172 Introduction to C++ Programming and Graphics
void operator ++ ();The associated class implementation is:
void algebra::operator ++ ()
{
x = x*x;
color= setcolor(x);
}Once this is done, we can state in the main program:
++A;where A is a declared point.
Even more interesting, we can twice overload the + operator by inserting
the following declaration in the public section of the class:
algebra operator + ();accompanied by the implementation:
void algebra::operator + ()
{
x = 2*x;
color= setcolor(x);
}Once this is done, we can write
+A;where A is a point.
Consider the classes of circles and squares introduced in Section 6.7. The
following global function defined outside these classes overloads the + operator:
void operator + (circle A, square B)
{
A.print();
B.print();
}Including in the main program the block of commands:
circle A = circle(0.1, 0.2, 0.3);
square B = square(0.9, 1.2, 5.3);
A+B;