Uni-directionals are easy

#include "body.h"

class cylinder : public body {

public:

cylinder (float,float);

virtual char* identify() const;

virtual float GetVolume() const;

virtual float GetSurface() const;

protected:

// a cylinder is described by

// its radius and height

float radius;

float height;

flavor *f;

};

This is what you’d write in C++,

my object has a pointer to another object of type flavor

#include "body.h"

class cylinder : public body {

public:

cylinder (float,float);

virtual char* identify() const;

virtual float GetVolume() const;

virtual float GetSurface() const;

protected:

// a cylinder is described by

// its radius and height

float radius;

float height;

ooRef(flavor) f;

};

This is what you’d write for Objy-

“object reference”, like a “smart pointer” to another persistent object of type flavor.

#include "body.h"

. . .

flavor *f[];

};

#include "body.h"

. . .

xxxxxxxxxxxxxxxxx

};

Same with lists

Oops, we don’t know that yet ...