Eigen::NumTraits<CGAL::Mpzf>

Number_types/include/CGAL/Mpzf.h

@@ -883,6 +883,7 @@ struct Mpzf {
   Mpzf& operator+=(Mpzf const&x){ *this=*this+x; return *this; }
   Mpzf& operator-=(Mpzf const&x){ *this=*this-x; return *this; }
   Mpzf& operator*=(Mpzf const&x){ *this=*this*x; return *this; }
+  Mpzf& operator/=(Mpzf const&x){ *this=*this/x; return *this; }
 
   bool is_canonical () const {
     if (size == 0) return true;
@@ -1147,6 +1148,35 @@ CGAL_DEFINE_COERCION_TRAITS_FROM_TO(mpz_class,Mpzf)
 
 }
 
+/* There isn't much Eigen can do with such a type,
+ * mostly this is here for IsInteger to protect people.
+ */
+namespace Eigen {
+  template<class> struct NumTraits;
+  template<> struct NumTraits<CGAL::Mpzf>
+  {
+    typedef CGAL::Mpzf Real;
+    /* Should this be Quotient<Mpzf>? Gmpq?  */
+    typedef CGAL::Mpzf NonInteger;
+    typedef CGAL::Mpzf Nested;
+
+    static inline Real epsilon() { return 0; }
+    static inline Real dummy_precision() { return 0; }
+
+    enum {
+      /* Only exact divisions are supported, close enough to an integer.
+       * This way we get compilation failures instead of runtime.  */
+      IsInteger = 1,
+      IsSigned = 1,
+      IsComplex = 0,
+      RequireInitialization = 1,
+      ReadCost = 6,
+      AddCost = 30,
+      MulCost = 50
+    };
+  };
+}
+
 #if defined(BOOST_MSVC)
 #  pragma warning(pop)
 #endif