message: iterator: s/_MSVC_VER/_MSC_VER/
diff: #if defined(__GNUC__)
  #include_next <iterator>
  -#elif defined(_MSVC_VER)
  +#elif defined(_MSC_VER)
  #include <../include/iterator> // HACKHACK
  #else
  #error "Cannot use range-v3 STL deep integration on this platform."
  