I really like Boost Program Options. I came up with this wild hare of being able to handle something like foo= int float Obviously, I could do it by instead using foo_int= int foo_float= float But what would be involved in being able to do something like add_options()(optionNameWork, po::value<std::pair<int, float>>() ? I would have to derive a class from boost::program_options::value_semantic? I would have to implement all of the abstract methods? The other classes also like abstract_variables_map? Or just variable_value? Volodya wrote in response to an earlier question "I would imagine this to be not hard. Either define operator>> for the class you use to represent rectangles, over override 'validate'" Is that what I should? Define operator>> for pair<int, float> ? Where is an example of a boost::program_options >> operator? Where is validate() declared? Sorry to be such a newbie at this level of C++ programming. You have to start somewhere. Charles