fragment::{Fragment, Match, Stmts};
 use internals::ast::{Body, Container, Field, Style, Variant};
 use internals::{attr, Ctxt};
 
@@ -132,14 +132,12 @@ 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,
+            &path!(_serde::Serialize),
+        ),
     }
 }
 
@@ -149,10 +147,8 @@ 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 {
@@ -259,16 +255,14 @@ 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.clone().expect("struct has unnamed fields");
+                let field_expr = get_field(params, field, ident);
+                quote!(if #path(#field_expr) { 0 } else { 1 })
+            }
+        })
         .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
 
     quote_block! {
@@ -286,11 +280,9 @@ fn serialize_enum(params: &Parameters, variants: &[Variant], cattrs: &attr::Cont
     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! {
@@ -321,13 +313,7 @@ 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,
@@ -356,34 +342,26 @@ fn serialize_variant(
                 let fields = variant
                     .fields
                     .iter()
-                    .map(
-                        |f| {
-                            f.ident
-                                .clone()
-                                .expect("struct variant has unnamed fields")
-                        },
-                    );
+                    .map(|f| f.ident.clone().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
@@ -441,28 +419,24 @@ 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,
+        ),
     }
 }
 
@@ -520,17 +494,15 @@ 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"),
     }
 }
@@ -546,48 +518,44 @@ 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 {
@@ -599,24 +567,14 @@ fn serialize_adjacently_tagged_variant(
             }
         }
         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::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(),
     };
 
     let (_, ty_generics, where_clause) = params.generics.split_for_impl();
@@ -753,7 +711,10 @@ enum StructVariant<'a> {
         variant_index: u32,
         variant_name: String,
     },
-    InternallyTagged { tag: &'a str, variant_name: String },
+    InternallyTagged {
+        tag: &'a str,
+        variant_name: String,
+    },
     Untagged,
 }
 
@@ -764,19 +725,14 @@ fn serialize_struct_variant<'a>(
     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),
-            )
-        }
+        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 serialize_fields = serialize_struct_visitor(fields, params, true, method, skip_method);
@@ -789,16 +745,14 @@ 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.clone().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 {
@@ -857,34 +811,32 @@ fn serialize_tuple_struct_visitor(
     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));
+                quote!(#id)
+            } else {
+                get_field(params, field, i)
+            };
 
-                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 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()
 }
 
@@ -898,44 +850,42 @@ fn serialize_struct_visitor(
     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.clone().expect("struct has unnamed field");
+            let mut field_expr = if is_enum {
+                quote!(#field_ident)
+            } else {
+                get_field(params, field, field_ident)
+            };
 
-                let key_expr = field.attrs.name().serialize_name();
+            let key_expr = field.attrs.name().serialize_name();
 
-                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, #key_expr, #field_expr));
-                };
+            let ser = quote! {
+                try!(#func(&mut __serde_state, #key_expr, #field_expr));
+            };
 
-                match skip {
-                    None => ser,
-                    Some(skip) => {
-                        quote! {
-                            if !#skip {
-                                #ser
-                            } else {
-                                try!(#skip_func(&mut __serde_state, #key_expr));
-                            }
+            match skip {
+                None => ser,
+                Some(skip) => {
+                    quote! {
+                        if !#skip {
+                            #ser
+                        } else {
+                            try!(#skip_func(&mut __serde_state, #key_expr));
                         }
                     }
                 }
-            },
-        )
+            }
+        })
         .collect()
 }
 
@@ -945,10 +895,7 @@ fn wrap_serialize_field_with(
     serialize_with: &syn::Path,
     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(
@@ -957,15 +904,24 @@ fn wrap_serialize_variant_with(
     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
+                .as_ref()
+                .map_or_else(|| Ident::new(format!("__field{}", i)), |id| id.clone());
             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(
@@ -1014,7 +970,11 @@ 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

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 = "0.18.1" # 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."

serde_derive_internals/src/ast.rs

@@ -49,27 +49,25 @@ impl<'a> Container<'a> {
         let 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::Enum(ref variants) => {
+                Body::Enum(enum_from_ast(cx, variants, &attrs.default()))
+            }
             syn::Body::Struct(ref variant_data) => {
-                let (style, fields) = struct_from_ast(cx, variant_data, None);
+                let (style, fields) = struct_from_ast(cx, variant_data, None, &attrs.default());
                 Body::Struct(style, fields)
             }
         };
 
