Chris@16: // Boost.Range library
Chris@16: //
Chris@16: //  Copyright Neil Groves 2007. 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_REPLACED_IF_IMPL_HPP_INCLUDED
Chris@16: #define BOOST_RANGE_ADAPTOR_REPLACED_IF_IMPL_HPP_INCLUDED
Chris@16: 
Chris@16: #include <boost/config.hpp>
Chris@16: #include <boost/range/adaptor/argument_fwd.hpp>
Chris@16: #include <boost/range/iterator_range.hpp>
Chris@16: #include <boost/range/begin.hpp>
Chris@16: #include <boost/range/end.hpp>
Chris@16: #include <boost/range/value_type.hpp>
Chris@101: #include <boost/range/concepts.hpp>
Chris@16: #include <boost/iterator/iterator_adaptor.hpp>
Chris@16: #include <boost/iterator/transform_iterator.hpp>
Chris@101: #include <boost/optional/optional.hpp>
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16:     namespace range_detail
Chris@16:     {
Chris@16:         template< class Pred, class Value >
Chris@16:         class replace_value_if
Chris@16:         {
Chris@16:         public:
Chris@16:             typedef const Value& result_type;
Chris@16:             typedef const Value& first_argument_type;
Chris@16: 
Chris@101:             // Rationale:
Chris@101:             // required to allow the iterator to be default constructible.
Chris@101:             replace_value_if()
Chris@101:             {
Chris@101:             }
Chris@101: 
Chris@16:             replace_value_if(const Pred& pred, const Value& to)
Chris@101:                 : m_impl(data(pred, to))
Chris@16:             {
Chris@16:             }
Chris@16: 
Chris@16:             const Value& operator()(const Value& x) const
Chris@16:             {
Chris@101:                 return m_impl->m_pred(x) ? m_impl->m_to : x;
Chris@16:             }
Chris@16: 
Chris@16:         private:
Chris@101:             struct data
Chris@101:             {
Chris@101:                 data(const Pred& p, const Value& t)
Chris@101:                     : m_pred(p), m_to(t)
Chris@101:                 {
Chris@101:                 }
Chris@101: 
Chris@101:                 Pred  m_pred;
Chris@101:                 Value m_to;
Chris@101:             };
Chris@101:             boost::optional<data> m_impl;
Chris@16:         };
Chris@16: 
Chris@16:         template< class Pred, class R >
Chris@16:         class replaced_if_range :
Chris@16:             public boost::iterator_range<
Chris@16:                 boost::transform_iterator<
Chris@16:                     replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type >,
Chris@16:                     BOOST_DEDUCED_TYPENAME range_iterator<R>::type > >
Chris@16:         {
Chris@16:         private:
Chris@16:             typedef replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type > Fn;
Chris@16: 
Chris@16:             typedef boost::iterator_range<
Chris@16:                 boost::transform_iterator<
Chris@16:                     replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type >,
Chris@16:                     BOOST_DEDUCED_TYPENAME range_iterator<R>::type > > base_t;
Chris@16: 
Chris@16:         public:
Chris@16:             typedef BOOST_DEDUCED_TYPENAME range_value<R>::type value_type;
Chris@16: 
Chris@16:             replaced_if_range( R& r, const Pred& pred, value_type to )
Chris@16:                 : base_t( make_transform_iterator( boost::begin(r), Fn(pred, to) ),
Chris@16:                           make_transform_iterator( boost::end(r), Fn(pred, to) ) )
Chris@16:             { }
Chris@16:         };
Chris@16: 
Chris@16:         template< class Pred, class T >
Chris@16:         class replace_if_holder
Chris@16:         {
Chris@16:         public:
Chris@16:             replace_if_holder( const Pred& pred, const T& to )
Chris@16:                 : m_pred(pred), m_to(to)
Chris@16:             { }
Chris@16: 
Chris@16:             const Pred& pred() const { return m_pred; }
Chris@16:             const T& to() const { return m_to; }
Chris@16: 
Chris@16:         private:
Chris@16:             Pred m_pred;
Chris@16:             T m_to;
Chris@16:         };
Chris@16: 
Chris@101:         template< class Pred, class SinglePassRange >
Chris@101:         inline replaced_if_range<Pred, SinglePassRange>
Chris@101:         operator|(
Chris@101:             SinglePassRange& r,
Chris@101:             const replace_if_holder<
Chris@101:                 Pred,
Chris@101:                 BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type>& f)
Chris@16:         {
Chris@101:             BOOST_RANGE_CONCEPT_ASSERT((
Chris@101:                 SinglePassRangeConcept<SinglePassRange>));
Chris@101: 
Chris@101:             return replaced_if_range<Pred, SinglePassRange>(
Chris@101:                 r, f.pred(), f.to());
Chris@16:         }
Chris@16: 
Chris@101:         template< class Pred, class SinglePassRange >
Chris@101:         inline replaced_if_range<Pred, const SinglePassRange>
Chris@101:         operator|(
Chris@101:             const SinglePassRange& r,
Chris@101:             const replace_if_holder<
Chris@101:                 Pred,
Chris@101:                 BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type>& f)
Chris@16:         {
Chris@101:             BOOST_RANGE_CONCEPT_ASSERT((
Chris@101:                 SinglePassRangeConcept<const SinglePassRange>));
Chris@101: 
Chris@101:             return replaced_if_range<Pred, const SinglePassRange>(
Chris@101:                 r, f.pred(), f.to());
Chris@16:         }
Chris@16:     } // 'range_detail'
Chris@16: 
Chris@16:     using range_detail::replaced_if_range;
Chris@16: 
Chris@16:     namespace adaptors
Chris@16:     {
Chris@16:         namespace
Chris@16:         {
Chris@16:             const range_detail::forwarder2TU<range_detail::replace_if_holder>
Chris@16:                 replaced_if =
Chris@16:                     range_detail::forwarder2TU<range_detail::replace_if_holder>();
Chris@16:         }
Chris@101: 
Chris@101:         template<class Pred, class SinglePassRange>
Chris@101:         inline replaced_if_range<Pred, SinglePassRange>
Chris@101:         replace_if(SinglePassRange& rng, Pred pred,
Chris@101:                    BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type to)
Chris@16:         {
Chris@101:             BOOST_RANGE_CONCEPT_ASSERT((
Chris@101:                 SinglePassRangeConcept<SinglePassRange>));
Chris@101: 
Chris@101:             return range_detail::replaced_if_range<Pred, SinglePassRange>(
Chris@101:                 rng, pred, to);
Chris@16:         }
Chris@16: 
Chris@101:         template<class Pred, class SinglePassRange>
Chris@101:         inline replaced_if_range<Pred, const SinglePassRange>
Chris@101:         replace_if(
Chris@101:             const SinglePassRange& rng,
Chris@101:             Pred pred,
Chris@101:             BOOST_DEDUCED_TYPENAME range_value<const SinglePassRange>::type to)
Chris@16:         {
Chris@101:             BOOST_RANGE_CONCEPT_ASSERT((
Chris@101:                 SinglePassRangeConcept<const SinglePassRange>));
Chris@101: 
Chris@101:             return range_detail::replaced_if_range<Pred, const SinglePassRange>(
Chris@101:                 rng, pred, to);
Chris@16:         }
Chris@16:     } // 'adaptors'
Chris@101: 
Chris@16: } // 'boost'
Chris@16: 
Chris@16: #endif // include guard