Obtains the number of bytes likely to be allocated upon a specific request.
SDKs
- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
Framework
- Core Foundation
Declaration
func CFAllocatorGetPreferredSizeForSize(_ allocator: CFAllocator!, _ size: CFIndex, _ hint: CFOptionParameters
allocatorThe allocator to use, or
NULLfor the default allocator.sizeThe number of bytes to allocate. If the value is
0or less, the result is the same value.hintA bitfield of type
CFOptions. Pass flags to the allocator that suggest how memory is to be allocated.Flags 0indicates no hints. No hints are currently defined, only0should be passed for this argument.
Return Value
The number of bytes likely to be allocated upon a specific request.
Discussion
The return value depends on the allocator's internal allocation strategy, and will be equal to or larger than size. Calling this function may help you better match your memory allocation or reallocation strategy to that of the allocator.
Note that the return value depends on the internal implementation of the allocator and the results may change from release to release or from platform to platform.
If no function callback is assigned to the preferred field of the allocator's context (see the CFAllocator structure), then the value of size is returned.