// Copyright Grant Rostig 2019

#include <iostream>

#include <chrono>

#include <bits/unique_ptr.h>

using namespace std;

struct Person_interface { // make this class "pure virtual" by making all functions virtual=0, except for the default constructor and destructor, this allows some compiler optimizations over just an "abstract class"

std::string name {"No Name Yet"};

int age {};

Person_interface() {

cout << "Person_interface()\n";

}

~Person_interface() {

cout << "~Person_interface()\n";

}

virtual void rename( std::string new_name )=0;

virtual void birthday()=0;

};

struct Child : public Person_interface {

Child() {

cout << "Child()\n";

// will also call parent() automatically

}

~Child() {

cout << "~Child()\n";

// will also call parent() automatically

}

void rename( std::string new_name ) override {

cout << "Child::rename()\n";

name = new_name; // this->name = new_name;

}

void birthday() override {

cout << "Child::birthday()\n";

++age;

}

};

struct Student : public Child {

string name_enrollment {};

Student() {

cout << "Student()\n";

}

void rename(std::string new_name) override final {

cout << "Student::rename()\n";

name_enrollment = new_name;

Child::rename( new_name );

};

};

int main() {

Child child1;

Person_interface * person_ptr;

person_ptr = &child1;

person_ptr->birthday(); // calls child's birthday, not person's version (which is NULL anyway).

cout << child1.age << endl;

Student student1;

// std::unique_ptr<Child> child_ptr; // todo: redo code with unique_ptr.

Child * child_ptr;

child_ptr = &student1;

person_ptr = &student1;

child_ptr->rename("Student Bob"); // calls student's rename, not child's.

person_ptr->birthday(); // would call student's birthday (if it existed), but gets child's birthday through inheritance.

cout << "child and person name: " << child_ptr->name <<", "<< person_ptr->name << endl;

cout << "###" << std::endl;

return 0;

}