Serialize a vector of serializable/serialized elements

Question

If we have a vector of serializable elements, how to serialize the vector?

In particular, how to process if each serialized element is a byte array (e.g [u8; 56])?

let mut byte_stream = data
    .iter()
    .map(|x| x.to_bytes())
    .collect::<Vec<_>>()

This snippet produces a variable of type Vec<[u8; 56]>.

To transmit data, I plan to use std::io::write but it requires a byte slice &[u8].