         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());
-                    }
+            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());
                 }
-            }
-            Body::Struct(_, ref mut fields) => {
-                for field in fields {
-                    field.attrs.rename_by_rule(attrs.rename_all());
-                }
-            }
+            },
+            Body::Struct(_, ref mut fields) => for field in fields {
+                field.attrs.rename_by_rule(attrs.rename_all());
+            },
         }
 
         let item = Container {
@@ -98,47 +96,63 @@ 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 [syn::Variant],
+    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.data, Some(&attrs), container_default);
+            Variant {
+                ident: variant.ident.clone(),
+                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>>) {
+fn struct_from_ast<'a>(
+    cx: &Ctxt,
+    data: &'a syn::VariantData,
+    attrs: Option<&attr::Variant>,
+    container_default: &attr::Default,
+) -> (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::Struct(ref fields) => (
+            Style::Struct,
+            fields_from_ast(cx, fields, attrs, container_default),
+        ),
+        syn::VariantData::Tuple(ref fields) if fields.len() == 1 => (
+            Style::Newtype,
+            fields_from_ast(cx, fields, attrs, container_default),
+        ),
+        syn::VariantData::Tuple(ref fields) => (
+            Style::Tuple,
+            fields_from_ast(cx, fields, attrs, container_default),
+        ),
         syn::VariantData::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 [syn::Field],
+    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.clone(),
+            attrs: attr::Field::from_ast(cx, i, field, attrs, container_default),
+            ty: &field.ty,
+        })
         .collect()
 }

serde_derive_internals/src/attr.rs

@@ -164,6 +164,15 @@ pub enum Identifier {
     Variant,
 }
 
+impl Identifier {
+    pub fn is_some(self) -> bool {
+        match self {
+            Identifier::No => false,
+            Identifier::Field | Identifier::Variant => true,
+        }
+    }
+}
+
 impl Container {
     /// Extract out the `#[serde(...)]` attributes from an item.
     pub fn from_ast(cx: &Ctxt, item: &syn::DeriveInput) -> Self {
@@ -207,11 +216,11 @@ impl Container {
                         if let Ok(s) = get_string_from_lit(cx, name.as_ref(), name.as_ref(), lit) {
                             match RenameRule::from_str(&s) {
                                 Ok(rename_rule) => rename_all.set(rename_rule),
-                                Err(()) => {
-                                    cx.error(format!("unknown rename rule for #[serde(rename_all \
-                                                      = {:?})]",
-                                                     s))
-                                }
+                                Err(()) => cx.error(format!(
+                                    "unknown rename rule for #[serde(rename_all \
+                                     = {:?})]",
+                                    s
+                                )),
                             }
                         }
                     }
@@ -222,19 +231,15 @@ impl Container {
                     }
 
                     // Parse `#[serde(default)]`
-                    MetaItem(Word(ref name)) if name == "default" => {
-                        match item.body {
-                            syn::Body::Struct(syn::VariantData::Struct(_)) => {
-                                default.set(Default::Default);
-                            }
-                            _ => {
-                                cx.error(
-                                    "#[serde(default)] can only be used on structs \
-                                          with named fields",
-                                )
-                            }
+                    MetaItem(Word(ref name)) if name == "default" => match item.body {
+                        syn::Body::Struct(syn::VariantData::Struct(_)) => {
+                            default.set(Default::Default);
                         }
-                    }
+                        _ => cx.error(
+                            "#[serde(default)] can only be used on structs \
+                             with named fields",
+                        ),
+                    },
 
                     // Parse `#[serde(default = "...")]`
                     MetaItem(NameValue(ref name, ref lit)) if name == "default" => {
@@ -243,12 +248,10 @@ impl Container {
                                 syn::Body::Struct(syn::VariantData::Struct(_)) => {
                                     default.set(Default::Path(path));
                                 }
-                                _ => {
-                                    cx.error(
-                                        "#[serde(default = \"...\")] can only be used \
-                                              on structs with named fields",
-                                    )
-                                }
+                                _ => cx.error(
+                                    "#[serde(default = \"...\")] can only be used \
+                                     on structs with named fields",
+                                ),
                             }
                         }
                     }
@@ -256,7 +259,8 @@ impl Container {
                     // Parse `#[serde(bound = "D: Serialize")]`
                     MetaItem(NameValue(ref name, ref lit)) if name == "bound" => {
                         if let Ok(where_predicates) =
-                            parse_lit_into_where(cx, name.as_ref(), name.as_ref(), lit) {
+                            parse_lit_into_where(cx, name.as_ref(), name.as_ref(), lit)
+                        {
                             ser_bound.set(where_predicates.clone());
                             de_bound.set(where_predicates);
                         }
@@ -271,16 +275,14 @@ impl Container {
                     }
 
