// overload5_b.cpp	By: Aiman Hanna -  ©1993-2006 Aiman Hanna
//
// This program is very similar to overload5.cpp. The difference between the 
// two programs lies in the way the overloaded "+=" operator is implemented. 
// With the default "+=" operator, we can write a statement like: 
//	x = y += z; // where x, y and z are of type "int" for example.
// With the implementation of the "+=" operator in overload5.cpp, such a 
// statement would be illegal. The intention of this program is to show an 
// example of how overloaded operators should be implemented so that 
// they are capable of providing as much flexibility as possible compared 
// to the original operators. 
//
// Key Points: 		1) What kind of functionality should an 
//			   overloaded operator provide? 
//					


#include "overload5.h"



// Free function that overloads the "+" operator. 
double operator+ (const Vehicle& vec1, const Vehicle& vec2)
{

	return vec1.price + vec2.price;
}




// Free function that overloads the "==" operator. 
bool operator== ( const Vehicle& vec1, const Vehicle& vec2 )
{

	return ((vec1.numdoors == vec2.numdoors) && (vec1.maxspeed == vec2.maxspeed) 
		     && (vec1.price == vec2.price));
}




// Free function that increments the price of a vehicle object by the price
// of another object. Notice that this function is not a "friend" function to 
// the Vehicle class. The function should return the incremented object if
// the "+=" operator is to behave in a similar fashion to the one provided
// by the language. 

Vehicle& operator+= ( Vehicle& vec1, Vehicle& vec2 )
{
   
    vec1.SetPrice( vec1.GetPrice() + vec2.GetPrice());
	return vec1;
}





Vehicle::Vehicle( int nd, double mxspd, double pr )
{
	numdoors = nd;
	maxspeed = mxspd;
	price = pr;

}




int Vehicle::GetNumDrs( void )
{
	return numdoors;
}



void Vehicle::SetNumDrs( int nd )
{
	numdoors = nd;
}



double Vehicle::GetmaxSpeed( void )
{
	return maxspeed; 
}



void Vehicle::SetMaxSpeed( double mxspd)
{
	maxspeed = mxspd;

}



double Vehicle::GetPrice( void )
{
	return price;

}



void Vehicle::SetPrice( double pr )
{
	price = pr;

}




void Vehicle::ShowInfo( void )
{
	cout << " The vehicle has " << numdoors << " doors, " << maxspeed 
         << " KM maximum speed, and its price is " << price << "$." << endl << endl;

}



int main()
{
	Vehicle v1(2, 180, 22000), v2(3, 220, 12000);
 

	cout << "\n Here is the information of v1: " << endl;
	cout << " ============================== " << endl;
	v1.ShowInfo();

	cout << "\n Here is the information of v2: " << endl;
	cout << " ============================== " << endl;
	v2.ShowInfo();


	if (v1 == v2)	// Use the overloaded operator "==" to the two vehicles are identical.
		cout << " v1 and v2 are identical objects. " << endl;
	else 
		cout << " v1 and v2 are not identical objects. " << endl;


  
	cout << "\n The total price of v1 and v2 is: " << v1 + v2  << endl;
 
 

	v1 += v2; // Use the "+=" operator to increment the price of v1 by the price of v2.

	cout << "\n Here is the information of v1 after incrementing its price: " << endl;
	cout << " ============================================================== \n" << endl;
	v1.ShowInfo();

 

	Vehicle v3(3, 180, 1000), v4(5, 200, 2000), v5(4, 220, 30000);

	cout << "\n Here is the information of v3: " << endl;
	cout << " ============================== " << endl;
	v3.ShowInfo();

	cout << "\n Here is the information of v4: " << endl;
	cout << " ============================== " << endl;
	v4.ShowInfo();

	cout << "\n Here is the information of v5: " << endl;
	cout << " ============================== " << endl;
	v5.ShowInfo();

 // Now you can use the "+=" operator in a similar fashion to the original operator
 // provided by the language. Notice that with the implementation of the overloaded 
 // "+=" operator in the previous program (overload5.cpp), a statement like that 
 // would be illegal.

	v3 = v4 += v5;


	cout << "\n Here is the information of v3 after being updated: " << endl;
	cout << " ==================================================== " << endl;
	v3.ShowInfo();

	cout << "\n Here is the information of v4 after being updated: " << endl;
	cout << " ==================================================== " << endl;
	v4.ShowInfo();

	return 0;
}


// The result of running the program 
/*
 
 Here is the information of v1:
 ==============================
 The vehicle has 2 doors, 180 KM maximum speed, and its price is 22000$.


 Here is the information of v2:
 ==============================
 The vehicle has 3 doors, 220 KM maximum speed, and its price is 12000$.

 v1 and v2 are not identical objects.

 The total price of v1 and v2 is: 34000

 Here is the information of v1 after incrementing its price:
 ==============================================================

 The vehicle has 2 doors, 180 KM maximum speed, and its price is 34000$.


 Here is the information of v3:
 ==============================
 The vehicle has 3 doors, 180 KM maximum speed, and its price is 1000$.


 Here is the information of v4:
 ==============================
 The vehicle has 5 doors, 200 KM maximum speed, and its price is 2000$.


 Here is the information of v5:
 ==============================
 The vehicle has 4 doors, 220 KM maximum speed, and its price is 30000$.


 Here is the information of v3 after being updated:
 ====================================================
 The vehicle has 5 doors, 200 KM maximum speed, and its price is 32000$.


 Here is the information of v4 after being updated:
 ====================================================
 The vehicle has 5 doors, 200 KM maximum speed, and its price is 32000$.

 

*/