CircularKernel::CompareYatX_2

An object fo of this type must provide two operators that compare a point p and an arc a on the vertical line passing through p.

Comparison_result fo ( CircularKernel::Circular_arc_point_2 p, CircularKernel::Circular_arc_2 a)
For a circular arc.
Precondition: The arc a must be monotone and p must be in the vertical range of a.

Comparison_result fo ( CircularKernel::Circular_arc_point_2 p, CircularKernel::Line_arc_2 a)
Same for a segment.