                     // Parse `#[serde(untagged)]`
-                    MetaItem(Word(ref name)) if name == "untagged" => {
-                        match item.body {
-                            syn::Body::Enum(_) => {
-                                untagged.set_true();
-                            }
-                            syn::Body::Struct(_) => {
-                                cx.error("#[serde(untagged)] can only be used on enums")
-                            }
+                    MetaItem(Word(ref name)) if name == "untagged" => match item.body {
+                        syn::Body::Enum(_) => {
+                            untagged.set_true();
                         }
-                    }
+                        syn::Body::Struct(_) => {
+                            cx.error("#[serde(untagged)] can only be used on enums")
+                        }
+                    },
 
                     // Parse `#[serde(tag = "type")]`
                     MetaItem(NameValue(ref name, ref lit)) if name == "tag" => {
@@ -303,12 +305,10 @@ impl Container {
                                 syn::Body::Enum(_) => {
                                     content.set(s);
                                 }
-                                syn::Body::Struct(_) => {
-                                    cx.error(
-                                        "#[serde(content = \"...\")] can only be used on \
-                                              enums",
-                                    )
-                                }
+                                syn::Body::Struct(_) => cx.error(
+                                    "#[serde(content = \"...\")] can only be used on \
+                                     enums",
+                                ),
                             }
                         }
                     }
@@ -345,8 +345,10 @@ impl Container {
                     }
 
                     MetaItem(ref meta_item) => {
-                        cx.error(format!("unknown serde container attribute `{}`",
-                                         meta_item.name()));
+                        cx.error(format!(
+                            "unknown serde container attribute `{}`",
+                            meta_item.name()
+                        ));
                     }
 
                     Literal(_) => {
@@ -434,13 +436,12 @@ fn decide_tag(
             if let syn::Body::Enum(ref variants) = item.body {
                 for variant in variants {
                     match variant.data {
-                        syn::VariantData::Struct(_) |
-                        syn::VariantData::Unit => {}
+                        syn::VariantData::Struct(_) | syn::VariantData::Unit => {}
                         syn::VariantData::Tuple(ref fields) => {
                             if fields.len() != 1 {
                                 cx.error(
                                     "#[serde(tag = \"...\")] cannot be used with tuple \
-                                        variants",
+                                     variants",
                                 );
                                 break;
                             }
@@ -455,21 +456,19 @@ fn decide_tag(
             EnumTag::External // doesn't matter, will error
         }
         (false, None, Some(_)) => {
-            cx.error("#[serde(tag = \"...\", content = \"...\")] must be used together",);
+            cx.error("#[serde(tag = \"...\", content = \"...\")] must be used together");
             EnumTag::External
         }
         (true, None, Some(_)) => {
             cx.error("untagged enum cannot have #[serde(content = \"...\")]");
             EnumTag::External
         }
-        (false, Some(tag), Some(content)) => {
-            EnumTag::Adjacent {
-                tag: tag,
-                content: content,
-            }
-        }
+        (false, Some(tag), Some(content)) => EnumTag::Adjacent {
+            tag: tag,
+            content: content,
+        },
         (true, Some(_), Some(_)) => {
-            cx.error("untagged enum cannot have #[serde(tag = \"...\", content = \"...\")]",);
+            cx.error("untagged enum cannot have #[serde(tag = \"...\", content = \"...\")]");
             EnumTag::External
         }
     }
@@ -484,7 +483,7 @@ fn decide_identifier(
     match (&item.body, field_identifier.get(), variant_identifier.get()) {
         (_, false, false) => Identifier::No,
         (_, true, true) => {
-            cx.error("`field_identifier` and `variant_identifier` cannot both be set",);
+            cx.error("`field_identifier` and `variant_identifier` cannot both be set");
             Identifier::No
         }
         (&syn::Body::Struct(_), true, false) => {
@@ -551,11 +550,11 @@ impl Variant {
                         if let Ok(s) = get_string_from_lit(cx, name.as_ref(), name.as_ref(), lit) {
                             match RenameRule::from_str(&s) {
                                 Ok(rename_rule) => rename_all.set(rename_rule),
-                                Err(()) => {
-                                    cx.error(format!("unknown rename rule for #[serde(rename_all \
-                                                      = {:?})]",
-                                                     s))
-                                }
+                                Err(()) => cx.error(format!(
+                                    "unknown rename rule for #[serde(rename_all \
+                                     = {:?})]",
+                                    s
+                                )),
                             }
                         }
                     }
@@ -602,19 +601,20 @@ impl Variant {
                     }
 
