error_code Class

Represents low-level system errors that are implementation-specific.

Syntax

class error_code;

Remarks

An object of type error_code class stores an error code value and a pointer to an object that represents a category of error codes that describe reported low-level system errors.

Members

Constructors

Typedefs

Functions

Operators

assign

Assigns an error code value and category to an error code.

void assign(value_type val, const error_category& _Cat);

Parameters

val
The error code value to store in the error_code.

_Cat
The error category to store in the error_code.

Remarks

The member function stores val as the error code value and a pointer to _Cat.

category

Returns the error category.

const error_category& category() const;

Remarks

clear

Clears the error code value and category.

clear();

Remarks

The member function stores a zero error code value and a pointer to the generic_category object.

default_error_condition

Returns the default error condition.

error_condition default_error_condition() const;

Return Value

The error_condition specified by default_error_condition.

Remarks

This member function returns category().default_error_condition(value()).

error_code

Constructs an object of type error_code.

error_code();

error_code(value_type val, const error_category& _Cat);

template <class _Enum>
error_code(_Enum _Errcode,
    typename enable_if<is_error_code_enum<_Enum>::value,
    error_code>::type* = 0);

Parameters

val
The error code value to store in the error_code.

_Cat
The error category to store in the error_code.

_Errcode
The enumeration value to store in the error_code.

Remarks

The first constructor stores a zero error code value and a pointer to the generic_category.

The second constructor stores val as the error code value and a pointer to error_category.

The third constructor stores (value_type)_Errcode as the error code value and a pointer to the generic_category.

message

Returns the name of the error code.

string message() const;

Return Value

A string representing the name of the error code.

Remarks

This member function returns category().message(value()).

operator==

Tests for equality between error_code objects.

bool operator==(const error_code& right) const;

Parameters

right
The object to be tested for equality.

Return Value

true if the objects are equal; false if objects are not equal.

Remarks

The member operator returns category() == right.category() && value == right.value().

operator!=

Tests for inequality between error_code objects.

bool operator!=(const error_code& right) const;

Parameters

right
The object to be tested for inequality.

Return Value

true if the error_code object is not equal to the error_code object passed in right; otherwise false.

Remarks

The member operator returns !(*this == right).

operator<

Tests if the error_code object is less than the error_code object passed in for comparison.

bool operator<(const error_code& right) const;

Parameters

right
The error_code object to be compared.

Return Value

true if the error_code object is less than the error_code object passed in for comparison; Otherwise, false.

Remarks

The member operator returns category() < right.category() || category() == right.category() && value < right.value().

operator=

Assigns a new enumeration value to the error_code object.

template <class _Enum>
typename enable_if<is_error_code_enum<_Enum>::value, error_code>::type&
    operator=(_Enum _Errcode);

Parameters

_Errcode
The enumeration value to assign to the error_code object.

Return Value

A reference to the error_code object that is being assigned the new enumeration value by the member function.

Remarks

The member operator stores (value_type)_Errcode as the error code value and a pointer to the generic_category. It returns *this.

operator bool

Casts a variable of type error_code.

explicit operator bool() const;

Return Value

The Boolean value of the error_code object.

Remarks

The operator returns a value convertible to true only if value is not equal to zero. The return type is convertible only to bool, not to void * or other known scalar types.

value

Returns the stored error code value.

value_type value() const;

Return Value

The stored error code value of type value_type.

value_type

A type that represents the stored error code value.

typedef int value_type;

Remarks

This type definition is a synonym for int.