erased-serde-0.3.23/.cargo_vcs_info.json0000644000000001360000000000100134640ustar { "git": { "sha1": "4ec783faba386010c0b9418ebaa06bc431f707ee" }, "path_in_vcs": "" }erased-serde-0.3.23/.clippy.toml000064400000000000000000000000201046102023000145170ustar 00000000000000msrv = "1.31.0" erased-serde-0.3.23/.github/FUNDING.yml000064400000000000000000000000201046102023000154210ustar 00000000000000github: dtolnay erased-serde-0.3.23/.github/workflows/ci.yml000064400000000000000000000032441046102023000167720ustar 00000000000000name: CI on: push: pull_request: schedule: [cron: "40 1 * * *"] env: RUSTFLAGS: -Dwarnings jobs: test: name: Rust ${{matrix.rust}} runs-on: ubuntu-latest strategy: fail-fast: false matrix: rust: [nightly, beta, stable] steps: - uses: actions/checkout@v3 - uses: dtolnay/rust-toolchain@master with: toolchain: ${{matrix.rust}} - run: cargo check - run: cargo check --manifest-path tests/crate/Cargo.toml - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc - run: cargo test - run: cargo test env: RUSTFLAGS: --cfg include_fnptr_in_fingerprint ${{env.RUSTFLAGS}} msrv: name: Rust 1.31.0 runs-on: ubuntu-latest steps: - uses: actions/checkout@v3 - uses: dtolnay/rust-toolchain@1.31.0 - run: cargo check - run: cargo check --manifest-path tests/crate/Cargo.toml clippy: name: Clippy runs-on: ubuntu-latest if: github.event_name != 'pull_request' steps: - uses: actions/checkout@v3 - uses: dtolnay/rust-toolchain@clippy - run: cargo clippy --tests -- -Dclippy::all -Dclippy::pedantic miri: name: Miri runs-on: ubuntu-latest steps: - uses: actions/checkout@v3 - uses: dtolnay/rust-toolchain@miri - run: cargo miri test env: MIRIFLAGS: -Zmiri-strict-provenance outdated: name: Outdated runs-on: ubuntu-latest if: github.event_name != 'pull_request' steps: - uses: actions/checkout@v3 - uses: dtolnay/install@cargo-outdated - run: cargo outdated --workspace --exit-code 1 erased-serde-0.3.23/.gitignore000064400000000000000000000000221046102023000142360ustar 00000000000000target Cargo.lock erased-serde-0.3.23/Cargo.toml0000644000000026700000000000100114670ustar # THIS FILE IS AUTOMATICALLY GENERATED BY CARGO # # When uploading crates to the registry Cargo will automatically # "normalize" Cargo.toml files for maximal compatibility # with all versions of Cargo and also rewrite `path` dependencies # to registry (e.g., crates.io) dependencies. # # If you are reading this file be aware that the original Cargo.toml # will likely look very different (and much more reasonable). # See Cargo.toml.orig for the original contents. [package] edition = "2018" rust-version = "1.31" name = "erased-serde" version = "0.3.23" authors = ["David Tolnay "] description = "Type-erased Serialize and Serializer traits" documentation = "https://docs.rs/erased-serde" readme = "README.md" keywords = [ "serde", "erasure", ] categories = [ "encoding", "rust-patterns", "no-std", ] license = "MIT OR Apache-2.0" repository = "https://github.com/dtolnay/erased-serde" [package.metadata.docs.rs] targets = ["x86_64-unknown-linux-gnu"] [[test]] name = "test" path = "tests/readme.rs" [dependencies.serde] version = "1.0.63" default-features = false [dev-dependencies.rustversion] version = "1.0" [dev-dependencies.serde_cbor] version = "0.11" [dev-dependencies.serde_derive] version = "1.0" [dev-dependencies.serde_json] version = "1.0" [dev-dependencies.trybuild] version = "1.0.49" features = ["diff"] [features] alloc = ["serde/alloc"] default = ["std"] std = ["serde/std"] unstable-debug = [] erased-serde-0.3.23/Cargo.toml.orig000064400000000000000000000017571046102023000151550ustar 00000000000000[package] name = "erased-serde" version = "0.3.23" authors = ["David Tolnay "] categories = ["encoding", "rust-patterns", "no-std"] description = "Type-erased Serialize and Serializer traits" documentation = "https://docs.rs/erased-serde" edition = "2018" keywords = ["serde", "erasure"] license = "MIT OR Apache-2.0" readme = "README.md" repository = "https://github.com/dtolnay/erased-serde" rust-version = "1.31" [dependencies] serde = { version = "1.0.63", default-features = false } [dev-dependencies] rustversion = "1.0" serde_cbor = "0.11" serde_derive = "1.0" serde_json = "1.0" trybuild = { version = "1.0.49", features = ["diff"] } [features] # Note: at least one of "std" or "alloc" must be enabled. default = ["std"] std = ["serde/std"] alloc = ["serde/alloc"] # requires Rust 1.36+ unstable-debug = [] [[test]] name = "test" path = "tests/readme.rs" [workspace] members = ["explanation", "tests/crate"] [package.metadata.docs.rs] targets = ["x86_64-unknown-linux-gnu"] erased-serde-0.3.23/LICENSE-APACHE000064400000000000000000000251371046102023000142100ustar 00000000000000 Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. 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While redistributing the Work or Derivative Works thereof, You may choose to offer, and charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations and/or rights consistent with this License. However, in accepting such obligations, You may act only on Your own behalf and on Your sole responsibility, not on behalf of any other Contributor, and only if You agree to indemnify, defend, and hold each Contributor harmless for any liability incurred by, or claims asserted against, such Contributor by reason of your accepting any such warranty or additional liability. END OF TERMS AND CONDITIONS APPENDIX: How to apply the Apache License to your work. To apply the Apache License to your work, attach the following boilerplate notice, with the fields enclosed by brackets "[]" replaced with your own identifying information. (Don't include the brackets!) The text should be enclosed in the appropriate comment syntax for the file format. We also recommend that a file or class name and description of purpose be included on the same "printed page" as the copyright notice for easier identification within third-party archives. Copyright [yyyy] [name of copyright owner] Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. erased-serde-0.3.23/LICENSE-MIT000064400000000000000000000020531046102023000137100ustar 00000000000000Copyright (c) 2016 Erased Serde Developers Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. erased-serde-0.3.23/README.md000064400000000000000000000142271046102023000135410ustar 00000000000000Erased Serde ============ [github](https://github.com/dtolnay/erased-serde) [crates.io](https://crates.io/crates/erased-serde) [docs.rs](https://docs.rs/erased-serde) [build status](https://github.com/dtolnay/erased-serde/actions?query=branch%3Amaster) 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/first-edition/trait-objects.html - [`erased_serde::Serialize`](https://docs.rs/erased-serde/0.3/erased_serde/trait.Serialize.html) - [`erased_serde::Serializer`](https://docs.rs/erased-serde/0.3/erased_serde/trait.Serializer.html) - [`erased_serde::Deserializer`](https://docs.rs/erased-serde/0.3/erased_serde/trait.Deserializer.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.** ```toml [dependencies] serde = "1.0" erased-serde = "0.3" ``` ## 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: &[u8] = br#"{"A": 65, "B": 66}"#; static CBOR: &[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"]); } ``` ## How it works This crate is based on a general technique for building trait objects of traits that have generic methods (like all of Serde's traits). [This example code] demonstrates the technique applied to a simplified case of a single generic method. [Try it in the playground.] [This example code]: https://github.com/dtolnay/erased-serde/blob/master/explanation/main.rs [Try it in the playground.]: https://play.rust-lang.org/?gist=c1111875e7462ba3d0190aacb2fc2211 In erased-serde things are a bit more complicated than in the example for three reasons but the idea is the same. - We need to deal with trait methods that take `self` by value -- effectively by implementing the object-safe trait for `Option` where `T` implements the real trait. - We need to deal with traits that have associated types like `Serializer::Ok` and `Visitor::Value` -- by carefully short-term stashing things behind a pointer. - We need to support trait methods that have a generic type in the return type but none of the argument types, like `SeqAccess::next_element` -- this can be flipped around into a callback style where the return value is instead passed on to a generic argument. In the future maybe the Rust compiler will be able to apply this technique automatically to any trait that is not already object safe by the current rules.
#### License Licensed under either of Apache License, Version 2.0 or MIT license at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions. erased-serde-0.3.23/build.rs000064400000000000000000000015721046102023000137260ustar 00000000000000use std::env; use std::process::Command; use std::str; fn main() { let compiler = match rustc_minor_version() { Some(compiler) => compiler, None => return, }; if compiler < 36 { // https://doc.rust-lang.org/std/mem/union.MaybeUninit.html println!("cargo:rustc-cfg=no_maybe_uninit"); } if compiler < 52 { // #![deny(unsafe_op_in_unsafe_fn)]. // https://github.com/rust-lang/rust/issues/71668 println!("cargo:rustc-cfg=no_unsafe_op_in_unsafe_fn_lint"); } } fn rustc_minor_version() -> Option { let rustc = env::var_os("RUSTC")?; let output = Command::new(rustc).arg("--version").output().ok()?; let version = str::from_utf8(&output.stdout).ok()?; let mut pieces = version.split('.'); if pieces.next() != Some("rustc 1") { return None; } pieces.next()?.parse().ok() } erased-serde-0.3.23/src/any.rs000064400000000000000000000131451046102023000142040ustar 00000000000000use crate::alloc::Box; #[cfg(no_maybe_uninit)] use core::marker::PhantomData; use core::mem; #[cfg(not(no_maybe_uninit))] use core::mem::MaybeUninit; use core::ptr; #[cfg(feature = "unstable-debug")] use core::any; pub struct Any { value: Value, drop: unsafe fn(&mut Value), fingerprint: Fingerprint, /// For panic messages only. Not used for comparison. #[cfg(feature = "unstable-debug")] type_name: &'static str, } union Value { ptr: *mut (), inline: [MaybeUninit; 2], } fn is_small() -> bool { cfg!(not(no_maybe_uninit)) && mem::size_of::() <= mem::size_of::() && mem::align_of::() <= mem::align_of::() } impl Any { // This is unsafe -- caller must not hold on to the Any beyond the lifetime // of T. // // Example of bad code: // // let s = "bad".to_owned(); // let a = Any::new(&s); // drop(s); // // Now `a.view()` and `a.take()` return references to a dead String. pub(crate) unsafe fn new(t: T) -> Self { let value: Value; let drop: unsafe fn(&mut Value); let fingerprint = Fingerprint::of::(); if is_small::() { let mut inline = [MaybeUninit::uninit(); 2]; unsafe { ptr::write(inline.as_mut_ptr() as *mut T, t) }; value = Value { inline }; unsafe fn inline_drop(value: &mut Value) { unsafe { ptr::drop_in_place(value.inline.as_mut_ptr() as *mut T) } } drop = inline_drop::; } else { let ptr = Box::into_raw(Box::new(t)) as *mut (); value = Value { ptr }; unsafe fn ptr_drop(value: &mut Value) { mem::drop(unsafe { Box::from_raw(value.ptr as *mut T) }); } drop = ptr_drop::; }; // Once attributes on struct literal fields are stable, do that instead. // https://github.com/rust-lang/rust/issues/41681 #[cfg(not(feature = "unstable-debug"))] { Any { value, drop, fingerprint, } } #[cfg(feature = "unstable-debug")] { let type_name = any::type_name::(); Any { value, drop, fingerprint, type_name, } } } // This is unsafe -- caller is responsible that T is the correct type. pub(crate) unsafe fn view(&mut self) -> &mut T { if cfg!