                     // Defer `#[serde(borrow)]` and `#[serde(borrow = "'a + 'b")]`
-                    MetaItem(ref mi) if mi.name() == "borrow" => {
-                        match variant.data {
-                            syn::VariantData::Tuple(ref fields) if fields.len() == 1 => {
-                                borrow.set(mi.clone());
-                            }
-                            _ => {
-                                cx.error("#[serde(borrow)] may only be used on newtype variants");
-                            }
+                    MetaItem(ref mi) if mi.name() == "borrow" => match variant.data {
+                        syn::VariantData::Tuple(ref fields) if fields.len() == 1 => {
+                            borrow.set(mi.clone());
                         }
-                    }
+                        _ => {
+                            cx.error("#[serde(borrow)] may only be used on newtype variants");
+                        }
+                    },
 
                     MetaItem(ref meta_item) => {
-                        cx.error(format!("unknown serde variant attribute `{}`", meta_item.name()));
+                        cx.error(format!(
+                            "unknown serde variant attribute `{}`",
+                            meta_item.name()
+                        ));
                     }
 
                     Literal(_) => {
@@ -714,7 +714,13 @@ pub enum Default {
 
 impl Field {
     /// Extract out the `#[serde(...)]` attributes from a struct field.
-    pub fn from_ast(cx: &Ctxt, index: usize, field: &syn::Field, attrs: Option<&Variant>) -> Self {
+    pub fn from_ast(
+        cx: &Ctxt,
+        index: usize,
+        field: &syn::Field,
+        attrs: Option<&Variant>,
+        container_default: &Default,
+    ) -> Self {
         let mut ser_name = Attr::none(cx, "rename");
         let mut de_name = Attr::none(cx, "rename");
         let mut skip_serializing = BoolAttr::none(cx, "skip_serializing");
@@ -739,7 +745,12 @@ impl Field {
             .as_ref()
             .map(|borrow| vec![MetaItem(borrow.clone())]);
 
-        for meta_items in field.attrs.iter().filter_map(get_serde_meta_items).chain(variant_borrow) {
+        for meta_items in field
+            .attrs
+            .iter()
+            .filter_map(get_serde_meta_items)
+            .chain(variant_borrow)
+        {
             for meta_item in meta_items {
                 match meta_item {
                     // Parse `#[serde(rename = "foo")]`
@@ -784,7 +795,7 @@ impl Field {
                     MetaItem(Word(ref name)) if name == "skip" => {
                         skip_serializing.set_true();
                         skip_deserializing.set_true();
-                    },
+                    }
 
                     // Parse `#[serde(skip_serializing_if = "...")]`
                     MetaItem(NameValue(ref name, ref lit)) if name == "skip_serializing_if" => {
@@ -822,7 +833,8 @@ impl Field {
                     // Parse `#[serde(bound = "D: Serialize")]`
                     MetaItem(NameValue(ref name, ref lit)) if name == "bound" => {
                         if let Ok(where_predicates) =
-                            parse_lit_into_where(cx, name.as_ref(), name.as_ref(), lit) {
+                            parse_lit_into_where(cx, name.as_ref(), name.as_ref(), lit)
+                        {
                             ser_bound.set(where_predicates.clone());
                             de_bound.set(where_predicates);
                         }
@@ -849,13 +861,10 @@ impl Field {
                             if let Ok(borrowable) = borrowable_lifetimes(cx, &ident, &field.ty) {
                                 for lifetime in &lifetimes {
                                     if !borrowable.contains(lifetime) {
-                                        cx.error(
-                                            format!(
-                                                "field `{}` does not have lifetime {}",
-                                                ident,
-                                                lifetime.ident
-                                            ),
-                                        );
+                                        cx.error(format!(
+                                            "field `{}` does not have lifetime {}",
+                                            ident, lifetime.ident
+                                        ));
                                     }
                                 }
                                 borrowed_lifetimes.set(lifetimes);
@@ -871,7 +880,10 @@ impl Field {
                     }
 
                     MetaItem(ref meta_item) => {
-                        cx.error(format!("unknown serde field attribute `{}`", meta_item.name()),);
+                        cx.error(format!(
+                            "unknown serde field attribute `{}`",
+                            meta_item.name()
+                        ));
                     }
 
