#include "memory.h"
#include <stdlib.h>

//    oldSize	 newSize	               Operation
//    0	        Non‑zero	            Allocate new block.
//    Non‑zero	0	                    Free allocation.
//    Non‑zero	Smaller than oldSize	Shrink existing allocation.
//    Non‑zero	Larger than oldSize	    Grow existing allocation.
void *reallocate(void *pointer, size_t oldSize, size_t newSize) {
  if (newSize == 0) {
    free(pointer);
    return NULL;
  }

  void *result = realloc(pointer, newSize);
  if (result == NULL) exit(1);
  return result;
}