CGAL 6.0.1  2D and 3D Linear Geometry Kernel

Operations  
A model of this concept must provide:  
bool  operator() (const Kernel::Line_2 &l, const Kernel::Point_2 &p, const Kernel::Point_2 &q) 
returns true if the signed distance from p and the oriented line l is smaller than the signed distance of q and l .  
bool  operator() (const Kernel::Point_2 &p, const Kernel::Point_2 &q, const Kernel::Point_2 &r, const Kernel::Point_2 &s) 
returns true if the signed distance from r and the oriented line l defined by p and q is smaller than the signed distance of s and l .  
bool Kernel::LessSignedDistanceToLine_2::operator()  (  const Kernel::Point_2 &  p, 
const Kernel::Point_2 &  q,  
const Kernel::Point_2 &  r,  
const Kernel::Point_2 &  s  
) 
returns true
if the signed distance from r
and the oriented line l
defined by p
and q
is smaller than the signed distance of s
and l
.
p != q
.