template <class Rep1, class Period1, class Rep2, class Period2>
struct common_type<std::chrono::duration<Rep1, Period1>,
std::chrono::duration<Rep2, Period2>> {
typedef std::chrono::duration<
typename std::common_type<Rep1, Rep2>::type, /*see note*/> type;
}; (since C++11)
Exposes the type named type, which is the common type of two std::chrono::durations.
Note
The period of the resulting duration is the greatest comm