title: C++ String insert iteration
body: <p>I have the string:</p>
  
  <pre><code>string str = "1234567890";
  
  //Magic code
  
  cout&lt;&lt;str&lt;&lt;endl;
  </code></pre>
  
  <p>Which i want to output: 12 34 56 78 90</p>
  
  <p>I assume std has some neat feature/function to help solve this. How do I that in the most convenient way?</p>