// ---------------------------
//  rect.cpp
// ---------------------------
#include <iostream.h>
#include <math.h>
class rect
{
  public: // access specifier
	rect(double x1i,double x2i, double y1i, double y2i);
	rect(const rect &ri);  // copy constructor
	rect &operator =(rect &ri); // assignment operator
	~rect() {}  // destructor  [ not really needed here ]
	double area();
	void move(double dx, double dy);
	friend void p(rect &r);
	friend void pl(rect &r);

  private:
	double x1,x2,y1,y2;
  };

  rect::rect(double x1i,double x2i, double y1i, double y2i):
	 x1(x1i),x2(x2i),y1(y1i),y2(y2i) {}

  rect::rect(const rect &ri):
		x1(ri.x1), x2(ri.x2),y1(ri.y1),y2(ri.y2) {}

  rect &rect::operator =(rect &ri)
  { x1 = ri.x1; x2 = ri.x2; y1 = ri.y1; y2 = ri.y2;
	 return *this; }


  void rect::move(double dx, double dy)
	{ x1 += dx; x2 += dx;
	  y1 += dy; y2 += dy; }

  double rect::area()
	{ return (x2-x1)*(y2-y1); }

// ----------------------------------------
// some constants
 const double Pi      = 3.1415926535897932;
 const double Exp1    = 2.7182818284590452;

// ----------------------------------------
// print and new line for strings

	void nl()
	  {
		 cout << "\n";
		 cout.flush(); // apply nl right now
		 cout << "  "; // left margin
	  }

	void p(char *s) { cout << s; }
	void pl(char *s) { p(s); nl(); }

	void p(char *s, double x) { p(s); cout << x; }
   void pl(char *s, double x) { p(s,x); nl(); }

// ----------------------------------------
// print for rect
	void p(rect &r)
	 { p("(",r.x1); p(",",r.x2);
		p(",",r.y1); p(",",r.y2);
		p(")"); }

	void pl(rect &r) { p(r); nl(); }

// ----------------------------------------------------
	void main()
	{
     nl(); // first left margin
	  pl("------------- ");
	  pl("  rect.cpp    ");
	  pl("------------- ");
	  rect r(Pi,5*Pi,Exp1,Pi); // constructor
	  p("r = "); pl(r);
	  pl("area of r = ", r.area()); nl();

	  r.move(1,2);
	  rect r1(r);    // copy constructor
	  p("r1 = "); pl(r1);
	  pl("area of r1 = ", r1.area()); nl();

	  r1.move(-1,-2);
	  rect r2 = r1;  // assignment operator
	  r = r2 = r1;   // this is alright
	  p("r = "); p(r); pl(" = r2 =");
	  p("  = "); pl(r2);
	  pl("area of r2 = ", r2.area());
	}
 /* output
  
  -------------
    rect.cpp
  -------------
  r = (3.14159,15.708,2.71828,3.14159)
  area of r = 5.31948

  r1 = (4.14159,16.708,4.71828,5.14159)
  area of r1 = 5.31948

  r = (3.14159,15.708,2.71828,3.14159) = r2 =
    = (3.14159,15.708,2.71828,3.14159)
  area of r2 = 5.31948




  */