// Program to demonstrate the use of operator overloading for a complex class.
// Assignment-24
// opovrld.cpp, Author - Krishna Kumar Khatri.

// Uncomment ONLY the following line if you are using Turbo/Borland compiler.
// #define TC
#ifdef TC
	#include <iostream.h>
#else
	#include <iostream>
	using namespace std;
#endif
#include <conio.h>  // For getch.

class Box
{
	   int l, b, h;
    public:
    	Box(int fl = 0, int fb = 0, int fh = 0) : l(fl), b(fb), h(fh)
            {	}
    	long int volume();
    	Box operator+(const Box&);
    	Box operator+(const int&);
    	Box operator-(const Box&);
    	Box operator-(const int&);
    	Box operator++();    // Pre.
    	Box operator++(int); // Post.
	    Box operator--();    // Pre.
    	Box operator--(int); // Post.
    	friend ostream& operator<<(ostream&, Box&);
};

long int Box::volume()
{
    long int vol;

    vol = l * b * h;
    return vol;
}

Box Box::operator+(const Box& bObj)
{
	Box tempObj;
	
	tempObj.l = this->l + bObj.l;
    tempObj.b = this->b + bObj.b;
	tempObj.h = this->h + bObj.h;

	return tempObj;
}

Box Box::operator+(const int& inc)
{
    Box tempObj;
    
	tempObj.l = this->l + inc;
    tempObj.b = this->b + inc;
	tempObj.h = this->h + inc;

    return tempObj;
}

Box Box::operator-(const Box& bObj)
{
	Box tempObj;

	tempObj.l = this->l - bObj.l;
	tempObj.b = this->b - bObj.b;
	tempObj.h = this->h - bObj.h;

	return tempObj;
}

Box Box::operator-(const int& dec)
{
    Box tempObj;
    
	tempObj.l = this->l - dec;
    tempObj.b = this->b - dec;
	tempObj.h = this->h - dec;

    return tempObj;
}

Box Box::operator++() 
{
    *this = *this + 1;
    return *this;
}

Box Box::operator++(int dummy) 
{
    Box tempObj = *this;
    *this = *this + 1;
    return tempObj;
}

Box Box::operator--()
{
    *this = *this - 1;
    return *this;
}

Box Box::operator--(int dummy)
{
    Box tempObj = *this;
    *this = *this - 1;
    return tempObj;
}

ostream& operator<<(ostream& os, Box& obj)
{
    os << "l=" << obj.l << ", b=" << obj.b << ", h=" << obj.h << endl; 
    return os;
}

int main()
{
    #ifdef TC
        clrscr();
    #endif
    Box objA(4, 5, 9);
    Box objB(1, 1, 1);
    Box objC;
    
	cout << "objA - " << objA;
	cout << "Voulme with objA : " << objA.volume() << endl << endl;
	cout << "objB - " << objB;	
	cout << "Volume with objB : " << objB.volume() << endl << endl;

	objC = objA + objB;
	cout << "objC - " << objC;
	cout << "Volume with objC (objA + objB), " << objC.volume() << endl;
	objC = objA + 4;
	cout << "objC - " << objC;
	cout << "Volume with objC (objA + 4), " << objC.volume() 
         << endl << endl;
    getch();
 
	objC = objA - objB;
	cout << "objC - " << objC;
	cout << "Volume with objC (objA - objB), " << objC.volume() << endl;
   	objC = objA - 1;
	cout << "objC - " << objC;
	cout << "Volume with objC (objA - 1), " << objC.volume() 
         << endl << endl;
    getch();

	++objC;
	cout << "objC - " << objC;
	cout << "Volume with ++objC, " << objC.volume() << endl;
	objC++;
	cout << "objC - " << objC;
	cout << "Volume with objC++, " << objC.volume()
         << endl << endl;
    getch();

	--objC;
	cout << "objC - " << objC;
	cout << "Volume with --objC, " << objC.volume() << endl;
	objC--;
	cout << "objC - " << objC;
	cout << "Volume with objC--, " << objC.volume();

    cout << endl << endl << "Program over. Press any key to exit...";
    getch();
    return 0; // Successful termination.
}