diff options
Diffstat (limited to '')
| -rw-r--r-- | vendor/serde/src/ser/fmt.rs | 174 | ||||
| -rw-r--r-- | vendor/serde/src/ser/impls.rs | 936 | ||||
| -rw-r--r-- | vendor/serde/src/ser/impossible.rs | 216 | ||||
| -rw-r--r-- | vendor/serde/src/ser/mod.rs | 1986 |
4 files changed, 3312 insertions, 0 deletions
diff --git a/vendor/serde/src/ser/fmt.rs b/vendor/serde/src/ser/fmt.rs new file mode 100644 index 000000000..e7e09a1bf --- /dev/null +++ b/vendor/serde/src/ser/fmt.rs @@ -0,0 +1,174 @@ +use lib::*; +use ser::{Error, Impossible, Serialize, Serializer}; + +impl Error for fmt::Error { + fn custom<T: Display>(_msg: T) -> Self { + fmt::Error + } +} + +macro_rules! fmt_primitives { + ($($f:ident: $t:ty,)*) => { + $( + fn $f(self, v: $t) -> fmt::Result { + Display::fmt(&v, self) + } + )* + }; +} + +/// ```edition2018 +/// use serde::Serialize; +/// use std::fmt::{self, Display}; +/// +/// #[derive(Serialize)] +/// #[serde(rename_all = "kebab-case")] +/// pub enum MessageType { +/// StartRequest, +/// EndRequest, +/// } +/// +/// impl Display for MessageType { +/// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { +/// self.serialize(f) +/// } +/// } +/// ``` +impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> { + type Ok = (); + type Error = fmt::Error; + type SerializeSeq = Impossible<(), fmt::Error>; + type SerializeTuple = Impossible<(), fmt::Error>; + type SerializeTupleStruct = Impossible<(), fmt::Error>; + type SerializeTupleVariant = Impossible<(), fmt::Error>; + type SerializeMap = Impossible<(), fmt::Error>; + type SerializeStruct = Impossible<(), fmt::Error>; + type SerializeStructVariant = Impossible<(), fmt::Error>; + + fmt_primitives! { + serialize_bool: bool, + serialize_i8: i8, + serialize_i16: i16, + serialize_i32: i32, + serialize_i64: i64, + serialize_u8: u8, + serialize_u16: u16, + serialize_u32: u32, + serialize_u64: u64, + serialize_f32: f32, + serialize_f64: f64, + serialize_char: char, + serialize_str: &str, + serialize_unit_struct: &'static str, + } + + serde_if_integer128! { + fmt_primitives! { + serialize_i128: i128, + serialize_u128: u128, + } + } + + fn serialize_unit_variant( + self, + _name: &'static str, + _variant_index: u32, + variant: &'static str, + ) -> fmt::Result { + Display::fmt(variant, self) + } + + fn serialize_newtype_struct<T: ?Sized>(self, _name: &'static str, value: &T) -> fmt::Result + where + T: Serialize, + { + Serialize::serialize(value, self) + } + + fn serialize_bytes(self, _v: &[u8]) -> fmt::Result { + Err(fmt::Error) + } + + fn serialize_none(self) -> fmt::Result { + Err(fmt::Error) + } + + fn serialize_some<T: ?Sized>(self, _value: &T) -> fmt::Result + where + T: Serialize, + { + Err(fmt::Error) + } + + fn serialize_unit(self) -> fmt::Result { + Err(fmt::Error) + } + + fn serialize_newtype_variant<T: ?Sized>( + self, + _name: &'static str, + _variant_index: u32, + _variant: &'static str, + _value: &T, + ) -> fmt::Result + where + T: Serialize, + { + Err(fmt::Error) + } + + fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, fmt::Error> { + Err(fmt::Error) + } + + fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, fmt::Error> { + Err(fmt::Error) + } + + fn serialize_tuple_struct( + self, + _name: &'static str, + _len: usize, + ) -> Result<Self::SerializeTupleStruct, fmt::Error> { + Err(fmt::Error) + } + + fn serialize_tuple_variant( + self, + _name: &'static str, + _variant_index: u32, + _variant: &'static str, + _len: usize, + ) -> Result<Self::SerializeTupleVariant, fmt::Error> { + Err(fmt::Error) + } + + fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, fmt::Error> { + Err(fmt::Error) + } + + fn serialize_struct( + self, + _name: &'static str, + _len: usize, + ) -> Result<Self::SerializeStruct, fmt::Error> { + Err(fmt::Error) + } + + fn serialize_struct_variant( + self, + _name: &'static str, + _variant_index: u32, + _variant: &'static str, + _len: usize, + ) -> Result<Self::SerializeStructVariant, fmt::Error> { + Err(fmt::Error) + } + + fn collect_str<T: ?Sized>(self, value: &T) -> fmt::Result + where + T: Display, + { + Display::fmt(value, self) + } +} diff --git a/vendor/serde/src/ser/impls.rs b/vendor/serde/src/ser/impls.rs new file mode 100644 index 000000000..7219f51b7 --- /dev/null +++ b/vendor/serde/src/ser/impls.rs @@ -0,0 +1,936 @@ +use lib::*; + +use ser::{Error, Serialize, SerializeTuple, Serializer}; + +//////////////////////////////////////////////////////////////////////////////// + +macro_rules! primitive_impl { + ($ty:ident, $method:ident $($cast:tt)*) => { + impl Serialize for $ty { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.$method(*self $($cast)*) + } + } + } +} + +primitive_impl!(bool, serialize_bool); +primitive_impl!(isize, serialize_i64 as i64); +primitive_impl!(i8, serialize_i8); +primitive_impl!(i16, serialize_i16); +primitive_impl!(i32, serialize_i32); +primitive_impl!(i64, serialize_i64); +primitive_impl!(usize, serialize_u64 as u64); +primitive_impl!(u8, serialize_u8); +primitive_impl!(u16, serialize_u16); +primitive_impl!(u32, serialize_u32); +primitive_impl!(u64, serialize_u64); +primitive_impl!(f32, serialize_f32); +primitive_impl!(f64, serialize_f64); +primitive_impl!(char, serialize_char); + +serde_if_integer128! { + primitive_impl!(i128, serialize_i128); + primitive_impl!(u128, serialize_u128); +} + +//////////////////////////////////////////////////////////////////////////////// + +impl Serialize for str { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.serialize_str(self) + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +impl Serialize for String { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.serialize_str(self) + } +} + +impl<'a> Serialize for fmt::Arguments<'a> { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.collect_str(self) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(feature = "std")] +impl Serialize for CStr { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.serialize_bytes(self.to_bytes()) + } +} + +#[cfg(feature = "std")] +impl Serialize for CString { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.serialize_bytes(self.to_bytes()) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +impl<T> Serialize for Option<T> +where + T: Serialize, +{ + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + match *self { + Some(ref value) => serializer.serialize_some(value), + None => serializer.serialize_none(), + } + } +} + +//////////////////////////////////////////////////////////////////////////////// + +impl<T: ?Sized> Serialize for PhantomData<T> { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.serialize_unit_struct("PhantomData") + } +} + +//////////////////////////////////////////////////////////////////////////////// + +// Does not require T: Serialize. +impl<T> Serialize for [T; 0] { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + try!(serializer.serialize_tuple(0)).end() + } +} + +macro_rules! array_impls { + ($($len:tt)+) => { + $( + impl<T> Serialize for [T; $len] + where + T: Serialize, + { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + let mut seq = try!(serializer.serialize_tuple($len)); + for e in self { + try!(seq.serialize_element(e)); + } + seq.end() + } + } + )+ + } +} + +array_impls! { + 01 02 03 04 05 06 07 08 09 10 + 11 12 13 14 15 16 17 18 19 20 + 21 22 23 24 25 26 27 28 29 30 + 31 32 +} + +//////////////////////////////////////////////////////////////////////////////// + +impl<T> Serialize for [T] +where + T: Serialize, +{ + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.collect_seq(self) + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +macro_rules! seq_impl { + ($ty:ident < T $(: $tbound1:ident $(+ $tbound2:ident)*)* $(, $typaram:ident : $bound:ident)* >) => { + impl<T $(, $typaram)*> Serialize for $ty<T $(, $typaram)*> + where + T: Serialize $(+ $tbound1 $(+ $tbound2)*)*, + $($typaram: $bound,)* + { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.collect_seq(self) + } + } + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +seq_impl!(BinaryHeap<T: Ord>); + +#[cfg(any(feature = "std", feature = "alloc"))] +seq_impl!(BTreeSet<T: Ord>); + +#[cfg(feature = "std")] +seq_impl!(HashSet<T: Eq + Hash, H: BuildHasher>); + +#[cfg(any(feature = "std", feature = "alloc"))] +seq_impl!(LinkedList<T>); + +#[cfg(any(feature = "std", feature = "alloc"))] +seq_impl!(Vec<T>); + +#[cfg(any(feature = "std", feature = "alloc"))] +seq_impl!(VecDeque<T>); + +//////////////////////////////////////////////////////////////////////////////// + +impl<Idx> Serialize for Range<Idx> +where + Idx: Serialize, +{ + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + use super::SerializeStruct; + let mut state = try!(serializer.serialize_struct("Range", 2)); + try!(state.serialize_field("start", &self.start)); + try!(state.serialize_field("end", &self.end)); + state.end() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(not(no_range_inclusive))] +impl<Idx> Serialize for RangeInclusive<Idx> +where + Idx: Serialize, +{ + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + use super::SerializeStruct; + let mut state = try!(serializer.serialize_struct("RangeInclusive", 2)); + try!(state.serialize_field("start", &self.start())); + try!(state.serialize_field("end", &self.end())); + state.end() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(not(no_ops_bound), all(feature = "std", not(no_collections_bound))))] +impl<T> Serialize for Bound<T> +where + T: Serialize, +{ + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + match *self { + Bound::Unbounded => serializer.serialize_unit_variant("Bound", 0, "Unbounded"), + Bound::Included(ref value) => { + serializer.serialize_newtype_variant("Bound", 1, "Included", value) + } + Bound::Excluded(ref value) => { + serializer.serialize_newtype_variant("Bound", 2, "Excluded", value) + } + } + } +} + +//////////////////////////////////////////////////////////////////////////////// + +impl Serialize for () { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.serialize_unit() + } +} + +#[cfg(feature = "unstable")] +impl Serialize for ! { + fn serialize<S>(&self, _serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + *self + } +} + +//////////////////////////////////////////////////////////////////////////////// + +macro_rules! tuple_impls { + ($($len:expr => ($($n:tt $name:ident)+))+) => { + $( + impl<$($name),+> Serialize for ($($name,)+) + where + $($name: Serialize,)+ + { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + let mut tuple = try!