dust3d/thirdparty/cgal/CGAL-4.13/include/CGAL/Is_a_predicate.h

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// Copyright (c) 2002
// Utrecht University (The Netherlands),
// ETH Zurich (Switzerland),
// INRIA Sophia-Antipolis (France),
// Max-Planck-Institute Saarbruecken (Germany),
// and Tel-Aviv University (Israel). 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) : Sylvain Pion
#ifndef CGAL_IS_A_PREDICATE_H
#define CGAL_IS_A_PREDICATE_H
// How to determine if a kernel functor is a predicate or a construction.
#include <CGAL/basic.h>
#include <CGAL/enum.h>
namespace CGAL {
namespace internal {
// By default it's a construction
template <typename Return_type>
struct Return_type_of_predicate {
typedef CGAL::Tag_false type;
};
// Specializations for predicates
template <>
struct Return_type_of_predicate<bool> {
typedef CGAL::Tag_true type;
};
template <>
struct Return_type_of_predicate<CGAL::Sign> {
typedef CGAL::Tag_true type;
};
template <>
struct Return_type_of_predicate<CGAL::Bounded_side> {
typedef CGAL::Tag_true type;
};
template <>
struct Return_type_of_predicate<CGAL::Angle> {
typedef CGAL::Tag_true type;
};
} // namespace internal
template <typename Functor>
struct Is_a_predicate {
typedef typename internal::Return_type_of_predicate<
typename Functor::result_type>::type type;
};
} //namespace CGAL
#endif // CGAL_IS_A_PREDICATE_H