title: What is the meaning of prepended double colon "::"?
body: <p>I found this line of a code in a class which I have to modify:</p>
  
  <pre><code>::Configuration * tmpCo = m_configurationDB;//pointer to current db
  </code></pre>
  
  <p>and I don't know what exactly means the double colon prepended to the class name. Without that I would read: declaration of <code>tmpCo</code> as a pointer to an object of the class <code>Configuration</code>... but the prepended double colon confuses me.</p>
  
  <p>I also found:</p>
  
  <pre><code>typedef ::config::set ConfigSet;
  </code></pre>