[Boost-users] Question regarding template

From: YYW (yyw1_25_at_[hidden])
Date: 2006-10-15 06:45:52

Hello all,
why the codes below is wrong in g++ 3.4.2?
an error occurs in the line: cout<<CMatrix<double>::eye(5);
--------------------------------------
#include <ostream>
#include <boost/numeric/ublas/matrix.hpp>
#include <boost/numeric/ublas/io.hpp>

using namespace boost::numeric::ublas;
using namespace std;

template <class T>
class CMatrix
{
    matrix<T>mat_;

public:
    CMatrix(const identity_matrix<T>& m) { mat_ = m; }
    static CMatrix<T> eye(int size) { return identity_matrix<T>(size); }

    template <class T_>
        friend ostream& operator << (ostream& os, CMatrix<T_>& m);
};

template<class T_>
ostream& operator << (ostream& os, CMatrix<T_>& m)
{
    os<<m.mat_;
    return os;
}

int main()
{
    CMatrix<double>I = CMatrix<double>::eye(5);
    cout<<I;

    cout<<CMatrix<double>::eye(5);//this line ==> error
}
----------------------------------------
Thanks in advance!