This patch addresses a static analysis issue reported by Cppcheck 2.9
where several classes in the toml/datetime.hpp header explicitly default
all their special member functions, including the default constructor,
but don't provide initializers for their data members. This might or
might not have caused any observable surprising behavior but I agree
with Cppcheck on this one in that an explicitly defaulted default
constructor should be expected to initialize all data members. So let's
do that.
Normally DST begins at A.M. 3 or 4. If we re-use conversion operator
of local_date and local_time independently, the conversion fails if
it is the day when DST begins or ends. Since local_date considers the
time is 00:00 A.M. and local_time does not consider DST because it
does not have any date information. We need to consider both date and
time information at the same time to convert it correctly.
std::chrono::seconds -= std::chrono::milliseconds cannot be done bc
it represents the duration as integer value and milliseconds are less
than seconds. it causes compilation error when we pass a duration to
toml::local_time. to avoid this, we need to type-cast the values to
smaller duration, like sec -> msec
