4-5~6 bitset 用法

#include <iostream>
using namespace std;

#include <bitset>
int main() {
    bitset<8> priv = 0xff;
    bitset<8> backup = (1 << 6);
    bitset<8> admin = (1 << 7);
    cout << priv << endl;
    cout << (priv & backup) << endl;
}