title: How to index and query STL map containers by multiple keys?
body: <p>I came across one requirement where the record is stored as</p>
  
  <pre><code>Name :  Employee_Id  :  Address
  </code></pre>
  
  <p>where Name and Employee_Id are supposed to be keys that is, a search function is to be provided on both Name and Employee Id.</p>
  
  <p>I can think of using a map to store this structure </p>
  
  <pre><code>std::map&lt; std:pair&lt;std::string,std::string&gt; , std::string &gt;  
  //      &lt;         &lt; Name   ,   Employee-Id&gt; , Address     &gt; 
  </code></pre>
  
  <p>but I'm not exactly sure how the search function will look like.</p>