(not(miri)) && self.fingerprint != Fingerprint::of::() { self.invalid_cast_to::(); } let ptr = if is_small::() { unsafe { self.value.inline.as_mut_ptr() as *mut T } } else { unsafe { self.value.ptr as *mut T } }; unsafe { &mut *ptr } } // This is unsafe -- caller is responsible that T is the correct type. pub(crate) unsafe fn take(mut self) -> T { if cfg!(not(miri)) && self.fingerprint != Fingerprint::of::() { self.invalid_cast_to::(); } if is_small::() { let ptr = unsafe { self.value.inline.as_mut_ptr() as *mut T }; let value = unsafe { ptr::read(ptr) }; mem::forget(self); value } else { let ptr = unsafe { self.value.ptr as *mut T }; let box_t = unsafe { Box::from_raw(ptr) }; mem::forget(self); *box_t } } #[cfg(not(feature = "unstable-debug"))] fn invalid_cast_to(&self) -> ! { panic!("invalid cast; enable `unstable-debug` feature to debug"); } #[cfg(feature = "unstable-debug")] fn invalid_cast_to(&self) -> ! { let from = self.type_name; let to = any::type_name::(); panic!("invalid cast: {} to {}", from, to); } } impl Drop for Any { fn drop(&mut self) { unsafe { (self.drop)(&mut self.value) } } } #[cfg(no_maybe_uninit)] #[derive(Copy, Clone)] struct MaybeUninit(PhantomData); #[cfg(no_maybe_uninit)] impl MaybeUninit { fn uninit() -> Self { MaybeUninit(PhantomData) } } #[derive(Debug, Eq, PartialEq)] struct Fingerprint { size: usize, align: usize, #[cfg(include_fnptr_in_fingerprint)] id: usize, } impl Fingerprint { fn of() -> Fingerprint { Fingerprint { size: mem::size_of::(), align: mem::align_of::(), // This is not foolproof -- theoretically Rust or LLVM could // deduplicate some or all of these methods. But in practice it's // great in debug mode when running our own test suite for catching // bugs early. #[cfg(include_fnptr_in_fingerprint)] id: Fingerprint::of:: as usize, } } } #[test] fn test_fingerprint() { assert_eq!(Fingerprint::of::(), Fingerprint::of::()); assert_eq!(Fingerprint::of::<&str>(), Fingerprint::of::<&'static str>()); assert_ne!(Fingerprint::of::(), Fingerprint::of::<[u8; 4]>()); assert_ne!(Fingerprint::of::(), Fingerprint::of::<[u32; 2]>()); if cfg!(all(include_fnptr_in_fingerprint, not(miri))) { assert_ne!(Fingerprint::of::(), Fingerprint::of::()); assert_ne!(Fingerprint::of::(), Fingerprint::of::<&usize>()); assert_ne!(Fingerprint::of::<&usize>(), Fingerprint::of::<&&usize>()); assert_ne!(Fingerprint::of::<&usize>(), Fingerprint::of::<&mut usize>()); struct A; struct B; assert_ne!(Fingerprint::of::(), Fingerprint::of::()); } } erased-serde-0.3.23/src/de.rs000064400000000000000000001605371046102023000140150ustar 00000000000000use crate::alloc::*; use crate::any::Any; use crate::error::Error; use crate::map::{OptionExt, ResultExt}; use core::fmt::{self, Display}; use serde::serde_if_integer128; /// Deserialize a value of type `T` from the given trait object. /// /// ```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"]); /// } /// ``` pub fn deserialize<'de, T>(deserializer: &mut dyn Deserializer<'de>) -> Result where T: serde::Deserialize<'de>, { serde::Deserialize::deserialize(deserializer) } // TRAITS ////////////////////////////////////////////////////////////////////// pub trait DeserializeSeed<'de> { fn erased_deserialize_seed(&mut self, d: &mut dyn Deserializer<'de>) -> Result; } /// An object-safe equivalent of Serde's `Deserializer` trait. /// /// Any implementation of Serde's `Deserializer` can be converted to an /// `&erased_serde::Deserializer` or `Box` trait /// object using `erased_serde::Deserializer::erase`. /// /// ```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"]); /// } /// ``` pub trait Deserializer<'de> { fn erased_deserialize_any(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_bool(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_u8(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_u16(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_u32(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_u64(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_i8(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_i16(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_i32(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_i64(&mut self, v: &mut dyn Visitor<'de>) -> Result; serde_if_integer128! { fn erased_deserialize_i128(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_u128(&mut self, v: &mut dyn Visitor<'de>) -> Result; } fn erased_deserialize_f32(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_f64(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_char(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_str(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_string(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_bytes(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_byte_buf(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_option(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_unit(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_unit_struct( &mut self, name: &'static str, v: &mut dyn Visitor<'de>, ) -> Result; fn erased_deserialize_newtype_struct( &mut self, name: &'static str, v: &mut dyn Visitor<'de>, ) -> Result; fn erased_deserialize_seq(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_tuple( &mut self, len: usize, v: &mut dyn Visitor<'de>, ) -> Result; fn erased_deserialize_tuple_struct( &mut self, name: &'static str, len: usize, v: &mut dyn Visitor<'de>, ) -> Result; fn erased_deserialize_map(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_struct( &mut self, name: &'static str, fields: &'static [&'static str], v: &mut dyn Visitor<'de>, ) -> Result; fn erased_deserialize_identifier(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_deserialize_enum( &mut self, name: &'static str, variants: &'static [&'static str], v: &mut dyn Visitor<'de>, ) -> Result; fn erased_deserialize_ignored_any(&mut self, v: &mut dyn Visitor<'de>) -> Result; fn erased_is_human_readable(&self) -> bool; } pub trait Visitor<'de> { fn erased_expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result; fn erased_visit_bool(&mut self, v: bool) -> Result; fn erased_visit_i8(&mut self, v: i8) -> Result; fn erased_visit_i16(&mut self, v: i16) -> Result; fn erased_visit_i32(&mut self, v: i32) -> Result; fn erased_visit_i64(&mut self, v: i64) -> Result; fn erased_visit_u8(&mut self, v: u8) -> Result; fn erased_visit_u16(&mut self, v: u16) -> Result; fn erased_visit_u32(&mut self, v: u32) -> Result; fn erased_visit_u64(&mut self, v: u64) -> Result; serde_if_integer128! { fn erased_visit_i128(&mut self, v: i128) -> Result; fn erased_visit_u128(&mut self, v: u128) -> Result; } fn erased_visit_f32(&mut self, v: f32) -> Result; fn erased_visit_f64(&mut self, v: f64) -> Result; fn erased_visit_char(&mut self, v: char) -> Result; fn erased_visit_str(&mut self, v: &str) -> Result; fn erased_visit_borrowed_str(&mut self, v: &'de str) -> Result; #[cfg(any(feature = "std", feature = "alloc"))] fn erased_visit_string(&mut self, v: String) -> Result; fn erased_visit_bytes(&mut self, v: &[u8]) -> Result; fn erased_visit_borrowed_bytes(&mut self, v: &'de [u8]) -> Result; #[cfg(any(feature = "std", feature = "alloc"))] fn erased_visit_byte_buf(&mut self, v: Vec) -> Result; fn erased_visit_none(&mut self) -> Result; fn erased_visit_some(&mut self, d: &mut dyn Deserializer<'de>) -> Result; fn erased_visit_unit(&mut self) -> Result; fn erased_visit_newtype_struct(&mut self, d: &mut dyn Deserializer<'de>) -> Result; fn erased_visit_seq(&mut self, s: &mut dyn SeqAccess<'de>) -> Result; fn erased_visit_map(&mut self, m: &mut dyn MapAccess<'de>) -> Result; fn erased_visit_enum(&mut self, e: &mut dyn EnumAccess<'de>) -> Result; } pub trait SeqAccess<'de> { fn erased_next_element( &mut self, d: &mut dyn DeserializeSeed<'de>, ) -> Result, Error>; fn erased_size_hint(&self) -> Option; } pub trait MapAccess<'de> { fn erased_next_key(&mut self, d: &mut dyn DeserializeSeed<'de>) -> Result, Error>; fn erased_next_value(&mut self, d: &mut dyn DeserializeSeed<'de>) -> Result; fn erased_next_entry( &mut self, key: &mut dyn DeserializeSeed<'de>, value: &mut dyn DeserializeSeed<'de>, ) -> Result, Error>; fn erased_size_hint(&self) -> Option; } pub trait EnumAccess<'de> { fn erased_variant_seed( &mut self, d: &mut dyn DeserializeSeed<'de>, ) -> Result<(Out, Variant<'de>), Error>; } impl<'de> dyn Deserializer<'de> { /// Convert any Serde `Deserializer` to a trait object. /// /// ```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"]); /// } /// ``` pub fn erase(deserializer: D) -> erase::Deserializer where D: serde::Deserializer<'de>, { erase::Deserializer { state: Some(deserializer), } } } // OUT ///////////////////////////////////////////////////////////////////////// pub struct Out(Any); impl Out { unsafe fn new(t: T) -> Self { Out(unsafe { Any::new(t) }) } unsafe fn take(self) -> T { unsafe { self.0.take() } } } // IMPL ERASED SERDE FOR SERDE ///////////////////////////////////////////////// mod erase { pub struct DeserializeSeed { pub(crate) state: Option, } impl DeserializeSeed { pub(crate) fn take(&mut self) -> D { self.state.take().unwrap() } } pub struct Deserializer { pub(crate) state: Option, } impl Deserializer { pub(crate) fn take(&mut self) -> D { self.state.take().unwrap() } pub(crate) fn as_ref(&self) -> &D { self.state.as_ref().unwrap() } } pub struct Visitor { pub(crate) state: Option, } impl Visitor { pub(crate) fn take(&mut self) -> D { self.state.take().unwrap() } pub(crate) fn as_ref(&self) -> &D { self.state.as_ref().unwrap() } } pub struct SeqAccess { pub(crate) state: D, } impl SeqAccess { pub(crate) fn as_ref(&self) -> &D { &self.state } pub(crate) fn as_mut(&mut self) -> &mut D { &mut self.state } } pub struct MapAccess { pub(crate) state: D, } impl MapAccess { pub(crate) fn as_ref(&self) -> &D { &self.state } pub(crate) fn as_mut(&mut self) -> &mut D { &mut self.state } } pub struct EnumAccess { pub(crate) state: Option, } impl EnumAccess { pub(crate) fn take(&mut self) -> D { self.state.take().unwrap() } } } impl<'de, T> DeserializeSeed<'de> for erase::DeserializeSeed where T: serde::de::DeserializeSeed<'de>, { fn erased_deserialize_seed( &mut self, deserializer: &mut dyn Deserializer<'de>, ) -> Result { unsafe { self.take().deserialize(deserializer).unsafe_map(Out::new) } } } impl<'de, T> Deserializer<'de> for erase::Deserializer where T: serde::Deserializer<'de>, { fn erased_deserialize_any(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_any(visitor).map_err(erase) } fn erased_deserialize_bool(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_bool(visitor).map_err(erase) } fn