Tools.h++ Manual

21-238 104011 Tandem Computers Incorporated
21
Given these definitions,
RWZone::local(new RWZoneSimple(RWZone::USCentral,
&usRuleLate)) ;
is equivalent to the first example given above and repeated here:
RWZone::local(new RWZoneSimple(RWZone::USCentral)) ;
Daylight savings time systems that cannot be represented with
RWDaylightRule and RWZoneSimple must be modeled by deriving from
RWZone and implementing its virtual functions.
For example, under Britain’s madcap Summer Time rules, alternate
timekeeping begins the morning after the third Saturday in April, unless that is
Easter (in which case it begins the week before) or unless the Council decides
on some other time for that year. In some years Summer Time has been two
hours ahead, or has extended through winter without a break. British Summer
Time clearly deserves a RWZone class all its own.
Constructors RWZoneSimple(RWZone::StdZone zone, RWZone::DstRule =
RWZone::NoAm) ;
Constructs an RWZoneSimple instance using internally held
RWDaylightRules . This is the simplest interface to RWZoneSimple . The first
argument is the time zone for which an RWZoneSimple is to be constructed.
The second argument is the daylight savings time rule which is to be followed.
RWZoneSimple(const RWDaylightRule* rule,
long tzoff, const RWCString& tzname,
long altoff, const RWCString& altname) ;
Constructs an RWZoneSimple instance which Daylight Savings Time is
computed according to the rule specified. Variables tzoff and tzname are the
offset from UTC (in seconds, positive if west of 0 degrees longitude) and the
name of standard time. Arguments altoff and altname are the offset
(typically equal to tzoff - 3600 ) and name when daylight savings time is in
effect. If rule is zero, daylight savings time is not observed.
RWZoneSimple(long tzoff, const RWCString& tzname) ;
Constructs an RWZoneSimple instance in which Daylight Savings Time is not
observed. Argument tzoff is the offset from UTC (in seconds, positive if west
of 0 degrees longitude) and tzname is the name of the zone.