[See also the file TODO_static_filters]

- Filtered_kernel<> should be a proper kernel.  It should be possible to use
  the Kernel_base stuff (see Kernel_traits paper)...
- mv test/include/*.C *.def ; Or use template functions ?

Concerning the main code:
-------------------------
- Policy for overlapping comparisons : another good (faster) solution
  would be to set a static boolean variable to indicate a buggy comparison
  happenned (a la IEEE inexact flags).  Drawback is that it's not thread safe,
  but could be made safe with pthread_key_create()...
  Clearly, all this stuff is policy.
    struct overlap_throw {
      void operator() const { throw(ce_qui_faut); }
    };
  Or :
    class overlap_static {
      static bool pipo = false;
    public:
      void operator() const { pipo = true; }
      void reset() const { pipo = false; }
    };
- Pentium 4 : gcc -march=pentium4 -mfpmath=sse supports something like:
    #include <xmmintrin.h>
    #include <iostream>
    
    int main()
    {
      int i = _mm_getcsr();
      std::cout << i << std::endl;

      x = _MM_GET_ROUNDING_MODE()
      _MM_SET_ROUNDING_MODE(x)
      return 0;
    }
  Faut juste bien faire gaffe a __SSE2__ pour savoir quelle unite est utilisee
  pour les calculs (x87 ou SSE2).  Ca pourrait meme etre les deux (bonjour le
  bordel...).
  Avantage : y'a pas de risque d'overflow/underflow avec la SSE2, donc on peut
  disabler le workaround.
  Y'a peut-etre meme des instructions interessantes pour speeder l'IA avec la
  SSE2.
- Use expression templates for Interval_nt<> and Lazy_exact_nt<>.
- Specializations for is_zero() and co, and make use of them in the kernel.
  [Filtered_exact<> doesn't define them either, it's a bug...]
- SunPro 5.x supports Interval arithmetic...
  http://docs.sun.com/htmlcoll/coll.693.1/iso-8859-1/CPPARITHPROG/iapg_bookTOC.html
  http://www.sun.com/forte/cplusplus/interval/index.html;$sessionid$GSXJDFYAABWVTAMTA1FU45Q
- Try to get rid of the libc5 compatible version (make benchmarks first).
- Have determinant_by_formula() overloading for Lazy_exact_nt<> ?
  And what about for Interval_nt<> too ?
- Turn CGAL_IA_CHECK_RESTRICT into an [expensive] assertion ?
- Get rid of convert_to() ?  This is a mess for nothing (benchmark first).
  Target convert_from_to (const Target, const Source) is fine ?
  It could maybe be made better this way:
    void convert_from_to(Target &, const Source &) ?
  Suggest that to Stefan for misc.h ?
- Handle in_smallest_orthogonalcircle_ftC2.h correctly (needs an include)
- Bench -fbranch-probabilities ?  Use __builtin_expect() for GCC 3 ?
- Mark the cache as "mutable" (see Stroustrup, page 232) ?
- Filter_Cache: Faire des benchs, et une test-suite qui soit raisonnable.
  Hum, rajouter un booléen pour calculer le cache seulement sur demande ?
  (ça évite de le faire inutilement pour les variables intermédiaires,
  mais ça prend un chouia plus de place... mais en comparaison du reste...)
- Replace CGAL_IA_MAX_DOUBLE by standard DBL_MAX in <cfloat>, if portable
  (add a test).  Not possible for CGAL_IA_MIN_DOUBLE, since DBL_MIN is the
  _normalized_ minimum.
- See the C++ Standard numeric_limits<>, section 18.2.
? See ISO C99 and http://http.cs.berkeley.edu/~fateman/fp98/korenF/node3.html.
- "C9x FP unordered compares":
  +  /* ISO C99 IEEE Unordered compares.  */
  +  builtin_function ("__builtin_isgreater", default_function_type,
  +                   BUILT_IN_ISGREATER, BUILT_IN_NORMAL, NULL_PTR);
  +  builtin_function ("__builtin_isgreaterequal", default_function_type,
  +                   BUILT_IN_ISGREATEREQUAL, BUILT_IN_NORMAL, NULL_PTR);
  +  builtin_function ("__builtin_isless", default_function_type,
  +                   BUILT_IN_ISLESS, BUILT_IN_NORMAL, NULL_PTR);
  +  builtin_function ("__builtin_islessequal", default_function_type,
  +                   BUILT_IN_ISLESSEQUAL, BUILT_IN_NORMAL, NULL_PTR);
  +  builtin_function ("__builtin_islessgreater", default_function_type,
  +                   BUILT_IN_ISLESSGREATER, BUILT_IN_NORMAL, NULL_PTR);
  +  builtin_function ("__builtin_isunordered", default_function_type,
  +                   BUILT_IN_ISUNORDERED, BUILT_IN_NORMAL, NULL_PTR);
  [voir le draft C99 ce que c'est]
? SUN: Add "-Wa,-xarch=v8plus" to fix the following "error":
  /usr/ccs/bin/as: "/var/tmp/ccBHnU0T.s", line 861: warning: 3 instructions
  required between ldfsr and next FBfcc; nops inserted

Concerning the script:
----------------------
- Produce separate files for declarations and definitions (=> libCGAL).

Concerning the doc:
-------------------
- In the 2.0 HTML doc, my enums are indexed twice.
  probably a cc_manual compliance bug from me.
  Idem, my fct to_double(Ia) is not the same as the others...
- add a pointer to my MISC'99 paper.
- DOCUMENT the new boolean template parameter, the script, the static filters.

Concerning the test-suite:
--------------------------
- Check it with GCOV again before the next public release.
- Make a more extensive test-suite for the filtered predicates.
  The script could output information to test them generically somehow.
- Test NaN propagation.  Comparisons with these should throw the exception...
  Check that they are correctly propagated (by min(), max(), even operator*...)