\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.12 - 2D and 3D Linear Geometry Kernel
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CGAL::Kernel_traits< T > Struct Template Reference
2D and 3D Linear Geometry Kernel Reference » Kernel Classes

#include <CGAL/Kernel_traits.h>

Definition

The class Kernel_traits provides access to the kernel model to which the argument type T belongs.

(Provided T belongs to some kernel model.) The default implementation assumes there is a local type T::Kernel referring to the kernel model of T. If this type does not exist, a specialization of Kernel_traits can be used to provide the desired information.

This class is, for example, useful in the following context. Assume you want to write a generic function that accepts two points p and q as argument and constructs the line segment between p and q. In order to specify the return type of this function, you need to know what is the segment type corresponding to the Point type representing p and q. Using Kernel_traits, this can be done as follows.

template < class Point >
typename Kernel_traits<Point>::Kernel::Segment
construct_segment(Point p, Point q)
{ ... }

Types

typedef T::R Kernel
 If T is a type K::Point_2 of some kernel model K, then Kernel is equal to K.