title: QAbstractTableModel inheritance vtable problem
body: <p>Here's another problem with qt:
  I extend a QAbstractTableModel, but I get a compiling error ( I'm using cmake)</p>
  
  <pre><code>// file.h
  #ifndef TABLEMODEL_H
  #define TABLEMODEL_H
  
  #include &lt;QAbstractTableModel&gt;
  
  class TableModel : public QAbstractTableModel
  {
  Q_OBJECT
  
  public:
  TableModel(QObject *parent = 0);
  int rowCount(const QModelIndex &amp;parent = QModelIndex()) const;
  int columnCount(const QModelIndex &amp;parent = QModelIndex()) const;
  };
  #endif
  
  // file.c
  #include "tableModel.h"
  
  TableModel::TableModel(QObject *parent)
  : QAbstractTableModel(parent){}
  int TableModel::rowCount(const QModelIndex &amp; ) const
  { return 1; }
  
  int TableModel::columnCount(const QModelIndex &amp; ) const
  { return 1;}
  </code></pre>
  
  <p>when I compile I get:</p>
  
  <p>In function <code>TableModel':
  /partd/unusedsvn/unusedpkg/iface/tableModel.cpp:4: undefined reference to</code>vtable for TableModel'
  /partd/unusedsvn/unusedpkg/iface/tableModel.cpp:4: undefined reference to <code>vtable for TableModel'
  collect2: ld returned 1 exit status</code></p>
  
  <p>does anybody got the same trouble??</p>