                     Literal(_) => {
@@ -881,9 +893,10 @@ impl Field {
             }
         }
 
-        // Is skip_deserializing, initialize the field to Default::default()
-        // unless a different default is specified by `#[serde(default = "...")]`
-        if skip_deserializing.0.value.is_some() {
+        // Is skip_deserializing, initialize the field to Default::default() unless a different
+        // default is specified by `#[serde(default = "...")]` on ourselves or our container (e.g.
+        // the struct we are in).
+        if container_default == &Default::None && skip_deserializing.0.value.is_some() {
             default.set_if_none(Default::Default);
         }
 
@@ -1018,13 +1031,11 @@ where
             }
 
             _ => {
-                cx.error(
-                    format!(
-                        "malformed {0} attribute, expected `{0}(serialize = ..., \
-                                  deserialize = ...)`",
-                        attr_name
-                    ),
-                );
+                cx.error(format!(
+                    "malformed {0} attribute, expected `{0}(serialize = ..., \
+                     deserialize = ...)`",
+                    attr_name
+                ));
                 return Err(());
             }
         }
@@ -1060,13 +1071,10 @@ fn get_string_from_lit(
     if let syn::Lit::Str(ref s, _) = *lit {
         Ok(s.clone())
     } else {
-        cx.error(
-            format!(
-                "expected serde {} attribute to be a string: `{} = \"...\"`",
-                attr_name,
-                meta_item_name
-            ),
-        );
+        cx.error(format!(
+            "expected serde {} attribute to be a string: `{} = \"...\"`",
+            attr_name, meta_item_name
+        ));
         Err(())
     }
 }
@@ -1097,11 +1105,12 @@ fn parse_lit_into_where(
 fn parse_lit_into_ty(cx: &Ctxt, attr_name: &str, lit: &syn::Lit) -> Result<syn::Ty, ()> {
     let string = try!(get_string_from_lit(cx, attr_name, attr_name, lit));
 
-    syn::parse_type(&string).map_err(
-        |_| {
-            cx.error(format!("failed to parse type: {} = {:?}", attr_name, string),)
-        },
-    )
+    syn::parse_type(&string).map_err(|_| {
+        cx.error(format!(
+            "failed to parse type: {} = {:?}",
+            attr_name, string
+        ))
+    })
 }
 
 // Parses a string literal like "'a + 'b + 'c" containing a nonempty list of
@@ -1132,7 +1141,7 @@ fn parse_lit_into_lifetimes(
             return Ok(set);
         }
     }
-    Err(cx.error(format!("failed to parse borrowed lifetimes: {:?}", string)),)
+    Err(cx.error(format!("failed to parse borrowed lifetimes: {:?}", string)))
 }
 
 // Whether the type looks like it might be `std::borrow::Cow<T>` where elem="T".
@@ -1176,8 +1185,8 @@ fn is_cow(ty: &syn::Ty, elem: &str) -> bool {
             return false;
         }
     };
-    seg.ident == "Cow" && params.lifetimes.len() == 1 &&
-    params.types == vec![syn::parse_type(elem).unwrap()] && params.bindings.is_empty()
+    seg.ident == "Cow" && params.lifetimes.len() == 1
+        && params.types == vec![syn::parse_type(elem).unwrap()] && params.bindings.is_empty()
 }
 
 // Whether the type looks like it might be `&T` where elem="T". This can have
@@ -1203,8 +1212,8 @@ fn is_cow(ty: &syn::Ty, elem: &str) -> bool {
 fn is_rptr(ty: &syn::Ty, elem: &str) -> bool {
     match *ty {
         syn::Ty::Rptr(Some(_), ref mut_ty) => {
-            mut_ty.mutability == syn::Mutability::Immutable &&
-            mut_ty.ty == syn::parse_type(elem).unwrap()
+            mut_ty.mutability == syn::Mutability::Immutable
+                && mut_ty.ty == syn::parse_type(elem).unwrap()
         }
         _ => false,
     }
@@ -1225,7 +1234,7 @@ fn borrowable_lifetimes(
     let mut lifetimes = BTreeSet::new();
     collect_lifetimes(ty, &mut lifetimes);
     if lifetimes.is_empty() {
-        Err(cx.error(format!("field `{}` has no lifetimes to borrow", name)),)
+        Err(cx.error(format!("field `{}` has no lifetimes to borrow", name)))
     } else {
         Ok(lifetimes)
     }
@@ -1233,9 +1242,7 @@ fn borrowable_lifetimes(
 
