Hi, I'm trying to use Boost.Exception library and I have some issues here. 1. How to build exception hierarchy correctly? According to examples I wrote: #include <iostream> #include <boost/exception/all.hpp> struct Error1 : virtual public std::exception, virtual public boost::exception { Error1(const char* msg) : std::exception(msg) {} }; struct Error2 : virtual public Error1 { Error2(const char* msg) : Error1(msg) {} }; ... std::cout << Error2("zzz").what() << std::endl; I've got "Unknown exception" instead of "zzz" 2. Strange behavior of boost::enable_error_info Look at this example: #include <iostream> #include <boost/exception/all.hpp> typedef boost::error_info<struct Tag1_, int> Tag1; typedef boost::error_info<struct Tag2_, int> Tag2; void f1(); void f2(); int main() { try { f1(); } catch (const std::exception& e) { std::cout << boost::diagnostic_information(e) << std::endl; } return 0; } void f1() { try { f2(); } catch (const std::exception& e) { throw boost::enable_error_info(e) << Tag1(1); } } void f2() { throw boost::enable_error_info(std::runtime_error("f2 exception")) << Tag2(2) ; } It prints: Throw location unknown (consider using BOOST_THROW_EXCEPTION) Dynamic exception type: boost::exception_detail::error_info_injector<std::exception> std::exception::what: std::exception [Tag1_*] = 1 Where is Tag2 data? Looks like enable_error_info erases all previous accumulated infos. Besides, type of exception is reported as "std::exception", not "std::runtime_error"