title: How do I give a default value to a map?
body: <p>I have an map that takes a string and it returns a integer. I want the integer of the map instance to be initialized to 0. How would I do that? For example:</p>
  
  <pre><code>std::map&lt;std::string, int&gt; x;
  </code></pre>
  
  <p>I want all the integers to be intialized to 0 as their starting point. How do I do this?</p>