Description of the real problem: - let "-b" be the name of the option - it disables, if not present in command line, the general app logging - it enables, if present in command line, the general app logging in a default chosen logfile - it enables, if present in command line with a string argument, the general app logging into the file specified as string argument Usage example:
program_name (no logging) program_name -b (logging enabled; goes to logfile.log) program_name -b "C:\otherlogfile.log" (logs where specified)
So far I found a solution based on implicit_value() behaviour, with "-b" of type string, but my main problem is that in this case I am forced to enter the value to be adjacent to "-b" (e.g. -b"C:\otherlogfile.log"). The desired form would be the one with a space between, in order to maintain our backward compatibility of scripts (e.g: -b "C:\otherlogfile.log"). Can you help me with a good solution? (Even solutions that crack into the source of boost program options library are appreciated.) Thank you for your time. -- Kind regards, Andrei LIHU -------------------- softNRG C++ Software Developer +40742545392