19 Diagnostics library [diagnostics]

19.5 System error support [syserr]

19.5.1 Class error_category [syserr.errcat] Class error_category virtual members [syserr.errcat.virtuals]

virtual const char* name() const noexcept = 0;

Returns: A string naming the error category.

virtual error_condition default_error_condition(int ev) const noexcept;

Returns: error_condition(ev, *this).

virtual bool equivalent(int code, const error_condition& condition) const noexcept;

Returns: default_error_condition(code) == condition.

virtual bool equivalent(const error_code& code, int condition) const noexcept;

Returns: *this == code.category() && code.value() == condition.

virtual string message(int ev) const = 0;

Returns: A string that describes the error condition denoted by ev.