minicbor-serde: add support for serializing / deserializing custom CBOR tags

[mpanav]

Hey!

I'm am interested in using minicbor-serde to deserialize CBOR payloads with custom CBOR tags. I noticed that the implementation for deserialize_* forwards to the decoder, which biases towards rejecting unknown tags, which makes sense.

I was wondering if you'd be open to take a patch to add support for serializing / deserializing custom CBOR tags in minicbor-serde? Also, has there been any previous discussion on this topic or implementation ideas for this?

BTW, thanks for the awesome project!

[twittner]

Thank you for your interest in this project. This is the first time someone is discussing tag support for minicbor-serde (minicbor and minicbor-derive do support tags already). Maybe you would like to describe what you intend to add?

[mpanav]

I looked into how other CBOR serde frameworks handle tags and I think ciborium's approach is pretty interesting. The library provides different wrapper types for tags (required, optional, any, etc) and it handles ser/de for tags through const generics.

My initial thought was to do something similar in minicbor-serde. Let me know what your thoughts are :)

[twittner]

Thanks @mpanav, feel free to open a PR.

[mpanav]

Hey @twittner, I've opened up a PR. Let me know if you have any feedback on the change!