#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 |