 fn collect_lifetimes(ty: &syn::Ty, out: &mut BTreeSet<syn::Lifetime>) {
     match *ty {
-        syn::Ty::Slice(ref elem) |
-        syn::Ty::Array(ref elem, _) |
-        syn::Ty::Paren(ref elem) => {
+        syn::Ty::Slice(ref elem) | syn::Ty::Array(ref elem, _) | syn::Ty::Paren(ref elem) => {
             collect_lifetimes(elem, out);
         }
         syn::Ty::Ptr(ref elem) => {
@@ -1245,11 +1252,9 @@ fn collect_lifetimes(ty: &syn::Ty, out: &mut BTreeSet<syn::Lifetime>) {
             out.extend(lifetime.iter().cloned());
             collect_lifetimes(&elem.ty, out);
         }
-        syn::Ty::Tup(ref elems) => {
-            for elem in elems {
-                collect_lifetimes(elem, out);
-            }
-        }
+        syn::Ty::Tup(ref elems) => for elem in elems {
+            collect_lifetimes(elem, out);
+        },
         syn::Ty::Path(ref qself, ref path) => {
             if let Some(ref qself) = *qself {
                 collect_lifetimes(&qself.ty, out);
@@ -1266,11 +1271,11 @@ fn collect_lifetimes(ty: &syn::Ty, out: &mut BTreeSet<syn::Lifetime>) {
                 }
             }
         }
-        syn::Ty::BareFn(_) |
-        syn::Ty::Never |
-        syn::Ty::TraitObject(_) |
-        syn::Ty::ImplTrait(_) |
-        syn::Ty::Infer |
-        syn::Ty::Mac(_) => {}
+        syn::Ty::BareFn(_)
+        | syn::Ty::Never
+        | syn::Ty::TraitObject(_)
+        | syn::Ty::ImplTrait(_)
+        | syn::Ty::Infer
+        | syn::Ty::Mac(_) => {}
     }
 }

serde_derive_internals/src/case.rs

@@ -31,7 +31,7 @@ pub enum RenameRule {
     /// Rename direct children to "kebab-case" style.
     KebabCase,
     /// Rename direct children to "SCREAMING-KEBAB-CASE" style.
-    ScreamingKebabCase
+    ScreamingKebabCase,
 }
 
 impl RenameRule {
@@ -52,7 +52,9 @@ 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('_', "-"),
         }
     }
 
@@ -80,7 +82,7 @@ impl RenameRule {
             }
             ScreamingSnakeCase => field.to_ascii_uppercase(),
             KebabCase => field.replace('_', "-"),
-            ScreamingKebabCase => ScreamingSnakeCase.apply_to_field(field).replace('_', "-")
+            ScreamingKebabCase => ScreamingSnakeCase.apply_to_field(field).replace('_', "-"),
         }
     }
 }
@@ -104,13 +106,28 @@ 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, 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"),
+    ] {
         assert_eq!(None.apply_to_variant(original), original);
         assert_eq!(LowerCase.apply_to_variant(original), lower);
         assert_eq!(PascalCase.apply_to_variant(original), original);
@@ -118,19 +135,35 @@ fn rename_variants() {
         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, 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"),
+    ] {
         assert_eq!(None.apply_to_field(original), original);
         assert_eq!(PascalCase.apply_to_field(original), pascal);
         assert_eq!(CamelCase.apply_to_field(original), camel);

serde_derive_internals/src/check.rs

@@ -31,7 +31,7 @@ fn check_getter(cx: &Ctxt, cont: &Container) {
             if cont.body.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 = \"...\")]",
                 );
             }
         }
@@ -53,10 +53,13 @@ fn check_identifier(cx: &Ctxt, cont: &Container) {
     };
 
     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");
             }
 
@@ -109,42 +112,58 @@ 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
+                    ));
                 }
             }
         }

serde_derive_internals/src/ctxt.rs

@@ -16,7 +16,9 @@ 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) {

serde_derive_internals/src/lib.rs

@@ -6,7 +6,7 @@
 // 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/0.18.1")]
 
 extern crate syn;
 #[macro_use]

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "1.0.19" # remember to update html_root_url
+version = "1.0.26" # 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());
     }
@@ -215,7 +231,7 @@ where
 ///
 /// assert_de_tokens_error::<S>(
 ///     &[
-///         Token::Struct { name: "S", len: 1 },
+///         Token::Struct { name: "S", len: 2 },
 ///         Token::Str("x"),
 ///     ],
 ///     "unknown field `x`, expected `a` or `b`",

