Question

I am writing some new code that will throw a custom exception – I want to include an error string and a status code. Which class should be exception derive from? std::exception? std::runtime_error? Any other ‘gotchas’ to worry about? I’m thinking of something like the following:

class MyException : public std::exception(?) { public:     enum Status     {         ERROR_FOO,         ERROR_BAR,         ...     };      MyException(const std::string& error, Status code) :         error_(error), code_(code)     {         ...     }      virtual const char* what() const     {         return error_.c_str();     }      Status code() const     {         return code_;     } private:     std::string error_;     Status code_; }; 

Then in the code:

throw MyException('Ooops!', MyException::ERROR_BAR); 

Answer 1

Boost has a great document on error and exception handling which talks about common gotchas and how to properly inherit from std::exception(s).