Creates an allocator object.


func CFAllocatorCreate(_ allocator: CFAllocator!, _ context: UnsafeMutablePointer<CFAllocatorContext>!) -> Unmanaged<CFAllocator>!



The existing allocator to use to allocate memory for the new allocator. Pass the kCFAllocatorUseContext constant for this parameter to allocate memory using the appropriate function callback specified in the context parameter. Pass NULL or kCFAllocatorDefault to allocate memory for the new allocator using the default allocator.


A structure of type CFAllocatorContext. The fields of this structure hold (among other things) function pointers to callbacks used for allocating, reallocating, and deallocating memory.

Return Value

The new allocator object, or NULL if there was a problem allocating memory. Ownership follows the The Create Rule.


You use this function to create custom allocators which you can then pass into various Core Foundation object-creation functions. You must implement a function callback that allocates memory and assign it to the allocate field of this structure. You typically also implement deallocate, reallocate, and preferred-size callbacks.