Class Data Encapsulation(private data) in operator overloading

Question

Below is the code

The Code:

#include 
using namespace std;

class Rational {
  int num;  // numerator
  int den;  // den         


        

Answer 1

Access specifiers apply at the level of classes, not instances, so the Rational class can see private data members of any other Rational instance. Since your Rational operator+ is a member function, it has access to private data of it's Rational argument.

Note: the canonical approach is to define a member operator +=, and then use that to implement a non-member operator+

struct Foo
{
  int i;

  Foo& operator+=(const Foo& rhs) 
  { 
    i += rhs.i;
    return *this;
  }

};

Foo operator+(Foo lhs, const Foo& rhs)
{
  return lhs += rhs;
}