Trait VersionedState 

pub trait VersionedState:
    Sized
    + Serialize
    + DeserializeOwned {
    // Required methods
    fn schema_version(&self) -> SchemaVersion;
    fn migrate_one_step(
        self,
        from: SchemaVersion,
        to: SchemaVersion,
    ) -> Result<Self>;

    // Provided methods
    fn next_version(current: SchemaVersion) -> Option<SchemaVersion> { ... }
    fn migrate(self, target: SchemaVersion) -> Result<Self> { ... }
}

Trait for types whose serialized representation carries a schema version and can be migrated forward to a newer version.

Implementors provide migrate_one_step, and the default migrate() method walks through all intermediate versions automatically.

Required Methods

fn schema_version(&self) -> SchemaVersion

Return the schema version this instance was created at.

fn migrate_one_step( self, from: SchemaVersion, to: SchemaVersion, ) -> Result<Self>

Perform a single version-to-version migration.

Implementors should match on (from, to) rather than branching on from alone, ensuring every transition is explicitly handled.

Provided Methods

fn next_version(current: SchemaVersion) -> Option<SchemaVersion>

The next schema version after current, if any.

fn migrate(self, target: SchemaVersion) -> Result<Self>

Migrate this instance to target, stepping through intermediate versions one at a time. Returns the fully migrated instance or an error if a migration step fails.

If target <= self.schema_version() this is a no-op.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl VersionedState for StoredSnapshot