Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 1385 insertions, 0 deletions

diff --git a/vendor/serde/src/private/ser.rs b/vendor/serde/src/private/ser.rs
new file mode 100644
index 0000000..50bcb25
--- /dev/null
+++ b/vendor/serde/src/private/ser.rs
@@ -0,0 +1,1385 @@
+use crate::lib::*;
+
+use crate::ser::{self, Impossible, Serialize, SerializeMap, SerializeStruct, Serializer};
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+use self::content::{
+    Content, ContentSerializer, SerializeStructVariantAsMapValue, SerializeTupleVariantAsMapValue,
+};
+
+/// Used to check that serde(getter) attributes return the expected type.
+/// Not public API.
+pub fn constrain<T: ?Sized>(t: &T) -> &T {
+    t
+}
+
+/// Not public API.
+pub fn serialize_tagged_newtype<S, T>(
+    serializer: S,
+    type_ident: &'static str,
+    variant_ident: &'static str,
+    tag: &'static str,
+    variant_name: &'static str,
+    value: &T,
+) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+    T: Serialize,
+{
+    value.serialize(TaggedSerializer {
+        type_ident,
+        variant_ident,
+        tag,
+        variant_name,
+        delegate: serializer,
+    })
+}
+
+struct TaggedSerializer<S> {
+    type_ident: &'static str,
+    variant_ident: &'static str,
+    tag: &'static str,
+    variant_name: &'static str,
+    delegate: S,
+}
+
+enum Unsupported {
+    Boolean,
+    Integer,
+    Float,
+    Char,
+    String,
+    ByteArray,
+    Optional,
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    UnitStruct,
+    Sequence,
+    Tuple,
+    TupleStruct,
+    Enum,
+}
+
+impl Display for Unsupported {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Unsupported::Boolean => formatter.write_str("a boolean"),
+            Unsupported::Integer => formatter.write_str("an integer"),
+            Unsupported::Float => formatter.write_str("a float"),
+            Unsupported::Char => formatter.write_str("a char"),
+            Unsupported::String => formatter.write_str("a string"),
+            Unsupported::ByteArray => formatter.write_str("a byte array"),
+            Unsupported::Optional => formatter.write_str("an optional"),
+            #[cfg(any(feature = "std", feature = "alloc"))]
+            Unsupported::UnitStruct => formatter.write_str("unit struct"),
+            Unsupported::Sequence => formatter.write_str("a sequence"),
+            Unsupported::Tuple => formatter.write_str("a tuple"),
+            Unsupported::TupleStruct => formatter.write_str("a tuple struct"),
+            Unsupported::Enum => formatter.write_str("an enum"),
+        }
+    }
+}
+
+impl<S> TaggedSerializer<S>
+where
+    S: Serializer,
+{
+    fn bad_type(self, what: Unsupported) -> S::Error {
+        ser::Error::custom(format_args!(
+            "cannot serialize tagged newtype variant {}::{} containing {}",
+            self.type_ident, self.variant_ident, what
+        ))
+    }
+}
+
+impl<S> Serializer for TaggedSerializer<S>
+where
+    S: Serializer,
+{
+    type Ok = S::Ok;
+    type Error = S::Error;
+
+    type SerializeSeq = Impossible<S::Ok, S::Error>;
+    type SerializeTuple = Impossible<S::Ok, S::Error>;
+    type SerializeTupleStruct = Impossible<S::Ok, S::Error>;
+    type SerializeMap = S::SerializeMap;
+    type SerializeStruct = S::SerializeStruct;
+
+    #[cfg(not(any(feature = "std", feature = "alloc")))]
+    type SerializeTupleVariant = Impossible<S::Ok, S::Error>;
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    type SerializeTupleVariant = SerializeTupleVariantAsMapValue<S::SerializeMap>;
+
+    #[cfg(not(any(feature = "std", feature = "alloc")))]
+    type SerializeStructVariant = Impossible<S::Ok, S::Error>;
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    type SerializeStructVariant = SerializeStructVariantAsMapValue<S::SerializeMap>;
+
+    fn serialize_bool(self, _: bool) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Boolean))
+    }
+
+    fn serialize_i8(self, _: i8) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i16(self, _: i16) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i32(self, _: i32) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i64(self, _: i64) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u8(self, _: u8) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u16(self, _: u16) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u32(self, _: u32) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u64(self, _: u64) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_f32(self, _: f32) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Float))
