Derive Macro Versioned 

#[derive(Versioned)]
{
    // Attributes available to this derive:
    #[versioned]
}

Derives the Versioned trait for a struct.

This macro generates:

• A version enum (e.g., UserVersion) with variants for each version
• Implementation of Versioned trait with from_version and to_version methods

Attributes

The macro accepts a versioned attribute with the following format:

#[versioned(versions = [Version1, Version2, ...])]

Requirements

• The struct must have named fields (not tuple structs or unit structs)
• Each version struct must implement FromVersion<CurrentStruct>
• Each version struct must implement Serialize, Deserialize, and Clone

Panics

This function will panic if versions is empty (which should be caught during compilation), or if the latest version cannot be determined.

Example

use serde_versioned::Versioned;
use serde::{Deserialize, Serialize};

#[derive(Versioned, Serialize, Deserialize, Clone)]
#[versioned(versions = [UserV1, UserV2])]
struct User {
    pub name: String,
    pub age: u32,
}

#[derive(Serialize, Deserialize, Clone)]
struct UserV1 {
    pub name: String,
}

#[derive(Serialize, Deserialize, Clone)]
struct UserV2 {
    pub name: String,
    pub age: u32,
}

impl serde_versioned::FromVersion<User> for UserV1 {
    fn convert(self) -> User {
        User { name: self.name, age: 0 }
    }
}

impl serde_versioned::FromVersion<User> for UserV2 {
    fn convert(self) -> User {
        User { name: self.name, age: self.age }
    }
}