erased_deserialize_u8(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_u8(visitor).map_err(erase) } fn erased_deserialize_u16(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_u16(visitor).map_err(erase) } fn erased_deserialize_u32(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_u32(visitor).map_err(erase) } fn erased_deserialize_u64(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_u64(visitor).map_err(erase) } fn erased_deserialize_i8(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_i8(visitor).map_err(erase) } fn erased_deserialize_i16(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_i16(visitor).map_err(erase) } fn erased_deserialize_i32(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_i32(visitor).map_err(erase) } fn erased_deserialize_i64(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_i64(visitor).map_err(erase) } serde_if_integer128! { fn erased_deserialize_i128(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_i128(visitor).map_err(erase) } fn erased_deserialize_u128(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_u128(visitor).map_err(erase) } } fn erased_deserialize_f32(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_f32(visitor).map_err(erase) } fn erased_deserialize_f64(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_f64(visitor).map_err(erase) } fn erased_deserialize_char(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_char(visitor).map_err(erase) } fn erased_deserialize_str(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_str(visitor).map_err(erase) } fn erased_deserialize_string(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_string(visitor).map_err(erase) } fn erased_deserialize_bytes(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_bytes(visitor).map_err(erase) } fn erased_deserialize_byte_buf( &mut self, visitor: &mut dyn Visitor<'de>, ) -> Result { self.take().deserialize_byte_buf(visitor).map_err(erase) } fn erased_deserialize_option(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_option(visitor).map_err(erase) } fn erased_deserialize_unit(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_unit(visitor).map_err(erase) } fn erased_deserialize_unit_struct( &mut self, name: &'static str, visitor: &mut dyn Visitor<'de>, ) -> Result { self.take() .deserialize_unit_struct(name, visitor) .map_err(erase) } fn erased_deserialize_newtype_struct( &mut self, name: &'static str, visitor: &mut dyn Visitor<'de>, ) -> Result { self.take() .deserialize_newtype_struct(name, visitor) .map_err(erase) } fn erased_deserialize_seq(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_seq(visitor).map_err(erase) } fn erased_deserialize_tuple( &mut self, len: usize, visitor: &mut dyn Visitor<'de>, ) -> Result { self.take().deserialize_tuple(len, visitor).map_err(erase) } fn erased_deserialize_tuple_struct( &mut self, name: &'static str, len: usize, visitor: &mut dyn Visitor<'de>, ) -> Result { self.take() .deserialize_tuple_struct(name, len, visitor) .map_err(erase) } fn erased_deserialize_map(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { self.take().deserialize_map(visitor).map_err(erase) } fn erased_deserialize_struct( &mut self, name: &'static str, fields: &'static [&'static str], visitor: &mut dyn Visitor<'de>, ) -> Result { self.take() .deserialize_struct(name, fields, visitor) .map_err(erase) } fn erased_deserialize_identifier( &mut self, visitor: &mut dyn Visitor<'de>, ) -> Result { self.take().deserialize_identifier(visitor).map_err(erase) } fn erased_deserialize_enum( &mut self, name: &'static str, variants: &'static [&'static str], visitor: &mut dyn Visitor<'de>, ) -> Result { self.take() .deserialize_enum(name, variants, visitor) .map_err(erase) } fn erased_deserialize_ignored_any( &mut self, visitor: &mut dyn Visitor<'de>, ) -> Result { self.take().deserialize_ignored_any(visitor).map_err(erase) } fn erased_is_human_readable(&self) -> bool { self.as_ref().is_human_readable() } } impl<'de, T> Visitor<'de> for erase::Visitor where T: serde::de::Visitor<'de>, { fn erased_expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { self.as_ref().expecting(formatter) } fn erased_visit_bool(&mut self, v: bool) -> Result { unsafe { self.take().visit_bool(v).unsafe_map(Out::new) } } fn erased_visit_i8(&mut self, v: i8) -> Result { unsafe { self.take().visit_i8(v).unsafe_map(Out::new) } } fn erased_visit_i16(&mut self, v: i16) -> Result { unsafe { self.take().visit_i16(v).unsafe_map(Out::new) } } fn erased_visit_i32(&mut self, v: i32) -> Result { unsafe { self.take().visit_i32(v).unsafe_map(Out::new) } } fn erased_visit_i64(&mut self, v: i64) -> Result { unsafe { self.take().visit_i64(v).unsafe_map(Out::new) } } fn erased_visit_u8(&mut self, v: u8) -> Result { unsafe { self.take().visit_u8(v).unsafe_map(Out::new) } } fn erased_visit_u16(&mut self, v: u16) -> Result { unsafe { self.take().visit_u16(v).unsafe_map(Out::new) } } fn erased_visit_u32(&mut self, v: u32) -> Result { unsafe { self.take().visit_u32(v).unsafe_map(Out::new) } } fn erased_visit_u64(&mut self, v: u64) -> Result { unsafe { self.take().visit_u64(v).unsafe_map(Out::new) } } serde_if_integer128! { fn erased_visit_i128(&mut self, v: i128) -> Result { unsafe { self.take().visit_i128(v).unsafe_map(Out::new) } } fn erased_visit_u128(&mut self, v: u128) -> Result { unsafe { self.take().visit_u128(v).unsafe_map(Out::new) } } } fn erased_visit_f32(&mut self, v: f32) -> Result { unsafe { self.take().visit_f32(v).unsafe_map(Out::new) } } fn erased_visit_f64(&mut self, v: f64) -> Result { unsafe { self.take().visit_f64(v).unsafe_map(Out::new) } } fn erased_visit_char(&mut self, v: char) -> Result { unsafe { self.take().visit_char(v).unsafe_map(Out::new) } } fn erased_visit_str(&mut self, v: &str) -> Result { unsafe { self.take().visit_str(v).unsafe_map(Out::new) } } fn erased_visit_borrowed_str(&mut self, v: &'de str) -> Result { unsafe { self.take().visit_borrowed_str(v).unsafe_map(Out::new) } } #[cfg(any(feature = "std", feature = "alloc"))] fn erased_visit_string(&mut self, v: String) -> Result { unsafe { self.take().visit_string(v).unsafe_map(Out::new) } } fn erased_visit_bytes(&mut self, v: &[u8]) -> Result { unsafe { self.take().visit_bytes(v).unsafe_map(Out::new) } } fn erased_visit_borrowed_bytes(&mut self, v: &'de [u8]) -> Result { unsafe { self.take().visit_borrowed_bytes(v).unsafe_map(Out::new) } } #[cfg(any(feature = "std", feature = "alloc"))] fn erased_visit_byte_buf(&mut self, v: Vec) -> Result { unsafe { self.take().visit_byte_buf(v).unsafe_map(Out::new) } } fn erased_visit_none(&mut self) -> Result { unsafe { self.take().visit_none().unsafe_map(Out::new) } } fn erased_visit_some( &mut self, deserializer: &mut dyn Deserializer<'de>, ) -> Result { unsafe { self.take().visit_some(deserializer).unsafe_map(Out::new) } } fn erased_visit_unit(&mut self) -> Result { unsafe { self.take().visit_unit().unsafe_map(Out::new) } } fn erased_visit_newtype_struct( &mut self, deserializer: &mut dyn Deserializer<'de>, ) -> Result { unsafe { self.take() .visit_newtype_struct(deserializer) .unsafe_map(Out::new) } } fn erased_visit_seq(&mut self, seq: &mut dyn SeqAccess<'de>) -> Result { unsafe { self.take().visit_seq(seq).unsafe_map(Out::new) } } fn erased_visit_map(&mut self, map: &mut dyn MapAccess<'de>) -> Result { unsafe { self.take().visit_map(map).unsafe_map(Out::new) } } fn erased_visit_enum(&mut self, data: &mut dyn EnumAccess<'de>) -> Result { unsafe { self.take().visit_enum(data).unsafe_map(Out::new) } } } impl<'de, T> SeqAccess<'de> for erase::SeqAccess where T: serde::de::SeqAccess<'de>, { fn erased_next_element( &mut self, seed: &mut dyn DeserializeSeed<'de>, ) -> Result, Error> { self.as_mut().next_element_seed(seed).map_err(erase) } fn erased_size_hint(&self) -> Option { self.as_ref().size_hint() } } impl<'de, T> MapAccess<'de> for erase::MapAccess where T: serde::de::MapAccess<'de>, { fn erased_next_key( &mut self, seed: &mut dyn DeserializeSeed<'de>, ) -> Result, Error> { self.as_mut().next_key_seed(seed).map_err(erase) } fn erased_next_value(&mut self, seed: &mut dyn DeserializeSeed<'de>) -> Result { self.as_mut().next_value_seed(seed).map_err(erase) } fn erased_next_entry( &mut self, k: &mut dyn DeserializeSeed<'de>, v: &mut dyn DeserializeSeed<'de>, ) -> Result, Error> { self.as_mut().next_entry_seed(k, v).map_err(erase) } fn erased_size_hint(&self) -> Option { self.as_ref().size_hint() } } impl<'de, T> EnumAccess<'de> for erase::EnumAccess where T: serde::de::EnumAccess<'de>, { fn erased_variant_seed( &mut self, seed: &mut dyn DeserializeSeed<'de>, ) -> Result<(Out, Variant<'de>), Error> { self.take() .variant_seed(seed) .map(|(out, variant)| { use serde::de::VariantAccess; let erased = Variant { data: unsafe { Any::new(variant) }, unit_variant: { unsafe fn unit_variant<'de, T>(a: Any) -> Result<(), Error> where T: serde::de::EnumAccess<'de>, { unsafe { a.take::().unit_variant().map_err(erase) } } unit_variant:: }, visit_newtype: { unsafe fn visit_newtype<'de, T>( a: Any, seed: &mut dyn DeserializeSeed<'de>, ) -> Result where T: serde::de::EnumAccess<'de>, { unsafe { a.take::() .newtype_variant_seed(seed) .map_err(erase) } } visit_newtype:: }, tuple_variant: { unsafe fn tuple_variant<'de, T>( a: Any, len: usize, visitor: &mut dyn Visitor<'de>, ) -> Result where T: serde::de::EnumAccess<'de>, { unsafe { a.take::() .tuple_variant(len, visitor) .map_err(erase) } } tuple_variant:: }, struct_variant: { unsafe fn struct_variant<'de, T>( a: Any, fields: &'static [&'static str], visitor: &mut dyn Visitor<'de>, ) -> Result where T: serde::de::EnumAccess<'de>, { unsafe { a.take::() .struct_variant(fields, visitor) .map_err(erase) } } struct_variant:: }, }; (out, erased) }) .map_err(erase) } } // IMPL SERDE FOR ERASED SERDE ///////////////////////////////////////////////// impl<'de, 'a> serde::de::DeserializeSeed<'de> for &'a mut dyn DeserializeSeed<'de> { type Value = Out; fn deserialize(self, deserializer: D) -> Result where D: serde::Deserializer<'de>, { let mut erased = erase::Deserializer { state: Some(deserializer), }; self.erased_deserialize_seed(&mut erased).map_err(unerase) } } macro_rules! impl_deserializer_for_trait_object { ({$($generics:tt)*} {$($mut:tt)*} $ty:ty) => { impl <$($generics)*> serde::Deserializer<'de> for $ty { type Error = Error; fn deserialize_any($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_any(&mut erased).unsafe_map(Out::take) } } fn deserialize_bool($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_bool(&mut erased).unsafe_map(Out::take) } } fn deserialize_u8($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_u8(&mut erased).unsafe_map(Out::take) } } fn deserialize_u16($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_u16(&mut erased).unsafe_map(Out::take) } } fn deserialize_u32($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_u32(&mut erased).unsafe_map(Out::take) } } fn deserialize_u64($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_u64(&mut erased).unsafe_map(Out::take) } } fn deserialize_i8($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_i8(&mut erased).unsafe_map(Out::take) } } fn