Attempt to in-place enlarge the memory block pointed to by p by at least minbytes beyond its current capacity, up to a maximum of maxsize. This does not attempt to move the memory block (like realloc() does).
0 if could not extend p, total size of entire memory block if successful.
See Implementation
Attempt to in-place enlarge the memory block pointed to by p by at least minbytes beyond its current capacity, up to a maximum of maxsize. This does not attempt to move the memory block (like realloc() does).