CGAL 5.6  2D and 3D Linear Geometry Kernel

AdaptableTernaryFunction
CGAL::Direction_2<Kernel>
Operations  
bool  operator() (const Kernel::Direction_2 &d, const Kernel::Direction_2 &d1, const Kernel::Direction_2 &d2) 
returns true iff d is not equal to d1 , and while rotating counterclockwise starting at d1 , d is reached strictly before d2 is reached. More...  
bool Kernel::CounterclockwiseInBetween_2::operator()  (  const Kernel::Direction_2 &  d, 
const Kernel::Direction_2 &  d1,  
const Kernel::Direction_2 &  d2  
) 
returns true
iff d
is not equal to d1
, and while rotating counterclockwise starting at d1
, d
is reached strictly before d2
is reached.
Note that true is returned if d1
== d2
, unless also d
== d1
.