deserialize_i16($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_i16(&mut erased).unsafe_map(Out::take) } } fn deserialize_i32($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_i32(&mut erased).unsafe_map(Out::take) } } fn deserialize_i64($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_i64(&mut erased).unsafe_map(Out::take) } } serde_if_integer128! { fn deserialize_i128($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_i128(&mut erased).unsafe_map(Out::take) } } fn deserialize_u128($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_u128(&mut erased).unsafe_map(Out::take) } } } fn deserialize_f32($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_f32(&mut erased).unsafe_map(Out::take) } } fn deserialize_f64($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_f64(&mut erased).unsafe_map(Out::take) } } fn deserialize_char($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_char(&mut erased).unsafe_map(Out::take) } } fn deserialize_str($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_str(&mut erased).unsafe_map(Out::take) } } fn deserialize_string($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_string(&mut erased).unsafe_map(Out::take) } } fn deserialize_bytes($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_bytes(&mut erased).unsafe_map(Out::take) } } fn deserialize_byte_buf($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_byte_buf(&mut erased).unsafe_map(Out::take) } } fn deserialize_option($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_option(&mut erased).unsafe_map(Out::take) } } fn deserialize_unit($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_unit(&mut erased).unsafe_map(Out::take) } } fn deserialize_unit_struct($($mut)* self, name: &'static str, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_unit_struct(name, &mut erased).unsafe_map(Out::take) } } fn deserialize_newtype_struct($($mut)* self, name: &'static str, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_newtype_struct(name, &mut erased).unsafe_map(Out::take) } } fn deserialize_seq($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_seq(&mut erased).unsafe_map(Out::take) } } fn deserialize_tuple($($mut)* self, len: usize, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_tuple(len, &mut erased).unsafe_map(Out::take) } } fn deserialize_tuple_struct($($mut)* self, name: &'static str, len: usize, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_tuple_struct(name, len, &mut erased).unsafe_map(Out::take) } } fn deserialize_map($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_map(&mut erased).unsafe_map(Out::take) } } fn deserialize_struct($($mut)* self, name: &'static str, fields: &'static [&'static str], visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_struct(name, fields, &mut erased).unsafe_map(Out::take) } } fn deserialize_identifier($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_identifier(&mut erased).unsafe_map(Out::take) } } fn deserialize_enum($($mut)* self, name: &'static str, variants: &'static [&'static str], visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_enum(name, variants, &mut erased).unsafe_map(Out::take) } } fn deserialize_ignored_any($($mut)* self, visitor: V) -> Result where V: serde::de::Visitor<'de> { let mut erased = erase::Visitor { state: Some(visitor) }; unsafe { self.erased_deserialize_ignored_any(&mut erased).unsafe_map(Out::take) } } fn is_human_readable(&self) -> bool { self.erased_is_human_readable() } } }; } impl_deserializer_for_trait_object!({'de, 'a} {} &'a mut dyn Deserializer<'de>); impl_deserializer_for_trait_object!({'de, 'a} {} &'a mut (dyn Deserializer<'de> + Send)); impl_deserializer_for_trait_object!({'de, 'a} {} &'a mut (dyn Deserializer<'de> + Sync)); impl_deserializer_for_trait_object!({'de, 'a} {} &'a mut (dyn Deserializer<'de> + Send + Sync)); impl_deserializer_for_trait_object!({'de} {mut} Box>); impl_deserializer_for_trait_object!({'de} {mut} Box + Send>); impl_deserializer_for_trait_object!({'de} {mut} Box + Sync>); impl_deserializer_for_trait_object!({'de} {mut} Box + Send + Sync>); impl<'de, 'a> serde::de::Visitor<'de> for &'a mut dyn Visitor<'de> { type Value = Out; fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { (**self).erased_expecting(formatter) } fn visit_bool(self, v: bool) -> Result where E: serde::de::Error, { self.erased_visit_bool(v).map_err(unerase) } fn visit_i8(self, v: i8) -> Result where E: serde::de::Error, { self.erased_visit_i8(v).map_err(unerase) } fn visit_i16(self, v: i16) -> Result where E: serde::de::Error, { self.erased_visit_i16(v).map_err(unerase) } fn visit_i32(self, v: i32) -> Result where E: serde::de::Error, { self.erased_visit_i32(v).map_err(unerase) } fn visit_i64(self, v: i64) -> Result where E: serde::de::Error, { self.erased_visit_i64(v).map_err(unerase) } fn visit_u8(self, v: u8) -> Result where E: serde::de::Error, { self.erased_visit_u8(v).map_err(unerase) } fn visit_u16(self, v: u16) -> Result where E: serde::de::Error, { self.erased_visit_u16(v).map_err(unerase) } fn visit_u32(self, v: u32) -> Result where E: serde::de::Error, { self.erased_visit_u32(v).map_err(unerase) } fn visit_u64(self, v: u64) -> Result where E: serde::de::Error, { self.erased_visit_u64(v).map_err(unerase) } serde_if_integer128! { fn visit_i128(self, v: i128) -> Result where E: serde::de::Error { self.erased_visit_i128(v).map_err(unerase) } fn visit_u128(self, v: u128) -> Result where E: serde::de::Error { self.erased_visit_u128(v).map_err(unerase) } } fn visit_f32(self, v: f32) -> Result where E: serde::de::Error, { self.erased_visit_f32(v).map_err(unerase) } fn visit_f64(self, v: f64) -> Result where E: serde::de::Error, { self.erased_visit_f64(v).map_err(unerase) } fn visit_char(self, v: char) -> Result where E: serde::de::Error, { self.erased_visit_char(v).map_err(unerase) } fn visit_str(self, v: &str) -> Result where E: serde::de::Error, { self.erased_visit_str(v).map_err(unerase) } fn visit_borrowed_str(self, v: &'de str) -> Result where E: serde::de::Error, { self.erased_visit_borrowed_str(v).map_err(unerase) } #[cfg(any(feature = "std", feature = "alloc"))] fn visit_string(self, v: String) -> Result where E: serde::de::Error, { self.erased_visit_string(v).map_err(unerase) } fn visit_bytes(self, v: &[u8]) -> Result where E: serde::de::Error, { self.erased_visit_bytes(v).map_err(unerase) } fn visit_borrowed_bytes(self, v: &'de [u8]) -> Result where E: serde::de::Error, { self.erased_visit_borrowed_bytes(v).map_err(unerase) } #[cfg(any(feature = "std", feature = "alloc"))] fn visit_byte_buf(self, v: Vec) -> Result where E: serde::de::Error, { self.erased_visit_byte_buf(v).map_err(unerase) } fn visit_none(self) -> Result where E: serde::de::Error, { self.erased_visit_none().map_err(unerase) } fn visit_some(self, deserializer: D) -> Result where D: serde::Deserializer<'de>, { let mut erased = erase::Deserializer { state: Some(deserializer), }; self.erased_visit_some(&mut erased).map_err(unerase) } fn visit_unit(self) -> Result where E: serde::de::Error, { self.erased_visit_unit().map_err(unerase) } fn visit_newtype_struct(self, deserializer: D) -> Result where D: serde::Deserializer<'de>, { let mut erased = erase::Deserializer { state: Some(deserializer), }; self.erased_visit_newtype_struct(&mut erased) .map_err(unerase) } fn visit_seq(self, seq: V) -> Result where V: serde::de::SeqAccess<'de>, { let mut erased = erase::SeqAccess { state: seq }; self.erased_visit_seq(&mut erased).map_err(unerase) } fn visit_map(self, map: V) -> Result where V: serde::de::MapAccess<'de>, { let mut erased = erase::MapAccess { state: map }; self.erased_visit_map(&mut erased).map_err(unerase) } fn visit_enum(self, data: V) -> Result where V: serde::de::EnumAccess<'de>, { let mut erased = erase::EnumAccess { state: Some(data) }; self.erased_visit_enum(&mut erased).map_err(unerase) } } impl<'de, 'a> serde::de::SeqAccess<'de> for &'a mut dyn SeqAccess<'de> { type Error = Error; fn next_element_seed(&mut self, seed: T) -> Result, Error> where T: serde::de::DeserializeSeed<'de>, { let mut seed = erase::DeserializeSeed { state: Some(seed) }; unsafe { (**self) .erased_next_element(&mut seed) .map(|opt| opt.unsafe_map(Out::take)) } } fn size_hint(&self) -> Option { (**self).erased_size_hint() } } impl<'de, 'a> serde::de::MapAccess<'de> for &'a mut dyn MapAccess<'de> { type Error = Error; fn next_key_seed(&mut self, seed: K) -> Result, Error> where K: serde::de::DeserializeSeed<'de>, { let mut erased = erase::DeserializeSeed { state: Some(seed) }; unsafe { (**self) .erased_next_key(&mut erased) .map(|opt| opt.unsafe_map(Out::take)) } } fn next_value_seed(&mut self, seed: V) -> Result where V: serde::de::DeserializeSeed<'de>, { let mut erased = erase::DeserializeSeed { state: Some(seed) }; unsafe { (**self) .erased_next_value(&mut erased) .unsafe_map(Out::take) } } fn size_hint(&self) -> Option { (**self).erased_size_hint() } } impl<'de, 'a> serde::de::EnumAccess<'de> for &'a mut dyn EnumAccess<'de> { type Error = Error; type Variant = Variant<'de>; fn variant_seed(self, seed: V) -> Result<(V::Value, Self::Variant), Self::Error> where V: serde::de::DeserializeSeed<'de>, { let mut erased = erase::DeserializeSeed { state: Some(seed) }; match self.erased_variant_seed(&mut erased) { Ok((out, variant)) => Ok((unsafe { out.take() }, variant)), Err(err) => Err(err), } } } pub struct Variant<'de> { data: Any, unit_variant: unsafe fn(Any) -> Result<(), Error>, visit_newtype: unsafe fn(Any, seed: &mut dyn DeserializeSeed<'de>) -> Result, tuple_variant: unsafe fn(Any, len: usize, visitor: &mut dyn Visitor<'de>) -> Result, struct_variant: unsafe fn( Any, fields: &'static [&'static str], visitor: &mut dyn Visitor<'de>, ) -> Result, } impl<'de> serde::de::VariantAccess<'de> for Variant<'de> { type Error = Error; fn unit_variant(self) -> Result<(), Error> { unsafe { (self.unit_variant)(self.data) } } fn newtype_variant_seed(self, seed: T) -> Result where T: serde::de::DeserializeSeed<'de>, { let mut erased = erase::DeserializeSeed { state: Some(seed) }; unsafe { (self.visit_newtype)(self.data, &mut erased).unsafe_map(Out::take) } } fn tuple_variant(self, len: usize, visitor: V) -> Result where V: serde::de::Visitor<'de>, { let mut erased = erase::Visitor { state: Some(visitor), }; unsafe { (self.tuple_variant)(self.data, len, &mut erased).unsafe_map(Out::take) } } fn struct_variant( self, fields: &'static [&'static str], visitor: V, ) -> Result where V: serde::de::Visitor<'de>, { let mut erased = erase::Visitor { state: Some(visitor), }; unsafe { (self.struct_variant)(self.data, fields, &mut erased).unsafe_map(Out::take) } } } // IMPL ERASED SERDE FOR ERASED SERDE ////////////////////////////////////////// macro_rules! deref_erased_deserializer { ($($imp:tt)+) => { impl $($imp)+ { fn erased_deserialize_any(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_any(visitor) } fn erased_deserialize_bool(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_bool(visitor) } fn erased_deserialize_u8(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_u8(visitor) } fn