A long time ago, I wrote an ORM to serialize/deserialize object data seamlessly into SQLite, with massive arrays of floats being stored as blobs.

In code, I could effectively mark which class members need to be stored/restored, and optionally provide a custom serialization function for them if needed.

The latter was effectively never necessary, because all the bases types and multi-dimensional arrays were handled by templates.

Really wish I open-sourced that thing then, but the corporate bureaucracy around that was tricky.

I remember sufficiently little about implementation details now that I think I can get to writing it again, without producing a copypasta of that code - and maybe I should :)