Why return a pointer? How about considering the use of a reference instead?
If you catch( foo & ), it is not guaranteed that it has an exception_info sub-object. For one thing, you may be converting existing code to the exception library, and there could be some throw foo() statements left around. But also, consider catching one of the standard exception types, for example std::length_error. It could have been thrown by the standard library and in that case it would not have exception_info sub-object; or, some other code could throw failed<std::length_error>(), and then there would be an exception_info sub-object. So, get_exception_info returns a pointer because it is intended to be used like this: catch( my_error & x ) { if( exception_info * xi = get_exception_info(x) ) { //use exception_info here } else { //handle the case of not having exception_info. } } --Emil