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- // 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, class Value >
- inline replaced_if_range<Pred, SinglePassRange>
- operator|(SinglePassRange& r, const replace_if_holder<Pred, Value>& f)
- {
- BOOST_RANGE_CONCEPT_ASSERT((
- SinglePassRangeConcept<SinglePassRange>));
- return replaced_if_range<Pred, SinglePassRange>(
- r, f.pred(), f.to());
- }
- template< class Pred, class SinglePassRange, class Value >
- inline replaced_if_range<Pred, const SinglePassRange>
- operator|(const SinglePassRange& r, const replace_if_holder<Pred, Value>& 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, class Value >
- inline replaced_if_range<Pred, SinglePassRange>
- replace_if(SinglePassRange& rng, Pred pred, Value to)
- {
- BOOST_RANGE_CONCEPT_ASSERT((
- SinglePassRangeConcept<SinglePassRange>));
- return range_detail::replaced_if_range<Pred, SinglePassRange>(
- rng, pred, to);
- }
- template< class Pred, class SinglePassRange, class Value >
- inline replaced_if_range<Pred, const SinglePassRange>
- replace_if(const SinglePassRange& rng, Pred pred, Value 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
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