Chris@16: #ifndef _DATE_TIME_TIME_ZONE_BASE__
Chris@16: #define _DATE_TIME_TIME_ZONE_BASE__
Chris@16: 
Chris@16: /* Copyright (c) 2003-2005 CrystalClear Software, Inc.
Chris@16:  * Subject to the Boost Software License, Version 1.0.
Chris@16:  * (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  * Author: Jeff Garland, Bart Garst
Chris@101:  * $Date$
Chris@16:  */
Chris@16: 
Chris@16: 
Chris@16: #include <string>
Chris@16: #include <sstream>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace date_time {
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16:   //! Interface class for dynamic time zones.
Chris@16:   /*! This class represents the base interface for all timezone
Chris@16:    *  representations.  Subclasses may provide different systems
Chris@16:    *  for identifying a particular zone.  For example some may
Chris@16:    *  provide a geographical based zone construction while others
Chris@16:    *  may specify the offset from GMT.  Another possible implementation
Chris@16:    *  would be to convert from POSIX timezone strings.  Regardless of
Chris@16:    *  the construction technique, this is the interface that these
Chris@16:    *  time zone types must provide.
Chris@16:    *
Chris@16:    * Note that this class is intended to be used as a shared
Chris@16:    * resource (hence the derivation from boost::counted_base.
Chris@16:    */
Chris@16:   template<typename time_type, typename CharT>
Chris@16:   class time_zone_base  {
Chris@16:   public:
Chris@16:     typedef CharT char_type;
Chris@16:     typedef std::basic_string<CharT> string_type;
Chris@16:     typedef std::basic_ostringstream<CharT> stringstream_type;
Chris@16:     typedef typename time_type::date_type::year_type year_type;
Chris@16:     typedef typename time_type::time_duration_type time_duration_type;
Chris@16: 
Chris@16:     time_zone_base() {}
Chris@16:     virtual ~time_zone_base() {}
Chris@16:     //!String for the timezone when in daylight savings (eg: EDT)
Chris@16:     virtual string_type dst_zone_abbrev() const=0;
Chris@16:     //!String for the zone when not in daylight savings (eg: EST)
Chris@16:     virtual string_type std_zone_abbrev() const=0;
Chris@16:     //!String for the timezone when in daylight savings (eg: Eastern Daylight Time)
Chris@16:     virtual string_type dst_zone_name() const=0;
Chris@16:     //!String for the zone when not in daylight savings (eg: Eastern Standard Time)
Chris@16:     virtual string_type std_zone_name() const=0;
Chris@16:     //! True if zone uses daylight savings adjustments otherwise false
Chris@16:     virtual bool has_dst() const=0;
Chris@16:     //! Local time that DST starts -- undefined if has_dst is false
Chris@16:     virtual time_type dst_local_start_time(year_type y) const=0;
Chris@16:     //! Local time that DST ends -- undefined if has_dst is false
Chris@16:     virtual time_type dst_local_end_time(year_type y) const=0;
Chris@16:     //! Base offset from UTC for zone (eg: -07:30:00)
Chris@16:     virtual time_duration_type base_utc_offset() const=0;
Chris@16:     //! Adjustment forward or back made while DST is in effect
Chris@16:     virtual time_duration_type dst_offset() const=0;
Chris@16:     //! Returns a POSIX time_zone string for this object
Chris@16:     virtual string_type to_posix_string() const =0;
Chris@16: 
Chris@16:   private:
Chris@16: 
Chris@16:   };
Chris@16: 
Chris@16: 
Chris@16:   //! Structure which holds the time offsets associated with daylight savings time
Chris@16:   /*!
Chris@16:    *@param time_duration_type A type used to represent the offset
Chris@16:    */
Chris@16:   template<class time_duration_type>
Chris@16:   class dst_adjustment_offsets
Chris@16:   {
Chris@16:   public:
Chris@16:     dst_adjustment_offsets(const time_duration_type& dst_adjust,
Chris@16:                            const time_duration_type& dst_start_offset,
Chris@16:                            const time_duration_type& dst_end_offset) :
Chris@16:       dst_adjust_(dst_adjust),
Chris@16:       dst_start_offset_(dst_start_offset),
Chris@16:       dst_end_offset_(dst_end_offset)
Chris@16:     {}
Chris@16: 
Chris@16:     //! Amount DST adjusts the clock eg: plus one hour
Chris@16:     time_duration_type dst_adjust_;
Chris@16:     //! Time past midnight on start transition day that dst starts
Chris@16:     time_duration_type dst_start_offset_;
Chris@16:     //! Time past midnight on end transition day that dst ends
Chris@16:     time_duration_type dst_end_offset_;
Chris@16:   };
Chris@16: 
Chris@16: 
Chris@16: } } //namespace date_time
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: #endif