inheritance question

[Glen Jenness]

What I want to do is take a predefined matrix class (ideally from Boost.matrix) and use inheritance to make a pseudo custom matrix class.

What I have for starters is:

#include <iostream>

#include <boost/numeric/ublas/matrix.hpp>
#include <boost/numeric/ublas/io.hpp>

namespace blas=boost::numeric::ublas;

template <typename T>

class Matrix<T>: public blas::matrix<T> {
    public:
        void testing(){ std::cout << "Testing" << std::endl;};

};

using namespace std;
using namespace blas;

int main() {
    Matrix<int> test(3,3);

    for (int i; i < 3; i++){
        for (int j; j < 3; j++){
            test(i,j) = i*j;
        }
    }

    cout << test << endl;

}

The error that I am getting is:

inheritence.cc:10:7: error: ‘Matrix’ is not a template
inheritence.cc: In function ‘int main()’:
inheritence.cc:20:25: error: no matching function for call to ‘Matrix<int>::Matrix(int, int)’
inheritence.cc:10:41: note: candidates are: Matrix<int>::Matrix()
inheritence.cc:10:41: note:                 Matrix<int>::Matrix(const Matrix<int>&)

Now, I will admit that I am NOT an expert in template arguments or inheritance, so this is pretty cobbled together :)

Any suggestions/advice on how to resolve this problem will be welcomed.

[HiteshVaghani1]

i think you need not to inherit predefined class rather than doing so you can simply include that class and make your own class definition.

[naraku9333]

You need to define the ctor to call the base ctor. Note the changes to your code.

#include <iostream>
 
#include <boost/numeric/ublas/matrix.hpp>
#include <boost/numeric/ublas/io.hpp>
 
namespace blas=boost::numeric::ublas;
 
template <typename T>
class Matrix: public blas::matrix<T> {
    public:
        Matrix(int x, int y){blas::matrix<T>(x,y);}
        void testing(){ std::cout << "Testing" << std::endl;};
 
};
 
using namespace std;
using namespace blas;
 
int main() {
    Matrix<int> test(3,3);
 
    for (int i; i < 3; i++){
        for (int j; j < 3; j++){
            test(i,j) = i*j;
        }
    }
 
    cout << test << endl;
 
}

[Glen Jenness]

Ah, thanks for the changes naraku! That did the trick and it compiled just fine and is working the way I wanted it to.