erased_deserialize_u16(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_u16(visitor) } fn erased_deserialize_u32(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_u32(visitor) } fn erased_deserialize_u64(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_u64(visitor) } fn erased_deserialize_i8(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_i8(visitor) } fn erased_deserialize_i16(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_i16(visitor) } fn erased_deserialize_i32(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_i32(visitor) } fn erased_deserialize_i64(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_i64(visitor) } serde_if_integer128! { fn erased_deserialize_i128(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_i128(visitor) } fn erased_deserialize_u128(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_u128(visitor) } } fn erased_deserialize_f32(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_f32(visitor) } fn erased_deserialize_f64(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_f64(visitor) } fn erased_deserialize_char(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_char(visitor) } fn erased_deserialize_str(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_str(visitor) } fn erased_deserialize_string(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_string(visitor) } fn erased_deserialize_bytes(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_bytes(visitor) } fn erased_deserialize_byte_buf(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_byte_buf(visitor) } fn erased_deserialize_option(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_option(visitor) } fn erased_deserialize_unit(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_unit(visitor) } fn erased_deserialize_unit_struct(&mut self, name: &'static str, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_unit_struct(name, visitor) } fn erased_deserialize_newtype_struct(&mut self, name: &'static str, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_newtype_struct(name, visitor) } fn erased_deserialize_seq(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_seq(visitor) } fn erased_deserialize_tuple(&mut self, len: usize, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_tuple(len, visitor) } fn erased_deserialize_tuple_struct(&mut self, name: &'static str, len: usize, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_tuple_struct(name, len, visitor) } fn erased_deserialize_map(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_map(visitor) } fn erased_deserialize_struct(&mut self, name: &'static str, fields: &'static [&'static str], visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_struct(name, fields, visitor) } fn erased_deserialize_identifier(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_identifier(visitor) } fn erased_deserialize_enum(&mut self, name: &'static str, variants: &'static [&'static str], visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_enum(name, variants, visitor) } fn erased_deserialize_ignored_any(&mut self, visitor: &mut dyn Visitor<'de>) -> Result { (**self).erased_deserialize_ignored_any(visitor) } fn erased_is_human_readable(&self) -> bool { (**self).erased_is_human_readable() } } }; } deref_erased_deserializer!(<'de, 'a> Deserializer<'de> for Box + 'a>); deref_erased_deserializer!(<'de, 'a> Deserializer<'de> for Box + Send + 'a>); deref_erased_deserializer!(<'de, 'a> Deserializer<'de> for Box + Sync + 'a>); deref_erased_deserializer!(<'de, 'a> Deserializer<'de> for Box + Send + Sync + 'a>); deref_erased_deserializer!(<'de, 'a, T: ?Sized + Deserializer<'de>> Deserializer<'de> for &'a mut T); // ERROR /////////////////////////////////////////////////////////////////////// fn erase(e: E) -> Error where E: Display, { serde::de::Error::custom(e) } fn unerase(e: Error) -> E where E: serde::de::Error, { E::custom(e) } // TEST //////////////////////////////////////////////////////////////////////// #[cfg(test)] mod tests { use super::*; use crate::alloc::ToOwned; use core::fmt::Debug; use serde_derive::Deserialize; fn test_json<'de, T>(json: &'de [u8]) where T: serde::Deserialize<'de> + PartialEq + Debug, { let expected: T = serde_json::from_slice(json).unwrap(); // test borrowed trait object { let mut de = serde_json::Deserializer::from_slice(json); let de: &mut dyn Deserializer = &mut ::erase(&mut de); assert_eq!(expected, deserialize::(de).unwrap()); } // test boxed trait object { let mut de = serde_json::Deserializer::from_slice(json); let mut de: Box = Box::new(::erase(&mut de)); assert_eq!(expected, deserialize::(&mut de).unwrap()); } } #[test] fn test_value() { test_json::(br#"["a", 1, [true], {"a": 1}]"#); } #[test] fn test_struct() { #[derive(Deserialize, PartialEq, Debug)] struct S { f: usize, } test_json::(br#"{"f":256}"#); } #[test] fn test_enum() { #[derive(Deserialize, PartialEq, Debug)] enum E { Unit, Newtype(bool), Tuple(bool, bool), Struct { t: bool, f: bool }, } test_json::(br#""Unit""#); test_json::(br#"{"Newtype":true}"#); test_json::(br#"{"Tuple":[true,false]}"#); test_json::(br#"{"Struct":{"t":true,"f":false}}"#); } #[test] fn test_borrowed() { let bytes = br#""borrowed""#.to_owned(); test_json::<&str>(&bytes); } #[test] fn assert_deserializer() { fn assert<'de, T: serde::Deserializer<'de>>() {} assert::<&mut dyn Deserializer>(); assert::<&mut (dyn Deserializer + Send)>(); assert::<&mut (dyn Deserializer + Sync)>(); assert::<&mut (dyn Deserializer + Send + Sync)>(); assert::<&mut (dyn Deserializer + Sync + Send)>(); assert::>(); assert::>(); assert::>(); assert::>(); assert::>(); } } erased-serde-0.3.23/src/error.rs000064400000000000000000000014141046102023000145420ustar 00000000000000use crate::alloc::{String, ToString}; use core::fmt::{self, Display}; /// Error when a `Serializer` or `Deserializer` trait object fails. #[derive(Debug)] pub struct Error { msg: String, } /// Result type alias where the error is `erased_serde::Error`. pub type Result = core::result::Result; impl Display for Error { fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { self.msg.fmt(formatter) } } impl serde::ser::StdError for Error {} impl serde::ser::Error for Error { fn custom(msg: T) -> Self { Error { msg: msg.to_string(), } } } impl serde::de::Error for Error { fn custom(msg: T) -> Self { Error { msg: msg.to_string(), } } } erased-serde-0.3.23/src/features_check/error.rs000064400000000000000000000001221046102023000175100ustar 00000000000000"erased-serde requires that either `std` (default) or `alloc` feature is enabled" erased-serde-0.3.23/src/features_check/mod.rs000064400000000000000000000004151046102023000171430ustar 00000000000000//! Shows a user-friendly compiler error on incompatible selected features. #[allow(unused_macros)] macro_rules! hide_from_rustfmt { ($mod:item) => { $mod }; } #[cfg(not(any(feature = "std", feature = "alloc")))] hide_from_rustfmt! { mod error; } erased-serde-0.3.23/src/lib.rs000064400000000000000000000125321046102023000141620ustar 00000000000000//! [![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/0.3.23")] #![cfg_attr(not(feature = "std"), no_std)] #![cfg_attr(not(no_unsafe_op_in_unsafe_fn_lint), deny(unsafe_op_in_unsafe_fn))] #![cfg_attr(no_unsafe_op_in_unsafe_fn_lint, allow(unused_unsafe))] #![allow( clippy::derive_partial_eq_without_eq, 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::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; erased-serde-0.3.23/src/macros.rs000064400000000000000000000126361046102023000147050ustar 00000000000000/// Implement `serde::Serialize` for a trait object that has /// `erased_serde::Serialize` as a supertrait. /// /// ``` /// use erased_serde::serialize_trait_object; /// /// trait Event: erased_serde::Serialize { /// /* ... */ /// } /// /// erased_serde::serialize_trait_object!(Event); /// ``` /// /// The macro supports traits that have type parameters and/or `where` clauses. /// /// ``` /// # use erased_serde::serialize_trait_object; /// # /// trait Difficult: erased_serde::Serialize where T: Copy { /// /* ... */ /// } /// /// serialize_trait_object!( Difficult where T: Copy); /// ``` #[macro_export] macro_rules! serialize_trait_object { ($($path:tt)+) => { $crate::__internal_serialize_trait_object!(begin $($path)+); }; } #[doc(hidden)] #[macro_export] macro_rules! __internal_serialize_trait_object { // Invocation started with `<`, parse generics. (begin < $($rest:tt)*) => { $crate::__internal_serialize_trait_object!(generics () () $($rest)*); }; // Invocation did not start with `<`. (begin $first:tt $($rest:tt)*) => { $crate::__internal_serialize_trait_object!(path () ($first) $($rest)*); }; // End of generics with trailing comma. (generics ($($generics:tt)*) () , > $($rest:tt)*) => { $crate::__internal_serialize_trait_object!(path ($($generics)* ,) () $($rest)*); }; // End of generics without trailing comma. (generics ($($generics:tt)*) () > $($rest:tt)*) => { $crate::__internal_serialize_trait_object!(path ($($generics)* ,) () $($rest)*); }; // Generics open bracket. (generics ($($generics:tt)*) ($($brackets:tt)*) < $($rest:tt)*) => { $crate::__internal_serialize_trait_object!(generics ($($generics)* <) ($($brackets)* <) $($rest)*); }; // Generics close bracket. (generics ($($generics:tt)*) (< $($brackets:tt)*) > $($rest:tt)*) => { $crate::__internal_serialize_trait_object!(generics ($($generics)* >) ($($brackets)*) $($rest)*); }; // Token inside of generics. (generics ($($generics:tt)*) ($($brackets:tt)*) $first:tt $($rest:tt)*) => { $crate::__internal_serialize_trait_object!(generics ($($generics)* $first) ($($brackets)*) $($rest)*); }; // End with `where` clause. (path ($($generics:tt)*) ($($path:tt)*) where $($rest:tt)*) => { $crate::__internal_serialize_trait_object!(sendsync ($($generics)*) ($($path)*) ($($rest)*)); }; // End without `where` clause. (path ($($generics:tt)*) ($($path:tt)*)) => { $crate::__internal_serialize_trait_object!(sendsync ($($generics)*) ($($path)*) ()); }; // Token inside of path. (path ($($generics:tt)*) ($($path:tt)*) $first:tt $($rest:tt)*) => { $crate::__internal_serialize_trait_object!(path ($($generics)*) ($($path)* $first) $($rest)*); }; // Expand into four impls. (sendsync ($($generics:tt)*) ($($path:tt)*) ($($bound:tt)*)) => { $crate::__internal_serialize_trait_object!(impl ($($generics)*) ($($path)*) ($($bound)*) { fn __check_erased_serialize_supertrait<$($generics)* __T>() where __T: ?$crate::__private::Sized + $($path)*, $($bound)* { $crate::__private::require_erased_serialize_impl::<__T>(); } }); $crate::__internal_serialize_trait_object!(impl ($($generics)*) ($($path)* + $crate::__private::Send) ($($bound)*)); $crate::__internal_serialize_trait_object!(impl ($($generics)*) ($($path)* + $crate::__private::Sync) ($($bound)*)); $crate::__internal_serialize_trait_object!