(serializer.serialize_tuple($len)); + $( + try!(tuple.serialize_element(&self.$n)); + )+ + tuple.end() + } + } + )+ + } +} + +tuple_impls! { + 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) +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(feature = "std", feature = "alloc"))] +macro_rules! map_impl { + ($ty:ident < K $(: $kbound1:ident $(+ $kbound2:ident)*)*, V $(, $typaram:ident : $bound:ident)* >) => { + impl<K, V $(, $typaram)*> Serialize for $ty<K, V $(, $typaram)*> + where + K: Serialize $(+ $kbound1 $(+ $kbound2)*)*, + V: Serialize, + $($typaram: $bound,)* + { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + serializer.collect_map(self) + } + } + } +} + +#[cfg(any(feature = "std", feature = "alloc"))] +map_impl!(BTreeMap<K: Ord, V>); + +#[cfg(feature = "std")] +map_impl!(HashMap<K: Eq + Hash, V, H: BuildHasher>); + +//////////////////////////////////////////////////////////////////////////////// + +macro_rules! deref_impl { + ( + $(#[doc = $doc:tt])* + <$($desc:tt)+ + ) => { + $(#[doc = $doc])* + impl <$($desc)+ { + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + (**self).serialize(serializer) + } + } + }; +} + +deref_impl!(<'a, T: ?Sized> Serialize for &'a T where T: Serialize); +deref_impl!(<'a, T: ?Sized> Serialize for &'a mut T where T: Serialize); + +#[cfg(any(feature = "std", feature = "alloc"))] +deref_impl!(<T: ?Sized> Serialize for Box<T> where T: Serialize); + +#[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))] +deref_impl! { + /// This impl requires the [`"rc"`] Cargo feature of Serde. + /// + /// Serializing a data structure containing `Rc` will serialize a copy of + /// the contents of the `Rc` each time the `Rc` is referenced within the + /// data structure. Serialization will not attempt to deduplicate these + /// repeated data. + /// + /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc + <T: ?Sized> Serialize for Rc<T> where T: Serialize +} + +#[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))] +deref_impl! { + /// This impl requires the [`"rc"`] Cargo feature of Serde. + /// + /// Serializing a data structure containing `Arc` will serialize a copy of + /// the contents of the `Arc` each time the `Arc` is referenced within the + /// data structure. Serialization will not attempt to deduplicate these + /// repeated data. + /// + /// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc + <T: ?Sized> Serialize for Arc<T> where T: Serialize +} + +#[cfg(any(feature = "std", feature = "alloc"))] +deref_impl!(<'a, T: ?Sized> Serialize for Cow<'a, T> where T: Serialize + ToOwned); + +//////////////////////////////////////////////////////////////////////////////// + +/// This impl requires the [`"rc"`] Cargo feature of Serde. +/// +/// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc +#[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))] +impl<T: ?Sized> Serialize for RcWeak<T> +where + T: Serialize, +{ + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + self.upgrade().serialize(serializer) + } +} + +/// This impl requires the [`"rc"`] Cargo feature of Serde. +/// +/// [`"rc"`]: https://serde.rs/feature-flags.html#-features-rc +#[cfg(all(feature = "rc", any(feature = "std", feature = "alloc")))] +impl<T: ?Sized> Serialize for ArcWeak<T> +where + T: Serialize, +{ + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + self.upgrade().serialize(serializer) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +macro_rules! nonzero_integers { + ( $( $T: ident, )+ ) => { + $( + #[cfg(not(no_num_nonzero))] + impl Serialize for num::$T { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + self.get().serialize(serializer) + } + } + )+ + } +} + +nonzero_integers! { + NonZeroU8, + NonZeroU16, + NonZeroU32, + NonZeroU64, + NonZeroUsize, +} + +#[cfg(not(no_num_nonzero_signed))] +nonzero_integers! { + NonZeroI8, + NonZeroI16, + NonZeroI32, + NonZeroI64, + NonZeroIsize, +} + +// Currently 128-bit integers do not work on Emscripten targets so we need an +// additional `#[cfg]` +serde_if_integer128! { + nonzero_integers! { + NonZeroU128, + } + + #[cfg(not(no_num_nonzero_signed))] + nonzero_integers! { + NonZeroI128, + } +} + +impl<T> Serialize for Cell<T> +where + T: Serialize + Copy, +{ + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + self.get().serialize(serializer) + } +} + +impl<T> Serialize for RefCell<T> +where + T: Serialize, +{ + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + match self.try_borrow() { + Ok(value) => value.serialize(serializer), + Err(_) => Err(S::Error::custom("already mutably borrowed")), + } + } +} + +#[cfg(feature = "std")] +impl<T> Serialize for Mutex<T> +where + T: Serialize, +{ + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + match self.lock() { + Ok(locked) => locked.serialize(serializer), + Err(_) => Err(S::Error::custom("lock poison error while serializing")), + } + } +} + +#[cfg(feature = "std")] +impl<T> Serialize for RwLock<T> +where + T: Serialize, +{ + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + match self.read() { + Ok(locked) => locked.serialize(serializer), + Err(_) => Err(S::Error::custom("lock poison error while serializing")), + } + } +} + +//////////////////////////////////////////////////////////////////////////////// + +impl<T, E> Serialize for Result<T, E> +where + T: Serialize, + E: Serialize, +{ + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + match *self { + Result::Ok(ref value) => serializer.serialize_newtype_variant("Result", 0, "Ok", value), + Result::Err(ref value) => { + serializer.serialize_newtype_variant("Result", 1, "Err", value) + } + } + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(any(feature = "std", not(no_core_duration)))] +impl Serialize for Duration { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + use super::SerializeStruct; + let mut state = try!(serializer.serialize_struct("Duration", 2)); + try!(state.serialize_field("secs", &self.as_secs())); + try!(state.serialize_field("nanos", &self.subsec_nanos())); + state.end() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(feature = "std")] +impl Serialize for SystemTime { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + use super::SerializeStruct; + let duration_since_epoch = self + .duration_since(UNIX_EPOCH) + .map_err(|_| S::Error::custom("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())); + state.end() + } +} + +//////////////////////////////////////////////////////////////////////////////// + +/// Serialize a value that implements `Display` as a string, when that string is +/// statically known to never have more than a constant `MAX_LEN` bytes. +/// +/// Panics if the `Display` impl tries to write more than `MAX_LEN` bytes. +#[cfg(feature = "std")] +macro_rules! serialize_display_bounded_length { + ($value:expr, $max:expr, $serializer:expr) => {{ + let mut buffer = [0u8; $max]; + let remaining_len = { + let mut remaining = &mut buffer[..]; + write!(remaining, "{}", $value).unwrap(); + remaining.len() + }; + let written_len = buffer.len() - remaining_len; + let written = &buffer[..written_len]; + + // write! only provides fmt::Formatter to Display implementations, which + // has methods write_str and write_char but no method to write arbitrary + // bytes. Therefore `written` must be valid UTF-8. + let written_str = str::from_utf8(written).expect("must be valid UTF-8"); + $serializer.serialize_str(written_str) + }}; +} + +#[cfg(feature = "std")] +impl Serialize for net::IpAddr { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + if serializer.is_human_readable() { + match *self { + net::IpAddr::V4(ref a) => a.serialize(serializer), + net::IpAddr::V6(ref a) => a.serialize(serializer), + } + } 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) + } + } + } + } +} + +#[cfg(feature = "std")] +const DEC_DIGITS_LUT: &'static [u8] = b"\ + 0001020304050607080910111213141516171819\ + 2021222324252627282930313233343536373839\ + 4041424344454647484950515253545556575859\ + 6061626364656667686970717273747576777879\ + 8081828384858687888990919293949596979899"; + +#[cfg(feature = "std")] +#[inline] +fn format_u8(mut n: u8, out: &mut [u8]) -> usize { + if n >= 100 { + let d1 = ((n % 100) << 1) as usize; + n /= 100; + out[0] = b'0' + n; + out[1] = DEC_DIGITS_LUT[d1]; + out[2] = DEC_DIGITS_LUT[d1 + 1]; + 3 + } else if n >= 10 { + let d1 = (n << 1) as usize; + out[0] = DEC_DIGITS_LUT[d1]; + out[1] = DEC_DIGITS_LUT[d1 + 1]; + 2 + } else { + out[0] = b'0' + n; + 1 + } +} + +#[cfg(feature = "std")] +#[test] +fn test_format_u8() { + let mut i = 0u8; + + loop { + let mut buf = [0u8; 3]; + let written = format_u8(i, &mut buf); + assert_eq!(i.to_string().as_bytes(), &buf[..written]); + + match i.checked_add(1) { + Some(next) => i = next, + None => break, + } + } +} + +#[cfg(feature = "std")] +impl Serialize for net::Ipv4Addr { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + if serializer.is_human_readable() { + const MAX_LEN: usize = 15; + debug_assert_eq!(MAX_LEN, "101.102.103.104".len()); + let mut buf = [b'.'; MAX_LEN]; + let mut written = format_u8(self.octets()[0], &mut buf); + for oct in &self.octets()[1..] { + // Skip over delimiters that we initialized buf with + written += format_u8(*oct, &mut buf[written + 1..]) + 1; + } + // We've only written ASCII bytes to the buffer, so it is valid UTF-8 + serializer.serialize_str(unsafe { str::from_utf8_unchecked(&buf[..written]) }) + } else { + self.octets().serialize(serializer) + } + } +} + +#[cfg(feature = "std")] +impl Serialize for net::Ipv6Addr { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + if serializer.is_human_readable() { + const MAX_LEN: usize = 39; + debug_assert_eq!