[Dev-C++] C++ question

[Ioannis V. <no...@ya...>]

Guys & girls i need your help. :)

We have the following C++ code:

#include <iostream>

class Matrix
{
 double m[4][4];

 public:
 friend Matrix operator+(const Matrix &, const Matrix &);
};

Matrix operator+(const Matrix &arg1, const Matrix &arg2)
{
 Matrix sum;

 for(int i=0; i<4; i++)
 {
  for(int j=0; j<4; j++)
     sum.m[i][j]=arg1.m[i][j] + arg2.m[i][j];
 }

 return sum;
}

int main()
{

 return 0;
}


It compiles ok. In the definition of operator+ we have the access of private
data members using the . notion directly. The code was taken from
Stroustrup's special edition. In that book i have seen the same access style
of private data members in all member functions of a class. What is the rule
here? Under what circumstances can we access directly private members of a
class?

I hope someone will help to figure it out.


Thanks in advance,
Ioannis

* Ioannis Vranos
* Programming pages: http://members.nbci.com/noicys
* Alternative URL: http://run.to/noicys