Chris@16: // Boost.Range library
Chris@16: //
Chris@16: //  Copyright Thorsten Ottosen, Neil Groves 2006 - 2008. Use, modification and
Chris@16: //  distribution is subject to the Boost Software License, Version
Chris@16: //  1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: //  http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: // For more information, see http://www.boost.org/libs/range/
Chris@16: //
Chris@16: 
Chris@16: #ifndef BOOST_RANGE_ADAPTOR_TRANSFORMED_HPP
Chris@16: #define BOOST_RANGE_ADAPTOR_TRANSFORMED_HPP
Chris@16: 
Chris@16: #include <boost/range/adaptor/argument_fwd.hpp>
Chris@101: #include <boost/range/detail/default_constructible_unary_fn.hpp>
Chris@16: #include <boost/range/iterator_range.hpp>
Chris@101: #include <boost/range/concepts.hpp>
Chris@16: #include <boost/iterator/transform_iterator.hpp>
Chris@16: #include <boost/utility/result_of.hpp>
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16:     namespace range_detail
Chris@16:     {
Chris@101:         // A type generator to produce the transform_iterator type conditionally
Chris@101:         // including a wrapped predicate as appropriate.
Chris@101:         template<typename P, typename It>
Chris@101:         struct transform_iterator_gen
Chris@101:         {
Chris@101:             typedef transform_iterator<
Chris@101:                 typename default_constructible_unary_fn_gen<
Chris@101:                     P,
Chris@101:                     typename transform_iterator<P, It>::reference
Chris@101:                 >::type,
Chris@101:                 It
Chris@101:             > type;
Chris@101:         };
Chris@16: 
Chris@16:         template< class F, class R >
Chris@16:         struct transformed_range :
Chris@16:             public boost::iterator_range<
Chris@101:                 typename transform_iterator_gen<
Chris@101:                     F, typename range_iterator<R>::type>::type>
Chris@16:         {
Chris@16:         private:
Chris@101:             typedef typename transform_iterator_gen<
Chris@101:                 F, typename range_iterator<R>::type>::type transform_iter_t;
Chris@101: 
Chris@101:             typedef boost::iterator_range<transform_iter_t> base;
Chris@16: 
Chris@16:         public:
Chris@101:             typedef typename default_constructible_unary_fn_gen<
Chris@101:                 F,
Chris@101:                 typename transform_iterator<
Chris@101:                     F,
Chris@101:                     typename range_iterator<R>::type
Chris@101:                 >::reference
Chris@101:             >::type transform_fn_type;
Chris@101: 
Chris@16:             typedef R source_range_type;
Chris@16: 
Chris@101:             transformed_range(transform_fn_type f, R& r)
Chris@101:                 : base(transform_iter_t(boost::begin(r), f),
Chris@101:                        transform_iter_t(boost::end(r), f))
Chris@101:             {
Chris@101:             }
Chris@16:         };
Chris@16: 
Chris@16:         template< class T >
Chris@16:         struct transform_holder : holder<T>
Chris@16:         {
Chris@16:             transform_holder( T r ) : holder<T>(r)
Chris@101:             {
Chris@101:             }
Chris@16:         };
Chris@16: 
Chris@101:         template< class SinglePassRange, class UnaryFunction >
Chris@101:         inline transformed_range<UnaryFunction,SinglePassRange>
Chris@101:         operator|( SinglePassRange& r,
Chris@16:                    const transform_holder<UnaryFunction>& f )
Chris@16:         {
Chris@101:             BOOST_RANGE_CONCEPT_ASSERT((
Chris@101:                 SinglePassRangeConcept<SinglePassRange>));
Chris@101: 
Chris@101:             return transformed_range<UnaryFunction,SinglePassRange>( f.val, r );
Chris@16:         }
Chris@16: 
Chris@101:         template< class SinglePassRange, class UnaryFunction >
Chris@101:         inline transformed_range<UnaryFunction, const SinglePassRange>
Chris@101:         operator|( const SinglePassRange& r,
Chris@16:                    const transform_holder<UnaryFunction>& f )
Chris@16:         {
Chris@101:             BOOST_RANGE_CONCEPT_ASSERT((
Chris@101:                 SinglePassRangeConcept<const SinglePassRange>));
Chris@101: 
Chris@101:            return transformed_range<UnaryFunction, const SinglePassRange>(
Chris@101:                f.val, r);
Chris@16:         }
Chris@16: 
Chris@16:     } // 'range_detail'
Chris@16: 
Chris@16:     using range_detail::transformed_range;
Chris@16: 
Chris@16:     namespace adaptors
Chris@16:     {
Chris@16:         namespace
Chris@16:         {
Chris@16:             const range_detail::forwarder<range_detail::transform_holder>
Chris@16:                     transformed =
Chris@16:                       range_detail::forwarder<range_detail::transform_holder>();
Chris@16:         }
Chris@16: 
Chris@101:         template<class UnaryFunction, class SinglePassRange>
Chris@101:         inline transformed_range<UnaryFunction, SinglePassRange>
Chris@101:         transform(SinglePassRange& rng, UnaryFunction fn)
Chris@16:         {
Chris@101:             BOOST_RANGE_CONCEPT_ASSERT((
Chris@101:                 SinglePassRangeConcept<SinglePassRange>));
Chris@101: 
Chris@101:             return transformed_range<UnaryFunction, SinglePassRange>(fn, rng);
Chris@16:         }
Chris@16: 
Chris@101:         template<class UnaryFunction, class SinglePassRange>
Chris@101:         inline transformed_range<UnaryFunction, const SinglePassRange>
Chris@101:         transform(const SinglePassRange& rng, UnaryFunction fn)
Chris@16:         {
Chris@101:             BOOST_RANGE_CONCEPT_ASSERT((
Chris@101:                 SinglePassRangeConcept<const SinglePassRange>));
Chris@101: 
Chris@101:             return transformed_range<UnaryFunction, const SinglePassRange>(
Chris@101:                 fn, rng);
Chris@16:         }
Chris@16:     } // 'adaptors'
Chris@16: 
Chris@16: }
Chris@16: 
Chris@16: #endif