log messages to file

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Hello everybody. I am trying to write a package for storing some information in a file in order to plot them later (usually in matlab). I need it in order to check if the things will work properly. Follows a more detailed description of the problem. What I would like to do is a simple logger class that would be initialized using the full path to the desired "log" file. A part from standard constructor and destructor i would like to have a function, lets say something like

void logMsg(<generic_msg> m);

That takes any ros msg as parameter and writes it to a file in matlab friendly format. Now I can think of multiple ways of doing it for example:

1. Use overloading. I will define multiple versions of logMsg with different parameters and code. Example:

   void logMsg(nav_msg::Odometry o);
   void logMsg(geometry_msg::Point p);
   

   PROS: easy to implement CONS: huge file, code repetition, poor flexibility

2. Taking a string as input. I will handle the messages as a string and print them to file as a string. However this requires the user to convert the string himself/herself, and this is not what I have in mind. Providing a function that formats the message in a string would end up in the problems above. Example:

   void logMsg(std::string s);
   std::string toString(<various_types_of_msgs>);

3. ????

I cannot think anything proper for the purpose, does anyone have any suggestions?

Thank you very much Andrea