feature: re-add OpenDriveMap::xml_doc holding the xml tree data

Author: pageldev

include/OpenDriveMap.h

@@ -42,6 +42,8 @@ class OpenDriveMap
     double      y_offs = 0;
     std::string xodr_file = "";
 
+    pugi::xml_document xml_doc; // only movable, owns tree data
+
     std::map<std::string, Road>     id_to_road;
     std::map<std::string, Junction> id_to_junction;
 };

src/OpenDriveMap.cpp

@@ -46,8 +46,7 @@ OpenDriveMap::OpenDriveMap(const std::string& xodr_file,
                            const bool         with_road_signals) :
     xodr_file(xodr_file)
 {
-    pugi::xml_document           xml_doc;
-    const pugi::xml_parse_result xml_parse_result = xml_doc.load_file(xodr_file.c_str());
+    const pugi::xml_parse_result xml_parse_result = this->xml_doc.load_file(xodr_file.c_str());
     if (!xml_parse_result)
         log::error("Error parsing xml: {}", xml_parse_result.description());