//! Converts a date to a tm struct. Throws out_of_range exception if date is a special value
inline
std::tm to_tm(const date& d)
{
if (d.is_special())
{
std::string s = "tm unable to handle ";
switch (d.as_special())
{
case date_time::not_a_date_time:
s += "not-a-date-time value";
break;
case date_time::neg_infin:
s += "-infinity date value";
break;
case date_time::pos_infin:
s += "+infinity date value";
break;
default:
s += "a special date value";
break;
}
boost::throw_exception(std::out_of_range(s));
}
std::tm datetm;
std::memset(&datetm, 0, sizeof(datetm));
boost::gregorian::date::ymd_type ymd = d.year_month_day();
datetm.tm_year = ymd.year - 1900;
datetm.tm_mon = ymd.month - 1;
datetm.tm_mday = ymd.day;
datetm.tm_wday = d.day_of_week();
datetm.tm_yday = d.day_of_year() - 1;
datetm.tm_isdst = -1; // negative because not enough info to set tm_isdst
return datetm;
}
