#include <string>
#include <iostream>

int main(int,char**){
    //[Error] 'to_string' is not a member of 'std'
    std::cout << std::to_string(10);

    std::string s = "12";
    //[Error] 'stoi' is not a member of 'std'
    std::cout << std::stoi(s);
}