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Diffstat (limited to 'vendor/serde/src/ser/mod.rs')
| -rw-r--r-- | vendor/serde/src/ser/mod.rs | 1952 |
1 files changed, 0 insertions, 1952 deletions
diff --git a/vendor/serde/src/ser/mod.rs b/vendor/serde/src/ser/mod.rs deleted file mode 100644 index 75c4514..0000000 --- a/vendor/serde/src/ser/mod.rs +++ /dev/null @@ -1,1952 +0,0 @@ -//! 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 [`postcard`]. -//! -//! 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 -//! [`postcard`]: https://github.com/jamesmunns/postcard -//! [`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 crate::lib::*; - -mod fmt; -mod impls; -mod impossible; - -pub use self::impossible::Impossible; - -#[cfg(not(any(feature = "std", feature = "unstable")))] -#[doc(no_inline)] -pub use crate::std_error::Error as StdError; -#[cfg(all(feature = "unstable", not(feature = "std")))] -#[doc(no_inline)] -pub use core::error::Error as StdError; -#[cfg(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. - /// - /// ```edition2021 - /// # 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][crate::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 -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. - /// - /// ```edition2021 - /// 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 Postcard. 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. - /// - /// ```edition2021 - /// # 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`. - /// - /// ```edition2021 - /// # 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`. - /// - /// ```edition2021 - /// # 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`. - /// - /// ```edition2021 - /// # 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. - /// - /// ```edition2021 - /// # 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>; - - /// Serialize an `i128` value. - /// - /// ```edition2021 - /// # 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) - /// } - /// } - /// ``` - /// - /// 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`. - /// - /// ```edition2021 - /// # 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`. - /// - /// ```edition2021 - /// # 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`. - /// - /// ```edition2021 - /// # 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. - /// - /// ```edition2021 - /// # 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>; - - /// Serialize a `u128` value. - /// - /// ```edition2021 - /// # 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) - /// } - /// } - /// ``` - /// - /// 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`. - /// - /// ```edition2021 - /// # 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. - /// - /// ```edition2021 - /// # 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`. - /// - /// ```edition2021 - /// # 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`. - /// - /// ```edition2021 - /// # 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: - /// - /// ```edition2021 - /// # 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. - /// - /// ```edition2021 - /// # 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. - /// - /// ```edition2021 - /// # 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. - /// - /// ```edition2021 - /// # 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`. - /// - /// ```edition2021 - /// 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. - /// - /// ```edition2021 - /// 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)`. - /// - /// ```edition2021 - /// 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. - /// - /// ```edition2021 - /// 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. - /// - /// ```edition2021 - /// # 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<dyn Iterator<Item = &'a T>>; - /// # - /// # fn into_iter(self) -> Self::IntoIter { - /// # unimplemented!() - /// # } - /// # } - /// # - /// use serde::ser::{Serialize, SerializeSeq, Serializer}; - /// - /// 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`. - /// - /// ```edition2021 - /// use serde::ser::{Serialize, SerializeTuple, Serializer}; - /// - /// # 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() - /// } - /// } - /// ``` - /// - /// ```edition2021 - /// 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. - /// - /// ```edition2021 - /// 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. - /// - /// ```edition2021 - /// 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. - /// - /// ```edition2021 - /// # 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<dyn Iterator<Item = (&'a K, &'a V)>>; - /// # - /// # fn into_iter(self) -> Self::IntoIter { - /// # unimplemented!() - /// # } - /// # } - /// # - /// use serde::ser::{Serialize, SerializeMap, Serializer}; - /// - /// 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. - /// - /// ```edition2021 - /// 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. - /// - /// ```edition2021 - /// 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. - /// - /// ```edition2021 - /// 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 mut iter = iter.into_iter(); - let mut serializer = tri!(self.serialize_seq(iterator_len_hint(&iter))); - tri!(iter.try_for_each(|item| 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. - /// - /// ```edition2021 - /// 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 mut iter = iter.into_iter(); - let mut serializer = tri!(self.serialize_map(iterator_len_hint(&iter))); - tri!(iter.try_for_each(|(key, value)| 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. - /// - /// ```edition2021 - /// # 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. - /// - /// ```edition2021 - /// # 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 Postcard will prefer the - /// compact one. - /// - /// ```edition2021 - /// # 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 -/// -/// ```edition2021 -/// # 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<dyn Iterator<Item = &'a T>>; -/// # fn into_iter(self) -> Self::IntoIter { -/// # unimplemented!() -/// # } -/// # } -/// # -/// use serde::ser::{Serialize, SerializeSeq, Serializer}; -/// -/// 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 -/// -/// ```edition2021 -/// use serde::ser::{Serialize, SerializeTuple, Serializer}; -/// -/// # 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() -/// } -/// } -/// ``` -/// -/// ```edition2021 -/// # 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<dyn Iterator<Item = &'a T>>; -/// # fn into_iter(self) -> Self::IntoIter { -/// # unimplemented!() -/// # } -/// # } -/// # -/// use serde::ser::{Serialize, SerializeTuple, Serializer}; -/// -/// # 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 -/// -/// ```edition2021 -/// 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 -/// -/// ```edition2021 -/// 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 -/// -/// ```edition2021 -/// # 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<dyn Iterator<Item = (&'a K, &'a V)>>; -/// # -/// # fn into_iter(self) -> Self::IntoIter { -/// # unimplemented!() -/// # } -/// # } -/// # -/// use serde::ser::{Serialize, SerializeMap, Serializer}; -/// -/// 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, - { - tri!(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 -/// -/// ```edition2021 -/// 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 -/// -/// ```edition2021 -/// 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, - } -} |