string迭代器报错

Question

#include<iostream>
#include<string>
using namespace std;
void reverse(string& s,int l,int r)
{
    auto it = s.begin() + l-1;
    auto it2 = s.begin() + r - 1;
    while (it != it2)
    {
        char temp = *it;
        *it = *it2;
        *it2 = temp;
        it++;
        it2--;
    }


}
int main()
{
    string str;
    cin >> str;
    int l = 0, r = 0;
    cin >> l >> r;
    reverse(str, l, r);
    cout << str << endl;



    return 0;
}

反转局部字符串，用string迭代器弄为啥报错啊xdm