(MAX_LEN, "1001:1002:1003:1004:1005:1006:1007:1008".len()); + serialize_display_bounded_length!(self, MAX_LEN, serializer) + } else { + self.octets().serialize(serializer) + } + } +} + +#[cfg(feature = "std")] +impl Serialize for net::SocketAddr { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + if serializer.is_human_readable() { + match *self { + net::SocketAddr::V4(ref addr) => addr.serialize(serializer), + net::SocketAddr::V6(ref addr) => addr.serialize(serializer), + } + } 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) + } + } + } + } +} + +#[cfg(feature = "std")] +impl Serialize for net::SocketAddrV4 { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + if serializer.is_human_readable() { + const MAX_LEN: usize = 21; + debug_assert_eq!(MAX_LEN, "101.102.103.104:65000".len()); + serialize_display_bounded_length!(self, MAX_LEN, serializer) + } else { + (self.ip(), self.port()).serialize(serializer) + } + } +} + +#[cfg(feature = "std")] +impl Serialize for net::SocketAddrV6 { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + if serializer.is_human_readable() { + const MAX_LEN: usize = 58; + debug_assert_eq!( + MAX_LEN, + "[1001:1002:1003:1004:1005:1006:1007:1008%4294967295]:65000".len() + ); + serialize_display_bounded_length!(self, MAX_LEN, serializer) + } else { + (self.ip(), self.port()).serialize(serializer) + } + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(feature = "std")] +impl Serialize for Path { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + match self.to_str() { + Some(s) => s.serialize(serializer), + None => Err(Error::custom("path contains invalid UTF-8 characters")), + } + } +} + +#[cfg(feature = "std")] +impl Serialize for PathBuf { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + self.as_path().serialize(serializer) + } +} + +#[cfg(all(feature = "std", any(unix, windows)))] +impl Serialize for OsStr { + #[cfg(unix)] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + use std::os::unix::ffi::OsStrExt; + serializer.serialize_newtype_variant("OsString", 0, "Unix", self.as_bytes()) + } + + #[cfg(windows)] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + use std::os::windows::ffi::OsStrExt; + let val = self.encode_wide().collect::<Vec<_>>(); + serializer.serialize_newtype_variant("OsString", 1, "Windows", &val) + } +} + +#[cfg(all(feature = "std", any(unix, windows)))] +impl Serialize for OsString { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + self.as_os_str().serialize(serializer) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +impl<T> Serialize for Wrapping<T> +where + T: Serialize, +{ + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + self.0.serialize(serializer) + } +} + +#[cfg(not(no_core_reverse))] +impl<T> Serialize for Reverse<T> +where + T: Serialize, +{ + #[inline] + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + self.0.serialize(serializer) + } +} + +//////////////////////////////////////////////////////////////////////////////// + +#[cfg(all(feature = "std", not(no_std_atomic)))] +macro_rules! atomic_impl { + ($($ty:ident)*) => { + $( + impl Serialize for $ty { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + // Matches the atomic ordering used in libcore for the Debug impl + self.load(Ordering::SeqCst).serialize(serializer) + } + } + )* + } +} + +#[cfg(all(feature = "std", not(no_std_atomic)))] +atomic_impl! { + AtomicBool + AtomicI8 AtomicI16 AtomicI32 AtomicIsize + AtomicU8 AtomicU16 AtomicU32 AtomicUsize +} + +#[cfg(all(feature = "std", not(no_std_atomic64)))] +atomic_impl! { + AtomicI64 AtomicU64 +} diff --git a/vendor/serde/src/ser/impossible.rs b/vendor/serde/src/ser/impossible.rs new file mode 100644 index 000000000..e8df9ca7a --- /dev/null +++ b/vendor/serde/src/ser/impossible.rs @@ -0,0 +1,216 @@ +//! This module contains `Impossible` serializer and its implementations. + +use lib::*; + +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. +/// +/// This type cannot be instantiated, but implements every one of the traits +/// corresponding to the [`Serializer`] compound types: [`SerializeSeq`], +/// [`SerializeTuple`], [`SerializeTupleStruct`], [`SerializeTupleVariant`], +/// [`SerializeMap`], [`SerializeStruct`], and [`SerializeStructVariant`]. +/// +/// ```edition2018 +/// # use serde::ser::{Serializer, Impossible}; +/// # use serde::__private::doc::Error; +/// # +/// # struct MySerializer; +/// # +/// impl Serializer for MySerializer { +/// type Ok = (); +/// type Error = Error; +/// +/// type SerializeSeq = Impossible<(), Error>; +/// /* other associated types */ +/// +/// /// This data format does not support serializing sequences. +/// fn serialize_seq(self, +/// len: Option<usize>) +/// -> Result<Self::SerializeSeq, Error> { +/// // Given Impossible cannot be instantiated, the only +/// // thing we can do here is to return an error. +/// # stringify! { +/// Err(...) +/// # }; +/// # unimplemented!() +/// } +/// +/// /* other Serializer methods */ +/// # serde::__serialize_unimplemented! { +/// # bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str bytes none some +/// # unit unit_struct unit_variant newtype_struct newtype_variant +/// # tuple tuple_struct tuple_variant map struct struct_variant +/// # } +/// } +/// ``` +/// +/// [`Serializer`]: trait.Serializer.html +/// [`SerializeSeq`]: trait.SerializeSeq.html +/// [`SerializeTuple`]: trait.SerializeTuple.html +/// [`SerializeTupleStruct`]: trait.SerializeTupleStruct.html +/// [`SerializeTupleVariant`]: trait.SerializeTupleVariant.html +/// [`SerializeMap`]: trait.SerializeMap.html +/// [`SerializeStruct`]: trait.SerializeStruct.html +/// [`SerializeStructVariant`]: trait.SerializeStructVariant.html +pub struct Impossible<Ok, Error> { + void: Void, + ok: PhantomData<Ok>, + error: PhantomData<Error>, +} + +enum Void {} + +impl<Ok, Error> SerializeSeq for Impossible<Ok, Error> +where + Error: ser::Error, +{ + type Ok = Ok; + type Error = Error; + + fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error> + where + T: Serialize, + { + let _ = value; + match self.void {} + } + + fn end(self) -> Result<Ok, Error> { + match self.void {} + } +} + +impl<Ok, Error> SerializeTuple for Impossible<Ok, Error> +where + Error: ser::Error, +{ + type Ok = Ok; + type Error = Error; + + fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error> + where + T: Serialize, + { + let _ = value; + match self.void {} + } + + fn end(self) -> Result<Ok, Error> { + match self.void {} + } +} + +impl<Ok, Error> SerializeTupleStruct for Impossible<Ok, Error> +where + Error: ser::Error, +{ + type Ok = Ok; + type Error = Error; + + fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error> + where + T: Serialize, + { + let _ = value; + match self.void {} + } + + fn end(self) -> Result<Ok, Error> { + match self.void {} + } +} + +impl<Ok, Error> SerializeTupleVariant for Impossible<Ok, Error> +where + Error: ser::Error, +{ + type Ok = Ok; + type Error = Error; + + fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error> + where + T: Serialize, + { + let _ = value; + match self.void {} + } + + fn end(self) -> Result<Ok, Error> { + match self.void {} + } +} + +impl<Ok, Error> SerializeMap for Impossible<Ok, Error> +where + Error: ser::Error, +{ + type Ok = Ok; + type Error = Error; + + fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Error> + where + T: Serialize, + { + let _ = key; + match self.void {} + } + + fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Error> + where + T: Serialize, + { + let _ = value; + match self.void {} + } + + fn end(self) -> Result<Ok, Error> { + match self.void {} + } +} + +impl<Ok, Error> SerializeStruct for Impossible<Ok, Error> +where + Error: ser::Error, +{ + type Ok = Ok; + type Error = Error; + + fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Error> + where + T: Serialize, + { + let _ = key; + let _ = value; + match self.void {} + } + + fn end(self) -> Result<Ok, Error> { + match self.void {} + } +} + +impl<Ok, Error> SerializeStructVariant for Impossible<Ok, Error> +where + Error: ser::Error, +{ + type Ok = Ok; + type Error = Error; + + fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> Result<(), Error> + where + T: Serialize, + { + let _ = key; + let _ = value; + match self.void {} + } + + fn end(self) -> Result<Ok, Error> { + match self.void {} + } +} diff --git a/vendor/serde/src/ser/mod.rs b/vendor/serde/src/ser/mod.rs new file mode 100644 index 000000000..eb226ae96 --- /dev/null +++ b/vendor/serde/src/ser/mod.rs @@ -0,0 +1,1986 @@ +//! Generic data structure serialization framework. +//! +//! The two most important traits in this module are [`Serialize`] and +//! [`Serializer`]. +//! +//! - **A type that implements `Serialize` is a data structure** that can be +//! serialized to any data format supported by Serde, and conversely +//! - **A type that implements `Serializer` is a data format** that can +//! serialize any data structure supported by Serde. +//! +//! # The Serialize trait +//! +//! Serde provides [`Serialize`] implementations for many Rust primitive and +//! standard library types. The complete list is below. All of these can be +//! serialized using Serde out of the box. +//! +//! Additionally, Serde provides a procedural macro called [`serde_derive`] to +//! automatically generate [`Serialize`] implementations for structs and enums +//! in your program. See the [derive section of the manual] for how to use this. +//! +//! In rare cases it may be necessary to implement [`Serialize`] manually for +//! some type in your program. See the [Implementing `Serialize`] section of the +//! manual for more about this. +//! +//! Third-party crates may provide [`Serialize`] implementations for types that +//! they expose. For example the [`linked-hash-map`] crate provides a +//! [`LinkedHashMap<K, V>`] type that is serializable by Serde because the crate +//! provides an implementation of [`Serialize`] for it. +//! +//! # The Serializer trait +//! +//! [`Serializer`] implementations are provided by third-party crates, for +//! example [`serde_json`], [`serde_yaml`] and [`bincode`]. +//! +//! A partial list of well-maintained formats is given on the [Serde +//! website][data formats]. +//! +//! # Implementations of Serialize provided by Serde +//! +//! - **Primitive types**: +//! - bool +//! - i8, i16, i32, i64, i128, isize +//! - u8, u16, u32, u64, u128, usize +//! - f32, f64 +//! - char +//! - str +//! - &T and &mut T +//! - **Compound types**: +//! - \[T\] +//! - \[T; 0\] through \[T; 32\] +//! - tuples up to size 16 +//! - **Common standard library types**: +//! - String +//! - Option\<T\> +//! - Result\<T, E\> +//! - PhantomData\<T\> +//! - **Wrapper types**: +//! - Box\<T\> +//! - Cow\<'a, T\> +//! - Cell\<T\> +//! - RefCell\<T\> +//! - Mutex\<T\> +//! - RwLock\<T\> +//! - Rc\<T\> *(if* features = ["rc"] *is enabled)* +//! - Arc\<T\> *(if* features = ["rc"] *is enabled)* +//! - **Collection types**: +//! - BTreeMap\<K, V\> +//! - BTreeSet\<T\> +//! - BinaryHeap\<T\> +//! - HashMap\<K, V, H\> +//! - HashSet\<T, H\> +//! - LinkedList\<T\> +//! - VecDeque\<T\> +//! - Vec\<T\> +//! - **FFI types**: +//! - CStr +//! - CString +//! - OsStr +//! - OsString +//! - **Miscellaneous standard library types**: +//! - Duration +//! - SystemTime +//! - Path +//! - PathBuf +//! - Range\<T\> +//! - RangeInclusive\<T\> +//! - Bound\<T\> +//! - num::NonZero* +//! - `!