Hi, I'm using boost.exception from trunk and I get following error (gcc-4.2.4): error: request for member 'what' is ambiguous /usr/include/c++/4.2/exception:64: error: candidates are: virtual const char* std::exception::what() const /opt/boost/include/boost-1_35/boost/exception/exception.hpp:52: error: virtual const char* boost::exception::what() const I'm using the code from the boost.exception tutorial: class error : public boost::exception, public std::exception {} ... try {...} catch ( error const& e) { std::cout << "error: " << e.what() << std::endl; } // solves the error class error : public boost::exception, public std::exception { public: char const * what() const throw() { return boost::exception::what(); } }; Oliver