Need more info regarding FAQ 14.110

Dear All:

The FAQ 14.110 “How do I render rubber-band lines?” shows the two approaches:
one is using the overlay and the other is using GL_COLOR_LOGIC_OP & GL_XOR. I wonder is anyone out there ever implementing the second approach for drawing a rubber-band line? Or anyone know where to find an example code for drawing the rubber band line?

Thanks for help.