Partial specialization for a parent of multiple classes

I want to use partial specialization for a template class so that all children of that template class will use that specialization. Let me explain it with an example :)

template < typename T, unsigned int rows, unsigned int cols>
class BaseMatrix {...};

This class will have children that specify the structure of the matrix, like sparse,dense,diagonal,..

template < typename T, unsigned int rows, unsigned int cols>
class DiagonalMatrix : public BaseMatrix<T,rows,cols>{..}

Then those classes will have children again that specify the storage : stack arrays, vectors, list, queues,..

template < typename T, unsigned int rows, unsigned int cols>
class StackDiagonalMatrix : public DiagonalMatrix<T, rows, cols> {..}

Then there is a class Matrix, which provides all the mathematical functionality. This template class implements operator+, operator-, etc...

   template <typename T, 
             template<typename, unsigned, unsigned> class MatrixContainer,
             unsigned Rows, 
             unsigned Cols>
    class matrix;

For this last class I want to write specializations like this:

template <typename T,unsigned Rows, unsigned Cols>
class matrix<T, BaseMatrix, Rows, Cols> {};

template <typename T,unsigned Rows, unsigned Cols>
class matrix<T, DiagonalMatrix, Rows, Cols>  {};

But when I write a StackDiagonalMatrix which inherits from DiagonalMatrix, it does not find the specialization for DiagonalMatrix -- it does not find a specialization at all actually.

error: aggregate ‘matrix<int, StackDenseMatrix, 3u, 2u> matrix’ has incomplete type and cannot be defined

Now is there a solution for this problem? Can you write a specialization for a parent of several template classes?

Many thanks!

Full Source that is involved :

    template <typename T, unsigned int rows, unsigned int cols>
    class BaseMatrix {
    protected:
        BaseMatrix(){};
        static const unsigned rowSize = rows;
        static const unsigned colSize = cols;
    };

    template <typename T, unsigned int rows, unsigned int cols>
    class DenseMatrix : public BaseMatrix<T, rows, cols> {
    protected:
        DenseMatrix(){};

    };

    template <typename T, unsigned int rows, unsigned int cols>
    class StackDenseMatrix : public DenseMatrix<T, rows, cols> {

    public:
        typedef T                                           value_type;

    private:
        value_type                                          grid[rows][cols];
        StackDenseMatrix();
    };

    template<typename value_type, unsigned int rows, unsigned int cols>
    StackDenseMatrix<value_type, rows,cols>::StackDenseMatrix () {
        for (unsigned int i = 0; i < this->rowSize; i++) {
            for (unsigned int j = 0; j < this->colSize; j++) {
                grid[i][j] = 0;
            }
        }
    }

    template <typename T, template<typename, unsigned, unsigned> class MatrixContainer ,unsigned Rows, unsigned Cols>
    class matrix;

    template <typename T,unsigned Rows, unsigned Cols>
    class matrix<T,BaseMatrix, Rows, Cols> {
         matrix(){};
};

int main () {
    matrix<int, StackDenseMatrix, 3, 2> matrix;
    return 0;
}