#define SWIG_exception_fail(code, msg) do { SWIG_Error(code, msg); SWIG_fail; } while(0) 
#define SWIG_Error(code, msg)                           sv_setpvf(GvSV(PL_errgv),"%s %s\n", SWIG_ErrorType(code), msg)
#define SWIG_ErrorType(code)                            SWIG_Perl_ErrorType(code)
SWIG_Perl_ErrorType(int code) { C code that returns a string describing the error code }
#define SWIG_fail                                       goto fail
#define SWIG_croak_null() croak(Nullch)