CGAL 5.5  2D Regularized Boolean SetOperations

Operations  
Comparison_result  operator() (ArrDirectionalTraits::X_monotone_curve_2 xc) 
accepts an input curve xc and compares its source and target points. More...  
Comparison_result ArrDirectionalTraits::CompareEndpointsXy_2::operator()  (  ArrDirectionalTraits::X_monotone_curve_2  xc  ) 
accepts an input curve xc
and compares its source and target points.
It returns SMALLER
if the curve is directed from lexicographically left to right, and LARGER
if it is directed from lexicographically right to left.