Coverage Report

Created: 2023-02-22 06:51

/src/icu/source/i18n/unicode/basictz.h
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// © 2016 and later: Unicode, Inc. and others.
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// License & terms of use: http://www.unicode.org/copyright.html
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/*
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*******************************************************************************
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* Copyright (C) 2007-2013, International Business Machines Corporation and
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* others. All Rights Reserved.
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*******************************************************************************
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*/
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#ifndef BASICTZ_H
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#define BASICTZ_H
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/**
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 * \file 
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 * \brief C++ API: ICU TimeZone base class
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 */
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#include "unicode/utypes.h"
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#if U_SHOW_CPLUSPLUS_API
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#if !UCONFIG_NO_FORMATTING
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#include "unicode/timezone.h"
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#include "unicode/tzrule.h"
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#include "unicode/tztrans.h"
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U_NAMESPACE_BEGIN
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// forward declarations
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class UVector;
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/**
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 * <code>BasicTimeZone</code> is an abstract class extending <code>TimeZone</code>.
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 * This class provides some additional methods to access time zone transitions and rules.
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 * All ICU <code>TimeZone</code> concrete subclasses extend this class.
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 * @stable ICU 3.8
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 */
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class U_I18N_API BasicTimeZone: public TimeZone {
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public:
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    /**
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     * Destructor.
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     * @stable ICU 3.8
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     */
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    virtual ~BasicTimeZone();
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    /**
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     * Clones this object polymorphically.
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     * The caller owns the result and should delete it when done.
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     * @return clone, or nullptr if an error occurred
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     * @stable ICU 3.8
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     */
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    virtual BasicTimeZone* clone() const = 0;
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    /**
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     * Gets the first time zone transition after the base time.
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     * @param base      The base time.
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     * @param inclusive Whether the base time is inclusive or not.
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     * @param result    Receives the first transition after the base time.
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     * @return  true if the transition is found.
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     * @stable ICU 3.8
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     */
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    virtual UBool getNextTransition(UDate base, UBool inclusive, TimeZoneTransition& result) const = 0;
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    /**
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     * Gets the most recent time zone transition before the base time.
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     * @param base      The base time.
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     * @param inclusive Whether the base time is inclusive or not.
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     * @param result    Receives the most recent transition before the base time.
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     * @return  true if the transition is found.
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     * @stable ICU 3.8
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     */
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    virtual UBool getPreviousTransition(UDate base, UBool inclusive, TimeZoneTransition& result) const = 0;
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    /**
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     * Checks if the time zone has equivalent transitions in the time range.
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     * This method returns true when all of transition times, from/to standard
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     * offsets and DST savings used by this time zone match the other in the
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     * time range.
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     * @param tz    The <code>BasicTimeZone</code> object to be compared with.
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     * @param start The start time of the evaluated time range (inclusive)
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     * @param end   The end time of the evaluated time range (inclusive)
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     * @param ignoreDstAmount
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     *              When true, any transitions with only daylight saving amount
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     *              changes will be ignored, except either of them is zero.
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     *              For example, a transition from rawoffset 3:00/dstsavings 1:00
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     *              to rawoffset 2:00/dstsavings 2:00 is excluded from the comparison,
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     *              but a transition from rawoffset 2:00/dstsavings 1:00 to
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     *              rawoffset 3:00/dstsavings 0:00 is included.
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     * @param ec    Output param to filled in with a success or an error.
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     * @return      true if the other time zone has the equivalent transitions in the
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     *              time range.
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     * @stable ICU 3.8
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     */
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    virtual UBool hasEquivalentTransitions(const BasicTimeZone& tz, UDate start, UDate end,
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        UBool ignoreDstAmount, UErrorCode& ec) const;
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    /**
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     * Returns the number of <code>TimeZoneRule</code>s which represents time transitions,
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     * for this time zone, that is, all <code>TimeZoneRule</code>s for this time zone except
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     * <code>InitialTimeZoneRule</code>.  The return value range is 0 or any positive value.
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     * @param status    Receives error status code.
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     * @return The number of <code>TimeZoneRule</code>s representing time transitions.
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     * @stable ICU 3.8
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     */
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    virtual int32_t countTransitionRules(UErrorCode& status) const = 0;
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    /**
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     * Gets the <code>InitialTimeZoneRule</code> and the set of <code>TimeZoneRule</code>
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     * which represent time transitions for this time zone.  On successful return,
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     * the argument initial points to non-NULL <code>InitialTimeZoneRule</code> and
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     * the array trsrules is filled with 0 or multiple <code>TimeZoneRule</code>
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     * instances up to the size specified by trscount.  The results are referencing the
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     * rule instance held by this time zone instance.  Therefore, after this time zone
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     * is destructed, they are no longer available.
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     * @param initial       Receives the initial timezone rule
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     * @param trsrules      Receives the timezone transition rules
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     * @param trscount      On input, specify the size of the array 'transitions' receiving
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     *                      the timezone transition rules.  On output, actual number of
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     *                      rules filled in the array will be set.
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     * @param status        Receives error status code.
