## CGAL::Arity_traits<F>

### Definition

The class Arity_traits<F> is used to define the arity of a functor class F, i.e., the number of arguments it takes. It is used as a compile time tag only, that is objects of this type are never created anywhere. Specializations of Arity_traits<F> can be defined, where existing functors cannot be changed easily to contain their Arity type.

#include <CGAL/functional_base.h>

Arity_traits<F>::Arity
| F::Arity

### See Also

AdaptableFunctor
CGAL::Arity_tag<int>