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

@@ -155,17 +155,13 @@
 //! # }
 //! ```
 
-#![doc(html_root_url = "https://docs.rs/serde_test/1.0.19")]
-
+#![doc(html_root_url = "https://docs.rs/serde_test/1.0.26")]
 #![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_self,
-))]
+#![cfg_attr(feature = "cargo-clippy",
+            allow(missing_docs_in_private_items, stutter, use_debug, use_self))]
 
 #[macro_use]
 extern crate serde;

serde_test/src/ser.rs

@@ -40,25 +40,43 @@ impl<'a> Serializer<'a> {
 
 macro_rules! assert_next_token {
     ($ser:expr, $expected:ident) => {
-        assert_next_token!($ser, $expected, Token::$expected, true);
+        assert_next_token!($ser, stringify!($expected), Token::$expected, true);
     };
     ($ser:expr, $expected:ident($v:expr)) => {
-        assert_next_token!($ser, $expected, Token::$expected(v), v == $v);
+        assert_next_token!(
+            $ser,
+            format_args!("{}({:?})", stringify!($expected), $v),
+            Token::$expected(v),
+            v == $v
+        );
     };
     ($ser:expr, $expected:ident { $($k:ident),* }) => {
         let compare = ($($k,)*);
-        assert_next_token!($ser, $expected, Token::$expected { $($k),* }, ($($k,)*) == compare);
+        let field_format = || {
+            use std::fmt::Write;
+            let mut buffer = String::new();
+            $(
+                write!(&mut buffer, "{}: {:?}, ", stringify!($k), $k).unwrap();
+            )*
+            buffer
+        };
+        assert_next_token!(
+            $ser,
+            format_args!("{} {{ {}}}", stringify!($expected), field_format()),
+            Token::$expected { $($k),* },
+            ($($k,)*) == compare
+        );
     };
-    ($ser:expr, $expected:ident, $pat:pat, $guard:expr) => {
+    ($ser:expr, $expected:expr, $pat:pat, $guard:expr) => {
         match $ser.next_token() {
             Some($pat) if $guard => {}
             Some(other) => {
                 panic!("expected Token::{} but serialized as {}",
-                       stringify!($expected), other);
+                       $expected, other);
             }
             None => {
                 panic!("expected Token::{} after end of serialized tokens",
-                       stringify!($expected));
+                       $expected);
             }
         }
     };

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

@@ -11,8 +11,8 @@ unstable = ["serde/unstable", "compiletest_rs"]
 fnv = "1.0"
 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]
-compiletest_rs = { version = "0.2", optional = true }
+compiletest_rs = { version = "0.3", optional = true }

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

@@ -49,14 +49,16 @@ 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 +79,35 @@ 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 +118,11 @@ 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)]
@@ -538,7 +566,7 @@ declare_tests! {
             Token::MapEnd,
         ],
         Struct { a: 1, b: 2, c: 0 } => &[
-            Token::Struct { name: "Struct", len: 3 },
+            Token::Struct { name: "Struct", len: 2 },
                 Token::Str("a"),
                 Token::I32(1),
 
@@ -570,7 +598,7 @@ declare_tests! {
             Token::MapEnd,
         ],
         Struct { a: 1, b: 2, c: 0 } => &[
-            Token::Struct { name: "Struct", len: 3 },
+            Token::Struct { name: "Struct", len: 2 },
                 Token::Str("a"),
                 Token::I32(1),
 
@@ -591,7 +619,7 @@ declare_tests! {
             Token::StructEnd,
         ],
         StructSkipAll { a: 0 } => &[
-            Token::Struct { name: "StructSkipAll", len: 1 },
+            Token::Struct { name: "StructSkipAll", len: 0 },
                 Token::Str("a"),
                 Token::I32(1),
 
@@ -600,6 +628,12 @@ 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 },
@@ -608,7 +642,7 @@ declare_tests! {
     }
     test_struct_default {
         StructDefault { a: 50, b: "overwritten".to_string() } => &[
-            Token::Struct { name: "StructDefault", len: 1 },
+            Token::Struct { name: "StructDefault", len: 2 },
                 Token::Str("a"),
                 Token::I32(50),
 
