//! [![github]](https://github.com/dtolnay/erased-serde) [![crates-io]](https://crates.io/crates/erased-serde) [![docs-rs]](https://docs.rs/erased-serde) //! //! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github //! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust //! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs //! //!
//! //! This crate provides type-erased versions of Serde's `Serialize`, `Serializer` //! and `Deserializer` traits that can be used as [trait objects]. //! //! [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 `&dyn Serialize` or boxed trait objects like //! `Box` because of Rust's ["object safety" rules]. In //! particular, all three traits contain generic methods which cannot be made //! into a trait object. //! //! ["object safety" rules]: http://huonw.github.io/blog/2015/01/object-safety/ //! //! This library should be considered a low-level building block for interacting //! with Serde APIs in an object-safe way. Most use cases will require higher //! level functionality such as provided by [`typetag`] which uses this crate //! internally. //! //! [`typetag`]: https://github.com/dtolnay/typetag //! //! **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 //! use erased_serde::{Serialize, Serializer}; //! use std::collections::BTreeMap as Map; //! use std::io; //! //! fn main() { //! // Construct some serializers. //! let json = &mut serde_json::Serializer::new(io::stdout()); //! let cbor = &mut serde_cbor::Serializer::new(serde_cbor::ser::IoWrite::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> = Map::new(); //! formats.insert("json", Box::new(::erase(json))); //! formats.insert("cbor", Box::new(::erase(cbor))); //! //! // These are boxed trait objects as well. Same thing here - type erasure //! // makes this possible. //! let mut values: Map<&str, Box> = 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 //! use erased_serde::Deserializer; //! use std::collections::BTreeMap as Map; //! //! 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::Deserializer::from_slice(JSON); //! let cbor = &mut serde_cbor::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> = Map::new(); //! formats.insert("json", Box::new(::erase(json))); //! formats.insert("cbor", Box::new(::erase(cbor))); //! //! // Pick a Deserializer out of the formats map. //! let format = formats.get_mut("json").unwrap(); //! //! let data: Map = erased_serde::deserialize(format).unwrap(); //! //! println!("{}", data["A"] + data["B"]); //! } //! ``` #![doc(html_root_url = "https://docs.rs/erased-serde/0.3.31")] #![cfg_attr(not(feature = "std"), no_std)] #![deny(unsafe_op_in_unsafe_fn)] #![allow( clippy::derive_partial_eq_without_eq, clippy::extra_unused_type_parameters, clippy::items_after_statements, clippy::manual_map, // https://github.com/rust-lang/rust-clippy/issues/7820 clippy::missing_errors_doc, clippy::needless_doctest_main, clippy::needless_pass_by_ref_mut, clippy::semicolon_if_nothing_returned, // https://github.com/rust-lang/rust-clippy/issues/7324 clippy::unused_self, clippy::wildcard_imports )] mod alloc { #[cfg(not(feature = "std"))] extern crate alloc; #[cfg(feature = "std")] use std as alloc; pub use self::alloc::borrow::ToOwned; pub use self::alloc::boxed::Box; pub use self::alloc::string::{String, ToString}; pub use self::alloc::{vec, vec::Vec}; } #[macro_use] mod macros; mod any; mod de; mod error; mod features_check; mod map; mod ser; pub use crate::de::{deserialize, Deserializer}; pub use crate::error::{Error, Result}; pub use crate::ser::{serialize, Serialize, Serializer}; // Not public API. #[doc(hidden)] #[path = "private.rs"] pub mod __private;