Return the (signed fractional) number of years between the specified beginDate and endDate according to the ISDA 1/1 day-count convention. If beginDate < endDate, then the result is one. If beginDate == endDate, then the result is zero. Note that reversing the order of beginDate and endDate negates the result; specifically, |yearsDiff(b, e) + yearsDiff(e, b)| <= 1.0e-15 for all dates b and e.
Declared in <bbldc_basicisda11.h>
static
double
yearsDiff(
bdlt::Date const& beginDate,
bdlt::Date const& endDate);