include/libsex/Exception.hxx

   1 #ifndef EXCEPTION_HXX
   2 #define EXCEPTION_HXX
   3
   4 #include <exception> // std::exception
   5 #include <stdexcept> // std::bad_alloc
   6 #include <ostream>   // std::ostream
   7
   8 namespace libsex {
   9
  10 /**
  11  * @brief Resembles a generic error, stores a
  12  *        message and optionally references one
  13  *        previous error (linked list).
  14  *
  15  * For OO error handling you should subclass this
  16  * class for every type of error. Inheriting by
  17  * hand is tedious, you usally don't want to do
  18  * this. There are some efficient macros in @file
  19  * create.hxx.
  20  *
  21  * @note The previous exceptions, if any, will
  22  *       be copied by calling clone() which may
  23  *       in turn throw bad_alloc. In that case, a
  24  *       notice is appended to this message (if
  25  *       enough chars left) and the exception is
  26  *       swallowed.
  27  */
  28 class Exception : public std::exception
  29 {
  30 public:
  31         static const unsigned short LENGTH = 500;
  32
  33         Exception(const char* const message) throw();
  34         Exception(
  35                 const char* const message,
  36                 const Exception& previous) throw();
  37         virtual ~Exception() throw();
  38
  39         void write(std::ostream& out) const throw(std::ios_base::failure);
  40         void backtrace(std::ostream& out) const throw(std::ios_base::failure);
  41
  42         virtual const Exception* clone() const
  43                 throw(std::bad_alloc) ;
  44
  45         virtual const char* what() const throw();
  46
  47 private:
  48         /**
  49          * @brief Copy of message passed to constructor.
  50          *
  51          * Length is Exception::LENGTH plus nullbyte.
  52          */
  53         char _message[LENGTH + 1];
  54         const Exception* _previous;
  55
  56         void _initMessage(const char* const message);
  57 };
  58
  59 }; // namespace
  60
  61 #endif