Array of pointers to derived classes of an abstract base class

[alsade]

i have two class:

class Rectangle:public Shape
{
	int height;
	int width;
public:
	void CreateRect(Rectangle*);
	int GetHeight(Rectangle*);
	int GetWidth (Rectangle*);
	float Area();
	int GetDiagonal();
	void printrect(Rectangle*);
};

and:

class Circle:public Shape
{
	int radius;
public:
	void CreateCirc(Circle*);
	int GetRadius(Circle*);
	float Area() ;
	int GetDiameter();
	friend class Shape;
	void printcircle(Circle*);
};

and a base class:

[code]class Shape
{
protected:
	int location;
	char * name;
	int x;
	int y;
public:
	void ChangeLocation();
	int GetLocation();
	virtual float Area()=0;
	friend class Circle;
	friend class rectangle;
};

i tried to initiate a string of pointers to the classe like this:
[/code]

int main()
{
Shape *picture[20];
picture[0]=new Circle;
}

but its not working and im unable to access the Circle's methods. can someone please explain to me how its done?

[long double main]

Required reading:
http://stackoverflow.com/questions/7196172/can-a-pointer-to-base-point-to-an-array-of-derived-objects?rq=1

[cwr2k]

Is there a reason you can't just use a vector here?

std::vector<Shape*> pictures;
pictures.push_back(new Circle);

You can also use a vector of smart ptrs so you don't have to worry about freeing the memory.

std::vector<std::unique_ptr<Shape>> pictures
pictures.push_back(std::unique_ptr<Circle>(new Circle));

Just be aware that unique_ptrs can't be copied. (That's why they're unique).

[ne555]

pointer arithmetic is not the problem here.
note that it does have an array of pointers.

> but its not working
you could be a little more specific

> and im unable to access the Circle's methods
¿and where in the code are you trying to do that?


Also, ¿why so friendly?