` *(unstable)* +//! - **Net types**: +//! - IpAddr +//! - Ipv4Addr +//! - Ipv6Addr +//! - SocketAddr +//! - SocketAddrV4 +//! - SocketAddrV6 +//! +//! [Implementing `Serialize`]: https://serde.rs/impl-serialize.html +//! [`LinkedHashMap<K, V>`]: https://docs.rs/linked-hash-map/*/linked_hash_map/struct.LinkedHashMap.html +//! [`Serialize`]: ../trait.Serialize.html +//! [`Serializer`]: ../trait.Serializer.html +//! [`bincode`]: https://github.com/bincode-org/bincode +//! [`linked-hash-map`]: https://crates.io/crates/linked-hash-map +//! [`serde_derive`]: https://crates.io/crates/serde_derive +//! [`serde_json`]: https://github.com/serde-rs/json +//! [`serde_yaml`]: https://github.com/dtolnay/serde-yaml +//! [derive section of the manual]: https://serde.rs/derive.html +//! [data formats]: https://serde.rs/#data-formats + +use lib::*; + +mod fmt; +mod impls; +mod impossible; + +pub use self::impossible::Impossible; + +#[cfg(feature = "std")] +#[doc(no_inline)] +pub use std::error::Error as StdError; +#[cfg(not(feature = "std"))] +#[doc(no_inline)] +pub use std_error::Error as StdError; + +//////////////////////////////////////////////////////////////////////////////// + +macro_rules! declare_error_trait { + (Error: Sized $(+ $($supertrait:ident)::+)*) => { + /// Trait used by `Serialize` implementations to generically construct + /// errors belonging to the `Serializer` against which they are + /// currently running. + /// + /// # Example implementation + /// + /// The [example data format] presented on the website shows an error + /// type appropriate for a basic JSON data format. + /// + /// [example data format]: https://serde.rs/data-format.html + pub trait Error: Sized $(+ $($supertrait)::+)* { + /// Used when a [`Serialize`] implementation encounters any error + /// while serializing a type. + /// + /// The message should not be capitalized and should not end with a + /// period. + /// + /// For example, a filesystem [`Path`] may refuse to serialize + /// itself if it contains invalid UTF-8 data. + /// + /// ```edition2018 + /// # struct Path; + /// # + /// # impl Path { + /// # fn to_str(&self) -> Option<&str> { + /// # unimplemented!() + /// # } + /// # } + /// # + /// use serde::ser::{self, Serialize, Serializer}; + /// + /// impl Serialize for Path { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// match self.to_str() { + /// Some(s) => serializer.serialize_str(s), + /// None => Err(ser::Error::custom("path contains invalid UTF-8 characters")), + /// } + /// } + /// } + /// ``` + /// + /// [`Path`]: https://doc.rust-lang.org/std/path/struct.Path.html + /// [`Serialize`]: ../trait.Serialize.html + fn custom<T>(msg: T) -> Self + where + T: Display; + } + } +} + +#[cfg(feature = "std")] +declare_error_trait!(Error: Sized + StdError); + +#[cfg(not(feature = "std"))] +declare_error_trait!(Error: Sized + Debug + Display); + +//////////////////////////////////////////////////////////////////////////////// + +/// A **data structure** that can be serialized into any data format supported +/// by Serde. +/// +/// Serde provides `Serialize` implementations for many Rust primitive and +/// standard library types. The complete list is [here][ser]. All of these can +/// be serialized using Serde out of the box. +/// +/// Additionally, Serde provides a procedural macro called [`serde_derive`] to +/// automatically generate `Serialize` implementations for structs and enums in +/// your program. See the [derive section of the manual] for how to use this. +/// +/// In rare cases it may be necessary to implement `Serialize` manually for some +/// type in your program. See the [Implementing `Serialize`] section of the +/// manual for more about this. +/// +/// Third-party crates may provide `Serialize` implementations for types that +/// they expose. For example the [`linked-hash-map`] crate provides a +/// [`LinkedHashMap<K, V>`] type that is serializable by Serde because the crate +/// provides an implementation of `Serialize` for it. +/// +/// [Implementing `Serialize`]: https://serde.rs/impl-serialize.html +/// [`LinkedHashMap<K, V>`]: https://docs.rs/linked-hash-map/*/linked_hash_map/struct.LinkedHashMap.html +/// [`linked-hash-map`]: https://crates.io/crates/linked-hash-map +/// [`serde_derive`]: https://crates.io/crates/serde_derive +/// [derive section of the manual]: https://serde.rs/derive.html +/// [ser]: https://docs.serde.rs/serde/ser/index.html +pub trait Serialize { + /// Serialize this value into the given Serde serializer. + /// + /// See the [Implementing `Serialize`] section of the manual for more + /// information about how to implement this method. + /// + /// ```edition2018 + /// use serde::ser::{Serialize, SerializeStruct, Serializer}; + /// + /// struct Person { + /// name: String, + /// age: u8, + /// phones: Vec<String>, + /// } + /// + /// // This is what #[derive(Serialize)] would generate. + /// impl Serialize for Person { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// let mut s = serializer.serialize_struct("Person", 3)?; + /// s.serialize_field("name", &self.name)?; + /// s.serialize_field("age", &self.age)?; + /// s.serialize_field("phones", &self.phones)?; + /// s.end() + /// } + /// } + /// ``` + /// + /// [Implementing `Serialize`]: https://serde.rs/impl-serialize.html + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer; +} + +//////////////////////////////////////////////////////////////////////////////// + +/// A **data format** that can serialize any data structure supported by Serde. +/// +/// The role of this trait is to define the serialization half of the [Serde +/// data model], which is a way to categorize every Rust data structure into one +/// of 29 possible types. Each method of the `Serializer` trait corresponds to +/// one of the types of the data model. +/// +/// Implementations of `Serialize` map themselves into this data model by +/// invoking exactly one of the `Serializer` methods. +/// +/// The types that make up the Serde data model are: +/// +/// - **14 primitive types** +/// - bool +/// - i8, i16, i32, i64, i128 +/// - u8, u16, u32, u64, u128 +/// - f32, f64 +/// - char +/// - **string** +/// - UTF-8 bytes with a length and no null terminator. +/// - When serializing, all strings are handled equally. When deserializing, +/// there are three flavors of strings: transient, owned, and borrowed. +/// - **byte array** - \[u8\] +/// - Similar to strings, during deserialization byte arrays can be +/// transient, owned, or borrowed. +/// - **option** +/// - Either none or some value. +/// - **unit** +/// - The type of `()` in Rust. It represents an anonymous value containing +/// no data. +/// - **unit_struct** +/// - For example `struct Unit` or `PhantomData<T>`. It represents a named +/// value containing no data. +/// - **unit_variant** +/// - For example the `E::A` and `E::B` in `enum E { A, B }`. +/// - **newtype_struct** +/// - For example `struct Millimeters(u8)`. +/// - **newtype_variant** +/// - For example the `E::N` in `enum E { N(u8) }`. +/// - **seq** +/// - A variably sized heterogeneous sequence of values, for example +/// `Vec<T>` or `HashSet<T>`. When serializing, the length may or may not +/// be known before iterating through all the data. When deserializing, +/// the length is determined by looking at the serialized data. +/// - **tuple** +/// - A statically sized heterogeneous sequence of values for which the +/// length will be known at deserialization time without looking at the +/// serialized data, for example `(u8,)` or `(String, u64, Vec<T>)` or +/// `[u64; 10]`. +/// - **tuple_struct** +/// - A named tuple, for example `struct Rgb(u8, u8, u8)`. +/// - **tuple_variant** +/// - For example the `E::T` in `enum E { T(u8, u8) }`. +/// - **map** +/// - A heterogeneous key-value pairing, for example `BTreeMap<K, V>`. +/// - **struct** +/// - A heterogeneous key-value pairing in which the keys are strings and +/// will be known at deserialization time without looking at the +/// serialized data, for example `struct S { r: u8, g: u8, b: u8 }`. +/// - **struct_variant** +/// - For example the `E::S` in `enum E { S { r: u8, g: u8, b: u8 } }`. +/// +/// Many Serde serializers produce text or binary data as output, for example +/// JSON or Bincode. This is not a requirement of the `Serializer` trait, and +/// there are serializers that do not produce text or binary output. One example +/// is the `serde_json::value::Serializer` (distinct from the main `serde_json` +/// serializer) that produces a `serde_json::Value` data structure in memory as +/// output. +/// +/// [Serde data model]: https://serde.rs/data-model.html +/// +/// # Example implementation +/// +/// The [example data format] presented on the website contains example code for +/// a basic JSON `Serializer`. