Status serializeRow(const Row& r, const ColumnNames& cols, JSON& doc, rj::Value& obj) { if (cols.empty()) { for (const auto& i : r) { doc.addRef(i.first, i.second, obj); } } else { for (const auto& c : cols) { auto i = r.find(c); if (i != r.end()) { doc.addRef(c, i->second, obj); } } } return Status(); }