warning in to_time_t when std::time_t is 32-bit

I have 32-bit std::time_t and boost 1.67 installed
Visual Studio gives me warning C4244: 'return': conversion from '__int64' to 'time_t', possible loss of data
at boost\date_time\posix_time\conversion.hpp
The warning is raised at boost::posix_time::to_time_t
May be wrap return statement by static_cast ? Is it safe enough?

Start in boost/date_time/posix_time/conversion.hpp at boost::posix_time::to_time_t and reproduce the C4244 warning with a 32-bit std::time_t under Visual Studio. Check whether the conversion can safely use an explicit std::time_t cast, then verify that the warning is resolved without changing valid conversion behavior.

Written by the indexing model from the issue text.