Just to drive the point home, serde does solve the n^2 → 2n problem: serialized data is first deserialized to serde's intermediate data model (consisting of, li

Just to drive the point home, serde does solve the n^2 → 2n problem: serialized data is first deserialized to serde's intermediate data model (consisting of, like, 30 or so different types), from which a bespoke Rust object is produced. So you define how your types (de)serialize oblivious to the fact that serde_json, say, will be on the other end doing the actual (de)serialization.