sg_io_exception (const char* message, const sg_location &location,
const char* origin = 0);
sg_io_exception (const std::string &message, const std::string &origin = "");
sg_io_exception (const char* message, const sg_location &location,
const char* origin = 0);
sg_io_exception (const std::string &message, const std::string &origin = "");