undefined reference to `vtable for stations::baseStation'
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/12573816/what-is-an-undefined-reference-unresolved-external-symbol-error-and-how-do-i-fix">What is an undefined reference/unresolved external symbol error and how do I fix it?</a>  </p>
</blockquote>



<p>I somehow get this error. This is my code:</p>

<pre><code>#ifndef BASESTATION_H_
#define BASESTATION_H_

#include &lt;list&gt;
#include "Song.h"
#include &lt;string&gt;

using mtm::Song;
using std::list;
namespace stations {

class baseStation {
public:
    explicit baseStation(double frequency) : frequency(frequency) {}
    double getFrequency() const;
    bool getIsFullVersion() const;
    bool isInPlaylist(const string&amp; author, const string&amp; name) const;
    virtual void addSong(const Song&amp; song);
    virtual const Song&amp; getCurrentSong() const;
    virtual const SongPart&amp; getCurrentlyPlayedPart(unsigned int time) const;
    virtual ~baseStation();

private:
    //keep it protected or not??
    double frequency;
    list&lt;Song&gt; playlist;
    list&lt;Song&gt;::iterator currentSong;
    bool isFullVersion;
};
</code></pre>

<p>and the error I get is: undefined reference to `vtable for stations::baseStation' on the "explicit" line.</p>

<p>Thanks a lot.`</p>
