title: ifstream and ofstream or fstream using in and out
body: <p>When dealing with files, which of the two examples below is preferred?
  Does one provide better performance than the other? Is there any difference at all? </p>
  
  <pre><code>ifstream input("input_file.txt");
  ofstream output("output_file.txt");
  </code></pre>
  
  <p>vs</p>
  
  <pre><code>fstream input("input_file.txt",istream::in);
  fstream output("output_file.txt",ostream::out);
  </code></pre>