<system_error> operators

operator==

Tests if the object on the left side of the operator is equal to the object on the right side.

bool operator==(const error_code& left,
    const error_condition& right);

bool operator==(const error_condition& left,
    const error_code& right);

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

Parameters

left
The object to test for equality.

right
The object to test for equality.

Return Value

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

Remarks

This function returns left.category() == right.category() && left.value() == right.value().

operator!=

Tests if the object on the left side of the operator is not equal to the object on the right side.

bool operator!=(const error_code& left, const error_condition& right);
bool operator!=(const error_condition& left, const error_code& right);
bool operator!=(const error_code& left, const error_code& right);
bool operator!=(const error_condition& left, const error_condition& right);

Parameters

left
The object to test for inequality.

right
The object to test for inequality.

Return Value

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

Remarks

This function returns !(left == right).

operator<

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

template <class _Enum>
inline bool operator<(
    _Enum left,
    typename enable_if<is_error_code_enum<_Enum>::value,
    const error_code&>::type right);

template <class _Enum>
inline bool operator<(
    typename enable_if<is_error_code_enum<_Enum>::value,
    const error_code&>::type left, _Enum right);

template <class _Enum>
inline bool operator<(
    _Enum left,
    typename enable_if<is_error_condition_enum<_Enum>::value,
    const error_condition&>::type right);

template <class _Enum>
inline bool operator<(
    typename enable_if<is_error_condition_enum<_Enum>::value,
    const error_condition&>::type left, _Enum right);

Parameters

left
The object to compare.

right
The object to compare.

Return Value

true if the object passed in left is less than the object passed in right; Otherwise, false.

Remarks

This function tests the error order.

operator<<

Inserts an error_code object into the output stream.

template <class charT, class traits>
basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os, const error_code& ec);

Parameters

os
The target output stream.

ec
The error_code object to output.

Return Value

A reference to the modified output stream.

Remarks

This operator does the equivalent of os << ec.category().name() << ':' << ec.value().

Example

#include <iostream>
#include <system_error>

int main()
{
    std::error_code ec(1234, std::generic_category());
    std::cout << ec;
}

generic:1234