/** \brief Exception handling standard UNIX errors (errno)
- This exception is thrown to signal generic errno failures.
+ This exception is thrown to signal generic \c errno failures. In addition to the \c errno
+ number (the code()), this class manages optional origin information. This parameter should
+ be provided to further describe, in what context the exception was created.
- \todo make where and err accessors and make the member variables private
+ This exception should not be used directly. Instead the derived class ErrnoException should
+ be thrown via one of the senf::throwErrno() helpers.
- \idea Add a template class derived from SystemException which takes the error number as a
- numeric argument. This allows catching specific errno conditions: ErrnoException<EPIPE> etc.
-
- \idea Add a generic error thrower which takes the origin string and errno value as an
- argument and will throw a corresponding template class instance. This would just be a big
- switch statement containing all possible errno values, probably created using some macro
- meta-programming.
+ \see ErrnoException
*/
class SystemException : public std::exception
{
public:
SystemException(); ///< SystemException without error location infor
/**< The error code is taken from the current value of the
- global 'errno' variable */
+ global \c errno variable */
explicit SystemException(int code); ///< SystemException without error location info
- /**< \param[in] code error number (the errno value) */
+ /**< \param[in] code error number (the \c errno value) */
explicit SystemException(char const * where); ///< SystemException with error location info
/**< The error code is taken from the current value of the
- global 'errno' variable
+ global \c errno variable
\param[in] where description of error origin */
SystemException(char const * where, int code); ///< SystemException with error location info
/**< \param[in] where description of error origin
- \param[in] code error number (the errno value) */
+ \param[in] code error number (the \c errno value) */
virtual char const * what() const throw(); ///< Return verbose error description
char const * where() const; ///< Error origin
- int code() const; ///< Error code (errno number)
+ int code() const; ///< Error code (\c errno number)
char const * description() const; ///< Error description (strerror() value)
bool anyOf(int c0, int c1=0, int c2=0, int c3=0, int c4=0, int c5=0,
int c6=0, int c7=0, int c8=0, int c9=0);
+ ///< \c true, if code() is one of \a c0 ... \a c9
virtual ~SystemException() throw();
void init();
char const * const where_;
- int const code_;
+ int const code_; // This must be const to make the derived ErrnoException
+ // class a valid derived class.
std::string buffer_;
};
+ /** \brief Error specific system exception
+
+ This template restricts the generic SystemException to a specific, compile-time constant
+ error number \p Code. This allows a specific \c errno number to be cached explicitly.
+
+ This exception is normally thrown via one of the senf::throwErrno() helpers. These helpers
+ take the numeric \c errno value (either from the \c errno variable or from their
+ argument) and will throw the corresponding ErrnoException:
+ \code
+ if ((fd = ::open(filename, O_RDWR)) < 0)
+ senf::throwErrno("open()");
+ \endcode
+ */
template <int Code>
class ErrnoException : public SystemException
{
public:
static int const fixed_code = Code;
- ErrnoException();
+ ErrnoException(); ///< ErrnoException without error location information
explicit ErrnoException(char const * where);
+ ///< ErrnoException with error location information
};
+
+ /** \brief Throw ErrnoException based on current \c errno value
+ \related ErrnoException
+ */
void throwErrno();
+
+ /** \brief Throw ErrnoException based on current \c errno value (with location info)
+ \related ErrnoException
+ */
void throwErrno(char const * where);
+
+ /** \brief Throw ErrnoException based on given \c errno value
+ \related ErrnoException
+ */
void throwErrno(int code);
+
+ /** \brief Throw ErrnoException based on given \c errno value (with location info)
+ \related ErrnoException
+ */
void throwErrno(char const * where, int code);
enum NoThrow_t { nothrow };