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait Serializer: Sized { + /// The output type produced by this `Serializer` during successful + /// serialization. Most serializers that produce text or binary output + /// should set `Ok = ()` and serialize into an [`io::Write`] or buffer + /// contained within the `Serializer` instance. Serializers that build + /// in-memory data structures may be simplified by using `Ok` to propagate + /// the data structure around. + /// + /// [`io::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html + type Ok; + + /// The error type when some error occurs during serialization. + type Error: Error; + + /// Type returned from [`serialize_seq`] for serializing the content of the + /// sequence. + /// + /// [`serialize_seq`]: #tymethod.serialize_seq + type SerializeSeq: SerializeSeq<Ok = Self::Ok, Error = Self::Error>; + + /// Type returned from [`serialize_tuple`] for serializing the content of + /// the tuple. + /// + /// [`serialize_tuple`]: #tymethod.serialize_tuple + type SerializeTuple: SerializeTuple<Ok = Self::Ok, Error = Self::Error>; + + /// Type returned from [`serialize_tuple_struct`] for serializing the + /// content of the tuple struct. + /// + /// [`serialize_tuple_struct`]: #tymethod.serialize_tuple_struct + type SerializeTupleStruct: SerializeTupleStruct<Ok = Self::Ok, Error = Self::Error>; + + /// Type returned from [`serialize_tuple_variant`] for serializing the + /// content of the tuple variant. + /// + /// [`serialize_tuple_variant`]: #tymethod.serialize_tuple_variant + type SerializeTupleVariant: SerializeTupleVariant<Ok = Self::Ok, Error = Self::Error>; + + /// Type returned from [`serialize_map`] for serializing the content of the + /// map. + /// + /// [`serialize_map`]: #tymethod.serialize_map + type SerializeMap: SerializeMap<Ok = Self::Ok, Error = Self::Error>; + + /// Type returned from [`serialize_struct`] for serializing the content of + /// the struct. + /// + /// [`serialize_struct`]: #tymethod.serialize_struct + type SerializeStruct: SerializeStruct<Ok = Self::Ok, Error = Self::Error>; + + /// Type returned from [`serialize_struct_variant`] for serializing the + /// content of the struct variant. + /// + /// [`serialize_struct_variant`]: #tymethod.serialize_struct_variant + type SerializeStructVariant: SerializeStructVariant<Ok = Self::Ok, Error = Self::Error>; + + /// Serialize a `bool` value. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for bool { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_bool(*self) + /// } + /// } + /// ``` + fn serialize_bool(self, v: bool) -> Result<Self::Ok, Self::Error>; + + /// Serialize an `i8` value. + /// + /// If the format does not differentiate between `i8` and `i64`, a + /// reasonable implementation would be to cast the value to `i64` and + /// forward to `serialize_i64`. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for i8 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_i8(*self) + /// } + /// } + /// ``` + fn serialize_i8(self, v: i8) -> Result<Self::Ok, Self::Error>; + + /// Serialize an `i16` value. + /// + /// If the format does not differentiate between `i16` and `i64`, a + /// reasonable implementation would be to cast the value to `i64` and + /// forward to `serialize_i64`. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for i16 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_i16(*self) + /// } + /// } + /// ``` + fn serialize_i16(self, v: i16) -> Result<Self::Ok, Self::Error>; + + /// Serialize an `i32` value. + /// + /// If the format does not differentiate between `i32` and `i64`, a + /// reasonable implementation would be to cast the value to `i64` and + /// forward to `serialize_i64`. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for i32 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_i32(*self) + /// } + /// } + /// ``` + fn serialize_i32(self, v: i32) -> Result<Self::Ok, Self::Error>; + + /// Serialize an `i64` value. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for i64 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_i64(*self) + /// } + /// } + /// ``` + fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error>; + + serde_if_integer128! { + /// Serialize an `i128` value. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for i128 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_i128(*self) + /// } + /// } + /// ``` + /// + /// This method is available only on Rust compiler versions >=1.26. The + /// default behavior unconditionally returns an error. + fn serialize_i128(self, v: i128) -> Result<Self::Ok, Self::Error> { + let _ = v; + Err(Error::custom("i128 is not supported")) + } + } + + /// Serialize a `u8` value. + /// + /// If the format does not differentiate between `u8` and `u64`, a + /// reasonable implementation would be to cast the value to `u64` and + /// forward to `serialize_u64`. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for u8 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_u8(*self) + /// } + /// } + /// ``` + fn serialize_u8(self, v: u8) -> Result<Self::Ok, Self::Error>; + + /// Serialize a `u16` value. + /// + /// If the format does not differentiate between `u16` and `u64`, a + /// reasonable implementation would be to cast the value to `u64` and + /// forward to `serialize_u64`. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for u16 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_u16(*self) + /// } + /// } + /// ``` + fn serialize_u16(self, v: u16) -> Result<Self::Ok, Self::Error>; + + /// Serialize a `u32` value. + /// + /// If the format does not differentiate between `u32` and `u64`, a + /// reasonable implementation would be to cast the value to `u64` and + /// forward to `serialize_u64`. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for u32 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_u32(*self) + /// } + /// } + /// ``` + fn serialize_u32(self, v: u32) -> Result<Self::Ok, Self::Error>; + + /// Serialize a `u64` value. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for u64 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_u64(*self) + /// } + /// } + /// ``` + fn serialize_u64(self, v: u64) -> Result<Self::Ok, Self::Error>; + + serde_if_integer128! { + /// Serialize a `u128` value. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for u128 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_u128(*self) + /// } + /// } + /// ``` + /// + /// This method is available only on Rust compiler versions >=1.26. The + /// default behavior unconditionally returns an error. + fn serialize_u128(self, v: u128) -> Result<Self::Ok, Self::Error> { + let _ = v; + Err(Error::custom("u128 is not supported")) + } + } + + /// Serialize an `f32` value. + /// + /// If the format does not differentiate between `f32` and `f64`, a + /// reasonable implementation would be to cast the value to `f64` and + /// forward to `serialize_f64`. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for f32 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_f32(*self) + /// } + /// } + /// ``` + fn serialize_f32(self, v: f32) -> Result<Self::Ok, Self::Error>; + + /// Serialize an `f64` value. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for f64 { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_f64(*self) + /// } + /// } + /// ``` + fn serialize_f64(self, v: f64) -> Result<Self::Ok, Self::Error>; + + /// Serialize a character. + /// + /// If the format does not support characters, it is reasonable to serialize + /// it as a single element `str` or a `u32`. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for char { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_char(*self) + /// } + /// } + /// ``` + fn serialize_char(self, v: char) -> Result<Self::Ok, Self::Error>; + + /// Serialize a `&str`. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for str { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_str(self) + /// } + /// } + /// ``` + fn serialize_str(self, v: &str) -> Result<Self::Ok, Self::Error>; + + /// Serialize a chunk of raw byte data. + /// + /// Enables serializers to serialize byte slices more compactly or more + /// efficiently than other types of slices. If no efficient implementation + /// is available, a reasonable implementation would be to forward to + /// `serialize_seq`. If forwarded, the implementation looks usually just + /// like this: + /// + /// ```edition2018 + /// # use serde::ser::{Serializer, SerializeSeq}; + /// # use serde::__private::doc::Error; + /// # + /// # struct MySerializer; + /// # + /// # impl Serializer for MySerializer { + /// # type Ok = (); + /// # type Error = Error; + /// # + /// fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok, Self::Error> { + /// let mut seq = self.serialize_seq(Some(v.len()))?; + /// for b in v { + /// seq.serialize_element(b)?; + /// } + /// seq.end() + /// } + /// # + /// # serde::__serialize_unimplemented! { + /// # bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str none some + /// # unit unit_struct unit_variant newtype_struct newtype_variant + /// # seq tuple tuple_struct tuple_variant map struct struct_variant + /// # } + /// # } + /// ``` + fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok, Self::Error>; + + /// Serialize a [`None`] value. + /// + /// ```edition2018 + /// # use serde::{Serialize, Serializer}; + /// # + /// # enum Option<T> { + /// # Some(T), + /// # None, + /// # } + /// # + /// # use self::Option::{Some, None}; + /// # + /// impl<T> Serialize for Option<T> + /// where + /// T: Serialize, + /// { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// match *self { + /// Some(ref value) => serializer.serialize_some(value), + /// None => serializer.serialize_none(), + /// } + /// } + /// } + /// # + /// # fn main() {} + /// ``` + /// + /// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None + fn serialize_none(self) -> Result<Self::Ok, Self::Error>; + + /// Serialize a [`Some(T)`] value. + /// + /// ```edition2018 + /// # use serde::{Serialize, Serializer}; + /// # + /// # enum Option<T> { + /// # Some(T), + /// # None, + /// # } + /// # + /// # use self::Option::{Some, None}; + /// # + /// impl<T> Serialize for Option<T> + /// where + /// T: Serialize, + /// { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// match *self { + /// Some(ref value) => serializer.serialize_some(value), + /// None => serializer.serialize_none(), + /// } + /// } + /// } + /// # + /// # fn main() {} + /// ``` + /// + /// [`Some(T)`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.Some + fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error> + where + T: Serialize; + + /// Serialize a `()` value. + /// + /// ```edition2018 + /// # use serde::Serializer; + /// # + /// # serde::__private_serialize!