Visual C++ friend function problem
i tired to use friend for << operator in Visual c++ but it gives me error that i cant access private variable in the class
can anyone help me how to fix this problem
thx u
here is examples of a simple program that is perfectly legal but n0t in visual c++
Code:
// Fraction.cpp
#include <iostream>
#include <cmath>
#include "Fraction.h"
using namespace std;
Fraction::Fraction() : numerator(0), denominator(1) { }
Fraction::Fraction(int n) : numerator(n), denominator(1) { }
Fraction::Fraction(int n, int d) {
if (0 == d) {
cout << "Illegal value for denominator" << endl;
exit(1);
}
numerator = n;
denominator = d;
reduce();
}
void Fraction::reduce() {
int g = gcd(abs(numerator), abs(denominator));
numerator /= g;
denominator /= g;
}
//ERROR in Visual C++ here, Can't access private variable
ostream& operator<< (ostream& output, const Fraction& f1) {
if (((f1.numerator < 0) || (f1.denominator < 0))
&& !((f1.numerator < 0) && (f1.denominator < 0)))
output << " - ";
output << abs(f1.numerator) << " / " << abs(f1.denominator);
return output;
}
istream& operator>> (istream& input, Fraction& f1) {
int n, d;
char ch;
input >> n >> ch >> d;
if (ch != '/') {
cout << "Fraction format error." << endl;
exit(1);
}
if (0 == d) {
cout << "Illegal value for denominator." << endl;
exit(1);
}
f1.numerator = n;
f1.denominator = d;
return input;
}
// Helper funtion which returns gcd of two numbers
int Fraction::gcd(int x, int y) {
if (x % y == 0)
return y;
return gcd(y, x % y);
}
Code:
// Fraction.h
#ifndef FRACTION_H
#define FRACTION_H
class Fraction {
public:
Fraction();
Fraction(int);
Fraction(int, int);
double getFraction() const {return ((double) numerator / denominator);}
int getNumerator() const {return numerator;}
int getDenominator() const {return denominator;}
friend ostream& operator<< (ostream&, const Fraction&);
friend istream& operator>> (istream&, Fraction&);
private:
void reduce();
static int gcd(int, int);
int numerator, denominator;
};
#endif
