title: c++ how to write/read ofstream in unicode / utf8
body: <p>I have UTF-8 text file , that I'm reading using simple :  </p>
  
  <pre><code>ifstream in("test.txt");
  </code></pre>
  
  <p>Now I'd like to create a new file that will be UTF-8 encoding or Unicode. 
  How can I do this with <code>ofstream</code> or other? 
  This creates ansi Encoding. </p>
  
  <pre><code>ofstream out(fileName.c_str(), ios::out | ios::app | ios::binary);
  </code></pre>