Pre-buffer offset?

[chrysn]

The separation of buffer (with its end) and length already allows having nanoCBOR encoded into the first block of a CoAP block-wise response. Would it be reasonable to extend the encoder by a field that counts how many initially encoded bytes to discard? (Similar to how the produced length tells how many bytes were discarded after the buffer).

I don't have a full use case yet, but looked at @silkeh's RIOT-OS/RIOT#17571, and that would appear to work great with CoAP block-wise. So this is not a full feature request yet, more like a "would it make sense to add this feature?"

(And it may happen that the next request is then for a checksum field that all the input is fed into, which would then generate ETags to detect whether the blocks can even be assembled).