CGAL 5.6  2D and 3D Linear Geometry Kernel

Functions  
template<typename Kernel >  
Comparison_result  CGAL::compare_xyz (const CGAL::Point_3< Kernel > &p, const CGAL::Point_3< Kernel > &q) 
Compares the Cartesian coordinates of points p and q lexicographically in \( xyz\) order: first \( x\)coordinates are compared, if they are equal, \( y\)coordinates are compared, and if both \( x\) and \( y\) coordinate are equal, \( z\)coordinates are compared.  