(); + /// # + /// impl Serialize for () { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_unit() + /// } + /// } + /// ``` + fn serialize_unit(self) -> Result<Self::Ok, Self::Error>; + + /// Serialize a unit struct like `struct Unit` or `PhantomData<T>`. + /// + /// A reasonable implementation would be to forward to `serialize_unit`. + /// + /// ```edition2018 + /// use serde::{Serialize, Serializer}; + /// + /// struct Nothing; + /// + /// impl Serialize for Nothing { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_unit_struct("Nothing") + /// } + /// } + /// ``` + fn serialize_unit_struct(self, name: &'static str) -> Result<Self::Ok, Self::Error>; + + /// Serialize a unit variant like `E::A` in `enum E { A, B }`. + /// + /// The `name` is the name of the enum, the `variant_index` is the index of + /// this variant within the enum, and the `variant` is the name of the + /// variant. + /// + /// ```edition2018 + /// use serde::{Serialize, Serializer}; + /// + /// enum E { + /// A, + /// B, + /// } + /// + /// impl Serialize for E { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// match *self { + /// E::A => serializer.serialize_unit_variant("E", 0, "A"), + /// E::B => serializer.serialize_unit_variant("E", 1, "B"), + /// } + /// } + /// } + /// ``` + fn serialize_unit_variant( + self, + name: &'static str, + variant_index: u32, + variant: &'static str, + ) -> Result<Self::Ok, Self::Error>; + + /// Serialize a newtype struct like `struct Millimeters(u8)`. + /// + /// Serializers are encouraged to treat newtype structs as insignificant + /// wrappers around the data they contain. A reasonable implementation would + /// be to forward to `value.serialize(self)`. + /// + /// ```edition2018 + /// use serde::{Serialize, Serializer}; + /// + /// struct Millimeters(u8); + /// + /// impl Serialize for Millimeters { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.serialize_newtype_struct("Millimeters", &self.0) + /// } + /// } + /// ``` + fn serialize_newtype_struct<T: ?Sized>( + self, + name: &'static str, + value: &T, + ) -> Result<Self::Ok, Self::Error> + where + T: Serialize; + + /// Serialize a newtype variant like `E::N` in `enum E { N(u8) }`. + /// + /// The `name` is the name of the enum, the `variant_index` is the index of + /// this variant within the enum, and the `variant` is the name of the + /// variant. The `value` is the data contained within this newtype variant. + /// + /// ```edition2018 + /// use serde::{Serialize, Serializer}; + /// + /// enum E { + /// M(String), + /// N(u8), + /// } + /// + /// impl Serialize for E { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// match *self { + /// E::M(ref s) => serializer.serialize_newtype_variant("E", 0, "M", s), + /// E::N(n) => serializer.serialize_newtype_variant("E", 1, "N", &n), + /// } + /// } + /// } + /// ``` + fn serialize_newtype_variant<T: ?Sized>( + self, + name: &'static str, + variant_index: u32, + variant: &'static str, + value: &T, + ) -> Result<Self::Ok, Self::Error> + where + T: Serialize; + + /// Begin to serialize a variably sized sequence. This call must be + /// followed by zero or more calls to `serialize_element`, then a call to + /// `end`. + /// + /// The argument is the number of elements in the sequence, which may or may + /// not be computable before the sequence is iterated. Some serializers only + /// support sequences whose length is known up front. + /// + /// ```edition2018 + /// # use std::marker::PhantomData; + /// # + /// # struct Vec<T>(PhantomData<T>); + /// # + /// # impl<T> Vec<T> { + /// # fn len(&self) -> usize { + /// # unimplemented!() + /// # } + /// # } + /// # + /// # impl<'a, T> IntoIterator for &'a Vec<T> { + /// # type Item = &'a T; + /// # type IntoIter = Box<Iterator<Item = &'a T>>; + /// # + /// # fn into_iter(self) -> Self::IntoIter { + /// # unimplemented!() + /// # } + /// # } + /// # + /// use serde::ser::{Serialize, Serializer, SerializeSeq}; + /// + /// impl<T> Serialize for Vec<T> + /// where + /// T: Serialize, + /// { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// let mut seq = serializer.serialize_seq(Some(self.len()))?; + /// for element in self { + /// seq.serialize_element(element)?; + /// } + /// seq.end() + /// } + /// } + /// ``` + fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error>; + + /// Begin to serialize a statically sized sequence whose length will be + /// known at deserialization time without looking at the serialized data. + /// This call must be followed by zero or more calls to `serialize_element`, + /// then a call to `end`. + /// + /// ```edition2018 + /// use serde::ser::{Serialize, Serializer, SerializeTuple}; + /// + /// # mod fool { + /// # trait Serialize {} + /// impl<A, B, C> Serialize for (A, B, C) + /// # {} + /// # } + /// # + /// # struct Tuple3<A, B, C>(A, B, C); + /// # + /// # impl<A, B, C> Serialize for Tuple3<A, B, C> + /// where + /// A: Serialize, + /// B: Serialize, + /// C: Serialize, + /// { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// let mut tup = serializer.serialize_tuple(3)?; + /// tup.serialize_element(&self.0)?; + /// tup.serialize_element(&self.1)?; + /// tup.serialize_element(&self.2)?; + /// tup.end() + /// } + /// } + /// ``` + /// + /// ```edition2018 + /// use serde::ser::{Serialize, SerializeTuple, Serializer}; + /// + /// const VRAM_SIZE: usize = 386; + /// struct Vram([u16; VRAM_SIZE]); + /// + /// impl Serialize for Vram { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// let mut seq = serializer.serialize_tuple(VRAM_SIZE)?; + /// for element in &self.0[..] { + /// seq.serialize_element(element)?; + /// } + /// seq.end() + /// } + /// } + /// ``` + fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple, Self::Error>; + + /// Begin to serialize a tuple struct like `struct Rgb(u8, u8, u8)`. This + /// call must be followed by zero or more calls to `serialize_field`, then a + /// call to `end`. + /// + /// The `name` is the name of the tuple struct and the `len` is the number + /// of data fields that will be serialized. + /// + /// ```edition2018 + /// use serde::ser::{Serialize, SerializeTupleStruct, Serializer}; + /// + /// struct Rgb(u8, u8, u8); + /// + /// impl Serialize for Rgb { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// let mut ts = serializer.serialize_tuple_struct("Rgb", 3)?; + /// ts.serialize_field(&self.0)?; + /// ts.serialize_field(&self.1)?; + /// ts.serialize_field(&self.2)?; + /// ts.end() + /// } + /// } + /// ``` + fn serialize_tuple_struct( + self, + name: &'static str, + len: usize, + ) -> Result<Self::SerializeTupleStruct, Self::Error>; + + /// Begin to serialize a tuple variant like `E::T` in `enum E { T(u8, u8) + /// }`. This call must be followed by zero or more calls to + /// `serialize_field`, then a call to `end`. + /// + /// The `name` is the name of the enum, the `variant_index` is the index of + /// this variant within the enum, the `variant` is the name of the variant, + /// and the `len` is the number of data fields that will be serialized. + /// + /// ```edition2018 + /// use serde::ser::{Serialize, SerializeTupleVariant, Serializer}; + /// + /// enum E { + /// T(u8, u8), + /// U(String, u32, u32), + /// } + /// + /// impl Serialize for E { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// match *self { + /// E::T(ref a, ref b) => { + /// let mut tv = serializer.serialize_tuple_variant("E", 0, "T", 2)?; + /// tv.serialize_field(a)?; + /// tv.serialize_field(b)?; + /// tv.end() + /// } + /// E::U(ref a, ref b, ref c) => { + /// let mut tv = serializer.serialize_tuple_variant("E", 1, "U", 3)?; + /// tv.serialize_field(a)?; + /// tv.serialize_field(b)?; + /// tv.serialize_field(c)?; + /// tv.end() + /// } + /// } + /// } + /// } + /// ``` + fn serialize_tuple_variant( + self, + name: &'static str, + variant_index: u32, + variant: &'static str, + len: usize, + ) -> Result<Self::SerializeTupleVariant, Self::Error>; + + /// Begin to serialize a map. This call must be followed by zero or more + /// calls to `serialize_key` and `serialize_value`, then a call to `end`. + /// + /// The argument is the number of elements in the map, which may or may not + /// be computable before the map is iterated. Some serializers only support + /// maps whose length is known up front. + /// + /// ```edition2018 + /// # use std::marker::PhantomData; + /// # + /// # struct HashMap<K, V>(PhantomData<K>, PhantomData<V>); + /// # + /// # impl<K, V> HashMap<K, V> { + /// # fn len(&self) -> usize { + /// # unimplemented!() + /// # } + /// # } + /// # + /// # impl<'a, K, V> IntoIterator for &'a HashMap<K, V> { + /// # type Item = (&'a K, &'a V); + /// # type IntoIter = Box<Iterator<Item = (&'a K, &'a V)>>; + /// # + /// # fn into_iter(self) -> Self::IntoIter { + /// # unimplemented!