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

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// Copyright (c) 2011 INRIA Saclay Ile-de-France (France).
// All rights reserved.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// 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.
//
// 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) : Marc Glisse
#ifndef CGAL_IS_ITERATOR_H
#define CGAL_IS_ITERATOR_H
#include <iterator>
#include <boost/type_traits/is_convertible.hpp>
#include <boost/type_traits/is_pointer.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/type_traits/remove_cv.hpp>
#include <boost/mpl/has_xxx.hpp>
namespace CGAL {
namespace internal {
BOOST_MPL_HAS_XXX_TRAIT_DEF(iterator_category)
BOOST_MPL_HAS_XXX_TRAIT_DEF(value_type)
BOOST_MPL_HAS_XXX_TRAIT_DEF(difference_type)
BOOST_MPL_HAS_XXX_TRAIT_DEF(pointer)
BOOST_MPL_HAS_XXX_TRAIT_DEF(reference)
//We request the type to be either a pointer or to
//provide all 5 nested types provided by iterator_traits
template <class T> struct is_iterator_ {
enum { value =
( has_iterator_category<T>::value &&
has_value_type<T>::value &&
has_difference_type<T>::value &&
has_pointer<T>::value &&
has_reference<T>::value
)
|| boost::is_pointer<T>::value };
};
template <class T,class U,bool=is_iterator_<T>::value>
struct is_iterator_type_ {
enum { value=false };
};
template <class T,class U> struct is_iterator_type_<T,U,true> :
//boost::is_base_of<U,typename std::iterator_traits<T>::iterator_category>
boost::is_convertible<typename std::iterator_traits<T>::iterator_category,U>
{};
}
// NOTE: we don't want the real std::decay or functions are included
template <class T> struct is_iterator :
internal::is_iterator_<typename boost::remove_cv<typename boost::remove_reference<T>::type>::type> {};
template <class T,class Tag> struct is_iterator_type :
internal::is_iterator_type_<typename boost::remove_cv<typename boost::remove_reference<T>::type>::type,Tag> {};
template <class T,class U,bool=is_iterator<T>::value> struct is_iterator_to {
enum { value=false };
};
template <class T,class U> struct is_iterator_to<T,U,true> :
boost::is_convertible<typename std::iterator_traits<T>::value_type,U>
{ };
}
#endif // CGAL_IS_ITERATOR_H