Instance Property

reallocate

A prototype for a function callback that reallocates memory of a requested size for an existing block of memory.

Declaration

Discussion

When 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 apply:

The ptr parameter is NULL.

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). If you set this callback to NULL the CFAllocatorReallocate(_:_:_:_:) function returns NULL in most cases when it attempts to use this allocator.