A prototype for a function callback that reallocates memory of a requested size for an existing block of memory.
- iOS 2.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
- Mac Catalyst 13.0+Beta
- Core Foundation
The block of memory to resize.
The size of the new allocation.
A bitfield that is currently not used (always set to 0).
An untyped pointer to program-defined data.
Pointer to the new block of memory.
In implementing this function, change the size of the block of memory pointed to by
ptr to the size specified by
newsize and return the pointer to the larger block of memory. Return NULL on any reallocation failure, leaving the old block of memory untouched. Also return NULL immediately if any of the following conditions if the ptr parameter is NULL or the
newsize parameter is not greater than 0. Leave the contents of the old block of memory unchanged up to the lesser of the new or old sizes. If the
ptr parameter is not a block of memory that has been previously allocated by the allocator, the results are undefined; abnormal program termination can occur. The
hint argument is a bitfield that you should currently not use (that is, assign 0).