message: std::ofstream::streampos is deprecated with c++17
diff: @@ -157,7 +157,7 @@ class Streaming_XML_exporter {
  m_xml_fstream << " </" << m_element_name << ">" << std::endl;
  // Save current pointer position
  - std::ofstream::streampos pos = m_xml_fstream.tellp();
  + auto pos = m_xml_fstream.tellp();
  // Close the XML file (temporarily) so that the XML file is always correct
  m_xml_fstream << "</" << m_list_name << ">" << std::endl;
  // Restore the pointer position so that the next "add_element" will overwrite
  