text: // Copyright (c) 2003-2006  INRIA Sophia-Antipolis (France).
  // All rights reserved.
  //
  // This file is part of CGAL (www.cgal.org).
  // You can redistribute it and/or modify it under the terms of the GNU
  // General Public License as published by the Free Software Foundation,
  // either version 3 of the License, or (at your option) any later version.
  //
  // Licensees holding a valid commercial license may use this file in
  // accordance with the commercial license agreement provided with the software.
  //
  // This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  // WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  //
  // $URL$
  // $Id$
  //
  // Author(s)     : Monique Teillaud, Sylvain Pion
  
  // Partially supported by the IST Programme of the EU as a Shared-cost
  // RTD (FET Open) Project under Contract No  IST-2000-26473 
  // (ECG - Effective Computational Geometry for Curves and Surfaces) 
  // and a STREP (FET Open) Project under Contract No  IST-006413 
  // (ACS -- Algorithms for Complex Shapes)
  
  #ifndef CGAL_ALGEBRAIC_KERNEL_FOR_CIRCLES_ROOT_FOR_CIRCLES_2_2_H
  #define CGAL_ALGEBRAIC_KERNEL_FOR_CIRCLES_ROOT_FOR_CIRCLES_2_2_H
  
  #include <iostream>
  #include <CGAL/Bbox_2.h>
  #include <CGAL/Root_of_traits.h>
  #include <CGAL/Handle_for.h>
  #include <boost/type_traits/is_same.hpp>
  
  namespace CGAL {
  
  template < typename RT_ >
  class Root_for_circles_2_2 {
  
    typedef RT_                                                              RT;
    typedef typename Root_of_traits< RT >::RootOf_2    Root_of_2;
    typedef typename Root_of_traits< RT >::RootOf_1    FT;
  
    private:
      Handle_for<Root_of_2> x_;
      Handle_for<Root_of_2> y_;
      
    public:
    Root_for_circles_2_2(){}
    
    Root_for_circles_2_2(const Root_of_2& r1, const Root_of_2& r2)
      : x_(r1), y_(r2)
    {
      // When it is an interval this assertion dont compile
      //CGAL_assertion((r1.is_rational() || r2.is_rational()) || 
      //               (r1.gamma() == r2.gamma()));
    }
  
    const Root_of_2& x() const 
    { return get_pointee_or_identity(x_); }
      
    const Root_of_2& y() const 
    { return get_pointee_or_identity(y_); }
  
    CGAL::Bbox_2 bbox() const
    {
      CGAL::Interval_nt<> 
       ix=to_interval(x()),
       iy=to_interval(y());
      return CGAL::Bbox_2(ix.inf(),iy.inf(),
  	                ix.sup(),iy.sup());
      /*
        const Root_of_2 &ox = x();
        const Root_of_2 &oy = y();
  
        if(ox.is_rational() || oy.is_rational()) {
          CGAL::Interval_nt<> 
            ix=to_interval(ox),
            iy=to_interval(oy);
          return CGAL::Bbox_2(ix.inf(),iy.inf(),
  	                ix.sup(),iy.sup());
        }
  
        // delta must be the same
        // WE HAVE TO TEST THE EXECUTION TIME
        // IT STILL NOT POSSIBLE BECAUSE OF THE 
        // PROBLEM ON THE ARRANGEMENT
        // (it is very likely to make it better with this changing)
        const CGAL::Interval_nt<true> alpha1 = to_interval(ox.alpha());
        const CGAL::Interval_nt<true> beta1 = to_interval(ox.beta());
        const CGAL::Interval_nt<true> alpha2 = to_interval(oy.alpha());
        const CGAL::Interval_nt<true> beta2 = to_interval(oy.beta());
        const CGAL::Interval_nt<true> g = to_interval(ox.gamma());
        const CGAL::Interval_nt<true> sqrtg = CGAL::sqrt(g);
        const CGAL::Interval_nt<true> ix = alpha1 + beta1 * sqrtg;
        const CGAL::Interval_nt<true> iy = alpha2 + beta2 * sqrtg;
        return CGAL::Bbox_2(ix.inf(),iy.inf(),
  	                ix.sup(),iy.sup());
      */
    }
  
    template < typename RT >
    friend bool operator == ( const Root_for_circles_2_2<RT>& r1,
     	                    const Root_for_circles_2_2<RT>& r2 );
  
  };
    
  template < typename RT >
  bool 
  operator == ( const Root_for_circles_2_2<RT>& r1,
  	      const Root_for_circles_2_2<RT>& r2 )
  { if (CGAL::identical(r1.x_, r2.x_) && CGAL::identical(r1.y_, r2.y_))
  	  return true;
    return (r1.x() == r2.x()) && (r1.y() == r2.y()); 
  }
  
  template < typename RT >
  std::ostream &
  operator<<(std::ostream & os, const Root_for_circles_2_2<RT> &r)
  { return os << r.x() << " " << r.y() << " "; }
  
  template < typename RT >
  std::istream &
  operator>>(std::istream & is, Root_for_circles_2_2<RT> &r)
  {
    typedef typename Root_of_traits< RT >::RootOf_2         Root_of_2;
    Root_of_2 x,y;
    
    is >> x >> y;
    if(is)
      r = Root_for_circles_2_2<RT>(x,y);
    return is;
  }
  
  } //namespace CGAL
  
  #endif // CGAL_ALGEBRAIC_KERNEL_FOR_CIRCLES_ROOT_FOR_CIRCLES_2_2_H
  