BOOST_VMD_EMPTY — Outputs emptiness.
// In header: <boost/vmd/empty.hpp> BOOST_VMD_EMPTY(...)
... = any variadic parameters. The parameters are ignored.
This macro is used to output emptiness ( nothing ) no matter what is passed to it.
If you use this macro to return a result, as in 'result BOOST_VMD_EMPTY' subsequently invoked, you should surround the result with BOOST_VMD_IDENTITY_RESULT to smooth over a VC++ problem.