How to use C++11 std::stoi with gcc? [duplicate]

Answer 1

#include <iostream>
#include <string>

int main()
{
    std::string test = "45";
    int myint = stoi(test);
    std::cout << myint << '\n';
}

or

#include <iostream>
#include <string>

using namespace std    

int main()
{
    string test = "45";
    int myint = stoi(test);
    cout << myint << '\n';
}

look at http://en.cppreference.com/w/cpp/string/basic_string/stol

Answer 2

std::stoi is a function at namespace scope, taking a string as its argument:

std::string s = "123";
int i = std::stoi(s);

From the error message, it looks like you expect it to be a member of string, invoked as s.stoi() (or perhaps std::string::stoi(s)); that is not the case. If that's not the problem, then please post the problematic code so we don't need to guess what's wrong with it.