Macro holochain_zome_types::fixed_array_serialization

macro_rules! fixed_array_serialization {
    ($t:ty, $len:expr) => { ... };
}

Serialization for fixed arrays is generally not available in a way that can be derived. Being able to wrap fixed size arrays is important e.g. for crypto safety etc. so this is a simple way to implement serialization so that we can send these types between the host/guest.