boost::program_options::store
// In header: <boost/program_options/variables_map.hpp> BOOST_PROGRAM_OPTIONS_DECL void store(const basic_parsed_options< char > & options, variables_map & m, bool utf8 = false);
Stores in 'm' all options that are defined in 'options'. If 'm' already has a non-defaulted value of an option, that value is not changed, even if 'options' specify some value.