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# Error domains

These constants define domains for CFError objects.

## Discussion

The value of “code” will correspond to preexisting values in these domains.

## Topics

### Constants

[`let kCFErrorDomainPOSIX: CFErrorDomain!`](/documentation/CoreFoundation/kCFErrorDomainPOSIX)

A constant that specified the POSIX domain.

[`let kCFErrorDomainOSStatus: CFErrorDomain!`](/documentation/CoreFoundation/kCFErrorDomainOSStatus)

A constant that specified the OS domain.

[`let kCFErrorDomainMach: CFErrorDomain!`](/documentation/CoreFoundation/kCFErrorDomainMach)

A constant that specified the Mach domain.

[`let kCFErrorDomainCocoa: CFErrorDomain!`](/documentation/CoreFoundation/kCFErrorDomainCocoa)

A constant that specified the Cocoa domain.


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