Опешите как работает программа С++

Опешите пожалуйста каждую строчку что делает, что значит

//---------------------------------------------------------------------------

#include

#pragma hdrstop
#include
#include
using namespace std;
//---------------------------------------------------------------------------
class PointXY;
class PointPolar;

class PointXY
{
public:
double x;
double y;
void show()
{
cout<<"(" << x << " , " << y << ")\n";
}
PointXY operator+(PointXY p2)
{
PointXY help;
help.x = x + p2.x;
help.y = y + p2.y;
return help;
}

operator PointPolar();

};

class PointPolar
{
public:
double r;
double phi;
void show()
{
cout<<"(" << r << " , " << phi << ")\n";
}

operator PointXY();

};

PointXY::operator PointPolar()
{
PointPolar help;
help.r = sqrt(x*x + y*y);
help.phi = atan2(x, y);
return help;
}

PointPolar::operator PointXY()
{
PointXY help;
help.x = r+ cos(phi);
help.y = r+ sin(phi);
return help;
}

#pragma argsused
int main(int argc, char* argv[])
{
PointXY p1, p2, p3;
PointPolar z1, z2, z3;
int i;

p1.x = 2; p1.y = 3;
p2.x = 1; p2.y = -2;

p3 = p1 +p2;

p1.show();
p2.show();
p3.show();

z1 = p1;
z1.show();

z1.r = 1;
z1.phi = 1.6;
p1 = z1;
p1.show();

z3 = p1+z2;
z3.show();

cin>>i;
return 0;
}
//---------------------------------------------------------------------------