This was a challenge and first time using #serde, so expected to take weeks (elapsed).
Thanks to the #Rust ecosystem, its awesome macros and serde's comprehensive type support it took a few days. 😱
More testing and tidying to do, but the really complex tricky stuff works.
To do this in the past would have been a large, complex, error prone task. I know because I've done it, save/load of a tree of complex structs including vectors, hashmaps and other library types.
