CGAL: Inheritance and the kernel

问题

CGAL question:

Im trying the add one property to the point class. The first step I guess is to inherit a kernel and replace the point class with my own which I inherit from CGAL's. But just trying to get this small first step I run into trouble.

Edit: Based on the comment below I changed the inheritance to the way it's described in the Manual. The code below gives the following compile error:

‘typename CGAL::Extended_homogeneous::Base’ names 'CGAL::Extended_homogeneous::Base’, which is not a class template|

among others.

MyBase.h

#include <CGAL/Extended_homogeneous.h>

template < typename K_, typename K_Base >
class My_base  : public K_Base::template Base<K_>::Type
{
  typedef typename K_Base::template Base<K_>::Type   OldK;

public:
  typedef K_                                Kernel;

  template < typename Kernel2 >
  struct Base { typedef My_base<Kernel2, K_Base>  Type; };
 };

template < typename RT_ >
struct MyKernel  : public CGAL::Type_equality_wrapper<My_base<MyKernel<RT_>, CGAL::Homogeneous<RT_> >,  MyKernel<RT_> >
{};

Minimal.cpp

#include "MyKernel.h"
#include <CGAL/Nef_polyhedron_3.h>
typedef MyKernel<CGAL::Gmpz>    Kernel;

typedef CGAL::Nef_polyhedron_3<Kernel>  Nef_Polyhedron;
typedef Nef_Polyhedron::Plane_3  Plane;

int main()
{
  Nef_Polyhedron half_space(Plane(1,1,1,1), Nef_Polyhedron::EXCLUDED);

  return 0;
}

If the inhertiance is changed to "public K_Base::Base::template B::Type" it will compile but Then I miss the propeties from the Extentensions I guess? Because I get the error

"Constructor not available for this kernel"

when I run the program

回答1:

The correct way to define your own kernel is described on the following page.

The things look complicated because of the type equality wrapper which makes Kernel::Point_2 equal to Point_2.

回答2:

You should read this thread here (see the 4th post by Sebastien): http://cgal-discuss.949826.n4.nabble.com/Exact-kernels-and-planes-td4655222.html

It explains the problem a little bit.

来源：https://stackoverflow.com/questions/10241969/cgal-inheritance-and-the-kernel

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