19 Diagnostics library [diagnostics]

19.5 System error support [syserr]

19.5.3 Class error_condition [syserr.errcondition]

19.5.3.4 Class error_condition observers [syserr.errcondition.observers]

int value() const noexcept;

1

Returns: val_.

const error_category& category() const noexcept;

2

Returns: *cat_.

string message() const;

3

Returns: category().message(value()).

explicit operator bool() const noexcept;

4

Returns: value() != 0.