+    }
+
+    fn serialize_f64(self, _: f64) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Float))
+    }
+
+    fn serialize_char(self, _: char) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Char))
+    }
+
+    fn serialize_str(self, _: &str) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::String))
+    }
+
+    fn serialize_bytes(self, _: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::ByteArray))
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Err(self.bad_type(Unsupported::Optional))
+    }
+
+    fn serialize_some<T: ?Sized>(self, _: &T) -> Result<Self::Ok, Self::Error>
+    where
+        T: Serialize,
+    {
+        Err(self.bad_type(Unsupported::Optional))
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        let mut map = tri!(self.delegate.serialize_map(Some(1)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        map.end()
+    }
+
+    fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
+        let mut map = tri!(self.delegate.serialize_map(Some(1)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        map.end()
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        inner_variant: &'static str,
+    ) -> Result<Self::Ok, Self::Error> {
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(inner_variant, &()));
+        map.end()
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(
+        self,
+        _: &'static str,
+        value: &T,
+    ) -> Result<Self::Ok, Self::Error>
+    where
+        T: Serialize,
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _: &'static str,
+        _: u32,
+        inner_variant: &'static str,
+        inner_value: &T,
+    ) -> Result<Self::Ok, Self::Error>
+    where
+        T: Serialize,
+    {
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_entry(inner_variant, inner_value));
+        map.end()
+    }
+
+    fn serialize_seq(self, _: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(self.bad_type(Unsupported::Sequence))
+    }
+
+    fn serialize_tuple(self, _: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(self.bad_type(Unsupported::Tuple))
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeTupleStruct, Self::Error> {
+        Err(self.bad_type(Unsupported::TupleStruct))
+    }
+
+    #[cfg(not(any(feature = "std", feature = "alloc")))]
+    fn serialize_tuple_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        _: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeTupleVariant, Self::Error> {
+        // Lack of push-based serialization means we need to buffer the content
+        // of the tuple variant, so it requires std.
+        Err(self.bad_type(Unsupported::Enum))
+    }
+
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    fn serialize_tuple_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        inner_variant: &'static str,
+        len: usize,
+    ) -> Result<Self::SerializeTupleVariant, Self::Error> {
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_key(inner_variant));
+        Ok(SerializeTupleVariantAsMapValue::new(
+            map,
+            inner_variant,
+            len,
+        ))
+    }
+
+    fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        let mut map = tri!(self.delegate.serialize_map(len.map(|len| len + 1)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        Ok(map)
+    }
+
+    fn serialize_struct(
+        self,
+        name: &'static str,
+        len: usize,
+    ) -> Result<Self::SerializeStruct, Self::Error> {
+        let mut state = tri!(self.delegate.serialize_struct(name, len + 1));
+        tri!(state.serialize_field(self.tag, self.variant_name));
+        Ok(state)
+    }
+
+    #[cfg(not(any(feature = "std", feature = "alloc")))]
+    fn serialize_struct_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        _: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeStructVariant, Self::Error> {
+        // Lack of push-based serialization means we need to buffer the content
+        // of the struct variant, so it requires std.
