I am trying to build the Boost 1.41.0 libraries with an evaluation copy of Intel C++ 11.1 for 64-bit Linux. My system is Fedora 12 with G++ 4.4.3 installed as the default compiler. This fatal error is preventing most of the libraries from building: /usr/include/c++/4.4.3/cmath(500): error: identifier "__builtin_fpclassify" is undefined return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, ^ detected during: instantiation of "__gnu_cxx::__enable_if<std::__is_arithmetic<_Tp>::__value, int>::__type std::fpclassify(_Tp) [with _Tp=float]" at line 65 of "./boost/functional/hash/detail/hash_float.hpp" instantiation of "size_t={unsigned long} boost::hash_detail::float_hash_value(T) [with T=float]" at line 282 of "./boost/functional/hash/hash.hpp" I am building the libraries with this command: bjam toolset=intel-linux threading=multi variant=release link=static,shared --stagedir=stageIF12 stage Release notes seem to indicate that someone has successfully built Boost libraries with Intel 11.1 and G++ 4.4.1 (whose cmath header looks the same as for 4.4.3). I have not used the Intel compiler for several years, so I may be missing something that is familiar to other users. Help? -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell@blueskystudios.com Blue Sky Studios http://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560