title: Convert octal string to decimal string in C++
body: <p>What is the easiest way to convert string holding octal number into string holding decimal representation of the same number? </p>
  
  <p>I could convert it into int value using strtol, then convert into string again using stringstream:</p>
  
  <pre><code>string oct_number("203"); 
  
  // converts into integer
  int value = strtol(oct_number.c_str(), NULL, 8);
  
  // converts int to decimal string
  stringstream ss;
  ss  &lt;&lt; value;
  string dec_number = ss.str();
  </code></pre>
  
  <p>But: is there any quicker way to do it? 
  I have a rather poor understanding of the stringstream class, am I missing something?</p>