Hi, When I compile with Xcode I get a 'declaration does not declare anything' error on boost/exception/diagnostic_information.hpp. However, the exception test run fine when I compile with bjam --toolset=darwin ... I am quite sure both use the same compiler (g++-4.0.1) and have the same options (I copied from the bjam set to Xcode). I now outcommented it (see below), but this is not a permanent solution. It should be valid, so what am I doing wrong regarding Xcode? Any help would be very much appreciated! Best, Dirk template <class T> struct enable_boost_exception_overload { struct yes { char q[100]; }; typedef char no; //static yes check(exception const *); //static no check(...); enum e { value=sizeof(/*check*/((T*)0))==sizeof(yes) }; }; template <class T> struct enable_std_exception_overload { struct yes { char q[100]; }; typedef char no; //static yes check(std::exception const *); //static no check(...); enum e { value = !enable_boost_exception_overload<T>::value && sizeof(/*check*/((T*)0))==sizeof(yes) }; };