Implemented test for conversions between existing clocks
(sys_clock, utc_clock, tai_clock, gps_clock) showing that
they can be used instead of to_clock_time functions.
Added an clock_time_conversion trait, that should be specialized
with SourceClock and DestClock respectively and provide an function
that convert time_point in SourceClock to equivalent time_point
in DestClock.
This function has following specializations:
1) <sys_clock, utc_clock> - convert sys_time to utc_time
2) <utc_clock, sys_clock> - convert utc_time to sys_time
3) <Clock, sys_clock> - calls Clock::to_sys if it returns sys_time
4) <Clock, utc_clock> - calls Clock::to_utc if it returns utc_time
5) <sys_clock, Clock> - calls Clock::from_sys if it returns time_point<Clock>
5) <utc_clock, Clock> - calls Clock::from_utc if it returns time_point<Clock>
Implemented an clock_cast<DestClock>(time_point<SourceClock, Dur> st), that
works as follow:
1) If DestClock is same as SourceClock, returns std
2) Otherwise, if clock_conversion<SourceClock, DestClock> available, uses it
3) Otherwise, if tries using clock_conversion<SourceClock, CommClock>
and clock_conversion<CommClock, DestClock> for CommClock being utc_time
or sys_time
4) Otherwise, tries using clock_conversion<SourceClock, utc_clock>
and clock_conversion<sys_clock, DestinationClock> or reversed (firstly
convert to sys_clock, then to utc_clock) to convert.
All the calls to `std::time_get::get` had `0` as end-of-range iterator.
E.g.
auto& f = use_facet<time_get<CharT>>(is.getloc());
// ...
f.get(is, 0, is, err, &tm, command, fmt+1);
^
Using `nullptr` instead of `0` doesn't trigger the GCC 5.x warning:
> warning: zero as null pointer constant [-Wzero-as-null-pointer-constant]
tm variable is not initialized in to_stream(), and valgrind warns about
"Conditional jump or move depends on uninitialised value(s)".
This is a false positive, as strftime always reads tm_hour, even if it
ends up never using it. To silence the warnings, initialize tm to zero.
* Apple changed the location of their IANA database in High Sierra,
breaking current_zone(). Now on Apple the location of the IANA
database is searched for at run time.
Tomasz Kamiński
Darrell Wright
Howard Hinnant
Tullio Menga
Alexander Karatarakis
Michael Maroszek
Aaron Bishop
Pavel Davydov
Manlio Morini
Tomi Valkeinen
tagunil
Markus Werle
Tony Walker
atkawa7
Kiryl Mikhneev
gm