Update option values ​​in boost :: program_options from a new source

Question

I am just starting to dig into boost::program_options for the first time. I like it quite a bit. However, what I am trying to do with this does not seem to be the way its designers took it into account.

I want to use boost::program_options to parse command line options, as well as configuration files. So far, so good. In addition, I would like to be able to check for updated settings (say, from a new configuration file) that could override previously analyzed parameters in my map_ variables.

Of course, I could do a separate parsing and try to combine the two cards. Perhaps this is what I will eventually do. I'm just curious, though, if someone has done something similar before and came up with a smooth solution.