Hi! Posting to devel, since I believe sucking ADL may be the cause ... I have a headache problem with VC8/SP1 which leads to some questions. 1. Can you confirm this behaviour? 2. Do you have a quick fix workaround for this? 3. Can this be fixed in future versions of boost The following innocent looking piece of code (boiled down within 2 days -sigh) ---snip--- #include <boost/numeric/interval.hpp> #include <boost/numeric/ublas/traits.hpp> #include <boost/numeric/ublas/vector.hpp> namespace ublas = boost::numeric::ublas; void trigger_ublas_compile_error() { ublas::vector<double> boom = ublas::zero_vector<double>(5); } ---EOF--- compiled with VC8 SP1 in DEBUG mode with a command line similar to (some private include paths ripped off) /Od /I "PATH_TO\boost_1_36_beta" /D "WIN32" /D "_WINDOWS" /D "_DEBUG" /D "_CRT_SECURE_NO_WARNINGS" /D "_SCL_SECURE_NO_WARNINGS" /D "BOOST_PYTHON_STATIC_LIB" /D "_MBCS" /Gm /EHsc /RTC1 /MTd /Fo"Debug\\" /Fd"Debug\vc80.pdb" /W3 /nologo /c /ZI /TP /errorReport:prompt /bigobj bails out with ------ Build started: Project: XXXX, Configuration: Debug Win32 ------ Compiling... TestBoostUblasError.cpp [...]\boost_1_36_beta\boost\numeric\ublas\traits.hpp(97) : error C2784: 'boost::numeric::interval<T,Policies> boost::numeric::sqrt (const boost::numeric::interval<T,Policies> &)' : could not deduce template argument for 'const boost::numeric::interval<T,Policies> &' from 'const double' [...]\boost_1_36_beta\boost\numeric\interval\arith2.hpp(198) : see declaration of 'boost::numeric::sqrt' [...]\boost_1_36_beta\boost\numeric\ublas\traits.hpp(93) : while compiling class template member function 'double boost::numeric::ublas::scalar_traits<T>::type_sqrt(const double &)' with [ T=double ] [...]\boost_1_36_beta\boost\numeric\ublas\traits.hpp(151) : see reference to class template instantiation 'boost::numeric::ublas::scalar_traits<T>' being compiled with [ T=double ] [...]\boost_1_36_beta\boost\numeric\ublas\traits.hpp(97) : fatal error C1903: unable to recover from previous error(s); stopping compilation [...] ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== Ugly as it is: it will compile in any release mode, be it static or dynamic linkage :-(