接上节内容，反向迭代器（aoto的价值显示的更明显）

int main()
{
	string s1("hello world");
	//string::reverse_iterator rit = s1.rbegin();
	auto rit = s1.rbegin();
	while (rit != s1.rend())
	{
		(*rit) += 3;

		cout << *rit << " ";
		++rit;
	}
	cout << endl;
	cout << s1 << endl;

	Func(s1);

	return 0;
}

这里就凸显的范围for 不能倒着遍历，只能正着遍历

四种迭代器：iterator,const_iterator,reverse_iterator,const_reverse_iterator