A prototype for a function callback that gives the size of memory likely to be allocated, given a certain request.
- iOS 2.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
- Mac Catalyst 13.0+Beta
- Core Foundation
The amount of memory requested.
A bitfield that is currently not used (always set to 0).
An untyped pointer to program-defined data.
The actual size the allocator is likely to allocate given this request.
A prototype for a function callback that determines whether there is enough free memory to satisfy a request. In implementing this function, return the actual size the allocator is likely to allocate given a request for a block of memory of size
hint argument is a bitfield that you should currently not use.