Does anybody know what the deal here? Test output: mslater - test - basic_cstring_test / mingw Linker output [2005-05-10 22:57:32 UTC]: "g++" "-Wl,--enable-auto-image-base" -g -Wl,--allow-multiple-definition -mno-cygwin -o "C:\testing\boost\results\bin\boost\libs\test\test\basic_cstring_test.test\mingw\debug\basic_cstring_test.exe" -L"C:/testing/boost/results/bin/boost/libs/test/build/libboost_unit_test_framework.lib/mingw/debug" "C:\testing\boost\results\bin\boost\libs\test\test\basic_cstring_test.test\mingw\debug\basic_cstring_test.obj" "C:\testing\boost\results\bin\boost\libs\test\build\libboost_unit_test_framework.lib\mingw\debug\libboost_unit_test_framework.lib" "C:\testing\boost\results\bin\boost\libs\test\build\libboost_unit_test_framework.lib\mingw\debug\libboost_unit_test_framework.lib" C:\testing\boost\results\bin\boost\libs\test\test\basic_cstring_test.test\mingw\debug\basic_cstring_test.obj(.text$_Z19asignment_test_implIwEvPN5boost4typeIT_EE+0xef): In function `ZSt4setwi': c:/mingw/include/c++/3.2.3/iomanip: undefined reference to `std::char_traits<wchar_t>::compare(wchar_t const*, wchar_t const*, unsigned)' And a lot more like this. Why references to std::char_traits<wchar_t> symbols are undefined? Gennadiy