title: Iterate multiple maps with single loop
body: <p>I am trying to iterate two maps with one loop. it works fine with one map. when I add second map(see code below) it gives me error "Cannot deduce 'auto' type"</p>
  
  <p>both variables are of same type. </p>
  
  <p>what is the best way to iterate two maps.</p>
  
  <pre><code> for ( auto&amp; insertEntry = insertedInstances.begin(),
         auto&amp; updateEntry = toUpdateInstances.begin(); 
         insertEntry != insertedInstances.end(); insertEntry++,updateEntry++
       )
   {
      //do something
   }
  </code></pre>