The class system_error describes an exception object used to report error conditions that have an associated error code. Such error conditions typically originate from the operating system or other low-level application program interfaces.
[ Note: If an error represents an out-of-memory condition, implementations are encouraged to throw an exception object of type bad_alloc [bad.alloc] rather than system_error. — end note ]
namespace std {
class system_error : public runtime_error {
public:
system_error(error_code ec, const string& what_arg);
system_error(error_code ec, const char* what_arg);
system_error(error_code ec);
system_error(int ev, const error_category& ecat,
const string& what_arg);
system_error(int ev, const error_category& ecat,
const char* what_arg);
system_error(int ev, const error_category& ecat);
const error_code& code() const noexcept;
const char* what() const noexcept;
};
} // namespace std