(impl ($($generics)*) ($($path)* + $crate::__private::Send + $crate::__private::Sync) ($($bound)*)); }; // The impl. (impl ($($generics:tt)*) ($($path:tt)*) ($($bound:tt)*) $({$($body:tt)*})*) => { impl<'erased, $($generics)*> $crate::__private::serde::Serialize for dyn $($path)* + 'erased where $($bound)* { fn serialize(&self, serializer: S) -> $crate::__private::Result where S: $crate::__private::serde::Serializer, { $($($body)*)* $crate::serialize(self, serializer) } } }; } // TEST //////////////////////////////////////////////////////////////////////// #[cfg(test)] mod tests { use crate::Serialize; fn assert_serialize() {} #[test] fn test_plain() { trait Trait: Serialize {} serialize_trait_object!(Trait); assert_serialize::(); assert_serialize::(); } #[test] fn test_type_parameter() { trait Trait: Serialize {} serialize_trait_object!( Trait); assert_serialize::>(); assert_serialize:: + Send>(); } #[test] fn test_generic_bound() { trait Trait, U>: Serialize {} serialize_trait_object!(, U> Trait); assert_serialize::>(); assert_serialize:: + Send>(); } #[test] fn test_where_clause() { trait Trait: Serialize where T: Clone, { } serialize_trait_object!( Trait where T: Clone); assert_serialize::>(); assert_serialize:: + Send>(); } } erased-serde-0.3.23/src/map.rs000064400000000000000000000012411046102023000141640ustar 00000000000000pub(crate) trait ResultExt { unsafe fn unsafe_map(self, op: unsafe fn(T) -> U) -> Result; } impl ResultExt for Result { unsafe fn unsafe_map(self, op: unsafe fn(T) -> U) -> Result { match self { Ok(t) => Ok(unsafe { op(t) }), Err(e) => Err(e), } } } pub(crate) trait OptionExt { unsafe fn unsafe_map(self, op: unsafe fn(T) -> U) -> Option; } impl OptionExt for Option { unsafe fn unsafe_map(self, op: unsafe fn(T) -> U) -> Option { match self { Some(t) => Some(unsafe { op(t) }), None => None, } } } erased-serde-0.3.23/src/private.rs000064400000000000000000000003531046102023000150640ustar 00000000000000//! Not public API. Used as `$crate::__private` by macros. pub use core::marker::{Send, Sized, Sync}; pub use core::result::Result; pub use serde; pub fn require_erased_serialize_impl() where T: ?Sized + crate::Serialize, { } erased-serde-0.3.23/src/ser.rs000064400000000000000000001343351046102023000142130ustar 00000000000000use crate::alloc::Box; use crate::any::Any; use crate::error::Error; use crate::map::ResultExt; use core::fmt::Display; use core::marker::PhantomData; use serde::ser::{ SerializeMap, SerializeSeq, SerializeStruct, SerializeStructVariant, SerializeTuple, SerializeTupleStruct, SerializeTupleVariant, }; use serde::serde_if_integer128; // TRAITS ////////////////////////////////////////////////////////////////////// /// An object-safe equivalent of Serde's `Serialize` trait. /// /// Any implementation of Serde's `Serialize` converts seamlessly to an /// `&erased_serde::Serialize` or `Box` trait object. /// /// ```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(); /// } /// ``` pub trait Serialize { fn erased_serialize(&self, v: &mut dyn Serializer) -> Result; } /// An object-safe equivalent of Serde's `Serializer` trait. /// /// Any implementation of Serde's `Serializer` can be converted to an /// `&erased_serde::Serializer` or `Box` trait object /// using `erased_serde::Serializer::erase`. /// /// ```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(); /// } /// ``` pub trait Serializer { fn erased_serialize_bool(&mut self, v: bool) -> Result; fn erased_serialize_i8(&mut self, v: i8) -> Result; fn erased_serialize_i16(&mut self, v: i16) -> Result; fn erased_serialize_i32(&mut self, v: i32) -> Result; fn erased_serialize_i64(&mut self, v: i64) -> Result; fn erased_serialize_u8(&mut self, v: u8) -> Result; fn erased_serialize_u16(&mut self, v: u16) -> Result; fn erased_serialize_u32(&mut self, v: u32) -> Result; fn erased_serialize_u64(&mut self, v: u64) -> Result; serde_if_integer128! { fn erased_serialize_i128(&mut self, v: i128) -> Result; fn erased_serialize_u128(&mut self, v: u128) -> Result; } fn erased_serialize_f32(&mut self, v: f32) -> Result; fn erased_serialize_f64(&mut self, v: f64) -> Result; fn erased_serialize_char(&mut self, v: char) -> Result; fn erased_serialize_str(&mut self, v: &str) -> Result; fn erased_serialize_bytes(&mut self, v: &[u8]) -> Result; fn erased_serialize_none(&mut self) -> Result; fn erased_serialize_some(&mut self, v: &dyn Serialize) -> Result; fn erased_serialize_unit(&mut self) -> Result; fn erased_serialize_unit_struct(&mut self, name: &'static str) -> Result; fn erased_serialize_unit_variant( &mut self, name: &'static str, variant_index: u32, variant: &'static str, ) -> Result; fn erased_serialize_newtype_struct( &mut self, name: &'static str, v: &dyn Serialize, ) -> Result; fn erased_serialize_newtype_variant( &mut self, name: &'static str, variant_index: u32, variant: &'static str, v: &dyn Serialize, ) -> Result; fn erased_serialize_seq(&mut self, len: Option) -> Result; fn erased_serialize_tuple(&mut self, len: usize) -> Result; fn erased_serialize_tuple_struct( &mut self, name: &'static str, len: usize, ) -> Result; fn erased_serialize_tuple_variant( &mut self, name: &'static str, variant_index: u32, variant: &'static str, len: usize, ) -> Result; fn erased_serialize_map(&mut self, len: Option) -> Result; fn erased_serialize_struct(&mut self, name: &'static str, len: usize) -> Result; fn erased_serialize_struct_variant( &mut self, name: &'static str, variant_index: u32, variant: &'static str, len: usize, ) -> Result; fn erased_is_human_readable(&self) -> bool; } impl dyn Serializer { /// Convert any Serde `Serializer` to a trait object. /// /// ```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(); /// } /// ``` pub fn erase(serializer: S) -> erase::Serializer where S: serde::Serializer, S::Ok: 'static, { erase::Serializer { state: Some(serializer), } } } // OK ////////////////////////////////////////////////////////////////////////// // Corresponds to the Serializer::Ok associated type. // // This struct is exposed to users by invoking methods on the Serialize or // Serializer trait objects, so we need to make sure they do not hold on to the // Ok beyond the lifetime of the data in the Any. // // We do this by enforcing S::Ok is 'static for every Serializer trait object // created by the user. pub struct Ok { data: Any, } impl Ok { unsafe fn new(t: T) -> Self { Ok { data: unsafe { Any::new(t) }, } } unsafe fn take(self) -> T { unsafe { self.data.take() } } } // IMPL ERASED SERDE FOR SERDE ///////////////////////////////////////////////// impl Serialize for T where T: ?Sized + serde::Serialize, { fn erased_serialize(&self, serializer: &mut dyn Serializer) -> Result { self.serialize(serializer) } } mod erase { pub struct Serializer { pub(crate) state: Option, } impl Serializer { pub(crate) fn take(&mut self) -> S { self.state.take().unwrap() } pub(crate) fn as_ref(&self) -> &S { self.state.as_ref().unwrap() } } } impl Serializer for erase::Serializer where T: serde::Serializer, { fn erased_serialize_bool(&mut self, v: bool) -> Result { unsafe { self.take() .serialize_bool(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_i8(&mut self, v: i8) -> Result { unsafe { self.take() .serialize_i8(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_i16(&mut self, v: i16) -> Result { unsafe { self.take() .serialize_i16(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_i32(&mut self, v: i32) -> Result { unsafe { self.take() .serialize_i32(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_i64(&mut self, v: i64) -> Result { unsafe { self.take() .serialize_i64(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_u8(&mut self, v: u8) -> Result { unsafe { self.take() .serialize_u8(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_u16(&mut self, v: u16) -> Result { unsafe { self.take() .serialize_u16(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_u32(&mut self, v: u32) -> Result { unsafe { self.take() .serialize_u32(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_u64(&mut self, v: u64) -> Result { unsafe { self.take() .serialize_u64(v) .unsafe_map(Ok::new) .map_err(erase) } } serde_if_integer128! { fn erased_serialize_i128(&mut self, v: i128) -> Result { unsafe { self.take() .serialize_i128(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_u128(&mut self, v: u128) -> Result { unsafe { self.take() .serialize_u128(v) .unsafe_map(Ok::new) .map_err(erase) } } } fn erased_serialize_f32(&mut self, v: f32) -> Result { unsafe { self.take() .serialize_f32(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_f64(&mut self, v: f64) -> Result { unsafe { self.take() .serialize_f64(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_char(&mut self, v: char) -> Result { unsafe { self.take() .serialize_char(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_str(&mut self, v: &str) -> Result { unsafe { self.take() .serialize_str(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_bytes(&mut self, v: &[u8]) -> Result { unsafe { self.take() .serialize_bytes(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_none(&mut self) -> Result { unsafe { self.take() .serialize_none() .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_some(&mut self, v: &dyn Serialize) -> Result { unsafe { self.take() .serialize_some(v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_unit(&mut self) -> Result { unsafe { self.take() .serialize_unit() .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_unit_struct(&mut self, name: &'static str) -> Result { unsafe { self.take() .serialize_unit_struct(name) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_unit_variant( &mut self, name: &'static str, variant_index: u32, variant: &'static str, ) -> Result { unsafe { self.take() .serialize_unit_variant(name, variant_index, variant) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_newtype_struct( &mut self, name: &'static str, v: &dyn Serialize, ) -> Result { unsafe { self.take() .serialize_newtype_struct(name, v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_newtype_variant( &mut self, name: &'static str, variant_index: u32, variant: &'static str, v: &dyn Serialize, ) -> Result { unsafe { self.take() .serialize_newtype_variant(name, variant_index, variant, v) .unsafe_map(Ok::new) .map_err(erase) } } fn erased_serialize_seq(&mut self, len: Option) -> Result { unsafe { self.take() .serialize_seq(len) .unsafe_map(Seq::new) .map_err(erase) } } fn erased_serialize_tuple(&mut self, len: usize) -> Result { unsafe { self.take() .serialize_tuple(len) .unsafe_map(Tuple::new) .map_err(erase) } } fn erased_serialize_tuple_struct( &mut self, name: &'static str, len: usize, ) -> Result { unsafe { self.take() .serialize_tuple_struct(name, len) .unsafe_map(TupleStruct::new) .map_err(erase) } } fn erased_serialize_tuple_variant( &mut self, name: &'static str, variant_index: u32, variant: &'static str, len: usize, ) -> Result { unsafe { self.take() .serialize_tuple_variant(name, variant_index, variant, len) .unsafe_map(TupleVariant::new) .map_err(erase) } } fn erased_serialize_map(&mut self, len: Option) -> Result { unsafe { self.take() .serialize_map(len) .unsafe_map(Map::new) .map_err(erase) } } fn erased_serialize_struct(&mut self, name: &'static str, len: usize) -> Result { unsafe { self.take() .serialize_struct(name, len) .unsafe_map(Struct::new) .map_err(erase) } } fn erased_serialize_struct_variant( &mut self, name: &'static str, variant_index: u32, variant: &'static str, len: usize, ) -> Result { unsafe { self.take() .serialize_struct_variant(name, variant_index, variant, len) .unsafe_map(StructVariant::new) .map_err(erase) } } fn erased_is_human_readable(&self) -> bool { self.as_ref().is_human_readable() } } // IMPL SERDE FOR ERASED SERDE ///////////////////////////////////////////////// /// Serialize the given type-erased serializable value. /// /// This can be used to implement `serde::Serialize` for trait objects that have /// `erased_serde::Serialize` as a supertrait. /// /// ``` /// trait Event: erased_serde::Serialize { /// /* ... */ /// } /// /// impl<'a> serde::Serialize for dyn Event + 'a { /// fn serialize(&self, serializer: S) -> Result /// where S: serde::Serializer /// { /// erased_serde::serialize(self, serializer) /// } /// } /// ``` /// /// Since this is reasonably common, the `serialize_trait_object!