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     * @stable ICU 3.8
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     */
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    virtual void getTimeZoneRules(const InitialTimeZoneRule*& initial,
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        const TimeZoneRule* trsrules[], int32_t& trscount, UErrorCode& status) const = 0;
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    /**
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     * Gets the set of time zone rules valid at the specified time.  Some known external time zone
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     * implementations are not capable to handle historic time zone rule changes.  Also some
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     * implementations can only handle certain type of rule definitions.
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     * If this time zone does not use any daylight saving time within about 1 year from the specified
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     * time, only the <code>InitialTimeZone</code> is returned.  Otherwise, the rule for standard
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     * time and daylight saving time transitions are returned in addition to the
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     * <code>InitialTimeZoneRule</code>.  The standard and daylight saving time transition rules are
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     * represented by <code>AnnualTimeZoneRule</code> with <code>DateTimeRule::DOW</code> for its date
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     * rule and <code>DateTimeRule::WALL_TIME</code> for its time rule.  Because daylight saving time
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     * rule is changing time to time in many time zones and also mapping a transition time rule to
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     * different type is lossy transformation, the set of rules returned by this method may be valid
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     * for short period of time.
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     * The time zone rule objects returned by this method is owned by the caller, so the caller is
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     * responsible for deleting them after use.
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     * @param date      The date used for extracting time zone rules.
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     * @param initial   Receives the <code>InitialTimeZone</code>, always not NULL.
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     * @param std       Receives the <code>AnnualTimeZoneRule</code> for standard time transitions.
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     *                  When this time time zone does not observe daylight saving times around the
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     *                  specified date, NULL is set.
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     * @param dst       Receives the <code>AnnualTimeZoneRule</code> for daylight saving time
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     *                  transitions.  When this time zone does not observer daylight saving times
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     *                  around the specified date, NULL is set.
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     * @param status    Receives error status code.
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     * @stable ICU 3.8
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     */
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    virtual void getSimpleRulesNear(UDate date, InitialTimeZoneRule*& initial,
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        AnnualTimeZoneRule*& std, AnnualTimeZoneRule*& dst, UErrorCode& status) const;
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#ifndef U_FORCE_HIDE_DRAFT_API
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    /**
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     * Get time zone offsets from local wall time.
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     * @draft ICU 69
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     */
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    virtual void getOffsetFromLocal(
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        UDate date, UTimeZoneLocalOption nonExistingTimeOpt,
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        UTimeZoneLocalOption duplicatedTimeOpt, int32_t& rawOffset,
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        int32_t& dstOffset, UErrorCode& status) const;
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#endif /* U_FORCE_HIDE_DRAFT_API */
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#ifndef U_HIDE_INTERNAL_API
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    /**
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     * The time type option bit flags used by getOffsetFromLocal
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     * @internal
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     */
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    enum {
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        kStandard = 0x01,
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        kDaylight = 0x03,
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        kFormer = 0x04, /* UCAL_TZ_LOCAL_FORMER */
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        kLatter = 0x0C  /* UCAL_TZ_LOCAL_LATTER */
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    };
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    /**
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     * Get time zone offsets from local wall time.
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     * @internal
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     */
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    void getOffsetFromLocal(UDate date, int32_t nonExistingTimeOpt, int32_t duplicatedTimeOpt,
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        int32_t& rawOffset, int32_t& dstOffset, UErrorCode& status) const;
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#endif  /* U_HIDE_INTERNAL_API */
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protected:
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#ifndef U_HIDE_INTERNAL_API
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    /**
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     * The time type option bit masks used by getOffsetFromLocal
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     * @internal
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     */
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    enum {
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        kStdDstMask = kDaylight,
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        kFormerLatterMask = kLatter
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    };
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#endif  /* U_HIDE_INTERNAL_API */
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    /**
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     * Default constructor.
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     * @stable ICU 3.8
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     */
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    BasicTimeZone();
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    /**
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     * Construct a timezone with a given ID.
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     * @param id a system time zone ID
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     * @stable ICU 3.8
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     */
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    BasicTimeZone(const UnicodeString &id);
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    /**
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     * Copy constructor.
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     * @param source the object to be copied.
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     * @stable ICU 3.8
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     */
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    BasicTimeZone(const BasicTimeZone& source);
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    /**
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     * Copy assignment.
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     * @stable ICU 3.8
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     */
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    BasicTimeZone& operator=(const BasicTimeZone&) = default;
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    /**
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     * Gets the set of TimeZoneRule instances applicable to the specified time and after.
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     * @param start     The start date used for extracting time zone rules
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     * @param initial   Receives the InitialTimeZone, always not NULL
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     * @param transitionRules   Receives the transition rules, could be NULL
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     * @param status    Receives error status code
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     */
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    void getTimeZoneRulesAfter(UDate start, InitialTimeZoneRule*& initial, UVector*& transitionRules,
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        UErrorCode& status) const;
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};
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U_NAMESPACE_END
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#endif /* #if !UCONFIG_NO_FORMATTING */
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#endif /* U_SHOW_CPLUSPLUS_API */
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#endif // BASICTZ_H
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//eof