It depends on your allocator. For example, jemalloc stores medium-sized allocations in big contiguous buffers, binned by size rounded up to 16 bytes. So if yo

It depends on your allocator. For example, jemalloc stores medium-sized allocations in big contiguous buffers, binned by size rounded up to 16 bytes. So if you realloc to a different size class, your pointer will change, because you need to move to a different big buffer.