#include <iostream>

using namespace std;

class SomeDataT {
   public:
       SomeDataT() {
          cout << "Constructor called " << endl;
       }

       ~SomeDataT() {
          cout << "Destructor called " << endl;
       }

       void Data(int newData) {
          data = newData;
       }

       int Data() const {
          return data;
       }

       SomeDataT operator ++(int) {
          SomeDataT originalValue{*this};
          ++data;
          return originalValue;
       }

       SomeDataT & operator ++() {
          ++data;
          return *this;
       }

   private:
       int data{4};
};

ostream & operator << (ostream & s, const SomeDataT & other);

SomeDataT & GoodFunction(SomeDataT & other);
SomeDataT & BadFunction(SomeDataT other);

int main() {
    SomeDataT data;

    data.Data(44);
    cout << "The data is ";
    cout << data  << endl;
    cout << endl;

    int i{10};
    int j;

    j = i;
    cout << "i = " << i << " j = " << j << endl;
    cout << endl;

    cout << "j = ++i" << endl;
    j = ++i;
    cout << "i = " << i << " j = " << j << endl;
    cout << endl;

    cout << "j = i++" << endl;
    j = i++;
    cout << "i = " << i << " j = " << j << endl;
    cout << endl;

    cout << "The same for our class " << endl;
    SomeDataT copy{data};

    cout << "data = " << data << " copy = " << copy << endl;
    cout << endl;

    cout << "copy = ++data" << endl;
    copy = ++data;
    cout << "data = " << data << " copy = " << copy << endl;
    cout << endl;

    cout << "copy = data++" << endl;
    copy = data++;
    cout << "data = " << data << " copy = " << copy << endl;
    cout << endl;


    return 0;
}

ostream & operator << (ostream & s, const SomeDataT & other){
     s << other.Data();
     return s;
}

SomeDataT & GoodFunction(SomeDataT & other){
    return other;
}
/*
SomeDataT & BadFunction(SomeDataT other){
    return other;
}
*/