() + /// # } + /// # } + /// # + /// use serde::ser::{Serialize, Serializer, SerializeMap}; + /// + /// impl<K, V> Serialize for HashMap<K, V> + /// where + /// K: Serialize, + /// V: Serialize, + /// { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// let mut map = serializer.serialize_map(Some(self.len()))?; + /// for (k, v) in self { + /// map.serialize_entry(k, v)?; + /// } + /// map.end() + /// } + /// } + /// ``` + fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, Self::Error>; + + /// Begin to serialize a struct like `struct Rgb { r: u8, g: u8, b: u8 }`. + /// This call must be followed by zero or more calls to `serialize_field`, + /// then a call to `end`. + /// + /// The `name` is the name of the struct and the `len` is the number of + /// data fields that will be serialized. + /// + /// ```edition2018 + /// use serde::ser::{Serialize, SerializeStruct, Serializer}; + /// + /// struct Rgb { + /// r: u8, + /// g: u8, + /// b: u8, + /// } + /// + /// impl Serialize for Rgb { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// let mut rgb = serializer.serialize_struct("Rgb", 3)?; + /// rgb.serialize_field("r", &self.r)?; + /// rgb.serialize_field("g", &self.g)?; + /// rgb.serialize_field("b", &self.b)?; + /// rgb.end() + /// } + /// } + /// ``` + fn serialize_struct( + self, + name: &'static str, + len: usize, + ) -> Result<Self::SerializeStruct, Self::Error>; + + /// Begin to serialize a struct variant like `E::S` in `enum E { S { r: u8, + /// g: u8, b: u8 } }`. This call must be followed by zero or more calls to + /// `serialize_field`, then a call to `end`. + /// + /// The `name` is the name of the enum, the `variant_index` is the index of + /// this variant within the enum, the `variant` is the name of the variant, + /// and the `len` is the number of data fields that will be serialized. + /// + /// ```edition2018 + /// use serde::ser::{Serialize, SerializeStructVariant, Serializer}; + /// + /// enum E { + /// S { r: u8, g: u8, b: u8 }, + /// } + /// + /// impl Serialize for E { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// match *self { + /// E::S { + /// ref r, + /// ref g, + /// ref b, + /// } => { + /// let mut sv = serializer.serialize_struct_variant("E", 0, "S", 3)?; + /// sv.serialize_field("r", r)?; + /// sv.serialize_field("g", g)?; + /// sv.serialize_field("b", b)?; + /// sv.end() + /// } + /// } + /// } + /// } + /// ``` + fn serialize_struct_variant( + self, + name: &'static str, + variant_index: u32, + variant: &'static str, + len: usize, + ) -> Result<Self::SerializeStructVariant, Self::Error>; + + /// Collect an iterator as a sequence. + /// + /// The default implementation serializes each item yielded by the iterator + /// using [`serialize_seq`]. Implementors should not need to override this + /// method. + /// + /// ```edition2018 + /// use serde::{Serialize, Serializer}; + /// + /// struct SecretlyOneHigher { + /// data: Vec<i32>, + /// } + /// + /// impl Serialize for SecretlyOneHigher { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.collect_seq(self.data.iter().map(|x| x + 1)) + /// } + /// } + /// ``` + /// + /// [`serialize_seq`]: #tymethod.serialize_seq + fn collect_seq<I>(self, iter: I) -> Result<Self::Ok, Self::Error> + where + I: IntoIterator, + <I as IntoIterator>::Item: Serialize, + { + let iter = iter.into_iter(); + let mut serializer = try!(self.serialize_seq(iterator_len_hint(&iter))); + + #[cfg(not(no_iterator_try_fold))] + { + let mut iter = iter; + try!(iter.try_for_each(|item| serializer.serialize_element(&item))); + } + + #[cfg(no_iterator_try_fold)] + { + for item in iter { + try!(serializer.serialize_element(&item)); + } + } + + serializer.end() + } + + /// Collect an iterator as a map. + /// + /// The default implementation serializes each pair yielded by the iterator + /// using [`serialize_map`]. Implementors should not need to override this + /// method. + /// + /// ```edition2018 + /// use serde::{Serialize, Serializer}; + /// use std::collections::BTreeSet; + /// + /// struct MapToUnit { + /// keys: BTreeSet<i32>, + /// } + /// + /// // Serializes as a map in which the values are all unit. + /// impl Serialize for MapToUnit { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.collect_map(self.keys.iter().map(|k| (k, ()))) + /// } + /// } + /// ``` + /// + /// [`serialize_map`]: #tymethod.serialize_map + fn collect_map<K, V, I>(self, iter: I) -> Result<Self::Ok, Self::Error> + where + K: Serialize, + V: Serialize, + I: IntoIterator<Item = (K, V)>, + { + let iter = iter.into_iter(); + let mut serializer = try!(self.serialize_map(iterator_len_hint(&iter))); + + #[cfg(not(no_iterator_try_fold))] + { + let mut iter = iter; + try!(iter.try_for_each(|(key, value)| serializer.serialize_entry(&key, &value))); + } + + #[cfg(no_iterator_try_fold)] + { + for (key, value) in iter { + try!(serializer.serialize_entry(&key, &value)); + } + } + + serializer.end() + } + + /// Serialize a string produced by an implementation of `Display`. + /// + /// The default implementation builds a heap-allocated [`String`] and + /// delegates to [`serialize_str`]. Serializers are encouraged to provide a + /// more efficient implementation if possible. + /// + /// ```edition2018 + /// # struct DateTime; + /// # + /// # impl DateTime { + /// # fn naive_local(&self) -> () { () } + /// # fn offset(&self) -> () { () } + /// # } + /// # + /// use serde::{Serialize, Serializer}; + /// + /// impl Serialize for DateTime { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.collect_str(&format_args!("{:?}{:?}", + /// self.naive_local(), + /// self.offset())) + /// } + /// } + /// ``` + /// + /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html + /// [`serialize_str`]: #tymethod.serialize_str + #[cfg(any(feature = "std", feature = "alloc"))] + fn collect_str<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error> + where + T: Display, + { + self.serialize_str(&value.to_string()) + } + + /// Serialize a string produced by an implementation of `Display`. + /// + /// Serializers that use `no_std` are required to provide an implementation + /// of this method. If no more sensible behavior is possible, the + /// implementation is expected to return an error. + /// + /// ```edition2018 + /// # struct DateTime; + /// # + /// # impl DateTime { + /// # fn naive_local(&self) -> () { () } + /// # fn offset(&self) -> () { () } + /// # } + /// # + /// use serde::{Serialize, Serializer}; + /// + /// impl Serialize for DateTime { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// serializer.collect_str(&format_args!("{:?}{:?}", + /// self.naive_local(), + /// self.offset())) + /// } + /// } + /// ``` + #[cfg(not(any(feature = "std", feature = "alloc")))] + fn collect_str<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error> + where + T: Display; + + /// Determine whether `Serialize` implementations should serialize in + /// human-readable form. + /// + /// Some types have a human-readable form that may be somewhat expensive to + /// construct, as well as a binary form that is compact and efficient. + /// Generally text-based formats like JSON and YAML will prefer to use the + /// human-readable one and binary formats like Bincode will prefer the + /// compact one. + /// + /// ```edition2018 + /// # use std::fmt::{self, Display}; + /// # + /// # struct Timestamp; + /// # + /// # impl Timestamp { + /// # fn seconds_since_epoch(&self) -> u64 { unimplemented!() } + /// # } + /// # + /// # impl Display for Timestamp { + /// # fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + /// # unimplemented!() + /// # } + /// # } + /// # + /// use serde::{Serialize, Serializer}; + /// + /// impl Serialize for Timestamp { + /// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + /// where + /// S: Serializer, + /// { + /// if serializer.is_human_readable() { + /// // Serialize to a human-readable string "2015-05-15T17:01:00Z". + /// self.to_string().serialize(serializer) + /// } else { + /// // Serialize to a compact binary representation. + /// self.seconds_since_epoch().serialize(serializer) + /// } + /// } + /// } + /// ``` + /// + /// The default implementation of this method returns `true`. Data formats + /// may override this to `false` to request a compact form for types that + /// support one. Note that modifying this method to change a format from + /// human-readable to compact or vice versa should be regarded as a breaking + /// 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 + } +} + +/// Returned from `Serializer::serialize_seq`. +/// +/// # Example use +/// +/// ```edition2018 +/// # use std::marker::PhantomData; +/// # +/// # struct Vec<T>(PhantomData<T>); +/// # +/// # impl<T> Vec<T> { +/// # fn len(&self) -> usize { +/// # unimplemented!() +/// # } +/// # } +/// # +/// # impl<'a, T> IntoIterator for &'a Vec<T> { +/// # type Item = &'a T; +/// # type IntoIter = Box<Iterator<Item = &'a T>>; +/// # fn into_iter(self) -> Self::IntoIter { +/// # unimplemented!() +/// # } +/// # } +/// # +/// use serde::ser::{Serialize, Serializer, SerializeSeq}; +/// +/// impl<T> Serialize for Vec<T> +/// where +/// T: Serialize, +/// { +/// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> +/// where +/// S: Serializer, +/// { +/// let mut seq = serializer.serialize_seq(Some(self.len()))?; +/// for element in self { +/// seq.serialize_element(element)?; +/// } +/// seq.end() +/// } +/// } +/// ``` +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `SerializeSeq` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait SerializeSeq { + /// Must match the `Ok` type of our `Serializer`. + type Ok; + + /// Must match the `Error` type of our `Serializer`. + type Error: Error; + + /// Serialize a sequence element. + fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> + where + T: Serialize; + + /// Finish serializing a sequence. + fn end(self) -> Result<Self::Ok, Self::Error>; +} + +/// Returned from `Serializer::serialize_tuple`. +/// +/// # Example use +/// +/// ```edition2018 +/// use serde::ser::{Serialize, Serializer, SerializeTuple}; +/// +/// # mod fool { +/// # trait Serialize {} +/// impl<A, B, C> Serialize for (A, B, C) +/// # {} +/// # } +/// # +/// # struct Tuple3<A, B, C>(A, B, C); +/// # +/// # impl<A, B, C> Serialize for Tuple3<A, B, C> +/// where +/// A: Serialize, +/// B: Serialize, +/// C: Serialize, +/// { +/// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> +/// where +/// S: Serializer, +/// { +/// let mut tup = serializer.serialize_tuple(3)?; +/// tup.serialize_element(&self.0)?; +/// tup.serialize_element(&self.1)?; +/// tup.serialize_element(&self.2)?; +/// tup.end() +/// } +/// } +/// ``` +/// +/// ```edition2018 +/// # use std::marker::PhantomData; +/// # +/// # struct Array<T>(PhantomData<T>); +/// # +/// # impl<T> Array<T> { +/// # fn len(&self) -> usize { +/// # unimplemented!