title: How do I get a const_iterator using auto?
body: <p>First question: is it possible to "force" a <code>const_iterator</code> using auto?
  For example:</p>
  
  <pre class="lang-cpp prettyprint-override"><code>map&lt;int&gt; usa;
  //...init usa
  auto city_it = usa.find("New York");
  </code></pre>
  
  <p>I just want to query, instead of changing anything pointed by <code>city_it</code>, so I'd like to have <code>city_it</code> to be <code>map&lt;int&gt;::const_iterator</code>. But by using auto, <code>city_it</code> is the same to the return type of <code>map::find()</code>, which is <code>map&lt;int&gt;::iterator</code>. Any suggestion?</p>