c++ 将16进制字符串转换成为int数值

#include<iostream>

#include<string>

#include<cstdlib>

using namespace std;

long hex2int(const string& hexStr)

{

char *offset;

if(hexStr.length() > 2)

{

   if(hexStr[0] == '0' && hexStr[1] == 'x')

   {

    return strtol(hexStr.c_str(), &offset, 0);

   }

}

return strtol(hexStr.c_str(), &offset, 16);

}

int main(int argc, char *argv[])

{

    string str1 = "0x12AB";

    cout << hex2int(str1) << endl;

    string str2 = "12AB";

    cout << hex2int(str2) << endl;

    string str3 = "QAFG";

    cout << hex2int(str3) << endl;