How to serialize a union without knowing its type?

[niebayes]

I have a union Signal and I want to dump it using this json library. This union only has POD field types. How can I implement the to_json and from_json for the union?

[nlohmann]

See https://json.nlohmann.me/features/arbitrary_types/

[niebayes]

Yes, I have read about it before I post this question. But my problem is that I only have a union which can be int32, int64, double64, or any other POD type. I don't know which type the union exactly is.

[nlohmann]

Then how should the library know? 🤔

[niebayes]

I am a newbee to cpp. Can I cast the union to bytes and serialize the bytes using this library? I can ingest the bytes later on at which moment I would know the exact type of the bytes.

[nlohmann]

If you can express this in code, you can implement this in the to_json function. I don't think this is a problem specific to this library.

[niebayes]

Thank you for your reply!