This examples shows, how loggers are usally written. There are a lot of loggers to download for your project. Boost also has a logger.
Look at the #defines in lines 6 through 14. Here the global logging level is used to decide if output into the logfile should be made. Also the access to the logger - which is a Meyers Singleton - is made much easier for the application programmer, since it hides the toruous call the singleton instance.
Algorithms often need parameters which need to be adjusted while testing the program. Instead of writing all parameters in a .h-file which requires that the code has to be compiled after each change, we propose a method which allows parameter handling during runtime in a uniform manner.
A basic requirement for this is, that the parameters may still be used in equations, calculations and conditions without having to deal with bloatware method calls.