inherited funcitons

[sql_lall]

Ok, having a few inheritence problems.

I have a class CMatrix;
It has a void Print() function and a constructor that takes 3 parameters (rows, cols, fill)

I also have a class CPoint, which uses CMatrix as a base.
When constructed, it takes size and fill, and calls the CMatrix constructor (1, size, fill)

No Problem yet, but how can i call a CPoint object to .Print(), and get it to use the CMatrix Print() Function without doing this:

void CPoint::Print()
{
CMatrix::Print();
}

Is there any better way?
Thanks

[Comreak]

So, you want to use CMatrix's print() in CPoint's print() function?

If your going to use inheritance, and print() is common to both classes, you can just use CMatrix's print() function (it carries over to CPoint after all). So, if you wanted to use the print() function in a driver program:

CPoint declaration:

class CPoint: public CMatrix;

print() usage in a driver program:

CPoint pt(1,2,3);
pt.print(); //print() carries over from CMatrix

Does that help any?

[CornedBee]

To clarify: if you don't actually do anything in the CPoint version of print other than calling the base version, simply omit the method completly from CPoint.

How is a point a matrix btw?

[sql_lall]

So, if i just leave out the function entirely from the Point class, then when i call
myPoint.Print()
then this will default to the Matrix Print() funciton??

Oh, and an n-dimensional point can be stored as a 1xn or nx1 matrix. Then you can do tranformations by using matrix multiplication, or do scaling, subtraction etc easily.

[Comreak]

Originally posted by sql_lall
So, if i just leave out the function entirely from the Point class, then when i call
myPoint.Print()
then this will default to the Matrix Print() funciton??

Yes, that's correct. CPoint inherits all of it's qualities from CMatrix, including print().

[sql_lall]

Thanks for that... i'll try it out soon

Oh, and just one more thing (sorry...)

I have some funcitons that take const parameters (i.e)
CMatrix& CMatrix:perator +(const CMatrix& InMat);
now, I also have some void functions, like:
void CMatrix::Print();

The only problem is if i try to call the Print function on one of the const parameters (i.e. i can't call InMat.Print() from before)

I am guessing this is because the compiler isn't guarenteed that InMat won't change when i call Print(), so the 'const'-ness isn't guarenteed, so there's an error.

What i am wondering is how to make the Print() funciton to be able to be called from constant Matrices..
something like:
const void CMatrix::Print() ???
Thanks

[CornedBee]

class CMatrix
{
public:
  void Print() const;
};

void CMatrix::Print() const
{
}