CLASS OPTIONS_DE(3)

NAME
boost::program_options::options_description

SYNOPSIS

// In header: <boost/program_options/options_description.hpp>
class options_description {
public:
  // construct/copy/destruct
  options_description(unsigned = m_default_line_length,
                      unsigned = m_default_line_length/2);
  options_description(const std::string &, unsigned = m_default_line_length,
                      unsigned = m_default_line_length/2);
  // public member functions
  void add(shared_ptr< option_description >);
  options_description & add(const options_description &);
  options_description_easy_init add_options();
  const option_description &
  find(const std::string &, bool, bool = false, bool = false) const;
  const option_description *
  find_nothrow(const std::string &, bool, bool = false, bool = false) const;
  const std::vector< shared_ptr< option_description > > & options() const;
  void print(std::ostream &) const;
  // friend functions
  friend BOOST_PROGRAM_OPTIONS_DECL std::ostream &
  operator<<(std::ostream &, const options_description &);
  static const unsigned m_default_line_length;
};

DESCRIPTION

A set of option descriptions. This provides convenient interface for adding new option (the add_options) method, and facilities to search for options by name.

See here for option adding interface discussion.

  options_description public construct/copy/destruct

    1.

    options_description(unsigned line_length = m_default_line_length,
                        unsigned min_description_length = m_default_line_length/2);

    Creates the instance.

    2.

    options_description(const std::string & caption,
                        unsigned line_length = m_default_line_length,
                        unsigned min_description_length = m_default_line_length/2);

    Creates the instance. The 'caption' parameter gives the name of this 'options_description' instance. Primarily useful for output. The 'description_length' specifies the number of columns that should be reserved for the description text; if the option text encroaches into this, then the description will start on the next line.

  options_description public member functions

    1.

    void add(shared_ptr< option_description > desc);

    Adds new variable description. Throws duplicate_variable_error if either short or long name matches that of already present one.

    2.

    options_description & add(const options_description & desc);

    Adds a group of option description. This has the same effect as adding all option_descriptions in 'desc' individually, except that output operator will show a separate group. Returns *this.

    3.

    options_description_easy_init add_options();

    Returns an object of implementation-defined type suitable for adding options to options_description. The returned object will have overloaded operator() with parameter type matching 'option_description' constructors. Calling the operator will create new option_description instance and add it.

    4.

    const option_description &
    find(const std::string & name, bool approx, bool long_ignore_case = false,
         bool short_ignore_case = false) const;

    5.

    const option_description *
    find_nothrow(const std::string & name, bool approx,
                 bool long_ignore_case = false, bool short_ignore_case = false) const;

    6.

    const std::vector< shared_ptr< option_description > > & options() const;

    7.

    void print(std::ostream & os) const;

    Outputs 'desc' to the specified stream, calling 'f' to output each option_description element.

  options_description friend functions

    1.

    friend BOOST_PROGRAM_OPTIONS_DECL std::ostream &
    operator<<(std::ostream & os, const options_description & desc);

    Produces a human readable output of 'desc', listing options, their descriptions and allowed parameters. Other options_description instances previously passed to add will be output separately.