Thread: Circular includes

Hi, I have a simple problem, most likely faced by someone before.

I have 3 classes Cell, Juxtacrine and Morphogen. Juxtacrine is derived from Cell, and Morphogen is derived from Cell also.

Basically the two derived classes both include the Cell.h to find the definition of Cell.

The problem comes when i need to use the Objects in the main function eg

Code:

#include "Juxtacrine.h"
#include "Morphogen.h"

int main()
{
	Juxtacrine j;
	Morphogen m;
	return 0;
}

This obviously causes the circular include, and was wondering if there is a way to use preprocessor directives to stop this happening eg

Code:

#ifndef CELL_H
#include "Cell.h"
#endif

But this doesnt seem to fix it. Has anyone got an idea how to get around this? I dont really want to have to work out what class includes what as ill have several classes with multiple inheritence later on, which will cause a headache working out the circular includes if i do it manually...

Heres my code if u need it...

Code:

class Cell 
{
  public:

	Cell();
	~Cell();

  private:

	virtual void signal();
};

Code:

#include "Cell.h"

class Juxtacrine : public Cell
{

  public:

	Juxtacrine();
	~Juxtacrine();

  private :

	void signal();
};

Code:

#include "Cell.h"

class Morphogen : public Cell
{

  public:

	Morphogen();
	~Morphogen();

  private :

	void signal();
};

Im Using WinXP / VC++ (if needed)

Code:

#ifndef CELL_H
#include "Cell.h"
#endif

should be

Code:

#ifndef CELL_H
#define CELL_H
#include "Cell.h"
#endif

But this would go in the header itself. so the source code would be:

Code:

 #include "Cell.h"
#include <blah blah blah>

and inside of the header you would have

Code:

#ifndef CELL_H
#define CELL_H

// All your definations and such

#endif

Excellent, thats fixed it ! Thanks!