'std::string' has no member named 'front'

Question

#include <string>
#include <algorithm>
#include <iostream>

int main()
{
    string str;
    string str1;
    int h = 0;
    cin >> str;
    if (str.length() > 10)
    {
        str1 += str.front();
        h = str.length() - 2;
        string s = to_string(h);
        str1 += s;
        str1 += str.back();
        cout << str1;
    }
    else cout << str;
    return 0;
}

compiles in XCode, but doesn`t on codeforces.ru/

 сan't compile program.cpp:
program.cpp: In function 'int main()':
program.cpp:23:21: error: 'std::string' has no member named 'front'
program.cpp:27:29: error: 'to_string' was not declared in this scope
program.cpp:32:21: error: 'std::string' has no member named 'back'

Answer 1

One thing is that string::front and std::to_string are introduced since C++11. You have to make sure that you are using a compiler that supports those new features.