CGAL 5.5  2D Arrangements

Concepts  
concept  ArrangementBasicTopologyTraits 
The concept ArrangementBasicTopologyTraits defines the minimal functionality needed for a model of a topology traits, which can substitutes the TopolTraits template parameters when the class template Arrangement_on_surface_2<GeomTraits, TopolTraits> is instantiated. In particular. a model of this concept holds the Dcel data structure used to represent the arrangement cells (i.e., vertices, edges, and facets) and the incident relations between them. More...  
concept  ArrangementTopologyTraits 
A geometry traits class encapsulates the definitions of the geometric entities and implements the geometric predicates and constructions needed by instances of the CGAL::Arrangement_on_surface_2 class template and by the peripheral algorithms that operate on objects of such instances. Essentially, it maintains the doublyconnected connected edge list (DCEL) used by the arrangement. More...  