reallocarray(ptr, nmemb, size)
{
	local tmp;
	local start;

	start = ptr;
	tmp = galloc(size);
	if (tmp == NULL)
		return NULL;
	if (ptr == NULL)
		return tmp;
	loop
	{
		if (start - ptr == nmemb)
			break;
		[tmp + start - ptr] = [start];
		start++;
	}
	free(ptr);
	return tmp;
}