+        Err(self.bad_type(Unsupported::Enum))
+    }
+
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    fn serialize_struct_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        inner_variant: &'static str,
+        len: usize,
+    ) -> Result<Self::SerializeStructVariant, Self::Error> {
+        let mut map = tri!(self.delegate.serialize_map(Some(2)));
+        tri!(map.serialize_entry(self.tag, self.variant_name));
+        tri!(map.serialize_key(inner_variant));
+        Ok(SerializeStructVariantAsMapValue::new(
+            map,
+            inner_variant,
+            len,
+        ))
+    }
+
+    #[cfg(not(any(feature = "std", feature = "alloc")))]
+    fn collect_str<T: ?Sized>(self, _: &T) -> Result<Self::Ok, Self::Error>
+    where
+        T: Display,
+    {
+        Err(self.bad_type(Unsupported::String))
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+mod content {
+    use crate::lib::*;
+
+    use crate::ser::{self, Serialize, Serializer};
+
+    pub struct SerializeTupleVariantAsMapValue<M> {
+        map: M,
+        name: &'static str,
+        fields: Vec<Content>,
+    }
+
+    impl<M> SerializeTupleVariantAsMapValue<M> {
+        pub fn new(map: M, name: &'static str, len: usize) -> Self {
+            SerializeTupleVariantAsMapValue {
+                map,
+                name,
+                fields: Vec::with_capacity(len),
+            }
+        }
+    }
+
+    impl<M> ser::SerializeTupleVariant for SerializeTupleVariantAsMapValue<M>
+    where
+        M: ser::SerializeMap,
+    {
+        type Ok = M::Ok;
+        type Error = M::Error;
+
+        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), M::Error>
+        where
+            T: Serialize,
+        {
+            let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
+            self.fields.push(value);
+            Ok(())
+        }
+
+        fn end(mut self) -> Result<M::Ok, M::Error> {
+            tri!(self
+                .map
+                .serialize_value(&Content::TupleStruct(self.name, self.fields)));
+            self.map.end()
+        }
+    }
+
+    pub struct SerializeStructVariantAsMapValue<M> {
+        map: M,
+        name: &'static str,
+        fields: Vec<(&'static str, Content)>,
+    }
+
+    impl<M> SerializeStructVariantAsMapValue<M> {
+        pub fn new(map: M, name: &'static str, len: usize) -> Self {
+            SerializeStructVariantAsMapValue {
+                map,
+                name,
+                fields: Vec::with_capacity(len),
+            }
+        }
+    }
+
+    impl<M> ser::SerializeStructVariant for SerializeStructVariantAsMapValue<M>
+    where
+        M: ser::SerializeMap,
+    {
+        type Ok = M::Ok;
+        type Error = M::Error;
+
+        fn serialize_field<T: ?Sized>(
+            &mut self,
+            key: &'static str,
+            value: &T,
+        ) -> Result<(), M::Error>
+        where
+            T: Serialize,
+        {
+            let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
+            self.fields.push((key, value));
+            Ok(())
+        }
+
+        fn end(mut self) -> Result<M::Ok, M::Error> {
+            tri!(self
+                .map
+                .serialize_value(&Content::Struct(self.name, self.fields)));
+            self.map.end()
+        }
+    }
+
+    pub enum Content {
+        Bool(bool),
+
+        U8(u8),
+        U16(u16),
+        U32(u32),
+        U64(u64),
+
+        I8(i8),
+        I16(i16),
+        I32(i32),
+        I64(i64),
+
+        F32(f32),
+        F64(f64),
+
+        Char(char),
+        String(String),
+        Bytes(Vec<u8>),
+
+        None,
+        Some(Box<Content>),
+
+        Unit,
+        UnitStruct(&'static str),
+        UnitVariant(&'static str, u32, &'static str),
+        NewtypeStruct(&'static str, Box<Content>),
+        NewtypeVariant(&'static str, u32, &'static str, Box<Content>),
+
+        Seq(Vec<Content>),
+        Tuple(Vec<Content>),
+        TupleStruct(&'static str, Vec<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)>,
+        ),
+    }
+
+    impl Serialize for Content {
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: Serializer,
+        {
+            match *self {
+                Content::Bool(b) => serializer.serialize_bool(b),
+                Content::U8(u) => serializer.serialize_u8(u),
+                Content::U16(u) => serializer.serialize_u16(u),
+                Content::U32(u) => serializer.serialize_u32(u),
+                Content::U64(u) => serializer.serialize_u64(u),
+                Content::I8(i) => serializer.serialize_i8(i),
+                Content::I16(i) => serializer.serialize_i16(i),
+                Content::I32(i) => serializer.serialize_i32(i),
+                Content::I64(i) => serializer.serialize_i64(i),