` macro /// generates such a Serialize impl. /// /// ``` /// use erased_serde::serialize_trait_object; /// # /// # trait Event: erased_serde::Serialize {} /// /// serialize_trait_object!(Event); /// ``` pub fn serialize(value: &T, serializer: S) -> Result where T: ?Sized + Serialize, S: serde::Serializer, { let mut erased = erase::Serializer { state: Some(serializer), }; unsafe { value .erased_serialize(&mut erased) .unsafe_map(Ok::take) .map_err(unerase) } } serialize_trait_object!(Serialize); macro_rules! impl_serializer_for_trait_object { ($ty:ty) => { impl<'a> serde::Serializer for $ty { type Ok = Ok; type Error = Error; type SerializeSeq = Seq<'a>; type SerializeTuple = Tuple<'a>; type SerializeTupleStruct = TupleStruct<'a>; type SerializeTupleVariant = TupleVariant<'a>; type SerializeMap = Map<'a>; type SerializeStruct = Struct<'a>; type SerializeStructVariant = StructVariant<'a>; fn serialize_bool(self, v: bool) -> Result { self.erased_serialize_bool(v) } fn serialize_i8(self, v: i8) -> Result { self.erased_serialize_i8(v) } fn serialize_i16(self, v: i16) -> Result { self.erased_serialize_i16(v) } fn serialize_i32(self, v: i32) -> Result { self.erased_serialize_i32(v) } fn serialize_i64(self, v: i64) -> Result { self.erased_serialize_i64(v) } fn serialize_u8(self, v: u8) -> Result { self.erased_serialize_u8(v) } fn serialize_u16(self, v: u16) -> Result { self.erased_serialize_u16(v) } fn serialize_u32(self, v: u32) -> Result { self.erased_serialize_u32(v) } fn serialize_u64(self, v: u64) -> Result { self.erased_serialize_u64(v) } serde_if_integer128! { fn serialize_i128(self, v: i128) -> Result { self.erased_serialize_i128(v) } fn serialize_u128(self, v: u128) -> Result { self.erased_serialize_u128(v) } } fn serialize_f32(self, v: f32) -> Result { self.erased_serialize_f32(v) } fn serialize_f64(self, v: f64) -> Result { self.erased_serialize_f64(v) } fn serialize_char(self, v: char) -> Result { self.erased_serialize_char(v) } fn serialize_str(self, v: &str) -> Result { self.erased_serialize_str(v) } fn serialize_bytes(self, v: &[u8]) -> Result { self.erased_serialize_bytes(v) } fn serialize_none(self) -> Result { self.erased_serialize_none() } fn serialize_some(self, v: &T) -> Result where T: ?Sized + serde::Serialize, { self.erased_serialize_some(&v) } fn serialize_unit(self) -> Result { self.erased_serialize_unit() } fn serialize_unit_struct(self, name: &'static str) -> Result { self.erased_serialize_unit_struct(name) } fn serialize_unit_variant( self, name: &'static str, variant_index: u32, variant: &'static str, ) -> Result { self.erased_serialize_unit_variant(name, variant_index, variant) } fn serialize_newtype_struct(self, name: &'static str, v: &T) -> Result where T: ?Sized + serde::Serialize, { self.erased_serialize_newtype_struct(name, &v) } fn serialize_newtype_variant( self, name: &'static str, variant_index: u32, variant: &'static str, v: &T, ) -> Result where T: ?Sized + serde::Serialize, { self.erased_serialize_newtype_variant(name, variant_index, variant, &v) } fn serialize_seq(self, len: Option) -> Result, Error> { self.erased_serialize_seq(len) } fn serialize_tuple(self, len: usize) -> Result, Error> { self.erased_serialize_tuple(len) } fn serialize_tuple_struct( self, name: &'static str, len: usize, ) -> Result, Error> { self.erased_serialize_tuple_struct(name, len) } fn serialize_tuple_variant( self, name: &'static str, variant_index: u32, variant: &'static str, len: usize, ) -> Result, Error> { self.erased_serialize_tuple_variant(name, variant_index, variant, len) } fn serialize_map(self, len: Option) -> Result, Error> { self.erased_serialize_map(len) } fn serialize_struct(self, name: &'static str, len: usize) -> Result, Error> { self.erased_serialize_struct(name, len) } fn serialize_struct_variant( self, name: &'static str, variant_index: u32, variant: &'static str, len: usize, ) -> Result, Error> { self.erased_serialize_struct_variant(name, variant_index, variant, len) } #[cfg(not(any(feature = "std", feature = "alloc")))] fn collect_str(self, value: &T) -> Result where T: ?Sized + Display, { unreachable!() } fn is_human_readable(&self) -> bool { self.erased_is_human_readable() } } }; } impl_serializer_for_trait_object!(&'a mut dyn Serializer); impl_serializer_for_trait_object!(&'a mut (dyn Serializer + Send)); impl_serializer_for_trait_object!(&'a mut (dyn Serializer + Sync)); impl_serializer_for_trait_object!(&'a mut (dyn Serializer + Send + Sync)); pub struct Seq<'a> { data: Any, serialize_element: unsafe fn(&mut Any, &dyn Serialize) -> Result<(), Error>, end: unsafe fn(Any) -> Result, lifetime: PhantomData<&'a dyn Serializer>, } impl<'a> Seq<'a> { unsafe fn new(data: T) -> Self where T: serde::ser::SerializeSeq, { Seq { data: unsafe { Any::new(data) }, serialize_element: { unsafe fn serialize_element( data: &mut Any, v: &dyn Serialize, ) -> Result<(), Error> where T: serde::ser::SerializeSeq, { unsafe { data.view::().serialize_element(v).map_err(erase) } } serialize_element:: }, end: { unsafe fn end(data: Any) -> Result where T: serde::ser::SerializeSeq, { unsafe { data.take::().end().unsafe_map(Ok::new).map_err(erase) } } end:: }, lifetime: PhantomData, } } } impl<'a> SerializeSeq for Seq<'a> { type Ok = Ok; type Error = Error; fn serialize_element(&mut self, value: &T) -> Result<(), Error> where T: ?Sized + serde::Serialize, { unsafe { (self.serialize_element)(&mut self.data, &value) } } fn end(self) -> Result { unsafe { (self.end)(self.data) } } } pub struct Tuple<'a> { data: Any, serialize_element: unsafe fn(&mut Any, &dyn Serialize) -> Result<(), Error>, end: unsafe fn(Any) -> Result, lifetime: PhantomData<&'a dyn Serializer>, } impl<'a> Tuple<'a> { unsafe fn new(data: T) -> Self where T: serde::ser::SerializeTuple, { Tuple { data: unsafe { Any::new(data) }, serialize_element: { unsafe fn serialize_element( data: &mut Any, v: &dyn Serialize, ) -> Result<(), Error> where T: serde::ser::SerializeTuple, { unsafe { data.view::().serialize_element(v).map_err(erase) } } serialize_element:: }, end: { unsafe fn end(data: Any) -> Result where T: serde::ser::SerializeTuple, { unsafe { data.take::().end().unsafe_map(Ok::new).map_err(erase) } } end:: }, lifetime: PhantomData, } } } impl<'a> SerializeTuple for Tuple<'a> { type Ok = Ok; type Error = Error; fn serialize_element(&mut self, value: &T) -> Result<(), Error> where T: ?Sized + serde::Serialize, { unsafe { (self.serialize_element)(&mut self.data, &value) } } fn end(self) -> Result { unsafe { (self.end)(self.data) } } } pub struct TupleStruct<'a> { data: Any, serialize_field: unsafe fn(&mut Any, &dyn Serialize) -> Result<(), Error>, end: unsafe fn(Any) -> Result, lifetime: PhantomData<&'a dyn Serializer>, } impl<'a> TupleStruct<'a> { unsafe fn new(data: T) -> Self where T: serde::ser::SerializeTupleStruct, { TupleStruct { data: unsafe { Any::new(data) }, serialize_field: { unsafe fn serialize_field(data: &mut Any, v: &dyn Serialize) -> Result<(), Error> where T: serde::ser::SerializeTupleStruct, { unsafe { data.view::().serialize_field(v).map_err(erase) } } serialize_field:: }, end: { unsafe fn end(data: Any) -> Result where T: serde::ser::SerializeTupleStruct, { unsafe { data.take::().end().unsafe_map(Ok::new).map_err(erase) } } end:: }, lifetime: PhantomData, } } } impl<'a> SerializeTupleStruct for TupleStruct<'a> { type Ok = Ok; type Error = Error; fn serialize_field(&mut self, value: &T) -> Result<(), Error> where T: ?Sized + serde::Serialize, { unsafe { (self.serialize_field)(&mut self.data, &value) } } fn end(self) -> Result { unsafe { (self.end)(self.data) } } } pub struct TupleVariant<'a> { data: Any, serialize_field: unsafe fn(&mut Any, &dyn Serialize) -> Result<(), Error>, end: unsafe fn(Any) -> Result, lifetime: PhantomData<&'a dyn Serializer>, } impl<'a> TupleVariant<'a> { unsafe fn new(data: T) -> Self where T: serde::ser::SerializeTupleVariant, { TupleVariant { data: unsafe { Any::new(data) }, serialize_field: { unsafe fn serialize_field(data: &mut Any, v: &dyn Serialize) -> Result<(), Error> where T: serde::ser::SerializeTupleVariant, { unsafe { data.view::().serialize_field(v).map_err(erase) } } serialize_field:: }, end: { unsafe fn end(data: Any) -> Result where T: serde::ser::SerializeTupleVariant, { unsafe { data.take::().end().unsafe_map(Ok::new).map_err(erase) } } end:: }, lifetime: PhantomData, } } } impl<'a> SerializeTupleVariant for TupleVariant<'a> { type Ok = Ok; type Error = Error; fn serialize_field(&mut self, value: &T) -> Result<(), Error> where T: ?Sized + serde::Serialize, { unsafe { (self.serialize_field)(&mut self.data, &value) } } fn end(self) -> Result { unsafe { (self.end)(self.data) } } } pub struct Map<'a> { data: Any, serialize_key: unsafe fn(&mut Any, &dyn Serialize) -> Result<(), Error>, serialize_value: unsafe fn(&mut Any, &dyn Serialize) -> Result<(), Error>, serialize_entry: unsafe fn(&mut Any, &dyn Serialize, &dyn Serialize) -> Result<(), Error>, end: unsafe fn(Any) -> Result, lifetime: PhantomData<&'a dyn Serializer>, } impl<'a> Map<'a> { unsafe fn new(data: T) -> Self where T: serde::ser::SerializeMap, { Map { data: unsafe { Any::new(data) }, serialize_key: { unsafe fn serialize_key(data: &mut Any, v: &dyn Serialize) -> Result<(), Error> where T: serde::ser::SerializeMap, { unsafe { data.view::().serialize_key(v).map_err(erase) } } serialize_key:: }, serialize_value: { unsafe fn serialize_value(data: &mut Any, v: &dyn Serialize) -> Result<(), Error> where T: serde::ser::SerializeMap, { unsafe { data.view::().serialize_value(v).map_err(erase) } } serialize_value:: }, serialize_entry: { unsafe fn serialize_entry( data: &mut Any, k: &dyn Serialize, v: &dyn Serialize, ) -> Result<(), Error> where T: serde::ser::SerializeMap, { unsafe { data.view::().serialize_entry(k, v).map_err(erase) } } serialize_entry:: }, end: { unsafe fn end(data: Any) -> Result where T: serde::ser::SerializeMap, { unsafe { data.take::().end().unsafe_map(Ok::new).map_err(erase) } } end:: }, lifetime: PhantomData, } } } impl<'a> SerializeMap for Map<'a> { type Ok = Ok; type Error = Error; fn serialize_key(&mut self, key: &T) -> Result<(), Error> where T: ?Sized + serde::Serialize, { unsafe { (self.serialize_key)(&mut