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Class error_with_option_name



// In header: <boost/program_options/errors.hpp>

class error_with_option_name : public boost::program_options::error {
  // construct/copy/destruct
  error_with_option_name(const std::string &, const std::string & = "", 
                         const std::string & = "", int = 0);

  // public member functions
  void set_substitute(const std::string &, const std::string &);
  void set_substitute_default(const std::string &, const std::string &, 
                              const std::string &);
  void add_context(const std::string &, const std::string &, int);
  void set_prefix(int);
  void set_option_name(const std::string &);
  std::string get_option_name() const;
  void set_original_token(const std::string &);
  const char * what() const;

  // protected member functions
  void substitute_placeholders(const std::string &) const;
  void replace_token(const std::string &, const std::string &) const;
  std::string get_canonical_option_name() const;
  std::string get_canonical_option_prefix() const;

  // public data members
  std::string m_error_template;


Base class for most exceptions in the library.

Substitutes the values for the parameter name placeholders in the template to create the human readable error message

Placeholders are surrounded by % signs: example% Poor man's version of boost::format

If a parameter name is absent, perform default substitutions instead so ugly placeholders are never left in-place.

Options are displayed in "canonical" form This is the most unambiguous form of the *parsed* option name and would correspond to option_description::format_name() i.e. what is shown by print_usage()

The "canonical" form depends on whether the option is specified in short or long form, using dashes or slashes or without a prefix (from a configuration file)

error_with_option_name public construct/copy/destruct

  1. error_with_option_name(const std::string & template_, 
                           const std::string & option_name = "", 
                           const std::string & original_token = "", 
                           int option_style = 0);
  2. ~error_with_option_name();

    gcc says that throw specification on dtor is loosened without this line

error_with_option_name public member functions

  1. void set_substitute(const std::string & parameter_name, 
                        const std::string & value);

    Substitute parameter_name->value to create the error message from the error template

  2. void set_substitute_default(const std::string & parameter_name, 
                                const std::string & from, const std::string & to);

    If the parameter is missing, then make the from->to substitution instead

  3. void add_context(const std::string & option_name, 
                     const std::string & original_token, int option_style);

    Add context to an exception

  4. void set_prefix(int option_style);
  5. void set_option_name(const std::string & option_name);

    Overridden in error_with_no_option_name

  6. std::string get_option_name() const;
  7. void set_original_token(const std::string & original_token);
  8. const char * what() const;

    Creates the error_message on the fly Currently a thin wrapper for substitute_placeholders()

error_with_option_name protected member functions

  1. void substitute_placeholders(const std::string & error_template) const;

    Makes all substitutions using the template

  2. void replace_token(const std::string & from, const std::string & to) const;
  3. std::string get_canonical_option_name() const;

    Construct option name in accordance with the appropriate prefix style: i.e. long dash or short slash etc

  4. std::string get_canonical_option_prefix() const;

error_with_option_name public public data members

  1. std::string m_error_template;

    template with placeholders