+                Content::F32(f) => serializer.serialize_f32(f),
+                Content::F64(f) => serializer.serialize_f64(f),
+                Content::Char(c) => serializer.serialize_char(c),
+                Content::String(ref s) => serializer.serialize_str(s),
+                Content::Bytes(ref b) => serializer.serialize_bytes(b),
+                Content::None => serializer.serialize_none(),
+                Content::Some(ref c) => serializer.serialize_some(&**c),
+                Content::Unit => serializer.serialize_unit(),
+                Content::UnitStruct(n) => serializer.serialize_unit_struct(n),
+                Content::UnitVariant(n, i, v) => serializer.serialize_unit_variant(n, i, v),
+                Content::NewtypeStruct(n, ref c) => serializer.serialize_newtype_struct(n, &**c),
+                Content::NewtypeVariant(n, i, v, ref c) => {
+                    serializer.serialize_newtype_variant(n, i, v, &**c)
+                }
+                Content::Seq(ref elements) => elements.serialize(serializer),
+                Content::Tuple(ref elements) => {
+                    use crate::ser::SerializeTuple;
+                    let mut tuple = tri!(serializer.serialize_tuple(elements.len()));
+                    for e in elements {
+                        tri!(tuple.serialize_element(e));
+                    }
+                    tuple.end()
+                }
+                Content::TupleStruct(n, ref fields) => {
+                    use crate::ser::SerializeTupleStruct;
+                    let mut ts = tri!(serializer.serialize_tuple_struct(n, fields.len()));
+                    for f in fields {
+                        tri!(ts.serialize_field(f));
+                    }
+                    ts.end()
+                }
+                Content::TupleVariant(n, i, v, ref fields) => {
+                    use crate::ser::SerializeTupleVariant;
+                    let mut tv = tri!(serializer.serialize_tuple_variant(n, i, v, fields.len()));
+                    for f in fields {
+                        tri!(tv.serialize_field(f));
+                    }
+                    tv.end()
+                }
+                Content::Map(ref entries) => {
+                    use crate::ser::SerializeMap;
+                    let mut map = tri!(serializer.serialize_map(Some(entries.len())));
+                    for (k, v) in entries {
+                        tri!(map.serialize_entry(k, v));
+                    }
+                    map.end()
+                }
+                Content::Struct(n, ref fields) => {
+                    use crate::ser::SerializeStruct;
+                    let mut s = tri!(serializer.serialize_struct(n, fields.len()));
+                    for &(k, ref v) in fields {
+                        tri!(s.serialize_field(k, v));
+                    }
+                    s.end()
+                }
+                Content::StructVariant(n, i, v, ref fields) => {
+                    use crate::ser::SerializeStructVariant;
+                    let mut sv = tri!(serializer.serialize_struct_variant(n, i, v, fields.len()));
+                    for &(k, ref v) in fields {
+                        tri!(sv.serialize_field(k, v));
+                    }
+                    sv.end()
+                }
+            }
+        }
+    }
+
+    pub struct ContentSerializer<E> {
+        error: PhantomData<E>,
+    }
+
+    impl<E> ContentSerializer<E> {
+        pub fn new() -> Self {
+            ContentSerializer { error: PhantomData }
+        }
+    }
+
+    impl<E> Serializer for ContentSerializer<E>
+    where
+        E: ser::Error,
+    {
+        type Ok = Content;
+        type Error = E;
+
+        type SerializeSeq = SerializeSeq<E>;
+        type SerializeTuple = SerializeTuple<E>;
+        type SerializeTupleStruct = SerializeTupleStruct<E>;
+        type SerializeTupleVariant = SerializeTupleVariant<E>;
+        type SerializeMap = SerializeMap<E>;
+        type SerializeStruct = SerializeStruct<E>;
+        type SerializeStructVariant = SerializeStructVariant<E>;
+
+        fn serialize_bool(self, v: bool) -> Result<Content, E> {
+            Ok(Content::Bool(v))
+        }
+
+        fn serialize_i8(self, v: i8) -> Result<Content, E> {
+            Ok(Content::I8(v))
+        }
+
+        fn serialize_i16(self, v: i16) -> Result<Content, E> {
+            Ok(Content::I16(v))
+        }
+
+        fn serialize_i32(self, v: i32) -> Result<Content, E> {
+            Ok(Content::I32(v))
+        }
+
+        fn serialize_i64(self, v: i64) -> Result<Content, E> {
+            Ok(Content::I64(v))
+        }
+
+        fn serialize_u8(self, v: u8) -> Result<Content, E> {
+            Ok(Content::U8(v))
+        }
+
+        fn serialize_u16(self, v: u16) -> Result<Content, E> {
