rkyv_dyn 0.6.6

# rkyv_dyn   [![Latest Version]][crates.io] [![License]][license path] [![requires: rustc 1.50+]][Rust 1.50]


[Latest Version]: https://img.shields.io/crates/v/rkyv_dyn.svg
[crates.io]: https://crates.io/crates/rkyv_dyn
[License]: https://img.shields.io/badge/license-MIT-blue.svg
[license path]: https://github.com/djkoloski/rkyv/blob/master/LICENSE
[requires: rustc 1.50+]: https://img.shields.io/badge/rustc-1.50+-lightgray.svg
[Rust 1.50]: https://blog.rust-lang.org/2020/10/08/Rust-1.50.html

Trait object serialization for rkyv.

---

## API Documentation


- [rkyv](https://docs.rs/rkyv), the core library
- [rkyv_dyn](https://docs.rs/rkyv_dyn), which adds trait object support to rkyv
- [rkyv_typename](https://docs.rs/rkyv_typename), a type naming library

## Book


- The [rkyv book](https://djkoloski.github.io/rkyv) covers the motivation and architecture of rkyv

## Sister Crates:


- [bytecheck](https://github.com/djkoloski/bytecheck), which rkyv uses for validation
- [ptr_meta](https://github.com/djkoloski/ptr_meta), which rkyv uses for pointer manipulation

---

## rkyv_dyn in action


```rust
use rkyv::{
    archived_value,
    de::deserializers::AllocDeserializer,
    ser::{
        serializers::AlignedSerializer,
        Serializer,
    },
    AlignedVec,
    Archive,
    Archived,
    Deserialize,
    Serialize,
};
use rkyv_dyn::archive_dyn;
use rkyv_typename::TypeName;

#[archive_dyn(deserialize)]

trait ExampleTrait {
    fn value(&self) -> String;
}

#[derive(Archive, Serialize, Deserialize)]

#[archive(derive(TypeName))]

struct StringStruct(String);

#[archive_dyn]

impl ExampleTrait for StringStruct {
    fn value(&self) -> String {
        self.0.clone()
    }
}

impl ExampleTrait for Archived<StringStruct> {
    fn value(&self) -> String {
        self.0.as_str().to_string()
    }
}

#[derive(Archive, Serialize, Deserialize)]

#[archive(derive(TypeName))]

struct IntStruct(i32);

#[archive_dyn(deserialize)]

impl ExampleTrait for IntStruct {
    fn value(&self) -> String {
        format!("{}", self.0)
    }
}

impl ExampleTrait for Archived<IntStruct> {
    fn value(&self) -> String {
        format!("{}", self.0)
    }
}

fn main() {
    let boxed_int = Box::new(IntStruct(42)) as Box<dyn SerializeExampleTrait>;
    let boxed_string = Box::new(StringStruct("hello world".to_string())) as Box<dyn SerializeExampleTrait>;
    let mut serializer = AlignedSerializer::new(AlignedVec::new());

    let int_pos = serializer.serialize_value(&boxed_int)
        .expect("failed to archive boxed int");
    let string_pos = serializer.serialize_value(&boxed_string)
        .expect("failed to archive boxed string");
    let buf = serializer.into_inner();

    let archived_int = unsafe { archived_value::<Box<dyn SerializeExampleTrait>>(buf.as_ref(), int_pos) };
    let archived_string = unsafe { archived_value::<Box<dyn SerializeExampleTrait>>(buf.as_ref(), string_pos) };
    assert_eq!(archived_int.value(), "42");
    assert_eq!(archived_string.value(), "hello world");

    let deserialized_int: Box<dyn SerializeExampleTrait> = archived_int.deserialize(&mut AllocDeserializer).unwrap();
    let deserialized_string: Box<dyn SerializeExampleTrait> = archived_string.deserialize(&mut AllocDeserializer).unwrap();
    assert_eq!(deserialized_int.value(), "42");
    assert_eq!(deserialized_string.value(), "hello world");
}
```