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[Evan Behar <>]

Ah, thanks. I also forgot to ask the other part of the question, though this helps me get to the point:

I want to convert values in my Point_3 to doubles (for rendering, output, etc.), but when I write

p.x().exact().to_double()

or

p.x().to_double() I get the error:

/home/ebehar/test/test.cpp:14:20: error: ‘const FT’ has no member named ‘exact’

   double d = p.x().exact().to_double();

                    ^

/home/ebehar/test/test.cpp:20:22: error: ‘const FT’ has no member named ‘to_double’

   d = p.x().to_double();

Is FT not Lazy_exact_nt< CGAL::Gmpq >? If it is, [1] says that Lazy_exact_nt< CGAL::Gmpq > has .exact() which should be CGAL::Gmpq, which does have .to_double().

[1] http://www.cgal.org/Manual/latest/doc_html/cgal_manual/NumberTypeSupport_ref/Class_Lazy_exact_nt.html

On Sat, Apr 27, 2013 at 5:46 PM, Marc Glisse <> wrote:

On Sat, 27 Apr 2013, Evan Behar wrote:

Hi,
I have the following code:

#include <CGAL/Polyhedron_3.h>
#include <CGAL/Gmpq.h>
#include <CGAL/Lazy_exact_nt.h>
#include <CGAL/Extended_cartesian.h>

typedef CGAL::Extended_cartesian< CGAL::Lazy_exact_nt<CGAL::Gmpq> > Kernel;
typedef CGAL::Point_3<Kernel>                                       Point;

Try Kernel::Point_3 instead, that's the proper way to use a traits class.

int main() {
  
  Point p(1.0f,1.0f,1.0f);

  return 0;
} 

When I try to compile this program, I get the following error:

In file included from /opt/local/CGAL-4.1/include/CGAL/assertions.h:34:0,
                 from /opt/local/CGAL-4.1/include/CGAL/basic.h:42,
                 from /opt/local/CGAL-4.1/include/CGAL/Polyhedron_3.h:24,
                 from /home/ebehar/test/test.cpp:1:
/opt/local/CGAL-4.1/include/CGAL/Point_3.h: In instantiation of ‘class
CGAL::Point_3<CGAL::Extended_cartesian<CGAL::Lazy_exact_nt<CGAL::Gmpq> > >’:
/home/ebehar/test/test.cpp:12:10:   required from here
/opt/local/CGAL-4.1/include/CGAL/assertions.h:124:6: error: invalid
application of ‘sizeof’ to incomplete type
‘boost::STATIC_ASSERTION_FAILURE<false>’
      BOOST_STATIC_ASSERT(EX)
      ^
/opt/local/CGAL-4.1/include/CGAL/Point_3.h:47:3: note: in expansion of macro
‘CGAL_static_assertion’
   CGAL_static_assertion((boost::is_same<Self, typename
R_::Point_3>::value));


Is there something additional I have forgotten to do in order to use the
Extended_cartesian kernel with Point_3 or Vector_3?

Thanks,
Evan

--
Marc Glisse

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