I have installed Clang 3.6.1 (along with previously used versions of GCC) downloaded from LLVM and using the clang for LLVM Windows installer on Windows 8.1 I:\modular-boost\libs\fixed_point\example>clang++ --version clang version 3.6.1 (tags/RELEASE_361/final) Target: i686-pc-windows-gnu Thread model: posix suggests that I have the compiler in place OK and it should be in my PATH (becos I asked for it to be). --debug-configuration notice: will use 'C:/LLVM/bin/clang++.exe' for clang-linux, condition <toolset>clang-linux-3.6.1 For a project, I have a jamfile starting project : requirements <include>../include # quickdox/include <include>../../.. # modular-boost root #toolset requirements. # GCC requirements. #<toolset>gcc:<cxxflags>-std=gnu++11 # If requires C++11 library. <toolset>gcc:<cxxflags>-Wno-unused-local-typedefs <toolset>gcc:<cxxflags>-Wno-missing-braces # Clang requirements. #<toolset>clang:<cxxflags>-std=c++11 # If requires C++11 library. (I also have environment BOOST_ROOT = I:\modular-boost) when I run b2 toolset=gcc all compiles and run as expected. when I run b2 toolset=clang I get messages like common.mkdir ..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-linux-3.6.1 common.mkdir ..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-linux-3.6.1\debug clang-linux.compile.c++.without-pth ..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\ clang-linux-3.6.1\debug\quick_auto_dox_index.obj quick_auto_dox_index.cpp:53:10: fatal error: 'iostream' file not found (or other files like cstddef, iomanip on other projects) #include <iostream> ^ 1 error generated. "C:/LLVM/bin/clang++.exe" -c -x c++ -O0 -g -fno-inline -Wall -g -march=i686 -m32 -DBOOST_ALL_NO_L IB=1 -I"..\..\.." -I"..\include" -o "..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test \clang-linux-3.6.1\debug\quick_auto_dox_index.obj" "quick_auto_dox_index.cpp" (Full log attached). This suggests that it is not finding the system file <iostream> ... but I'm puzzled at what is missing (and why). Suggestions most welcome. Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830