+            Ok(Content::U16(v))
+        }
+
+        fn serialize_u32(self, v: u32) -> Result<Content, E> {
+            Ok(Content::U32(v))
+        }
+
+        fn serialize_u64(self, v: u64) -> Result<Content, E> {
+            Ok(Content::U64(v))
+        }
+
+        fn serialize_f32(self, v: f32) -> Result<Content, E> {
+            Ok(Content::F32(v))
+        }
+
+        fn serialize_f64(self, v: f64) -> Result<Content, E> {
+            Ok(Content::F64(v))
+        }
+
+        fn serialize_char(self, v: char) -> Result<Content, E> {
+            Ok(Content::Char(v))
+        }
+
+        fn serialize_str(self, value: &str) -> Result<Content, E> {
+            Ok(Content::String(value.to_owned()))
+        }
+
+        fn serialize_bytes(self, value: &[u8]) -> Result<Content, E> {
+            Ok(Content::Bytes(value.to_owned()))
+        }
+
+        fn serialize_none(self) -> Result<Content, E> {
+            Ok(Content::None)
+        }
+
+        fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Content, E>
+        where
+            T: Serialize,
+        {
+            Ok(Content::Some(Box::new(tri!(value.serialize(self)))))
+        }
+
+        fn serialize_unit(self) -> Result<Content, E> {
+            Ok(Content::Unit)
+        }
+
+        fn serialize_unit_struct(self, name: &'static str) -> Result<Content, E> {
+            Ok(Content::UnitStruct(name))
+        }
+
+        fn serialize_unit_variant(
+            self,
+            name: &'static str,
+            variant_index: u32,
+            variant: &'static str,
+        ) -> Result<Content, E> {
+            Ok(Content::UnitVariant(name, variant_index, variant))
+        }
+
+        fn serialize_newtype_struct<T: ?Sized>(
+            self,
+            name: &'static str,
+            value: &T,
+        ) -> Result<Content, E>
+        where
+            T: Serialize,
+        {
+            Ok(Content::NewtypeStruct(
+                name,
+                Box::new(tri!(value.serialize(self))),
+            ))
+        }
+
+        fn serialize_newtype_variant<T: ?Sized>(
+            self,
+            name: &'static str,
+            variant_index: u32,
+            variant: &'static str,
+            value: &T,
+        ) -> Result<Content, E>
+        where
+            T: Serialize,
+        {
+            Ok(Content::NewtypeVariant(
+                name,
+                variant_index,
+                variant,
+                Box::new(tri!(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,
+            })
+        }
+
+        fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple, E> {
+            Ok(SerializeTuple {
+                elements: Vec::with_capacity(len),
+                error: PhantomData,
+            })
+        }
+
+        fn serialize_tuple_struct(
+            self,
+            name: &'static str,
+            len: usize,
+        ) -> Result<Self::SerializeTupleStruct, E> {
+            Ok(SerializeTupleStruct {
+                name,
+                fields: Vec::with_capacity(len),
+                error: PhantomData,
+            })
+        }
+
+        fn serialize_tuple_variant(
+            self,
+            name: &'static str,
+            variant_index: u32,
+            variant: &'static str,
+            len: usize,
+        ) -> Result<Self::SerializeTupleVariant, E> {
+            Ok(SerializeTupleVariant {
+                name,
+                variant_index,
+                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,
+            })
+        }
+
+        fn serialize_struct(
+            self,
+            name: &'static str,
+            len: usize,
+        ) -> Result<Self::SerializeStruct, E> {
+            Ok(SerializeStruct {
+                name,
+                fields: Vec::with_capacity(len),
+                error: PhantomData,
+            })
+        }
+
+        fn serialize_struct_variant(
+            self,
+            name: &'static str,
+            variant_index: u32,
+            variant: &'static str,
+            len: usize,
+        ) -> Result<Self::SerializeStructVariant, E> {
+            Ok(SerializeStructVariant {
+                name,
+                variant_index,
+                variant,
+                fields: Vec::with_capacity(len),
+                error: PhantomData,
+            })
+        }
+    }
+
+    pub struct SerializeSeq<E> {
+        elements: Vec<Content>,
+        error: PhantomData<E>,
+    }
+
+    impl<E> ser::SerializeSeq for SerializeSeq<E>
+    where
+        E: ser::Error,
+    {
+        type Ok = Content;
+        type Error = E;
+
+        fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        where
+            T: Serialize,
+        {
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
