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

daminetreg's answer works, but it can be a little verbose when used for lots of option entries. I just hacked together an overload for the value( T* v ) template to construct my value_sematics with an additional value_name: using

template
typed_value*
value(T* v, const char * value_typename)
{
    typed_value* r = new typed_value(v);
    r->value_name( value_typename );

    return r;        
}

you can create and add a new program_option like this:

int width;
desc.add_options()
    ("width", boost::program_options::value( &width, "NUM"),
     "Give width");

(Note: this doesn't address all the other construction templates, especially not the default value() constructor that the OP wants to use)