title: GetPrivateProfileString - c++ class - return string - memory pre calculation
body: <p>In <code>GetPrivateProfileString</code>, <code>lpReturnedString</code> returns the string value present in the key of a particular section of an ini file.</p>
  
  <p>My question is that how will i know exactly, how much memory has to be allocated, rather than just allocation a large chunk prior to calling this function.</p>
  
  <pre><code>DWORD WINAPI GetPrivateProfileString(
    __in   LPCTSTR lpAppName,
    __in   LPCTSTR lpKeyName,
    __in   LPCTSTR lpDefault,
    __out  LPTSTR lpReturnedString,
    __in   DWORD nSize,
    __in   LPCTSTR lpFileName
  );
  </code></pre>