cgal/Circulator/include/CGAL/Circulator/Circulator_concepts.h

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// Copyright (c) 2012
// 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) : Philipp Möller
#ifndef CGAL_CIRCULATOR_CONCEPTS_H
#define CGAL_CIRCULATOR_CONCEPTS_H
#include <boost/concept/assert.hpp>
#include <boost/concept_check.hpp>
#include <boost/concept/detail/concept_def.hpp>
#include <iterator>
#include <CGAL/circulator_bases.h>
namespace CGAL { namespace Concepts {
template <typename T>
void deref(T& t) {
t.operator->();
}
template <typename T>
void deref(T*) {
// valid anyway
}
// N.B.: there is no such concept as Circulator as it is immaterial
template <typename C>
struct ForwardCirculator
: boost::Assignable<C>, boost::DefaultConstructible<C>
, boost::CopyConstructible<C>
{
// for some odd reason circulators have no associated traits
typedef typename C::value_type value_type;
typedef typename C::reference reference;
typedef typename C::pointer pointer;
typedef typename C::difference_type difference_type;
// odd name but useful for compatibility
typedef typename C::iterator_category iterator_category;
// this requirement ought to be a mistake because it breaks
// compatibility with iterators
// typedef typename C::size_type size_type;
BOOST_CONCEPT_USAGE(ForwardCirculator)
{
// CGAL_UNUSED is needed with g++ 4.8, otherwise it warns:
// "typedef boost_concept_check68 locally defined but not used
// [-Wunused-local-typedefs]"
BOOST_CONCEPT_ASSERT((boost::SignedInteger<difference_type>)) CGAL_UNUSED;
BOOST_CONCEPT_ASSERT((boost::Convertible<iterator_category, CGAL::Forward_circulator_tag>)) CGAL_UNUSED;
boost::require_boolean_expr(a == NULL);
boost::require_boolean_expr(a != NULL);
++a;
a++;
(void)*a; // suppress unused warning, don't check the return type
// to allow for proxies
deref(a);
}
private:
C a;
};
template<typename C>
struct BidirectionalCirculator
: ForwardCirculator<C>
{
BOOST_CONCEPT_USAGE(BidirectionalCirculator)
{
BOOST_CONCEPT_ASSERT((boost::Convertible<typename C::iterator_category, CGAL::Bidirectional_circulator_tag>)) CGAL_UNUSED;
--a;
a--;
}
private:
C a;
};
template<typename C>
struct RandomAccessCirculator
: BidirectionalCirculator<C>
{
BOOST_CONCEPT_USAGE(RandomAccessCirculator)
{
BOOST_CONCEPT_ASSERT((boost::Convertible<typename C::iterator_category, CGAL::Random_access_circulator_tag>)) CGAL_UNUSED;
c += n; // addition
c = c + n; c = n + c;
c -= n; // subtraction
c = c - n;
n = c - b; // difference
(void)c[n]; // operator[]
c.min_circulator(); // minimum
}
private:
C c, b;
C i;
typename C::difference_type n;
};
} // Concept
} // CGAL
#include <boost/concept/detail/concept_undef.hpp>
#endif /* CGAL_CIRCULATOR_CONCEPTS_H */