title: Member function as a map comparator?
body: <p>I know how to create a function that serves as a custom map comparator:</p>
  
  <pre><code>std::map&lt;std::string, std::string, bool (*)(std::string, std::string)&gt; myMap(MapComparator);
  
  bool MapComparator(std::string left, std::string right)
  {
      return left &lt; right;
  }
  </code></pre>
  
  <p>But I don't know how to do the same with a <strong>member</strong> function:</p>
  
  <pre><code>bool MyClass::MapComparator(std::string left, std::string right)
  {
      return left &lt; right;
  }
  </code></pre>