+            self.elements.push(value);
+            Ok(())
+        }
+
+        fn end(self) -> Result<Content, E> {
+            Ok(Content::Seq(self.elements))
+        }
+    }
+
+    pub struct SerializeTuple<E> {
+        elements: Vec<Content>,
+        error: PhantomData<E>,
+    }
+
+    impl<E> ser::SerializeTuple for SerializeTuple<E>
+    where
+        E: ser::Error,
+    {
+        type Ok = Content;
+        type Error = E;
+
+        fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        where
+            T: Serialize,
+        {
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
+            self.elements.push(value);
+            Ok(())
+        }
+
+        fn end(self) -> Result<Content, E> {
+            Ok(Content::Tuple(self.elements))
+        }
+    }
+
+    pub struct SerializeTupleStruct<E> {
+        name: &'static str,
+        fields: Vec<Content>,
+        error: PhantomData<E>,
+    }
+
+    impl<E> ser::SerializeTupleStruct for SerializeTupleStruct<E>
+    where
+        E: ser::Error,
+    {
+        type Ok = Content;
+        type Error = E;
+
+        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        where
+            T: Serialize,
+        {
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
+            self.fields.push(value);
+            Ok(())
+        }
+
+        fn end(self) -> Result<Content, E> {
+            Ok(Content::TupleStruct(self.name, self.fields))
+        }
+    }
+
+    pub struct SerializeTupleVariant<E> {
+        name: &'static str,
+        variant_index: u32,
+        variant: &'static str,
+        fields: Vec<Content>,
+        error: PhantomData<E>,
+    }
+
+    impl<E> ser::SerializeTupleVariant for SerializeTupleVariant<E>
+    where
+        E: ser::Error,
+    {
+        type Ok = Content;
+        type Error = E;
+
+        fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        where
+            T: Serialize,
+        {
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
+            self.fields.push(value);
+            Ok(())
+        }
+
+        fn end(self) -> Result<Content, E> {
+            Ok(Content::TupleVariant(
+                self.name,
+                self.variant_index,
+                self.variant,
+                self.fields,
+            ))
+        }
+    }
+
+    pub struct SerializeMap<E> {
+        entries: Vec<(Content, Content)>,
+        key: Option<Content>,
+        error: PhantomData<E>,
+    }
+
+    impl<E> ser::SerializeMap for SerializeMap<E>
+    where
+        E: ser::Error,
+    {
+        type Ok = Content;
+        type Error = E;
+
+        fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), E>
+        where
+            T: Serialize,
+        {
+            let key = tri!(key.serialize(ContentSerializer::<E>::new()));
+            self.key = Some(key);
+            Ok(())
+        }
+
+        fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), E>
+        where
+            T: Serialize,
+        {
+            let key = self
+                .key
+                .take()
+                .expect("serialize_value called before serialize_key");
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
+            self.entries.push((key, value));
+            Ok(())
+        }
+
+        fn end(self) -> Result<Content, E> {
+            Ok(Content::Map(self.entries))
+        }
+
+        fn serialize_entry<K: ?Sized, V: ?Sized>(&mut self, key: &K, value: &V) -> Result<(), E>
+        where
+            K: Serialize,
+            V: Serialize,
+        {
+            let key = tri!(key.serialize(ContentSerializer::<E>::new()));
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
+            self.entries.push((key, value));
+            Ok(())
+        }
+    }
+
+    pub struct SerializeStruct<E> {
+        name: &'static str,
+        fields: Vec<(&'static str, Content)>,
+        error: PhantomData<E>,
+    }
+
+    impl<E> ser::SerializeStruct for SerializeStruct<E>
+    where
+        E: ser::Error,
+    {
+        type Ok = Content;
+        type Error = E;
+
+        fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), E>
+        where
+            T: Serialize,
+        {
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
+            self.fields.push((key, value));
+            Ok(())
+        }
+
+        fn end(self) -> Result<Content, E> {
+            Ok(Content::Struct(self.name, self.fields))
+        }
+    }
+
+    pub struct SerializeStructVariant<E> {
+        name: &'static str,
+        variant_index: u32,
+        variant: &'static str,
+        fields: Vec<(&'static str, Content)>,
+        error: PhantomData<E>,
+    }
+
+    impl<E> ser::SerializeStructVariant for SerializeStructVariant<E>
+    where
+        E: ser::Error,
+    {
