On Wed, Aug 23, 2006 at 11:20:20AM -0700, Emil Dotchevski wrote:
If I understand you correctly, you are storing a user message in the exception when you throw it, and then use std::exception::what() to retrieve it, right? This approach is problematic for several reasons, most notably
Indeed. I don't localize error messages, in fact I've never met a program that correctly and completely implemented localized error messages. I guess it's because the problem doesn't scale so well.
because the user message has to be localized, but also because different programs may need to output different messages in response to the same exception thrown by a shared library.
Hmmm... Can you give an example? I try to restrict the what() string to be indepentent of library usage and add more information higher up the call stack, possibly re-throwing afterwards. E.g., a file object constructor might throw "couldn't open <filename>: <error>" and then, it's caller might prepend some more context information to make that either "Reading configuration file: couldn't open <filename>: <error>" or "Parsing data file: couldn't open <filename>: <error>" This works quite well, but yeah, maybe there are situations where string concatenation is too simplistic. Regards -Gerhard