boost/program_options/variables_map.hpp
// Copyright Vladimir Prus 2002-2004. // Distributed under the Boost Software License, Version 1.0. // (See accompanying file LICENSE_1_0.txt // or copy at http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_VARIABLES_MAP_VP_2003_05_19 #define BOOST_VARIABLES_MAP_VP_2003_05_19 #include <boost/program_options/config.hpp> #include <boost/any.hpp> #include <boost/shared_ptr.hpp> #include <string> #include <map> #include <set> #if defined(BOOST_MSVC) # pragma warning (push) # pragma warning (disable:4251) // 'boost::program_options::variable_value::v' : class 'boost::any' needs to have dll-interface to be used by clients of class 'boost::program_options::variable_value #endif namespace boost { namespace program_options { template<class charT> class basic_parsed_options; class value_semantic; class variables_map; // forward declaration /** Stores in 'm' all options that are defined in 'options'. If 'm' already has a non-defaulted value of an option, that value is not changed, even if 'options' specify some value. */ BOOST_PROGRAM_OPTIONS_DECL void store(const basic_parsed_options<char>& options, variables_map& m, bool utf8 = false); /** Stores in 'm' all options that are defined in 'options'. If 'm' already has a non-defaulted value of an option, that value is not changed, even if 'options' specify some value. This is wide character variant. */ BOOST_PROGRAM_OPTIONS_DECL void store(const basic_parsed_options<wchar_t>& options, variables_map& m); /** Runs all 'notify' function for options in 'm'. */ BOOST_PROGRAM_OPTIONS_DECL void notify(variables_map& m); /** Class holding value of option. Contains details about how the value is set and allows to conveniently obtain the value. */ class BOOST_PROGRAM_OPTIONS_DECL variable_value { public: variable_value() : m_defaulted(false) {} variable_value(const boost::any& xv, bool xdefaulted) : v(xv), m_defaulted(xdefaulted) {} /** If stored value if of type T, returns that value. Otherwise, throws boost::bad_any_cast exception. */ template<class T> const T& as() const { return boost::any_cast<const T&>(v); } /** @overload */ template<class T> T& as() { return boost::any_cast<T&>(v); } /// Returns true if no value is stored. bool empty() const; /** Returns true if the value was not explicitly given, but has default value. */ bool defaulted() const; /** Returns the contained value. */ const boost::any& value() const; /** Returns the contained value. */ boost::any& value(); private: boost::any v; bool m_defaulted; // Internal reference to value semantic. We need to run // notifications when *final* values of options are known, and // they are known only after all sources are stored. By that // time options_description for the first source might not // be easily accessible, so we need to store semantic here. shared_ptr<const value_semantic> m_value_semantic; friend BOOST_PROGRAM_OPTIONS_DECL void store(const basic_parsed_options<char>& options, variables_map& m, bool); friend BOOST_PROGRAM_OPTIONS_DECL class variables_map; }; /** Implements string->string mapping with convenient value casting facilities. */ class BOOST_PROGRAM_OPTIONS_DECL abstract_variables_map { public: abstract_variables_map(); abstract_variables_map(const abstract_variables_map* next); virtual ~abstract_variables_map() {} /** Obtains the value of variable 'name', from *this and possibly from the chain of variable maps. - if there's no value in *this. - if there's next variable map, returns value from it - otherwise, returns empty value - if there's defaulted value - if there's next varaible map, which has a non-defauled value, return that - otherwise, return value from *this - if there's a non-defauled value, returns it. */ const variable_value& operator[](const std::string& name) const; /** Sets next variable map, which will be used to find variables not found in *this. */ void next(abstract_variables_map* next); private: /** Returns value of variable 'name' stored in *this, or empty value otherwise. */ virtual const variable_value& get(const std::string& name) const = 0; const abstract_variables_map* m_next; }; /** Concrete variables map which store variables in real map. This class is derived from std::map<std::string, variable_value>, so you can use all map operators to examine its content. */ class BOOST_PROGRAM_OPTIONS_DECL variables_map : public abstract_variables_map, public std::map<std::string, variable_value> { public: variables_map(); variables_map(const abstract_variables_map* next); // Resolve conflict between inherited operators. const variable_value& operator[](const std::string& name) const { return abstract_variables_map::operator[](name); } // Override to clear some extra fields. void clear(); void notify(); private: /** Implementation of abstract_variables_map::get which does 'find' in *this. */ const variable_value& get(const std::string& name) const; /** Names of option with 'final' values -- which should not be changed by subsequence assignments. */ std::set<std::string> m_final; friend BOOST_PROGRAM_OPTIONS_DECL void store(const basic_parsed_options<char>& options, variables_map& xm, bool utf8); /** Names of required options, filled by parser which has access to options_description. The map values are the "canonical" names for each corresponding option. This is useful in creating diagnostic messages when the option is absent. */ std::map<std::string, std::string> m_required; }; /* * Templates/inlines */ inline bool variable_value::empty() const { return v.empty(); } inline bool variable_value::defaulted() const { return m_defaulted; } inline const boost::any& variable_value::value() const { return v; } inline boost::any& variable_value::value() { return v; } }} #if defined(BOOST_MSVC) # pragma warning (pop) #endif #endif