message: Implement write_packet
diff: @@ -276,12 +276,13 @@ private:
  }
  packet_queue_.pop_front();
  };
  - // TODO: Implement this with span<vector*>
  -
  - // Write buffers from the write_queue_ for as long as possible.
  - /*while (!packet_queue_.empty()) {
  + // Write as many bytes as possible.
  + while (!packet_queue_.empty()) {
  auto& packet = packet_queue_.front();
  - auto write_ret = write(handle_, make_span(packet.bytes),
  + std::vector<std::vector<byte>*> ptrs;
  + for(auto& buf : packet.bytes)
  + ptrs.emplace_back(&buf);
  + auto write_ret = write(handle_, make_span(ptrs),
  packet.destination);
  if (auto num_bytes = get_if<size_t>(&write_ret)) {
  CAF_LOG_DEBUG(CAF_ARG(handle_.id) << CAF_ARG(*num_bytes));
  @@ -297,7 +298,7 @@ private:
  }
  return true;
  }
  - }*/
  + }
  return false;
  }
  