+        type Ok = Content;
+        type Error = E;
+
+        fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), E>
+        where
+            T: Serialize,
+        {
+            let value = tri!(value.serialize(ContentSerializer::<E>::new()));
+            self.fields.push((key, value));
+            Ok(())
+        }
+
+        fn end(self) -> Result<Content, E> {
+            Ok(Content::StructVariant(
+                self.name,
+                self.variant_index,
+                self.variant,
+                self.fields,
+            ))
+        }
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub struct FlatMapSerializer<'a, M: 'a>(pub &'a mut M);
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> FlatMapSerializer<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    fn bad_type(what: Unsupported) -> M::Error {
+        ser::Error::custom(format_args!(
+            "can only flatten structs and maps (got {})",
+            what
+        ))
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> Serializer for FlatMapSerializer<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    type Ok = ();
+    type Error = M::Error;
+
+    type SerializeSeq = Impossible<Self::Ok, M::Error>;
+    type SerializeTuple = Impossible<Self::Ok, M::Error>;
+    type SerializeTupleStruct = Impossible<Self::Ok, M::Error>;
+    type SerializeMap = FlatMapSerializeMap<'a, M>;
+    type SerializeStruct = FlatMapSerializeStruct<'a, M>;
+    type SerializeTupleVariant = FlatMapSerializeTupleVariantAsMapValue<'a, M>;
+    type SerializeStructVariant = FlatMapSerializeStructVariantAsMapValue<'a, M>;
+
+    fn serialize_bool(self, _: bool) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Boolean))
+    }
+
+    fn serialize_i8(self, _: i8) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i16(self, _: i16) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i32(self, _: i32) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_i64(self, _: i64) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u8(self, _: u8) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u16(self, _: u16) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u32(self, _: u32) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_u64(self, _: u64) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Integer))
+    }
+
+    fn serialize_f32(self, _: f32) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Float))
+    }
+
+    fn serialize_f64(self, _: f64) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Float))
+    }
+
+    fn serialize_char(self, _: char) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Char))
+    }
+
+    fn serialize_str(self, _: &str) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::String))
+    }
+
+    fn serialize_bytes(self, _: &[u8]) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::ByteArray))
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
+        Ok(())
+    }
+
+    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
+    where
+        T: Serialize,
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
+        Ok(())
+    }
+
+    fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::UnitStruct))
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        _: &'static str,
+    ) -> Result<Self::Ok, Self::Error> {
+        Err(Self::bad_type(Unsupported::Enum))
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(
+        self,
+        _: &'static str,
+        value: &T,
+    ) -> Result<Self::Ok, Self::Error>
+    where
+        T: Serialize,
+    {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _: &'static str,
+        _: u32,
+        variant: &'static str,
+        value: &T,
+    ) -> Result<Self::Ok, Self::Error>
+    where
+        T: Serialize,
+    {
+        tri!(self.0.serialize_key(variant));
+        self.0.serialize_value(value)
+    }
+
+    fn serialize_seq(self, _: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
+        Err(Self::bad_type(Unsupported::Sequence))
+    }
+
+    fn serialize_tuple(self, _: usize) -> Result<Self::SerializeTuple, Self::Error> {
+        Err(Self::bad_type(Unsupported::Tuple))
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeTupleStruct, Self::Error> {
+        Err(Self::bad_type(Unsupported::TupleStruct))
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        variant: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeTupleVariant, Self::Error> {
+        tri!(self.0.serialize_key(variant));
+        Ok(FlatMapSerializeTupleVariantAsMapValue::new(self.0))
+    }
+
+    fn serialize_map(self, _: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
+        Ok(FlatMapSerializeMap(self.0))
+    }
+
+    fn serialize_struct(
+        self,
+        _: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeStruct, Self::Error> {
