C++中vector模拟实现中的迭代器失效问题

iterator insert(iterator pos, const T& x)
{
	// 扩容
	if (_finish == _end_of_storage)
	{
		size_t len = pos - _stare;
		reserve(capacity() == 0 ? 4 : capacity() * 2);
		pos = _stare + len;
	}
 
	iterator end = _finish - 1;
	while (end >= pos)
	{
		*(end + 1) = *end;
		--end;
	}
	*pos = x;
 
	++_finish;
 
	return pos;
}

void test_vector2()
{
	std::vector<int> v;
	v.push_back(1);
	v.push_back(2);
	v.push_back(3);
	v.push_back(4);
	v.push_back(5);

	Cao::print_container(v);

	/*v.insert(v.begin() + 2, 30);
	print_vector(v);*/

	int x;
	cin >> x;
	auto p = find(v.begin(), v.end(), x);
	if (p != v.end())
	{
		p = v.insert(p, 40);
		(*(p + 1)) *= 10;
	}
	Cao::print_container(v);
}

void test_vector2()
{
	std::vector<int> v;
	v.push_back(1);
	v.push_back(2);
	v.push_back(3);
	v.push_back(4);
	v.push_back(5);

	Cao::print_container(v);

	int x;
	cin >> x;
	auto p = find(v.begin(), v.end(), x);
	if (p != v.end())
	{
		p = v.insert(p, 40);
		(*(p + 1)) *= 10;
	}
	Cao::print_container(v);
}