CGAL 5.3 - 2D and 3D Linear Geometry Kernel
Kernel::LessXYZ_3 Concept Reference

Operations

A model of this concept must provide:

bool operator() (const Kernel::Point_3 &p, const Kernel::Point_3 &q)
returns true iff the $$x$$-coordinate of p is smaller than the $$x$$-coordinate of q or if the are the same and the $$y$$-coordinate of p is smaller than the $$y$$-coordinate of q, or, if both $$x$$- and $$y$$- coordinate are identical and the $$z$$-coordinate of p is smaller than the $$z$$-coordinate of q.