| //! 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/servo/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::ser::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))); |
| 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))); |
| 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, |
| } |
| } |
