...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::invalid_command_line_style
class invalid_command_line_style : public boost::program_options::error { public: // construct/copy/destruct invalid_command_line_style(const std::string &); };