cbor_tag_value
cbor_item_t *tag = cbor_build_tag(cbor_tag_value(item), item_copy);
fprintf(out, "Value: %" PRIu64 "\n", cbor_tag_value(item));
_cbor_encoded_header_size(cbor_tag_value(item)),
size_t written = cbor_encode_tag(cbor_tag_value(item), buffer, buffer_size);
_CBOR_NODISCARD CBOR_EXPORT uint64_t cbor_tag_value(const cbor_item_t *item);