I have a data structure that deserializes from a #JSON object. It has a field for storing all unknown JSON properties. It also contains a couple of subobjects that are to be flattened into the containing object, as in #Rust serde(flatten) or #Java JsonAnyGetter/JsonAnySetter.

This has created a curious problem: upon serializing, any property in one of the flattened subobjects is *duplicated* in the list of unknown properties!

#programming