...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::program_options::duplicate_option_error
// In header: <boost/program_options/options_description.hpp> class duplicate_option_error : public boost::program_options::error { public: // public member functions duplicate_option_error(const std::string &); };