Struct UpcastRegistration 

pub struct UpcastRegistration {
    pub kind_bits: u16,
    pub from_version: u16,
    pub step: fn(Value) -> Result<Value, Box<dyn Error + Send + Sync>>,
}

Registration item emitted once per (KIND, from_version) upcast step.

Mirrors EventPayloadRegistration: collected link-time via inventory so the decode seam can look up the registered vN→vN+1 migration for a given stored kind/version without a runtime registry. The step operates on a type-erased rmpv::Value so a single chain runner is lane-neutral (it works for both the JSON and raw-msgpack replay lanes). The concrete error type is owned by batpak core, so step returns a boxed dyn Error here to keep this support crate dependency-light.

Fields

kind_bits: u16

Packed (category << 12) | type_id; equals EventKind::as_raw_u16.

from_version: u16

The stored version this step upgrades from (it produces from + 1).

step: fn(Value) -> Result<Value, Box<dyn Error + Send + Sync>>

The migration applied to a decoded rmpv::Value of version from_version, producing a value of version from_version + 1.

Trait Implementations

impl Collect for UpcastRegistration