| // Boost.Range library |
| // |
| // Copyright Neil Groves 2007. Use, modification and |
| // distribution is subject to the Boost Software License, Version |
| // 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| // |
| // For more information, see http://www.boost.org/libs/range/ |
| // |
| |
| #ifndef BOOST_RANGE_ADAPTOR_REPLACED_IF_IMPL_HPP_INCLUDED |
| #define BOOST_RANGE_ADAPTOR_REPLACED_IF_IMPL_HPP_INCLUDED |
| |
| #include <boost/config.hpp> |
| #include <boost/range/adaptor/argument_fwd.hpp> |
| #include <boost/range/iterator_range.hpp> |
| #include <boost/range/begin.hpp> |
| #include <boost/range/end.hpp> |
| #include <boost/range/value_type.hpp> |
| #include <boost/range/concepts.hpp> |
| #include <boost/iterator/iterator_adaptor.hpp> |
| #include <boost/iterator/transform_iterator.hpp> |
| #include <boost/optional/optional.hpp> |
| |
| namespace boost |
| { |
| namespace range_detail |
| { |
| template< class Pred, class Value > |
| class replace_value_if |
| { |
| public: |
| typedef const Value& result_type; |
| typedef const Value& first_argument_type; |
| |
| // Rationale: |
| // required to allow the iterator to be default constructible. |
| replace_value_if() |
| { |
| } |
| |
| replace_value_if(const Pred& pred, const Value& to) |
| : m_impl(data(pred, to)) |
| { |
| } |
| |
| const Value& operator()(const Value& x) const |
| { |
| return m_impl->m_pred(x) ? m_impl->m_to : x; |
| } |
| |
| private: |
| struct data |
| { |
| data(const Pred& p, const Value& t) |
| : m_pred(p), m_to(t) |
| { |
| } |
| |
| Pred m_pred; |
| Value m_to; |
| }; |
| boost::optional<data> m_impl; |
| }; |
| |
| template< class Pred, class R > |
| class replaced_if_range : |
| public boost::iterator_range< |
| boost::transform_iterator< |
| replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type >, |
| BOOST_DEDUCED_TYPENAME range_iterator<R>::type > > |
| { |
| private: |
| typedef replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type > Fn; |
| |
| typedef boost::iterator_range< |
| boost::transform_iterator< |
| replace_value_if< Pred, BOOST_DEDUCED_TYPENAME range_value<R>::type >, |
| BOOST_DEDUCED_TYPENAME range_iterator<R>::type > > base_t; |
| |
| public: |
| typedef BOOST_DEDUCED_TYPENAME range_value<R>::type value_type; |
| |
| replaced_if_range( R& r, const Pred& pred, value_type to ) |
| : base_t( make_transform_iterator( boost::begin(r), Fn(pred, to) ), |
| make_transform_iterator( boost::end(r), Fn(pred, to) ) ) |
| { } |
| }; |
| |
| template< class Pred, class T > |
| class replace_if_holder |
| { |
| public: |
| replace_if_holder( const Pred& pred, const T& to ) |
| : m_pred(pred), m_to(to) |
| { } |
| |
| const Pred& pred() const { return m_pred; } |
| const T& to() const { return m_to; } |
| |
| private: |
| Pred m_pred; |
| T m_to; |
| }; |
| |
| template< class Pred, class SinglePassRange > |
| inline replaced_if_range<Pred, SinglePassRange> |
| operator|( |
| SinglePassRange& r, |
| const replace_if_holder< |
| Pred, |
| BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type>& f) |
| { |
| BOOST_RANGE_CONCEPT_ASSERT(( |
| SinglePassRangeConcept<SinglePassRange>)); |
| |
| return replaced_if_range<Pred, SinglePassRange>( |
| r, f.pred(), f.to()); |
| } |
| |
| template< class Pred, class SinglePassRange > |
| inline replaced_if_range<Pred, const SinglePassRange> |
| operator|( |
| const SinglePassRange& r, |
| const replace_if_holder< |
| Pred, |
| BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type>& f) |
| { |
| BOOST_RANGE_CONCEPT_ASSERT(( |
| SinglePassRangeConcept<const SinglePassRange>)); |
| |
| return replaced_if_range<Pred, const SinglePassRange>( |
| r, f.pred(), f.to()); |
| } |
| } // 'range_detail' |
| |
| using range_detail::replaced_if_range; |
| |
| namespace adaptors |
| { |
| namespace |
| { |
| const range_detail::forwarder2TU<range_detail::replace_if_holder> |
| replaced_if = |
| range_detail::forwarder2TU<range_detail::replace_if_holder>(); |
| } |
| |
| template<class Pred, class SinglePassRange> |
| inline replaced_if_range<Pred, SinglePassRange> |
| replace_if(SinglePassRange& rng, Pred pred, |
| BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type to) |
| { |
| BOOST_RANGE_CONCEPT_ASSERT(( |
| SinglePassRangeConcept<SinglePassRange>)); |
| |
| return range_detail::replaced_if_range<Pred, SinglePassRange>( |
| rng, pred, to); |
| } |
| |
| template<class Pred, class SinglePassRange> |
| inline replaced_if_range<Pred, const SinglePassRange> |
| replace_if( |
| const SinglePassRange& rng, |
| Pred pred, |
| BOOST_DEDUCED_TYPENAME range_value<const SinglePassRange>::type to) |
| { |
| BOOST_RANGE_CONCEPT_ASSERT(( |
| SinglePassRangeConcept<const SinglePassRange>)); |
| |
| return range_detail::replaced_if_range<Pred, const SinglePassRange>( |
| rng, pred, to); |
| } |
| } // 'adaptors' |
| |
| } // 'boost' |
| |
| #endif // include guard |