Fungsi Fibonacci Iteratif c++

#include <cstdlib>
#include <iostream>
#include <conio.h>
using namespace std;
class fibonacci {
friend istream& operator>>(istream&,fibonacci&);
friend ostream& operator<<(ostream&,fibonacci&);

public :
fibonacci(int f1=0, int f2=1, int f3=0, int n=0){
angka1=f1;
angka2=f2;
angka3=f3;
suku=n;
}
private :
int angka1;
int angka2;
int angka3;
int suku;
};
istream& operator>>(istream& in,fibonacci& a){
cout<<"masukkan n = ";
in>> a.suku;
return in;
}
ostream& operator<<(ostream& out, fibonacci& b){
b.angka1=0;
b.angka2=1;
b.angka3=b.angka1+b.angka2;
out<<b.angka1<<" "<<b.angka2<<" ";
for(int i=1;i<=b.suku;i++){
b.angka3=b.angka1+b.angka2;
b.angka1=b.angka2;
b.angka2=b.angka3;
if (b.angka3<=b.suku){
out<<b.angka3<<" ";
}
i++;
}
return out;
}

int main(){
fibonacci c;
cin>>c;
cout<<c;
system("pause");
return 0;
}