+        Ok(FlatMapSerializeStruct(self.0))
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _: &'static str,
+        _: u32,
+        inner_variant: &'static str,
+        _: usize,
+    ) -> Result<Self::SerializeStructVariant, Self::Error> {
+        tri!(self.0.serialize_key(inner_variant));
+        Ok(FlatMapSerializeStructVariantAsMapValue::new(
+            self.0,
+            inner_variant,
+        ))
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub struct FlatMapSerializeMap<'a, M: 'a>(&'a mut M);
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> ser::SerializeMap for FlatMapSerializeMap<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    type Ok = ();
+    type Error = M::Error;
+
+    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
+    where
+        T: Serialize,
+    {
+        self.0.serialize_key(key)
+    }
+
+    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    where
+        T: Serialize,
+    {
+        self.0.serialize_value(value)
+    }
+
+    fn serialize_entry<K: ?Sized, V: ?Sized>(
+        &mut self,
+        key: &K,
+        value: &V,
+    ) -> Result<(), Self::Error>
+    where
+        K: Serialize,
+        V: Serialize,
+    {
+        self.0.serialize_entry(key, value)
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub struct FlatMapSerializeStruct<'a, M: 'a>(&'a mut M);
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> ser::SerializeStruct for FlatMapSerializeStruct<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    type Ok = ();
+    type Error = M::Error;
+
+    fn serialize_field<T: ?Sized>(
+        &mut self,
+        key: &'static str,
+        value: &T,
+    ) -> Result<(), Self::Error>
+    where
+        T: Serialize,
+    {
+        self.0.serialize_entry(key, value)
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub struct FlatMapSerializeTupleVariantAsMapValue<'a, M: 'a> {
+    map: &'a mut M,
+    fields: Vec<Content>,
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> FlatMapSerializeTupleVariantAsMapValue<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    fn new(map: &'a mut M) -> Self {
+        FlatMapSerializeTupleVariantAsMapValue {
+            map,
+            fields: Vec::new(),
+        }
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> ser::SerializeTupleVariant for FlatMapSerializeTupleVariantAsMapValue<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    type Ok = ();
+    type Error = M::Error;
+
+    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
+    where
+        T: Serialize,
+    {
+        let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
+        self.fields.push(value);
+        Ok(())
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        tri!(self.map.serialize_value(&Content::Seq(self.fields)));
+        Ok(())
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub struct FlatMapSerializeStructVariantAsMapValue<'a, M: 'a> {
+    map: &'a mut M,
+    name: &'static str,
+    fields: Vec<(&'static str, Content)>,
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> FlatMapSerializeStructVariantAsMapValue<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    fn new(map: &'a mut M, name: &'static str) -> FlatMapSerializeStructVariantAsMapValue<'a, M> {
+        FlatMapSerializeStructVariantAsMapValue {
+            map,
+            name,
+            fields: Vec::new(),
+        }
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, M> ser::SerializeStructVariant for FlatMapSerializeStructVariantAsMapValue<'a, M>
+where
+    M: SerializeMap + 'a,
+{
+    type Ok = ();
+    type Error = M::Error;
+
+    fn serialize_field<T: ?Sized>(
+        &mut self,
+        key: &'static str,
+        value: &T,
+    ) -> Result<(), Self::Error>
+    where
+        T: Serialize,
+    {
+        let value = tri!(value.serialize(ContentSerializer::<M::Error>::new()));
+        self.fields.push((key, value));
+        Ok(())
+    }
+
+    fn end(self) -> Result<(), Self::Error> {
+        tri!(self
+            .map
+            .serialize_value(&Content::Struct(self.name, self.fields)));
+        Ok(())
+    }
+}
+
+pub struct AdjacentlyTaggedEnumVariant {
+    pub enum_name: &'static str,
+    pub variant_index: u32,
+    pub variant_name: &'static str,
+}
+
+impl Serialize for AdjacentlyTaggedEnumVariant {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_unit_variant(self.enum_name, self.variant_index, self.variant_name)
+    }
+}
+
+// Error when Serialize for a non_exhaustive remote enum encounters a variant
+// that is not recognized.
+pub struct CannotSerializeVariant<T>(pub T);
+
+impl<T> Display for CannotSerializeVariant<T>
+where
+    T: Debug,
+{
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "enum variant cannot be serialized: {:?}", self.0)
+    }
+}