range/adaptor/indirected.hpp

0001 // Boost.Range library
0002 //
0003 //  Copyright Thorsten Ottosen, Neil Groves 2006 - 2008. Use, modification and
0004 //  distribution is subject to the Boost Software License, Version
0005 //  1.0. (See accompanying file LICENSE_1_0.txt or copy at
0006 //  http://www.boost.org/LICENSE_1_0.txt)
0007 //
0008 // For more information, see http://www.boost.org/libs/range/
0009 //
0010
0011 #ifndef BOOST_RANGE_ADAPTOR_INDIRECTED_HPP
0012 #define BOOST_RANGE_ADAPTOR_INDIRECTED_HPP
0013
0014 #include <boost/range/iterator_range.hpp>
0015 #include <boost/range/concepts.hpp>
0016 #include <boost/iterator/indirect_iterator.hpp>
0017
0018 namespace boost
0019 {
0020     namespace range_detail
0021     {
0022         template< class R >
0023         struct indirected_range :
0024             public boost::iterator_range<
0025                         boost::indirect_iterator<
0026                             BOOST_DEDUCED_TYPENAME range_iterator<R>::type
0027                         >
0028                     >
0029         {
0030         private:
0031             typedef boost::iterator_range<
0032                         boost::indirect_iterator<
0033                             BOOST_DEDUCED_TYPENAME range_iterator<R>::type
0034                         >
0035                     >
0036                 base;
0037
0038         public:
0039             explicit indirected_range( R& r )
0040                 : base( r )
0041             { }
0042         };
0043
0044         struct indirect_forwarder {};
0045
0046         template< class SinglePassRange >
0047         inline indirected_range<SinglePassRange>
0048         operator|( SinglePassRange& r, indirect_forwarder )
0049         {
0050             BOOST_RANGE_CONCEPT_ASSERT((
0051                 SinglePassRangeConcept<SinglePassRange>));
0052
0053             return indirected_range<SinglePassRange>( r );
0054         }
0055
0056         template< class SinglePassRange >
0057         inline indirected_range<const SinglePassRange>
0058         operator|( const SinglePassRange& r, indirect_forwarder )
0059         {
0060             BOOST_RANGE_CONCEPT_ASSERT((
0061                 SinglePassRangeConcept<const SinglePassRange>));
0062
0063             return indirected_range<const SinglePassRange>( r );
0064         }
0065
0066     } // 'range_detail'
0067
0068     using range_detail::indirected_range;
0069
0070     namespace adaptors
0071     {
0072         namespace
0073         {
0074             const range_detail::indirect_forwarder indirected =
0075                                             range_detail::indirect_forwarder();
0076         }
0077
0078         template<class SinglePassRange>
0079         inline indirected_range<SinglePassRange>
0080         indirect(SinglePassRange& rng)
0081         {
0082             BOOST_RANGE_CONCEPT_ASSERT((
0083                 SinglePassRangeConcept<SinglePassRange>));
0084             return indirected_range<SinglePassRange>(rng);
0085         }
0086
0087         template<class SinglePassRange>
0088         inline indirected_range<const SinglePassRange>
0089         indirect(const SinglePassRange& rng)
0090         {
0091             BOOST_RANGE_CONCEPT_ASSERT((
0092                 SinglePassRangeConcept<const SinglePassRange>));
0093
0094             return indirected_range<const SinglePassRange>(rng);
0095         }
0096     } // 'adaptors'
0097
0098 }
0099
0100 #endif