id summary reporter owner description type status milestone component version severity resolution keywords cc 11833 Boost usage of __int128 when compiled with clang-cl Yaron Keren John Maddock "Boost compiled with clang-cl targetting MSVC toolchain should not probably use __int128 as the support functions __umodti3 and friends, usually available from libgcc are not available from the MSVC libs leading to error LNK2019: unresolved external symbol __umodti3. This may be solved either by using compiler-rt along with the MSVC libs or by not defining BOOST_HAS_INT128 in clang.hpp: #if defined(__SIZEOF_INT128__) && !defined(__CUDACC__) && !defined(_MSC_VER) # define BOOST_HAS_INT128 #endif I'm not sure which is the right way to go here, but this should be at least be documented. " Bugs closed To Be Determined config Boost 1.59.0 Problem fixed