| #ifndef _DATE_TIME_TIME_ZONE_BASE__ |
| #define _DATE_TIME_TIME_ZONE_BASE__ |
| |
| /* Copyright (c) 2003-2005 CrystalClear Software, Inc. |
| * Subject to the Boost Software License, Version 1.0. |
| * (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt) |
| * Author: Jeff Garland, Bart Garst |
| * $Date: 2008-02-27 15:00:24 -0500 (Wed, 27 Feb 2008) $ |
| */ |
| |
| |
| #include <string> |
| #include <sstream> |
| |
| namespace boost { |
| namespace date_time { |
| |
| |
| |
| //! Interface class for dynamic time zones. |
| /*! This class represents the base interface for all timezone |
| * representations. Subclasses may provide different systems |
| * for identifying a particular zone. For example some may |
| * provide a geographical based zone construction while others |
| * may specify the offset from GMT. Another possible implementation |
| * would be to convert from POSIX timezone strings. Regardless of |
| * the construction technique, this is the interface that these |
| * time zone types must provide. |
| * |
| * Note that this class is intended to be used as a shared |
| * resource (hence the derivation from boost::counted_base. |
| */ |
| template<typename time_type, typename CharT> |
| class time_zone_base { |
| public: |
| typedef CharT char_type; |
| typedef std::basic_string<CharT> string_type; |
| typedef std::basic_ostringstream<CharT> stringstream_type; |
| typedef typename time_type::date_type::year_type year_type; |
| typedef typename time_type::time_duration_type time_duration_type; |
| |
| time_zone_base() {}; |
| virtual ~time_zone_base() {}; |
| //!String for the timezone when in daylight savings (eg: EDT) |
| virtual string_type dst_zone_abbrev() const=0; |
| //!String for the zone when not in daylight savings (eg: EST) |
| virtual string_type std_zone_abbrev() const=0; |
| //!String for the timezone when in daylight savings (eg: Eastern Daylight Time) |
| virtual string_type dst_zone_name() const=0; |
| //!String for the zone when not in daylight savings (eg: Eastern Standard Time) |
| virtual string_type std_zone_name() const=0; |
| //! True if zone uses daylight savings adjustments otherwise false |
| virtual bool has_dst() const=0; |
| //! Local time that DST starts -- undefined if has_dst is false |
| virtual time_type dst_local_start_time(year_type y) const=0; |
| //! Local time that DST ends -- undefined if has_dst is false |
| virtual time_type dst_local_end_time(year_type y) const=0; |
| //! Base offset from UTC for zone (eg: -07:30:00) |
| virtual time_duration_type base_utc_offset() const=0; |
| //! Adjustment forward or back made while DST is in effect |
| virtual time_duration_type dst_offset() const=0; |
| //! Returns a POSIX time_zone string for this object |
| virtual string_type to_posix_string() const =0; |
| |
| private: |
| |
| }; |
| |
| |
| //! Structure which holds the time offsets associated with daylight savings time |
| /*! |
| *@param time_duration_type A type used to represent the offset |
| */ |
| template<class time_duration_type> |
| class dst_adjustment_offsets |
| { |
| public: |
| dst_adjustment_offsets(const time_duration_type& dst_adjust, |
| const time_duration_type& dst_start_offset, |
| const time_duration_type& dst_end_offset) : |
| dst_adjust_(dst_adjust), |
| dst_start_offset_(dst_start_offset), |
| dst_end_offset_(dst_end_offset) |
| {} |
| |
| //! Amount DST adjusts the clock eg: plus one hour |
| time_duration_type dst_adjust_; |
| //! Time past midnight on start transition day that dst starts |
| time_duration_type dst_start_offset_; |
| //! Time past midnight on end transition day that dst ends |
| time_duration_type dst_end_offset_; |
| }; |
| |
| |
| } } //namespace date_time |
| |
| |
| |
| #endif |