Hello, I just finished an update to the exception library I am planning to propose for addition to Boost. I appreciate all feedback, including incompatibility reports with various compilers (I believe the implementation to be standard-conforming, but I have only tested with msvc 7.1/8.0 and gcc 3.4.4). As usual, the latest documentation is here: http://www.revergestudios.com/boost-exception/boost-exception.htm Here is a zip file with the source code, complete with jamfiles and tests: http://www.revergestudios.com/boost-exception/boost-exception.zip Here's what's new in this update: class boost::exception now defines what() function, similarly to std::exception. It automatically formats a message which combines all exception info stored by operator<< in the boost::exception object. The message is not user-friendly; it is designed for dumping in log files and for other debugging systems. For what() to work, the system needs to be able to convert the exception info values stored in a boost::exception to string. Because this is not a critical feature, I thought it wouldn't be a good idea to require the user code to provide such a conversion for everything. The current implementation generates a string representation of each exception info value (at the time exception_info is called) as follows: - If a suitable overload for the unqualified call to to_string (passing the exception info value as the only argument) is found, that overload is used. - Otherwise, if a suitable overload for serializing the exception info value into a std::ostringstream is found, that overload is used. - Otherwise the system gives up and uses a generic "stub" string to indicate that the exception info value could not be converted to string. This is accomplished through the to_string function template, which has the following signature: template <class T> std::string to_string( T const &, char const * stub ); Do you think that to_string is universally useful? Is there anything in Boost with similar functionality? Perhaps we can make to_string a separate addition to Boost? Thanks, Emil