title: Private class functions vs Functions in unnamed namespace
body: <p>I've found myself that I tend not to have private class functions. If possible, all candidates to private class function rather I put in to unnamed namespace and pass all necessary information as function parameters. I don't have a sound explanation why I'm doing that but at least it looks more naturally to me. As a consequence I need to expose less internal details in the header file.</p>
  
  <p>What is your opinion - is it correct practice?</p>