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//! This crate provides type-erased versions of Serde's `Serialize`, `Serializer` //! and `Deserializer` traits that can be used as [trait //! objects](https://doc.rust-lang.org/book/trait-objects.html). //! //! The usual Serde `Serialize`, `Serializer` and `Deserializer` traits cannot //! be used as trait objects like `&Serialize` or boxed trait objects like //! `Box<Serialize>` because of Rust's ["object safety" //! rules](http://huonw.github.io/blog/2015/01/object-safety/). In particular, //! all three traits contain generic methods which cannot be made into a trait //! object. //! //! **The traits in this crate work seamlessly with any existing Serde //! `Serialize` and `Deserialize` type and any existing Serde `Serializer` and //! `Deserializer` format.** //! //! ## Serialization //! //! ```rust //! extern crate erased_serde; //! extern crate serde_json; //! extern crate serde_cbor; //! //! use std::collections::BTreeMap as Map; //! use std::io; //! //! use erased_serde::{Serialize, Serializer}; //! //! fn main() { //! // Construct some serializers. //! let json = &mut serde_json::ser::Serializer::new(io::stdout()); //! let cbor = &mut serde_cbor::ser::Serializer::new(io::stdout()); //! //! // The values in this map are boxed trait objects. Ordinarily this would not //! // be possible with serde::Serializer because of object safety, but type //! // erasure makes it possible with erased_serde::Serializer. //! let mut formats: Map<&str, Box<Serializer>> = Map::new(); //! formats.insert("json", Box::new(Serializer::erase(json))); //! formats.insert("cbor", Box::new(Serializer::erase(cbor))); //! //! // These are boxed trait objects as well. Same thing here - type erasure //! // makes this possible. //! let mut values: Map<&str, Box<Serialize>> = Map::new(); //! values.insert("vec", Box::new(vec!["a", "b"])); //! values.insert("int", Box::new(65536)); //! //! // Pick a Serializer out of the formats map. //! let format = formats.get_mut("json").unwrap(); //! //! // Pick a Serialize out of the values map. //! let value = values.get("vec").unwrap(); //! //! // This line prints `["a","b"]` to stdout. //! value.erased_serialize(format).unwrap(); //! } //! ``` //! //! ## Deserialization //! //! ```rust //! extern crate erased_serde; //! extern crate serde_json; //! extern crate serde_cbor; //! //! use std::collections::BTreeMap as Map; //! //! use erased_serde::Deserializer; //! //! fn main() { //! static JSON: &'static [u8] = br#"{"A": 65, "B": 66}"#; //! static CBOR: &'static [u8] = &[162, 97, 65, 24, 65, 97, 66, 24, 66]; //! //! // Construct some deserializers. //! let json = &mut serde_json::de::Deserializer::from_slice(JSON); //! let cbor = &mut serde_cbor::de::Deserializer::from_slice(CBOR); //! //! // The values in this map are boxed trait objects, which is not possible //! // with the normal serde::Deserializer because of object safety. //! let mut formats: Map<&str, Box<Deserializer>> = Map::new(); //! formats.insert("json", Box::new(Deserializer::erase(json))); //! formats.insert("cbor", Box::new(Deserializer::erase(cbor))); //! //! // Pick a Deserializer out of the formats map. //! let format = formats.get_mut("json").unwrap(); //! //! let data: Map<String, usize> = erased_serde::deserialize(format).unwrap(); //! //! println!("{}", data["A"] + data["B"]); //! } //! ``` #![doc(html_root_url = "https://docs.rs/erased-serde/0.3.9")] #![cfg_attr(feature = "unstable-debug", feature(core_intrinsics))] #[macro_use] extern crate serde; #[cfg(test)] #[macro_use] extern crate serde_derive; #[cfg(test)] extern crate serde_json; #[macro_use] mod macros; mod any; mod de; mod error; mod ser; pub use de::{deserialize, Deserializer}; pub use error::{Error, Result}; pub use ser::{serialize, Serialize, Serializer}; // Not public API. #[doc(hidden)] pub mod private;