[abs]

i think you misunderstood my question...

i took the template...

template<typename T>
class C2DMatrix 
{
 public:
  C2DMatrix() {}
  C2DMatrix(unsigned, unsigned );
  T& operator() (unsigned, unsigned);
  const T& operator() (unsigned i, unsigned j) const;   
  size_t nRows_;
  size_t nCols_;
  vector<vector<T> > data_;
 private:
  template <typename _T>
    friend ostream& operator<<(ostream&  os, C2DMatrix<_T>& c2d );
};

and changed the class to 'int' type..

class C2DMatrix 
{
 public:
  C2DMatrix() {}
  C2DMatrix(unsigned, unsigned );
  
  int operator() (unsigned, unsigned);
  const int operator() (unsigned i, unsigned j) const;   
  size_t nRows_;
  size_t nCols_;
  vector<vector<int> > data_;
 private:
    friend ostream& operator<<(ostream&  os, C2DMatrix& c2d );
};

now assignment (ex: array(int,int) = int ) gives me that lvalue error.
So I was asking if there were anything different about how template classes are interpreted or referenced, compared to a non-template class. My understanding of templates is that the template type is bound at compile time, so I don't see why C2DMatrix<int> array, would be any different from C2DMatrix array (if C2DMatrix was hardcoded to type 'int'). ;p