text: // Copyright (c) 2016 GeometryFactory (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 Lesser 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.
  //
  // $URL$
  // $Id$
  // SPDX-License-Identifier: LGPL-3.0+
  //
  // Author(s) : Jane Tournois
  
  
  #ifndef CGAL_HAS_MEMBER_ID_H
  #define CGAL_HAS_MEMBER_ID_H
  
  namespace CGAL {
  namespace internal {
  
    template <typename Type>
    class Has_member_id
    {
      typedef char yes[1];
      typedef char no[2];
  
      struct BaseWithId
      {
        void id(){}
      };
      struct Base : public Type, public BaseWithId {};
  
      template <typename T, T t>
      class Helper{};
  
      template <typename U>
      static no &check(U*, Helper<void (BaseWithId::*)(), &U::id>* = 0);
  
      static yes &check(...);
  
    public:
      static const bool value = (sizeof(yes) == sizeof(check((Base*)(0))));
    };
  
  }  // internal
  }  // cgal
  
  #endif /* CGAL_HAS_MEMBER_ID_H */
  