title: fill right side of stringstream variable with '0' c++
body: <p>I have the next code: </p>
  
  <pre><code>ofstream dataIndex;
  dataIndex.open("file");
  
  index="2222";
  std::stringstream sstr1;
  sstr1&lt;&lt;index&lt;&lt;'1';
  sstr1&lt;&lt;setfill('0')&lt;&lt;setw(index.length()-9);
  string index1= sstr1.str();
  dataIndex&lt;&lt;index1;
  
  dataIndex.close()
  </code></pre>
  
  <p>and i hope the result:</p>
  
  <pre><code>2222100000
  </code></pre>
  
  <p>but only i get</p>
  
  <pre><code>22221
  </code></pre>
  
  <p>without zeros? what happened?</p>