Describes one possible command line/config file option. More...

#include <options_description.hpp>

Public Types
enum	match_result { no_match, full_match, approximate_match }

Public Member Functions
	option_description ()

	option_description (const char name, const value_semantic s)
	Initializes the object with the passed data. More...

	option_description (const char name, const value_semantic s, const char *description)
	Initializes the class with the passed data. More...

virtual	~option_description ()

match_result	match (const std::string &option, bool approx, bool long_ignore_case, bool short_ignore_case) const
	Given 'option', specified in the input source, returns 'true' if 'option' specifies *this. More...

const std::string &	key (const std::string &option) const
	Returns the key that should identify the option, in particular in the variables_map class. More...

std::string	canonical_display_name (int canonical_option_style=0) const
	Returns the canonical name for the option description to enable the user to recognised a matching option. More...

const std::string &	long_name () const

const std::string &	description () const
	Explanation of this option. More...

shared_ptr< const value_semantic >	semantic () const
	Semantic of option's value. More...

std::string	format_name () const
	Returns the option name, formatted suitably for usage message. More...

std::string	format_parameter () const
	Returns the parameter name and properties, formatted suitably for usage message. More...

Detailed Description

Describes one possible command line/config file option.

There are two kinds of properties of an option. First describe it syntactically and are used only to validate input. Second affect interpretation of the option, for example default value for it or function that should be called when the value is finally known. Routines which perform parsing never use second kind of properties – they are side effect free.

See also: options_description

Member Enumeration Documentation

enum boost::program_options::option_description::match_result

Enumerator
no_match
full_match
approximate_match

Constructor & Destructor Documentation

boost::program_options::option_description::option_description ( )

boost::program_options::option_description::option_description	(	const char *	name,
		const value_semantic *	s
	)

Initializes the object with the passed data.

Note: it would be nice to make the second parameter auto_ptr, to explicitly pass ownership. Unfortunately, it's often needed to create objects of types derived from 'value_semantic': options_description d; d.add_options()("a", parameter<int>("n")->default_value(1)); Here, the static type returned by 'parameter' should be derived from value_semantic.

Alas, derived->base conversion for auto_ptr does not really work, see http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2000/n1232.pdf http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#84

So, we have to use plain old pointers. Besides, users are not expected to use the constructor directly.

The 'name' parameter is interpreted by the following rules:

if there's no "," character in 'name', it specifies long name
otherwise, the part before "," specifies long name and the part after – short name.

boost::program_options::option_description::option_description	(	const char *	name,
		const value_semantic *	s,
		const char *	description
	)

Initializes the class with the passed data.

virtual boost::program_options::option_description::~option_description ( )

virtual

Member Function Documentation

std::string boost::program_options::option_description::canonical_display_name ( int canonical_option_style = 0 ) const

Returns the canonical name for the option description to enable the user to recognised a matching option.

1) For short options ('-', '/'), returns the short name prefixed. 2) For long options ('–' / '-') returns the long name prefixed 3) All other cases, returns the long name (if present) or the short name, unprefixed.

const std::string& boost::program_options::option_description::description ( ) const

Explanation of this option.

std::string boost::program_options::option_description::format_name ( ) const

Returns the option name, formatted suitably for usage message.

std::string boost::program_options::option_description::format_parameter ( ) const

Returns the parameter name and properties, formatted suitably for usage message.

const std::string& boost::program_options::option_description::key ( const std::string & option ) const

Returns the key that should identify the option, in particular in the variables_map class.

The 'option' parameter is the option spelling from the input source. If option name contains '*', returns 'option'. If long name was specified, it's the long name, otherwise it's a short name with prepended '-'.

const std::string& boost::program_options::option_description::long_name ( ) const

match_result boost::program_options::option_description::match	(	const std::string &	option,
		bool	approx,
		bool	long_ignore_case,
		bool	short_ignore_case
	)		const

Given 'option', specified in the input source, returns 'true' if 'option' specifies *this.

shared_ptr<const value_semantic> boost::program_options::option_description::semantic ( ) const

Semantic of option's value.

The documentation for this class was generated from the following file:

boost_1_57_0/boost/program_options/options_description.hpp

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation