Is this function designed intentionally? boost::date_time::c_time::gmtime doesn't touch the result pointer passed.

`inline static std::tm* gmtime(const std::time_t* t, std::tm* result);`

I assume this function will change the result pointer by filling the struct; but it doesn't;

`Windows 10;
MSVC 16.11.7`

https://github.com/boostorg/date_time/blob/7156392706faa282044ce9f1d6ba9fdd207f6da9/include/boost/date_time/c_time.hpp#L109-L120