title: C++ constructor bug
body: <p>This is a part of my code :
  Declaration in the .h file :</p>
  
  <pre><code>virtual bool operator==(const File&amp; file) const = 0;
  </code></pre>
  
  <p>and in the .cpp file</p>
  
  <pre><code>bool File::operator==(const File&amp; file) const {
      return true;
  }
  </code></pre>
  
  <p>I get this compilation error :</p>
  
  <pre><code> 1&gt;c:\users\talw\desktop\hw5\hw5\project1\main.cpp(76): error C2259: 
                'Directory' : cannot instantiate abstract class
   1&gt;          due to following members:  
   1&gt;          'bool File::operator ==(const File &amp;) const' : is abstract
   1&gt;          c:\users\talw\desktop\hw5\hw5\project1\file.h(57) : see  
                declaration of 'File::operator =='
  </code></pre>
  
  <p>Please help.
  Thanks</p>