@@ -617,7 +651,7 @@ declare_tests! {
             Token::StructEnd,
         ],
         StructDefault { a: 100, b: "default".to_string() } => &[
-            Token::Struct { name: "StructDefault",  len: 0 },
+            Token::Struct { name: "StructDefault",  len: 2 },
             Token::StructEnd,
         ],
     }
@@ -954,7 +988,7 @@ fn test_cstr_internal_null_end() {
 declare_error_tests! {
     test_unknown_field<StructDenyUnknown> {
         &[
-            Token::Struct { name: "StructDenyUnknown", len: 2 },
+            Token::Struct { name: "StructDenyUnknown", len: 1 },
                 Token::Str("a"),
                 Token::I32(0),
 
@@ -964,14 +998,14 @@ declare_error_tests! {
     }
     test_skipped_field_is_unknown<StructDenyUnknown> {
         &[
-            Token::Struct { name: "StructDenyUnknown", len: 2 },
+            Token::Struct { name: "StructDenyUnknown", len: 1 },
                 Token::Str("b"),
         ],
         "unknown field `b`, expected `a`",
     }
     test_skip_all_deny_unknown<StructSkipAllDenyUnknown> {
         &[
-            Token::Struct { name: "StructSkipAllDenyUnknown", len: 1 },
+            Token::Struct { name: "StructSkipAllDenyUnknown", len: 0 },
                 Token::Str("a"),
         ],
         "unknown field `a`, there are no fields",

test_suite/tests/test_gen.rs

@@ -11,7 +11,6 @@
 // types involved.
 
 #![deny(warnings)]
-
 #![cfg_attr(feature = "unstable", feature(non_ascii_idents))]
 
 #[macro_use]
@@ -23,6 +22,7 @@ use self::serde::de::{DeserializeOwned, Deserializer};
 
 use std::borrow::Cow;
 use std::marker::PhantomData;
+use std::option::Option as StdOption;
 use std::result::Result as StdResult;
 
 // Try to trip up the generated code if it fails to use fully qualified paths.
@@ -32,6 +32,12 @@ struct Result;
 struct Ok;
 #[allow(dead_code)]
 struct Err;
+#[allow(dead_code)]
+struct Option;
+#[allow(dead_code)]
+struct Some;
+#[allow(dead_code)]
+struct None;
 
 //////////////////////////////////////////////////////////////////////////
 
@@ -40,7 +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>>();
@@ -48,7 +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>>();
@@ -56,8 +62,8 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     struct WithRef<'a, T: 'a> {
         #[serde(skip_deserializing)]
-        t: Option<&'a T>,
-        #[serde(serialize_with="ser_x", deserialize_with="de_x")]
+        t: StdOption<&'a T>,
+        #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
         x: X,
     }
     assert::<WithRef<i32>>();
@@ -77,9 +83,9 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     struct NoBounds<T> {
         t: T,
-        option: Option<T>,
+        option: StdOption<T>,
         boxed: Box<T>,
-        option_boxed: Option<Box<T>>,
+        option_boxed: StdOption<Box<T>>,
     }
     assert::<NoBounds<i32>>();
 
@@ -87,17 +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,
         },
     }
@@ -117,16 +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>>();
 
@@ -136,7 +142,9 @@ fn test_gen() {
             left: Box<TreeNode<D>>,
             right: Box<TreeNode<D>>,
         },
-        Leaf { data: D },
+        Leaf {
+            data: D,
+        },
     }
     assert::<TreeNode<i32>>();
 
@@ -175,35 +183,34 @@ fn test_gen() {
 
     #[derive(Serialize)]
     struct OptionStatic<'a> {
-        a: Option<&'a str>,
-        b: Option<&'static str>,
+        a: StdOption<&'a str>,
+        b: StdOption<&'static str>,
     }
     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>>();
@@ -265,14 +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)]
@@ -300,7 +307,7 @@ fn test_gen() {
         },
         TupleSkip(
             #[serde(skip_deserializing)]
-            u8
+            u8,
         ),
     }
 
@@ -316,7 +323,7 @@ fn test_gen() {
         },
         TupleSkip(
             #[serde(skip_deserializing)]
-            u8
+            u8,
         ),
     }
 
@@ -396,10 +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")]
@@ -422,10 +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")]
@@ -453,10 +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")]
@@ -484,10 +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")]
@@ -510,10 +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),
     }
@@ -563,7 +555,7 @@ 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 {
@@ -579,27 +571,33 @@ 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

@@ -85,23 +85,32 @@ 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 +119,10 @@ 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 +131,39 @@ 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 +173,8 @@ 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_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,
+    },
 }
 
 //////////////////////////////////////////////////////////////////////////