Method foreach

src/common/recordio.hpp:245–254

    }

    foreach (const std::string& record, decode.get()) {
      Result<T> t = deserialize(record);

      if (!waiters.empty()) {
        waiters.front()->set(std::move(t));
        waiters.pop();
      } else {
        records.push(std::move(t));
      }
    }

    consume();
  }