3 // Copyright Thorsten Ottosen, Neil Groves 2006 - 2008. Use, modification and
4 // distribution is subject to the Boost Software License, Version
5 // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
6 // http://www.boost.org/LICENSE_1_0.txt)
8 // For more information, see http://www.boost.org/libs/range/
11 #ifndef BOOST_RANGE_ADAPTOR_TRANSFORMED_HPP
12 #define BOOST_RANGE_ADAPTOR_TRANSFORMED_HPP
14 #include <boost/range/adaptor/argument_fwd.hpp>
15 #include <boost/range/detail/default_constructible_unary_fn.hpp>
16 #include <boost/range/iterator_range.hpp>
17 #include <boost/range/concepts.hpp>
18 #include <boost/iterator/transform_iterator.hpp>
19 #include <boost/utility/result_of.hpp>
23 namespace range_detail
25 // A type generator to produce the transform_iterator type conditionally
26 // including a wrapped predicate as appropriate.
27 template<typename P, typename It>
28 struct transform_iterator_gen
30 typedef transform_iterator<
31 typename default_constructible_unary_fn_gen<
33 typename transform_iterator<P, It>::reference
39 template< class F, class R >
40 struct transformed_range :
41 public boost::iterator_range<
42 typename transform_iterator_gen<
43 F, typename range_iterator<R>::type>::type>
46 typedef typename transform_iterator_gen<
47 F, typename range_iterator<R>::type>::type transform_iter_t;
49 typedef boost::iterator_range<transform_iter_t> base;
52 typedef typename default_constructible_unary_fn_gen<
54 typename transform_iterator<
56 typename range_iterator<R>::type
58 >::type transform_fn_type;
60 typedef R source_range_type;
62 transformed_range(transform_fn_type f, R& r)
63 : base(transform_iter_t(boost::begin(r), f),
64 transform_iter_t(boost::end(r), f))
70 struct transform_holder : holder<T>
72 transform_holder( T r ) : holder<T>(r)
77 template< class SinglePassRange, class UnaryFunction >
78 inline transformed_range<UnaryFunction,SinglePassRange>
79 operator|( SinglePassRange& r,
80 const transform_holder<UnaryFunction>& f )
82 BOOST_RANGE_CONCEPT_ASSERT((
83 SinglePassRangeConcept<SinglePassRange>));
85 return transformed_range<UnaryFunction,SinglePassRange>( f.val, r );
88 template< class SinglePassRange, class UnaryFunction >
89 inline transformed_range<UnaryFunction, const SinglePassRange>
90 operator|( const SinglePassRange& r,
91 const transform_holder<UnaryFunction>& f )
93 BOOST_RANGE_CONCEPT_ASSERT((
94 SinglePassRangeConcept<const SinglePassRange>));
96 return transformed_range<UnaryFunction, const SinglePassRange>(
102 using range_detail::transformed_range;
108 const range_detail::forwarder<range_detail::transform_holder>
110 range_detail::forwarder<range_detail::transform_holder>();
113 template<class UnaryFunction, class SinglePassRange>
114 inline transformed_range<UnaryFunction, SinglePassRange>
115 transform(SinglePassRange& rng, UnaryFunction fn)
117 BOOST_RANGE_CONCEPT_ASSERT((
118 SinglePassRangeConcept<SinglePassRange>));
120 return transformed_range<UnaryFunction, SinglePassRange>(fn, rng);
123 template<class UnaryFunction, class SinglePassRange>
124 inline transformed_range<UnaryFunction, const SinglePassRange>
125 transform(const SinglePassRange& rng, UnaryFunction fn)
127 BOOST_RANGE_CONCEPT_ASSERT((
128 SinglePassRangeConcept<const SinglePassRange>));
130 return transformed_range<UnaryFunction, const SinglePassRange>(