() +/// # } +/// # } +/// # +/// # impl<'a, T> IntoIterator for &'a Array<T> { +/// # type Item = &'a T; +/// # type IntoIter = Box<Iterator<Item = &'a T>>; +/// # fn into_iter(self) -> Self::IntoIter { +/// # unimplemented!() +/// # } +/// # } +/// # +/// use serde::ser::{Serialize, Serializer, SerializeTuple}; +/// +/// # mod fool { +/// # trait Serialize {} +/// impl<T> Serialize for [T; 16] +/// # {} +/// # } +/// # +/// # impl<T> Serialize for Array<T> +/// where +/// T: Serialize, +/// { +/// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> +/// where +/// S: Serializer, +/// { +/// let mut seq = serializer.serialize_tuple(16)?; +/// for element in self { +/// seq.serialize_element(element)?; +/// } +/// seq.end() +/// } +/// } +/// ``` +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `SerializeTuple` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait SerializeTuple { + /// Must match the `Ok` type of our `Serializer`. + type Ok; + + /// Must match the `Error` type of our `Serializer`. + type Error: Error; + + /// Serialize a tuple element. + fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> + where + T: Serialize; + + /// Finish serializing a tuple. + fn end(self) -> Result<Self::Ok, Self::Error>; +} + +/// Returned from `Serializer::serialize_tuple_struct`. +/// +/// # Example use +/// +/// ```edition2018 +/// use serde::ser::{Serialize, SerializeTupleStruct, Serializer}; +/// +/// struct Rgb(u8, u8, u8); +/// +/// impl Serialize for Rgb { +/// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> +/// where +/// S: Serializer, +/// { +/// let mut ts = serializer.serialize_tuple_struct("Rgb", 3)?; +/// ts.serialize_field(&self.0)?; +/// ts.serialize_field(&self.1)?; +/// ts.serialize_field(&self.2)?; +/// ts.end() +/// } +/// } +/// ``` +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `SerializeTupleStruct` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait SerializeTupleStruct { + /// Must match the `Ok` type of our `Serializer`. + type Ok; + + /// Must match the `Error` type of our `Serializer`. + type Error: Error; + + /// Serialize a tuple struct field. + fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> + where + T: Serialize; + + /// Finish serializing a tuple struct. + fn end(self) -> Result<Self::Ok, Self::Error>; +} + +/// Returned from `Serializer::serialize_tuple_variant`. +/// +/// # Example use +/// +/// ```edition2018 +/// use serde::ser::{Serialize, SerializeTupleVariant, Serializer}; +/// +/// enum E { +/// T(u8, u8), +/// U(String, u32, u32), +/// } +/// +/// impl Serialize for E { +/// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> +/// where +/// S: Serializer, +/// { +/// match *self { +/// E::T(ref a, ref b) => { +/// let mut tv = serializer.serialize_tuple_variant("E", 0, "T", 2)?; +/// tv.serialize_field(a)?; +/// tv.serialize_field(b)?; +/// tv.end() +/// } +/// E::U(ref a, ref b, ref c) => { +/// let mut tv = serializer.serialize_tuple_variant("E", 1, "U", 3)?; +/// tv.serialize_field(a)?; +/// tv.serialize_field(b)?; +/// tv.serialize_field(c)?; +/// tv.end() +/// } +/// } +/// } +/// } +/// ``` +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `SerializeTupleVariant` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait SerializeTupleVariant { + /// Must match the `Ok` type of our `Serializer`. + type Ok; + + /// Must match the `Error` type of our `Serializer`. + type Error: Error; + + /// Serialize a tuple variant field. + fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> + where + T: Serialize; + + /// Finish serializing a tuple variant. + fn end(self) -> Result<Self::Ok, Self::Error>; +} + +/// Returned from `Serializer::serialize_map`. +/// +/// # Example use +/// +/// ```edition2018 +/// # use std::marker::PhantomData; +/// # +/// # struct HashMap<K, V>(PhantomData<K>, PhantomData<V>); +/// # +/// # impl<K, V> HashMap<K, V> { +/// # fn len(&self) -> usize { +/// # unimplemented!() +/// # } +/// # } +/// # +/// # impl<'a, K, V> IntoIterator for &'a HashMap<K, V> { +/// # type Item = (&'a K, &'a V); +/// # type IntoIter = Box<Iterator<Item = (&'a K, &'a V)>>; +/// # +/// # fn into_iter(self) -> Self::IntoIter { +/// # unimplemented!() +/// # } +/// # } +/// # +/// use serde::ser::{Serialize, Serializer, SerializeMap}; +/// +/// impl<K, V> Serialize for HashMap<K, V> +/// where +/// K: Serialize, +/// V: Serialize, +/// { +/// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> +/// where +/// S: Serializer, +/// { +/// let mut map = serializer.serialize_map(Some(self.len()))?; +/// for (k, v) in self { +/// map.serialize_entry(k, v)?; +/// } +/// map.end() +/// } +/// } +/// ``` +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `SerializeMap` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait SerializeMap { + /// Must match the `Ok` type of our `Serializer`. + type Ok; + + /// Must match the `Error` type of our `Serializer`. + type Error: Error; + + /// Serialize a map key. + /// + /// If possible, `Serialize` implementations are encouraged to use + /// `serialize_entry` instead as it may be implemented more efficiently in + /// some formats compared to a pair of calls to `serialize_key` and + /// `serialize_value`. + fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error> + where + T: Serialize; + + /// Serialize a map value. + /// + /// # Panics + /// + /// Calling `serialize_value` before `serialize_key` is incorrect and is + /// allowed to panic or produce bogus results. + fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> + where + T: Serialize; + + /// Serialize a map entry consisting of a key and a value. + /// + /// Some [`Serialize`] types are not able to hold a key and value in memory + /// at the same time so `SerializeMap` implementations are required to + /// support [`serialize_key`] and [`serialize_value`] individually. The + /// `serialize_entry` method allows serializers to optimize for the case + /// where key and value are both available. [`Serialize`] implementations + /// are encouraged to use `serialize_entry` if possible. + /// + /// The default implementation delegates to [`serialize_key`] and + /// [`serialize_value`]. This is appropriate for serializers that do not + /// care about performance or are not able to optimize `serialize_entry` any + /// better than this. + /// + /// [`Serialize`]: ../trait.Serialize.html + /// [`serialize_key`]: #tymethod.serialize_key + /// [`serialize_value`]: #tymethod.serialize_value + fn serialize_entry<K: ?Sized, V: ?Sized>( + &mut self, + key: &K, + value: &V, + ) -> Result<(), Self::Error> + where + K: Serialize, + V: Serialize, + { + try!(self.serialize_key(key)); + self.serialize_value(value) + } + + /// Finish serializing a map. + fn end(self) -> Result<Self::Ok, Self::Error>; +} + +/// Returned from `Serializer::serialize_struct`. +/// +/// # Example use +/// +/// ```edition2018 +/// use serde::ser::{Serialize, SerializeStruct, Serializer}; +/// +/// struct Rgb { +/// r: u8, +/// g: u8, +/// b: u8, +/// } +/// +/// impl Serialize for Rgb { +/// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> +/// where +/// S: Serializer, +/// { +/// let mut rgb = serializer.serialize_struct("Rgb", 3)?; +/// rgb.serialize_field("r", &self.r)?; +/// rgb.serialize_field("g", &self.g)?; +/// rgb.serialize_field("b", &self.b)?; +/// rgb.end() +/// } +/// } +/// ``` +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `SerializeStruct` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait SerializeStruct { + /// Must match the `Ok` type of our `Serializer`. + type Ok; + + /// Must match the `Error` type of our `Serializer`. + type Error: Error; + + /// Serialize a struct field. + fn serialize_field<T: ?Sized>( + &mut self, + key: &'static str, + value: &T, + ) -> Result<(), Self::Error> + where + T: Serialize; + + /// Indicate that a struct field has been skipped. + #[inline] + fn skip_field(&mut self, key: &'static str) -> Result<(), Self::Error> { + let _ = key; + Ok(()) + } + + /// Finish serializing a struct. + fn end(self) -> Result<Self::Ok, Self::Error>; +} + +/// Returned from `Serializer::serialize_struct_variant`. +/// +/// # Example use +/// +/// ```edition2018 +/// use serde::ser::{Serialize, SerializeStructVariant, Serializer}; +/// +/// enum E { +/// S { r: u8, g: u8, b: u8 }, +/// } +/// +/// impl Serialize for E { +/// fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> +/// where +/// S: Serializer, +/// { +/// match *self { +/// E::S { +/// ref r, +/// ref g, +/// ref b, +/// } => { +/// let mut sv = serializer.serialize_struct_variant("E", 0, "S", 3)?; +/// sv.serialize_field("r", r)?; +/// sv.serialize_field("g", g)?; +/// sv.serialize_field("b", b)?; +/// sv.end() +/// } +/// } +/// } +/// } +/// ``` +/// +/// # Example implementation +/// +/// The [example data format] presented on the website demonstrates an +/// implementation of `SerializeStructVariant` for a basic JSON data format. +/// +/// [example data format]: https://serde.rs/data-format.html +pub trait SerializeStructVariant { + /// Must match the `Ok` type of our `Serializer`. + type Ok; + + /// Must match the `Error` type of our `Serializer`. + type Error: Error; + + /// Serialize a struct variant field. + fn serialize_field<T: ?Sized>( + &mut self, + key: &'static str, + value: &T, + ) -> Result<(), Self::Error> + where + T: Serialize; + + /// Indicate that a struct variant field has been skipped. + #[inline] + fn skip_field(&mut self, key: &'static str) -> Result<(), Self::Error> { + let _ = key; + Ok(()) + } + + /// Finish serializing a struct variant. + fn end(self) -> Result<Self::Ok, Self::Error>; +} + +fn iterator_len_hint<I>(iter: &I) -> Option<usize> +where + I: Iterator, +{ + match iter.size_hint() { + (lo, Some(hi)) if lo == hi => Some(lo), + _ => None, + } +} |