self.data, &key) } } fn serialize_value(&mut self, value: &T) -> Result<(), Error> where T: ?Sized + serde::Serialize, { unsafe { (self.serialize_value)(&mut self.data, &value) } } fn serialize_entry(&mut self, key: &K, value: &V) -> Result<(), Error> where K: ?Sized + serde::Serialize, V: ?Sized + serde::Serialize, { unsafe { (self.serialize_entry)(&mut self.data, &key, &value) } } fn end(self) -> Result { unsafe { (self.end)(self.data) } } } pub struct Struct<'a> { data: Any, serialize_field: unsafe fn(&mut Any, &'static str, &dyn Serialize) -> Result<(), Error>, end: unsafe fn(Any) -> Result, lifetime: PhantomData<&'a dyn Serializer>, } impl<'a> Struct<'a> { unsafe fn new(data: T) -> Self where T: serde::ser::SerializeStruct, { Struct { data: unsafe { Any::new(data) }, serialize_field: { unsafe fn serialize_field( data: &mut Any, k: &'static str, v: &dyn Serialize, ) -> Result<(), Error> where T: serde::ser::SerializeStruct, { unsafe { data.view::().serialize_field(k, v).map_err(erase) } } serialize_field:: }, end: { unsafe fn end(data: Any) -> Result where T: serde::ser::SerializeStruct, { unsafe { data.take::().end().unsafe_map(Ok::new).map_err(erase) } } end:: }, lifetime: PhantomData, } } } impl<'a> SerializeStruct for Struct<'a> { type Ok = Ok; type Error = Error; fn serialize_field(&mut self, name: &'static str, field: &T) -> Result<(), Error> where T: ?Sized + serde::Serialize, { unsafe { (self.serialize_field)(&mut self.data, name, &field) } } fn end(self) -> Result { unsafe { (self.end)(self.data) } } } pub struct StructVariant<'a> { data: Any, serialize_field: unsafe fn(&mut Any, &'static str, &dyn Serialize) -> Result<(), Error>, end: unsafe fn(Any) -> Result, lifetime: PhantomData<&'a dyn Serializer>, } impl<'a> StructVariant<'a> { unsafe fn new(data: T) -> Self where T: serde::ser::SerializeStructVariant, { StructVariant { data: unsafe { Any::new(data) }, serialize_field: { unsafe fn serialize_field( data: &mut Any, k: &'static str, v: &dyn Serialize, ) -> Result<(), Error> where T: serde::ser::SerializeStructVariant, { unsafe { data.view::().serialize_field(k, v).map_err(erase) } } serialize_field:: }, end: { unsafe fn end(data: Any) -> Result where T: serde::ser::SerializeStructVariant, { unsafe { data.take::().end().unsafe_map(Ok::new).map_err(erase) } } end:: }, lifetime: PhantomData, } } } impl<'a> SerializeStructVariant for StructVariant<'a> { type Ok = Ok; type Error = Error; fn serialize_field(&mut self, name: &'static str, field: &T) -> Result<(), Error> where T: ?Sized + serde::Serialize, { unsafe { (self.serialize_field)(&mut self.data, name, &field) } } fn end(self) -> Result { unsafe { (self.end)(self.data) } } } // IMPL ERASED SERDE FOR ERASED SERDE ////////////////////////////////////////// macro_rules! deref_erased_serializer { ($($imp:tt)+) => { impl $($imp)+ { fn erased_serialize_bool(&mut self, v: bool) -> Result { (**self).erased_serialize_bool(v) } fn erased_serialize_i8(&mut self, v: i8) -> Result { (**self).erased_serialize_i8(v) } fn erased_serialize_i16(&mut self, v: i16) -> Result { (**self).erased_serialize_i16(v) } fn erased_serialize_i32(&mut self, v: i32) -> Result { (**self).erased_serialize_i32(v) } fn erased_serialize_i64(&mut self, v: i64) -> Result { (**self).erased_serialize_i64(v) } fn erased_serialize_u8(&mut self, v: u8) -> Result { (**self).erased_serialize_u8(v) } fn erased_serialize_u16(&mut self, v: u16) -> Result { (**self).erased_serialize_u16(v) } fn erased_serialize_u32(&mut self, v: u32) -> Result { (**self).erased_serialize_u32(v) } fn erased_serialize_u64(&mut self, v: u64) -> Result { (**self).erased_serialize_u64(v) } serde_if_integer128! { fn erased_serialize_i128(&mut self, v: i128) -> Result { (**self).erased_serialize_i128(v) } fn erased_serialize_u128(&mut self, v: u128) -> Result { (**self).erased_serialize_u128(v) } } fn erased_serialize_f32(&mut self, v: f32) -> Result { (**self).erased_serialize_f32(v) } fn erased_serialize_f64(&mut self, v: f64) -> Result { (**self).erased_serialize_f64(v) } fn erased_serialize_char(&mut self, v: char) -> Result { (**self).erased_serialize_char(v) } fn erased_serialize_str(&mut self, v: &str) -> Result { (**self).erased_serialize_str(v) } fn erased_serialize_bytes(&mut self, v: &[u8]) -> Result { (**self).erased_serialize_bytes(v) } fn erased_serialize_none(&mut self) -> Result { (**self).erased_serialize_none() } fn erased_serialize_some(&mut self, v: &dyn Serialize) -> Result { (**self).erased_serialize_some(v) } fn erased_serialize_unit(&mut self) -> Result { (**self).erased_serialize_unit() } fn erased_serialize_unit_struct(&mut self, name: &'static str) -> Result { (**self).erased_serialize_unit_struct(name) } fn erased_serialize_unit_variant(&mut self, name: &'static str, variant_index: u32, variant: &'static str) -> Result { (**self).erased_serialize_unit_variant(name, variant_index, variant) } fn erased_serialize_newtype_struct(&mut self, name: &'static str, v: &dyn Serialize) -> Result { (**self).erased_serialize_newtype_struct(name, v) } fn erased_serialize_newtype_variant(&mut self, name: &'static str, variant_index: u32, variant: &'static str, v: &dyn Serialize) -> Result { (**self).erased_serialize_newtype_variant(name, variant_index, variant, v) } fn erased_serialize_seq(&mut self, len: Option) -> Result { (**self).erased_serialize_seq(len) } fn erased_serialize_tuple(&mut self, len: usize) -> Result { (**self).erased_serialize_tuple(len) } fn erased_serialize_tuple_struct(&mut self, name: &'static str, len: usize) -> Result { (**self).erased_serialize_tuple_struct(name, len) } fn erased_serialize_tuple_variant(&mut self, name: &'static str, variant_index: u32, variant: &'static str, len: usize) -> Result { (**self).erased_serialize_tuple_variant(name, variant_index, variant, len) } fn erased_serialize_map(&mut self, len: Option) -> Result { (**self).erased_serialize_map(len) } fn erased_serialize_struct(&mut self, name: &'static str, len: usize) -> Result { (**self).erased_serialize_struct(name, len) } fn erased_serialize_struct_variant(&mut self, name: &'static str, variant_index: u32, variant: &'static str, len: usize) -> Result { (**self).erased_serialize_struct_variant(name, variant_index, variant, len) } fn erased_is_human_readable(&self) -> bool { (**self).erased_is_human_readable() } } }; } deref_erased_serializer!(<'a> Serializer for Box); deref_erased_serializer!(<'a> Serializer for Box); deref_erased_serializer!(<'a> Serializer for Box); deref_erased_serializer!(<'a> Serializer for Box); deref_erased_serializer!(<'a, T: ?Sized + Serializer> Serializer for &'a mut T); // ERROR /////////////////////////////////////////////////////////////////////// fn erase(e: E) -> Error where E: Display, { serde::ser::Error::custom(e) } fn unerase(e: Error) -> E where E: serde::ser::Error, { E::custom(e) } // TEST //////////////////////////////////////////////////////////////////////// #[cfg(test)] mod tests { use super::*; use crate::alloc::{vec, Vec}; use serde_derive::Serialize; fn test_json(t: T) where T: serde::Serialize, { let expected = serde_json::to_vec(&t).unwrap(); // test borrowed trait object { let obj: &dyn Serialize = &t; let mut buf = Vec::new(); { let mut ser = serde_json::Serializer::new(&mut buf); let ser: &mut dyn Serializer = &mut ::erase(&mut ser); obj.erased_serialize(ser).unwrap(); } assert_eq!(buf, expected); } // test boxed trait object { let obj: Box = Box::new(t); let mut buf = Vec::new(); { let mut ser = serde_json::Serializer::new(&mut buf); let mut ser: Box = Box::new(::erase(&mut ser)); obj.erased_serialize(&mut ser).unwrap(); } assert_eq!(buf, expected); } } #[test] fn test_vec() { test_json(vec!["a", "b"]); } #[test] fn test_struct() { #[derive(Serialize)] struct S { f: usize, } test_json(S { f: 256 }); } #[test] fn test_enum() { #[derive(Serialize)] enum E { Unit, Newtype(bool), Tuple(bool, bool), Struct { t: bool, f: bool }, } test_json(E::Unit); test_json(E::Newtype(true)); test_json(E::Tuple(true, false)); test_json(E::Struct { t: true, f: false }); } #[test] fn assert_serialize() { fn assert() {} assert::<&dyn Serialize>(); assert::<&(dyn Serialize + Send)>(); assert::<&(dyn Serialize + Sync)>(); assert::<&(dyn Serialize + Send + Sync)>(); assert::<&(dyn Serialize + Sync + Send)>(); assert::>(); assert::>(); assert::>(); assert::>(); assert::>(); assert::>(); assert::>(); assert::>>(); assert::>>(); } #[test] fn assert_serializer() { fn assert() {} assert::<&mut dyn Serializer>(); assert::<&mut (dyn Serializer + Send)>(); assert::<&mut (dyn Serializer + Sync)>(); assert::<&mut (dyn Serializer + Send + Sync)>(); assert::<&mut (dyn Serializer + Sync + Send)>(); } } erased-serde-0.3.23/tests/compiletest.rs000064400000000000000000000002461046102023000163160ustar 00000000000000#[rustversion::attr(not(nightly), ignore)] #[cfg_attr(miri, ignore)] #[test] fn ui() { let t = trybuild::TestCases::new(); t.compile_fail("tests/ui/*.rs"); } erased-serde-0.3.23/tests/readme.rs000064400000000000000000000043461046102023000152300ustar 00000000000000// Please also update README.md when making changes to this code. use erased_serde::{Deserializer, Serialize, Serializer}; use std::collections::BTreeMap as Map; use std::io; #[test] fn serialization() { // 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(); } #[test] fn deserialization() { static JSON: &[u8] = br#"{"A": 65, "B": 66}"#; static CBOR: &[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"]); } erased-serde-0.3.23/tests/traitobject.rs000064400000000000000000000003621046102023000162770ustar 00000000000000use erased_serde::serialize_trait_object; pub trait MyTrait: erased_serde::Serialize {} serialize_trait_object!(MyTrait); pub trait MyGenericTrait<'a, T>: erased_serde::Serialize {} serialize_trait_object!(<'a, T> MyGenericTrait<'a, T>); erased-serde-0.3.23/tests/ui/missing-supertrait.rs000064400000000000000000000001611046102023000202500ustar 00000000000000use erased_serde::serialize_trait_object; pub trait MyTrait {} serialize_trait_object!(MyTrait); fn main() {} erased-serde-0.3.23/tests/ui/missing-supertrait.stderr000064400000000000000000000017371046102023000211410ustar 00000000000000error[E0277]: the trait bound `__T: serde::ser::Serialize` is not satisfied --> tests/ui/missing-supertrait.rs:5:1 | 5 | serialize_trait_object!(MyTrait); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `serde::ser::Serialize` is not implemented for `__T` | = note: required for `__T` to implement `erased_serde::Serialize` note: required by a bound in `require_erased_serialize_impl` --> src/private.rs | | T: ?Sized + crate::Serialize, | ^^^^^^^^^^^^^^^^ required by this bound in `require_erased_serialize_impl` = note: this error originates in the macro `$crate::__internal_serialize_trait_object` which comes from the expansion of the macro `serialize_trait_object` (in Nightly builds, run with -Z macro-backtrace for more info) help: consider further restricting this bound | 5 | serialize_trait_object!(MyTrait + erased_serde::__private::serde::ser::Serialize); | ++++++++++++++++++++++++++++++++++++++++++++++++