overload insertion and extraction operator in c++ code example

Example 1: overload input operator c++

#include <iostream>
using namespace std;
 
class Distance {
   private:
      int feet;             // 0 to infinite
      int inches;           // 0 to 12
      
   public:
      // required constructors
      Distance() {
         feet = 0;
         inches = 0;
      }
      Distance(int f, int i) {
         feet = f;
         inches = i;
      }
      friend ostream &operator<<( ostream &output, const Distance &D ) { 
         output << "F : " << D.feet << " I : " << D.inches;
         return output;            
      }

      friend istream &operator>>( istream  &input, Distance &D ) { 
         input >> D.feet >> D.inches;
         return input;            
      }
};

int main() {
   Distance D1(11, 10), D2(5, 11), D3;

   cout << "Enter the value of object : " << endl;
   cin >> D3;
   cout << "First Distance : " << D1 << endl;
   cout << "Second Distance :" << D2 << endl;
   cout << "Third Distance :" << D3 << endl;

   return 0;
}

Example 2: insertion and extraction operator overloading in c++

//<<<<<<<<<<<<<<<<<<<<<<<<<<<insertion operator overloading<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< Amir Ammar
std::ostream& operator<<(std::ostream& out, const Bigint& i){
  for(auto b = i.m_digits.begin(); b != i.m_digits.end(); ++b){
    out<<(*b);
  }
  return (out);
}
//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>extraction operator overloading>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Efi Fogel
std::istream& operator>>(std::istream& in, Bigint& i) {
  char c;
  in.get(c);
  if (c == '-') i.m_is_negative = true;
  else {
    if (! std::isdigit(c)) throw std::runtime_error("Invalid input");
    i.m_digits.emplace_front(c);
  }
  while (in.get(c) && (c != 0xa)) {
    if (! std::isdigit(c)) throw std::runtime_error("Invalid input");
    i.m_digits.emplace_front(c);
  }
  i.m_digits.reverse(); // additional method to return the reversed value (the real input)
  while(i.m_digits.front()=='0'&&i.m_digits.size()!= 1){ // while loop to earse additional zeroes 
    i.m_digits.pop_front();
    if(i.m_digits.size()== 1)
      break;
  }
  return in;
}