## CGAL::Apollonius_graph_traits_2<K,Method_tag>

### Definition

The class Apollonius_graph_traits_2<K,Method_tag> provides a model for the ApolloniusGraphTraits_2 concept. This class has two template parameters. The first template parameter must be a model of the Kernel concept. The second template parameter corresponds to how predicates are evaluated. There are two predefined possible values for Method_tag, namely CGAL::Sqrt_field_tag and CGAL::Ring_tag. The first one must be used when the number type used in the representation supports the exact evaluation of signs of expressions involving all four basic operations and square roots, whereas the second one requires the exact evaluation of signs of ring-type expressions, i.e., expressions involving only additions, subtractions and multiplications. The default value for Method_tag is CGAL::Ring_tag. The way the predicates are evaluated is discussed in [KE02, KE03].

#include <CGAL/Apollonius_graph_traits_2.h>

### Is Model for the Concept

ApolloniusGraphTraits_2

### Creation

Apollonius_graph_traits_2<K,Method_tag> traits;
| Default constructor.
Apollonius_graph_traits_2<K,Method_tag> traits ( other);
| Copy constructor.

Apollonius_graph_traits_2<K,Method_tag>
| traits = other | Assignment operator.

### See Also

Kernel
ApolloniusGraphTraits_2
CGAL::Ring_tag
CGAL::Sqrt_field_tag
CGAL::Apollonius_graph_2<Gt,Agds>
CGAL::Apollonius_graph_filtered_traits_2<CK,CM,EK,EM,FK,FM>