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regarded and expertly designed C++ library projects in the
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— Herb Sutter and Andrei
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Coding Standards
boost::program_options::options_description
// 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 &); // public data members static const unsigned m_default_line_length; };
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.
See Also:
options_description
public
construct/copy/destructoptions_description(unsigned line_length = m_default_line_length, unsigned min_description_length = m_default_line_length/2);
Creates the instance.
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 functionsvoid 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.
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.
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.
const option_description & find(const std::string & name, bool approx, bool long_ignore_case = false, bool short_ignore_case = false) const;
const option_description * find_nothrow(const std::string & name, bool approx, bool long_ignore_case = false, bool short_ignore_case = false) const;
const std::vector< shared_ptr< option_description > > & options() const;
void print(std::ostream & os) const;
Outputs 'desc' to the specified stream, calling 'f' to output each option_description
element.
options_description
friend functionsfriend 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.