Macro serde_impl_ser_fixed_bytes_ref 

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

Macro to generate serde::Serialize implementation for types $t that can be referenced as a byte array of fixed size, The resulting structure will support serialization into human-readable formats using hex encoding, as well as binary formats.