title: Error: Invalid base class C++
body: <p>Could anyone, please, explain what can cause this error?</p>
  
  <pre><code>Error: Invalid base class
  </code></pre>
  
  <p>I've got two classes where one of them is derived from second:</p>
  
  <pre><code>#if !defined(_CGROUND_H)
  #define _CGROUND_H
  
  #include "stdafx.h"
  #include "CGameObject.h"
  
  
  class CGround : public CGameObject // CGameObject is said to be "invalid base class"
  {
  private:
      bool m_bBlocked;
      bool m_bFluid;
      bool m_bWalkable;
  
  public:
      bool draw();
  
      CGround();
      CGround(int id, std::string name, std::string description, std::string graphics[], bool bBlocked, bool bFluid, bool bWalkable);
      ~CGround(void);
  };
  
  #endif  //_CGROUND_H
  </code></pre>
  
  <p>And CGameObject looks like this:</p>
  
  <pre><code>#if !defined(_CGAMEOBJECT_H)
  #define _CGAMEOBJECT_H
  
  #include "stdafx.h"
  
  class CGameObject
  {
  protected:
      int m_id;
      std::string m_name;
      std::string m_description;
      std::string m_graphics[];
  
  public:
      virtual bool draw();
  
      CGameObject() {}
      CGameObject(int id, std::string name, std::string description, std::string graphics) {}
  
      virtual ~CGameObject(void);
  };
  
  #endif  //_CGAMEOBJECT_H
  </code></pre>
  
  <p>I tried cleaning my project but in vain.</p>