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;
}
