When using boost::program_options, how does one set the name of the argument?

Question

When using boost::program_options, how do I set the name of an argument for boost::program_options::value<>()?

#include 

        

Answer 1

The program_options::value_semantic class doesn't parameterize the argument name, so I think you will have to define your own class. Something like this:

struct my_arg_type
    : public boost::program_options::typed_value
{
    my_arg_type(std::string const& name)
        : boost::program_options::typed_value(&my_value)
        , my_name(name)
        , my_value(0)
    {
    }
    std::string name() const { return my_name; }
    std::string my_name;
    int my_value;
};

boost::program_options::options_description desc;

my_arg_type arg("foo");
desc.add_options()
    ("width", &arg, "give width");

This should give something like:

--witdh foo    give width