int main ( int argc, char *argv[] )
{
 Matrise A(3,3);
 KvMatrise B(3);
 cin >> A;
 B = A;  ( KvMatrise = Matrise ) <- invoking the assignment operator WHY DOES THIS NOT WORK ?!
}

class KvMatrise : public Matrise
{
        public:
                KvMatrise(int);
                KvMatrise(Matrise);
                KvMatrise& operator=(const Matrise&);
};

class Matrise {
        public:
                Matrise();
                Matrise(int c, int r);
                Matrise(const Matrise &src);
                ~Matrise();
                Matrise& operator=(const Matrise&);
};

KvMatrise::KvMatrise(int n): Matrise(n,n){}
KvMatrise::KvMatrise(Matrise m): Matrise(m){}

KvMatrise& KvMatrise::operator=(const Matrise& km)
{
        cout << "Calling assignment operator" << endl;
        static_cast<Matrise>(*this) = km;
        return *this;
}

Matrise::Matrise(): cols(1), rows(1) {}
Matrise::Matrise(int c, int r) : cols(c), rows(r) {
        matrise = new int*[rows];
        for(int i=0; i<rows; i++)
        {
                matrise[i] = new int[cols];
                for(int j=0; j<cols; j++)
                {
                        matrise[i][j] = 0;
                }
        }
}

Matrise::Matrise(const Matrise& src)
{
        rows = src.rows;
        cols = src.cols;

        matrise = new int*[rows];
        for(int i=0; i<rows; i++)
        {
                matrise[i] = new int[cols];
                for(int j=0; j<cols; j++)
                {
                        matrise[i][j] = src.matrise[i][j];
                }
        }
}