Question

I have the following classes where I try to acces a protected member of the Base class but I get an error in eclipse “Field Factorized could not be resolved”. Can someone explain to me what am I doing wrong? Why can’t I access to the variable mFactorized ??

BASE CLASS

template <typename ValueType>
class AbstractDirectLinearSolver{
protected:
    bool mFactorized;
public:
    //Constructors, destructor
    AbstractDirectLinearSolver(){
        mFactorized = false;
    }

    virtual ~AbstractDirectLinearSolver();

    //Methods
    virtual void Solve(Vector<ValueType>& x, const Vector<ValueType>& b) const = 0;
    virtual void Factorize(AbstractMatrix<ValueType>& A) = 0;
};

DERIVED CLASS

#include "AbstractDirectLinearSolver.hpp"

template<typename ValueType>
class CholeskySolver: public AbstractDirectLinearSolver {
private:
    AbstractMatrix<ValueType> *mR; //Pointer = Abstract class NOT ALLOWS instantiation !!
public:
    CholeskySolver() {
        mR = NULL;
    }

    ~CholeskySolver() {
        if (this->mFactorized) {  //ERROR HERE
            delete mR;
        }
    }

    void Solve(const Vector<ValueType>& x, const Vector<ValueType>& b) {
        Vector<ValueType> y(mR->ApplyLowInv(b));
        x = mR->ApplyLowerTransponse(y);
    }

    void Factorize(AbstractMatrix<ValueType>& A) {
        if (mR != NULL)
            delete mR;
        mR = NULL;
        A.CholeskyFactorization(mR);
        this->mFactorized;           //ERROR HERE
    }
};

Answer 1

You are trying to inherit from a class template, rather than a class. Change the class header to:

template<typename ValueType>
class CholeskySolver: public AbstractDirectLinearSolver<ValueType>
                                                       ^^^^^^^^^^^

It looks like the compiler bails out after complaining that mFactorized wasn’t a member (because it didn’t know about the base class), but before complaining that the base-class specifier was invalid.

If you were to comment out the problematic lines, then you’d get a slightly better (though still rather confusing) error: expected class-name before ‘{’ token.