Review the code implementation of memcpy function

void* memcpy(void* pvTo, const void* pvFrom, size_t size)
{
	assert((pvTo!= NULL) && (pvFrom!= NULL));
	unsigned char* pbTo = (unsigned char*)pvTo;
	unsigned char* pbFrom = (unsigned char*)pvFrom;
	while(size-- > 0)
	{
		*pbTo++ = *pbFrom++;
	}
	return pvTo;
}

The above is memcpy Code implementation of , Very streamlined , But it doesn't deal with memory overlap , The back is empty ！