std::error_code Class Reference
Diagnostics

`#include <system_error>`

## Public Member Functions

template<typename _ErrorCodeEnum, typename = _Check<_ErrorCodeEnum>>
| error_code (_ErrorCodeEnum __e) noexcept
| error_code (const error_code &)=default
| error_code (int __v, const error_category &__cat) noexcept
void | assign (int __v, const error_category &__cat) noexcept
const error_category & | category () const noexcept
void | clear () noexcept
error_condition | default_error_condition () const noexcept
string | message () const
| operator bool () const noexcept
error_code & | operator= (const error_code &)=default
int | value () const noexcept

## Related Symbols

(Note that these are not member symbols.)
error_code | make_error_code (errc __e) noexcept
template<typename _CharT, typename _Traits>
basic_ostream< _CharT, _Traits > & | operator<< (basic_ostream< _CharT, _Traits > &__os, const error_code &__e)
strong_ordering | operator<=> (const error_code &__lhs, const error_code &__rhs) noexcept

## Detailed Description

Class error_code

This class is a value type storing an integer error number and a category that gives meaning to the error number. Typically this is done close the the point where the error happens, to capture the original error value.

An error_code object can be used to store the original error value emitted by some subsystem, with a category relevant to the subsystem. For example, errors from POSIX library functions can be represented by an errno value and the "generic" category, but errors from an HTTP library might be represented by an HTTP response status code (e.g. 404) and a custom category defined by the library.

Since
  C++11

Definition at line 225 of file system_error.

## Constructor & Destructor Documentation

## error_code() [1/3]

std::error_code::error_code | ( |  | ) |

inline noexcept

Definition at line 231 of file system_error.

## error_code() [2/3]

std::error_code::error_code | ( | int | __v,
|  | const error_category & | __cat )

inline noexcept

Definition at line 234 of file system_error.

## error_code() [3/3]

template<typename _ErrorCodeEnum, typename = _Check<_ErrorCodeEnum>>

std::error_code::error_code | ( | _ErrorCodeEnum | __e | ) |

inline noexcept

Initialize with a user-defined type, by calling make_error_code.

Definition at line 240 of file system_error.

References make_error_code().

## Member Function Documentation

## assign()

void std::error_code::assign | ( | int | __v,
|  | const error_category & | __cat )

inline noexcept

Definition at line 250 of file system_error.

## category()

const error_category & std::error_code::category | ( |  | ) | const

inline noexcept

The error category that this error belongs to.

Definition at line 268 of file system_error.

Referenced by message().

## clear()

void std::error_code::clear | ( |  | ) |

inline noexcept

Definition at line 257 of file system_error.

## default_error_condition()

error_condition std::error_code::default_error_condition | ( |  | ) | const

noexcept

An error_condition for this error's category and value.

## message()

string std::error_code::message | ( |  | ) | const

inline

The category's description of the value.

Definition at line 277 of file system_error.

References category(), std::_V2::error_category::message(), message(), and value().

Referenced by message().

## operator bool()

std::error_code::operator bool | ( |  | ) | const

inline explicit noexcept

Test whether value() is non-zero.

Definition at line 282 of file system_error.

## value()

int std::error_code::value | ( |  | ) | const

inline noexcept

The error value.

Definition at line 263 of file system_error.

Referenced by message().

The documentation for this class was generated from the following file:

- system_error