title: No Member named stoi in namespace std
body: <p>I am testing out <code>std::stoi</code> function found in the link below:
  <a href="http://en.cppreference.com/w/cpp/string/basic_string/stol" rel="noreferrer">http://en.cppreference.com/w/cpp/string/basic_string/stol</a><br>
  but I got the error:</p>
  
  <blockquote>
    <p>No Member named stoi in namespace std.</p>
  </blockquote>
  
  <p>What should I do?
  Please advise thanks.</p>
  
  <p>P.S: I am using Xcode Ide to do my c++.</p>
  
  <pre><code>#include &lt;iostream&gt;
  #include &lt;string&gt;
  
  int main()  {
     std::string test = "45";
     int myint = std::stoi(test);
     std::cout &lt;&lt; myint &lt;&lt; '\n';
  }
  </code></pre>
  
  <p>Image</p>
  
  <p><img src="https://i.stack.imgur.com/ftep8.png" alt="no member named stoi in namespace &#39;std&#39;"></p>
  
  <p><img src="https://i.stack.imgur.com/Klapp.png" alt="error"></p>