Hello, I would like to ask if it is possible to change value_semantic associated with a program_option after it has been created ? I create `program_options` instance and populate it with add_options. Like in the examples provided by the documentation. I would like to change the semantics of a particular option later on. Is this even possible, or is this functionality deliberately disabled. I figured out that one can use options_description::find(), then strip it out `const`ness and dynamic cast to `typed_value_base` and use its methods. My motivation is such a design. I have a set of applications, which have a common subset of command line options/switches. However, they differ a bit in semantics. I.e. default value. I decided to refactor common parts into some `BasicApp` class and I thought I could move common options along with it as `boost::program_options` OO design should naturally support it. And it worked like a charm with `add_options` semantics to add new options. Up to the point I needed to change existing default values. Is there a proper way to do it ? Removing `const` constraint seems a bad approach since it looks like it's left there on purpose. Or my use-case is ill or hopeless. With regards, Łukasz.