170 lines
5.5 KiB
C++
170 lines
5.5 KiB
C++
// Boost.Range library
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//
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// Copyright Neil Groves 2007. Use, modification and
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// distribution is subject to the Boost Software License, Version
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// 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// For more information, see http://www.boost.org/libs/range/
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//
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#ifndef BOOST_RANGE_ADAPTOR_REPLACED_IMPL_HPP_INCLUDED
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#define BOOST_RANGE_ADAPTOR_REPLACED_IMPL_HPP_INCLUDED
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#include <boost/config.hpp>
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#include <boost/range/adaptor/argument_fwd.hpp>
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#include <boost/range/iterator_range.hpp>
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#include <boost/range/begin.hpp>
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#include <boost/range/end.hpp>
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#include <boost/range/value_type.hpp>
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#include <boost/range/concepts.hpp>
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#include <boost/iterator/iterator_adaptor.hpp>
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#include <boost/iterator/transform_iterator.hpp>
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#include <boost/optional/optional.hpp>
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namespace boost
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{
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namespace range_detail
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{
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template< class Value >
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class replace_value
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{
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public:
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typedef const Value& result_type;
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typedef const Value& first_argument_type;
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// Rationale:
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// The default constructor is required to allow the transform
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// iterator to properly model the iterator concept.
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replace_value()
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{
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}
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replace_value(const Value& from, const Value& to)
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: m_impl(data(from, to))
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{
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}
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const Value& operator()(const Value& x) const
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{
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return (x == m_impl->m_from) ? m_impl->m_to : x;
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}
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private:
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struct data
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{
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data(const Value& from, const Value& to)
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: m_from(from)
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, m_to(to)
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{
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}
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Value m_from;
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Value m_to;
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};
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boost::optional<data> m_impl;
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};
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template< class R >
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class replaced_range :
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public boost::iterator_range<
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boost::transform_iterator<
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replace_value< BOOST_DEDUCED_TYPENAME range_value<R>::type >,
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BOOST_DEDUCED_TYPENAME range_iterator<R>::type > >
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{
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private:
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typedef replace_value< BOOST_DEDUCED_TYPENAME range_value<R>::type > Fn;
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typedef boost::iterator_range<
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boost::transform_iterator<
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replace_value< BOOST_DEDUCED_TYPENAME range_value<R>::type >,
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BOOST_DEDUCED_TYPENAME range_iterator<R>::type > > base_t;
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public:
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typedef BOOST_DEDUCED_TYPENAME range_value<R>::type value_type;
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replaced_range( R& r, value_type from, value_type to )
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: base_t( make_transform_iterator( boost::begin(r), Fn(from, to) ),
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make_transform_iterator( boost::end(r), Fn(from, to) ) )
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{ }
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};
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template< class T >
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class replace_holder : public holder2<T>
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{
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public:
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replace_holder( const T& from, const T& to )
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: holder2<T>(from, to)
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{ }
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private:
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// not assignable
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void operator=(const replace_holder&);
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};
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template< class SinglePassRange >
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inline replaced_range<SinglePassRange>
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operator|(
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SinglePassRange& r,
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const replace_holder<
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BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type>& f )
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{
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BOOST_RANGE_CONCEPT_ASSERT((
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SinglePassRangeConcept<SinglePassRange>));
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return replaced_range<SinglePassRange>(r, f.val1, f.val2);
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}
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template< class SinglePassRange >
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inline replaced_range<const SinglePassRange>
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operator|(
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const SinglePassRange& r,
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const replace_holder<
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BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type>& f)
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{
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BOOST_RANGE_CONCEPT_ASSERT((
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SinglePassRangeConcept<const SinglePassRange>));
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return replaced_range<const SinglePassRange>(r, f.val1, f.val2);
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}
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} // 'range_detail'
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using range_detail::replaced_range;
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namespace adaptors
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{
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namespace
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{
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const range_detail::forwarder2<range_detail::replace_holder>
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replaced =
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range_detail::forwarder2<range_detail::replace_holder>();
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}
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template<class SinglePassRange>
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inline replaced_range<SinglePassRange>
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replace(SinglePassRange& rng,
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BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type from,
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BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type to)
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{
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BOOST_RANGE_CONCEPT_ASSERT((
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SinglePassRangeConcept<SinglePassRange>));
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return replaced_range<SinglePassRange>(rng, from, to);
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}
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template<class SinglePassRange>
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inline replaced_range<const SinglePassRange>
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replace(const SinglePassRange& rng,
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BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type from,
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BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type to)
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{
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BOOST_RANGE_CONCEPT_ASSERT((
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SinglePassRangeConcept<const SinglePassRange>));
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return replaced_range<const SinglePassRange>(rng, from ,to);
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}
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} // 'adaptors'
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} // 'boost'
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#endif // include guard
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