> even a really cool library that makes Rust do this.

The first library that comes to mind when I think of this is `serde` with `#[derive(Serialize, Deserialize)]`, but that gives persistence-format output as you describe is preferable to the former case. I usually use it with JSON.

So, this seems like it may be a false dichotomy.

I know "serde" is a take on "codec" but *rewrite* was right there! Also, as long as I'm whinging about naming? 'print' and 'parse' are five letter p words in a bidirectional relationship. Oh! Oh! push, peek, poke, ... pull! It even makes more sense than pop! And it's four letters!

Maybe a little bit. But serde works with JSON (among other formats), and you can use it to read and write JSON that interoperates with other libraries and languages just fine. Kind of like how SQLAlchemy looks kind of like you’re writing normal Python code, but it interoperates with SQL.

rkyv is not like this.