error_condition Class

Represents user-defined error codes.

Syntax

class error_condition;

Remarks

An object of type error_condition stores an error code value and a pointer to an object that represents a category of error codes used for reported user-defined errors.

Members

Constructors

Typedefs

Functions

Operators

assign

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

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;

Return Value

A reference to the stored error category

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.

error_condition

Constructs an object of type error_condition.

error_condition();

error_condition(value_type val, const error_category& _Cat);

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

Parameters

val
The error code value to store in the error_condition.

_Cat
The error category to store in the error_condition.

_Errcode
The enumeration value to store in the error_condition.

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_condition objects.

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

Parameters

right
The ojbect 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_condition objects.

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

Parameters

right
The object to be tested for inequality.

Return Value

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

Remarks

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

operator<

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

bool operator<(const error_condition& right) const;

Parameters

right
The error_condition object to be compared.

Return Value

true if the error_condition object is less than the error_condition 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_condition object.

template <class _Enum>
error_condition(_Enum error,
    typename enable_if<is_error_condition_enum<_Enum>::value,
    error_condition>::type&
    operator=(Enum _Errcode);

Parameters

_Errcode
The enumeration value to assign to the error_condition object.

Return Value

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

Remarks

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

operator bool

Casts a variable of type error_condition.

explicit operator bool() const;

Return Value

The Boolean value of the error_condition 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.

Remarks

value_type

A type that represents the stored error code value.

typedef int value_type;

Remarks

The type definition is a synonym for int.